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The Dependence of Net Assimilation Rate on Leaf-area Index
Abstract
The leaf-area index (leaf area per unit area of land, L) of field crops of kale and sugar-beet was varied experimentally by removing different fractions of the plant population distributed uniformly through the crop. The net assimilation rate (E) was determined in subsequent periods of 10–14 days.
For kale, E decreased nearly linearly with increase of L throughout the range from I to 5. E of sugar-beet was less affected by change in L and was apparently not decreased until L rose above about 3.
Because of this dependence of E on L, the rate of dry-matter production per unit area of land, or crop growth-rate (C=EL), showed a curved relation to L; for kale it increased to a maximum when L was between 3 and 4 and fell again at higher values of L. Maximal C for sugar-beet occurred beyond the range of L tested, probably between L=6 and L=9. This optimal L for dry-matter production by sugar-beet crops probably lies near the upper limit of the current agricultural range, so there is little, if any, scope for increasing the dry-matter yield by further increase in L. For heavy kale crops L is already far in excess of the optimum, and it may be possible to increase the total dry-matter yield of kale by repeated thinning or defoliation to hold L near the optimum.
... Photosynthesis is the foundation of biomass generation, and these photosynthetic materials provide the carbon skeleton that assembles the entire plant [43,44]. The dry matter production is primarily determined by photosynthetic efficiency, leaf area index (LAI), and the duration time during which photosynthesis continues [45]. LAI is defined as the area of total leaves in each unit of the land area [46][47][48] and is also a key parameter to characterize crop growth [49]. ...
... Most of the dry matter of green plants (about 80 to 90%) comes from photosynthesis, while the rest comes from the soil [61]. The dry matter production of green plants is a gradual and accumulative process and is primarily determined by photosynthetic efficiency, LAI, and the duration time during which photosynthesis continues [45]. Most of the biomass of rice is concentrated in the aboveground part [62]. ...
... The "net assimilation rate" (NAR) is a useful indicator of green plants' photosynthetic efficiency. It is defined as the rate of increase in dry weight per unit of leaf area [45,63]. Hence, the relationship between aboveground dry biomass, NAR, and LAI is given by: where W is the aboveground dry biomass. ...
The effective and accurate aboveground biomass (AGB) estimation facilitates evaluating crop growth and site-specific crop management. Considering that rice accumulates AGB mainly through green leaf photosynthesis, we proposed the photosynthetic accumulation model (PAM) and its simplified version and compared them for estimating AGB. These methods estimate the AGB of various rice cultivars throughout the growing season by integrating vegetation index (VI) and canopy height based on images acquired by unmanned aerial vehicles (UAV). The results indicated that the correlation of VI and AGB was weak for the whole growing season of rice and the accuracy of the height model was also limited for the whole growing season. In comparison with the NDVI-based rice AGB estimation model in 2019 data ( R ² = 0.03, RMSE = 603.33 g/m ² ) and canopy height ( R ² = 0.79, RMSE = 283.33 g/m ² ), the PAM calculated by NDVI and canopy height could provide a better estimate of AGB of rice ( R ² = 0.95, RMSE = 136.81 g/m ² ). Then, based on the time-series analysis of the accumulative model, a simplified photosynthetic accumulation model (SPAM) was proposed that only needs limited observations to achieve R ² above 0.8. The PAM and SPAM models built by using 2 years of samples successfully predicted the third year of samples and also demonstrated the robustness and generalization ability of the models. In conclusion, these methods can be easily and efficiently applied to the UAV estimation of rice AGB over the entire growing season, which has great potential to serve for large-scale field management and also for breeding.
... LAI is the ratio of leaf surface area per unit of land surface. This was determined as described by Watson (1958) thus; ...
... Net Assimilatory Rate (NAR) gm -2 wk -1 : This expresses the photosynthetic efficiency of the assimilatory surface. This was estimated as described by Watson [16]. ...
... Relative Growth Rate (g g -1 day -1 ) the rate of increment is known as relative growth rate. It was computed by using the Fischer , s formula (1971) [8] , The Net Assimilation Rate (g dm -2 day -1 ) was calculated by using the formula suggested by Williams (1946) and expressed as g dm -2 day -1 and the Crop Growth Rate (g m -2 day -1 ) was calculated by using the formula suggested by Watson (1958) [29] and expressed as g m -2 day -1 . ...
... Relative Growth Rate (g g -1 day -1 ) the rate of increment is known as relative growth rate. It was computed by using the Fischer , s formula (1971) [8] , The Net Assimilation Rate (g dm -2 day -1 ) was calculated by using the formula suggested by Williams (1946) and expressed as g dm -2 day -1 and the Crop Growth Rate (g m -2 day -1 ) was calculated by using the formula suggested by Watson (1958) [29] and expressed as g m -2 day -1 . ...
A field experiment was conducted during rabi 2021-22, to study the drought tolerance studies in different genotypes of linseed under rainfed condition genotypes NL-339, NL-367, NL-369, NL-371, NL-407, NL-408, TL-99, LSL-93, PKV NL-260 (LC), T-397 (NC) were studied. The experiment was laid down in randomized block design and complete randomized design with ten genotypes and three replications at research farm of AICRP on Linseed and Mustard, College of Agriculture, Nagpur. The aim of this work was to study the drought tolerant associated morpho-physiological traits and yield of linseed under rainfed condition. Observations about morpho-physiological parameters like plant height, number of leaves plant-1 , total dry matter production, leaf area, leaf area index, relative water content, germination stress index (GSI) and dry matter stress index (DMSI) were also estimated. Observations on yield traits like grain yield plant-1 , plot-1 , ha-1 , harvest index recorded. Genotypes PKV NL-260 followed by NL-369 and NL-371 significantly enhanced morpho-physiological traits and yield of linseed under rainfed condition, when compared with national check T-397 and rest of the genotypes under study.
... At 90 and 120 DAS, 10 plants samples were taken from each plot to measure the following traits: Relative growth rate (RGR) mg/day was calculated according to the following formula (Watson 1958): ...
... While, A 1 and A 2 refer to leaf area at first (T 1 ) and second (T 2 ) times, respectively. Crop growth rate (CGR) in mg/cm 2 /day was calculated according to the following formula (Watson 1958): ...
... The Crop Growth Rate is the rate of increase in dry matter per unit land area per unit time. It was calculated by using the formula suggested by Watson (1958) [18] and was recorded between 45 to 90 DAS, 90 to 135 DAS and 135 DAS to harvest intervals. Dry matter partitioning i.e root and top dry matter production were also studied at different intervals from 45 DAS to harvest. ...
... The Crop Growth Rate is the rate of increase in dry matter per unit land area per unit time. It was calculated by using the formula suggested by Watson (1958) [18] and was recorded between 45 to 90 DAS, 90 to 135 DAS and 135 DAS to harvest intervals. Dry matter partitioning i.e root and top dry matter production were also studied at different intervals from 45 DAS to harvest. ...
... Crop growth rate was estimated as suggested by Watson (1958) and expressed in kg ha 1 day -1 W here, W 1 and W 2 were DMP in kg ha -1 at times t 1 and t 2 , respectively. ...
Background: Globally rice is cultivated under lowland condition. Increasing water scarcity and imbalanced fertilizer application affects the productivity of rice. Effective as well as efficient irrigation method and proper nutrient management enhance the growth and yield of rice besides increasing the input use efficiency. Methods: A field experiment was carried in Agricultural College and Research Institute at Madurai during Kharif season 2022. Design executed was split plot with three main and seven sub plots. Irrigation methods was assigned to main plot and nutrient management to sub plot. Result: The experiment result revealed that adopting alternate wetting and drying irrigation method coupled with combination of 50 percent N and K given as conventional fertilizer + foliar spray of Nano N and K had significant impact on growth attributes, physiological characters and yield beside with limited use of inputs.
... The LAI was calculated as the ratio of unit leaf area to unit ground area covered, as described by Watson (1958), at heading stages. ...
The productivity of sorghum, an important staple food crop in Ethiopia, has been constrained by environmental stresses and declining soil fertility, and addressing these constraints improves the productivity of sorghum. A field experiment was conducted in Raya Valley to evaluate the responses of eight sorghum varieties to NPSZn and NP fertilizers and to select the varieties that combine desirable traits. The field experiment was laid out in RCBD in three replications. The varieties showed significant (p<0.001) variations for phenological, agronomic, and physiological traits. Meko and Melkam were the early maturing varieties with different yielding potential. Melkam was the second highest (4808 kg ha-1) yielding variety after Dagnew. Melkam has combined desirable traits, earliness, and high yield, for production in semi-arid drought-prone areas like the Raya valley. The local sorghum varieties outperformed Meko in most traits, which shows their potential use in breeding and production systems. NPSZn and NP fertilizers did not affect the studied traits differently but differed significantly from the zero treatment. The variety × fertilizer interaction effect was significant on most traits except PW, TGW, and GY. NPSZn treatment has increased biomass yield by 18.4% and 8.6% over NP in Gombilu and Dagnew, respectively. High LA and LAI were recorded from the high-yielding varieties, Dagnew and Melkam, and vice versa for low-yielding varieties. It can be concluded that working for varietal selection could be more rewarding than switching the application of NP to NPSZn fertilizer type in the Raya Valley to enhance sorghum production and productivity. The 100 kg ha-1 NPSZn blend recommendation, however, makes a 50% fertilizer price discount. Hence, Melkam from improved and Dagnew from the local varieties had better performance and can be preferably cultivated by farming communities.
... Five plants were randomly collected from the middle ridges of each sub-plot at 110 days from sowing to determine the following: 1. Leaf area index (LAI): Leaf area was measured using the disk method according to Watson (1958), and then the following equation was used: LAI = Leaf area per plant (cm 2 )/plant ground area (cm 2 ) 2. Photosynthetic pigments i.e., chlorophyll a, b, and carotenoids (mg/g leaf fresh weight) were determined according to the method described by Wettstein (1957), where: ...
... Additionally, the weight of 1000 grains randomly selected from five plants was recorded and expressed in grams (g). The crop growth rate (CGR) was estimated at 30, 60 DAS and at harvest stage by using the formula as suggested by Watson (1958) and expressed in g/m 2 /day. The intercropping system was evaluated using economic indicators such as the gross returns (₹/ha), net returns (₹/ha) and B:C ratio. ...
An experiment was conducted during 2019, 2020 and 2021 at Centre of Excellence in Millets, (Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu), Athiyandal, Tiruvanamalai, Tamil Nadu. to study the performance of little millet (Panicum flexuosum Retz.) based cropping system for rainfed agro ecosystems for north-eastern part of Tamil Nadu. The experiment was laid out in randomized block design (RBD) comprised of 9 treatments, viz. T1, Little millet + Redgram [Cajanus cajan (L.) Millsp.] (4:1)-Moth bean [Vigna aconitifolia (Jacq.) Marechal]; T2, Little millet + Redgram (4:1)-Blackgram [Vigna mungo (L.) Hepper]; T3, Little millet + Redgram (4:1)-Horsegram [Macrotyloma uniflorum (Lam.) Verdc.]; T4, Little millet + Redgram (6:2)-Moth bean; T5, Little millet + Redgram (6:2)-Blackgram; T6, Little millet + Redgram (6:2)-Horsegram; T7, Little millet + Redgram (8:2)- Mothbean; T8, Little millet + Redgram (8:2)-Blackgram; T9, Little millet + Redgram (8:2)- Horsegram, with three replications. The good quality seeds of little millet (CO 4), redgram (Paiyur 2), horsegram (Paiyur 2), blackgram (VBN 3) and mothbean [TMV (Mb) 1] were used. The result shows that the higher yield for little millet and intercropped redgram was recorded in T9 (985 and 362 kg/ha) followed by T7 (853 and 356 kg/ha) and T8 (834 and 337 kg/ ha). The 8:2 row ratio exhibited the highest little millet equivalent yield when compared to 6:2 and 4:1 row ratio. The highest economic return and benefit cost (B:C) ratio was observed in T9 with gross return of ₹60,962/ha, net returns of ₹35,362/ha and B:C ratio (2.38). This was followed by T7 which had gross returns of ₹51,314/ha, net returns of ₹25,989/ha and B:C ratio (2.10).
... The crop growth rate is defined as the rate of increase in dry weight per unit area per unit of time. The CGR was computed using the formula suggested by Watson [9] and expressed in g m 2 day -1 . ...
The present investigation was undertaken to validate the integrated use of inorganic fertilizers and biofertilizers inoculated in organic manures on the physiological attributes and of pearl millet in the School of Agricultural Science, Karunya Institute of Technology and Sciences, Coimbatore, India. The experiment was laid out in Randomized Block Design (RBD) with three replications, during the rabi season of 2023-24. Results outlined that the integrated nutrient management practice of applying Azospirillum & PSB enriched vermicompost @ 6 t ha-1 + 100% Recommended dose of N, P2O5 & K2O has significantly increased the physiological attributes (leaf area index, crop growth rate, chlorophyll index), and yield (grain yield and stover yield) of pearl millet. This was statistically on par with the treatment Azospirillum & PSB enriched FYM @12.5 t ha-1 + 100% RDF dose of N, P2O5 & K2O.
... (LA 2 + LA 1 ) LAI = ______________________ 2 P Where, the LA 1 and LA 2 represent the leaf area of two consecutive intervals and 'P' stands for ground area (Watson, 1974). ...
The present field investigation was carried out at department of Plantation, Spices, Medicinal and Aromatic Crops, College of Horticulture, R.V.S.K.V.V., Mandsaur (M.P.) during the year 2021-2022 in RBD Design with three replications. The plots of individual treatments were applied different levels of FYM, vermicompost, bio-fertilizers (PSB, Azotobactor and Azospirillum) and control plots. Result revealed that T 8-FYM@20 tonha-1 + bio-fertilizers@3 kg ha-1 had highest plant height (41.90, 67.23, 80.91, 81.81 and 81.81 cm plant-1), number of branches (8.67, 28.17, 23.33, 24.00 and 24.00 plant-1),number of inflorescence (5.40, 49.67, 68.87, 69.87 and 69.87 plant-1), length of inflorescence (7.20, 19.93, 20.97, 21.05 and 21.05 cm plant-1), fresh weight (108.33, 243.02, 368.00, 259.80 and 236.10 g plant-1) and dry weight (4.26, 9.05, 42.83, 112.40 and 135.86 g plant-1), leaf area index (0.30, 0.97, 2.07 and 2.83), leaf area duration (244.27, 789.03, 1677.94 and 2291.38 cm 2 day-1), crop growth rate (0.61, 0.14, 0.19 and 0.05 g cm-2 day-1) and relative growth rate (0.13, 0.08, 0.09 and 0.04 g g-1 day-1) at different intervals. Dry herb yield (49.47 q plant-1), Seed yield (10.75 q ha-1) essential oil content (0.77% at 70 DAT and 0.86% at 110 DAT) also gross return (263425 Rs. ha-1), net return (187322.27 Rs. ha-1) and benefit: cost ratio (2.5) in T 8-FYM@20 ton ha-1 + bio-fertilizers @ 3 kg ha-1. ABSTRACT Introduction
... The CGR & NAR were worked out as per the formulae described by Watson et al. [23] and Watson [24], respectively. The portable photosynthesis system called Infrared Gas Analyzer (IRGA) was used to measure the physiology of wheat plant during experimentation as suggested by Pandey et al. [25]. ...
Intense cultivation with narrow row spacing in wheat, a common practice in the Indo-Gangetic plains of South Asia, renders the crop more susceptible to lodging during physiological maturity. This susceptibility, compounded by the use of traditional crop cultivars, has led to a substantial decline in overall crop productivity. In response to these challenges, a two-year field study on the system of wheat intensification (SWI) was conducted. The study involved three different cultivation methods in horizontal plots and four wheat genotypes in vertical plots, organized in a strip plot design. Our results exhibited that adoption of SWI at 20 cm × 20 cm resulted in significantly higher intercellular CO 2 concentration (5.9–6.3%), transpiration rate (13.2–15.8%), stomatal conductance (55–59%), net photosynthetic rate (126–160%), and photosynthetically active radiation (PAR) interception (1.6–25.2%) over the existing conventional method (plant geometry 22.5 cm × continuous plant to plant spacing) of wheat cultivation. The lodging resistance capacity of both the lower and upper 3 rd nodes was significantly higher in the SWI compared to other cultivation methods. Among different genotypes, HD 2967 demonstrated the highest recorded value for lodging resistance capacity, followed by HD 2851, HD 3086, and HD 2894. In addition, adoption of the SWI at 20 cm × 20 cm enhanced crop grain yield by 36.9–41.6%, and biological yield by 27.5–29.8%. Significantly higher soil dehydrogenase activity (12.06 μg TPF g ⁻¹ soil hr ⁻¹ ), arylsulfatase activity (82.8 μg p-nitro phenol g ⁻¹ soil hr ⁻¹ ), alkaline phosphatase activity (3.11 n moles ethylene g ⁻¹ soil hr ⁻¹ ), total polysaccharides, soil microbial biomass carbon, and soil chlorophyll content were also noted under SWI over conventional method of the production. Further, increased root volumes, surface root density and higher NPK uptake were recorded under SWI at 20×20 cm in comparison to rest of the treatments. Among the tested wheat genotypes, HD-2967 and HD-3086 had demonstrated notable increases in grain and biological yields, as well as improvements in the photosynthetically active radiation (PAR) and chlorophyll content. Therefore, adoption of SWI at 20 cm ×20 cm (square planting) with cultivars HD 2967 might be the best strategy for enhancing crop productivity and resource-use efficiency under the similar wheat growing conditions of India and similar agro-ecotypes of the globe.
... Data on growth characters on per plant basis were taken from five tagged plants at two weeks interval beginning from the (6 th ) sixth week after transplanting. The leaf area index was measured using handheld leaf area meter and CGR Crop growth rate which is dry matter accumulation per unit of land area per unit of time, was determined using the procedure described by (Watson, 1958).and expressed in g/cm 2 /wk. ...
Field experiments were conducted between 2004 and 2006 at the Institute for Agricultural Research Farm, Samaru Zaria in the Northern guinea savannah ecological zone of Nigeria, to study the response of chilli pepper (Capsicum frutescence L.) to sheep manure, plant population and nitrogen levels. Treatments evaluated consisted of four levels of sheep manure rates (0 t, 5 t, 10 t, and15 t ha-1), three plant populations (22,222; 44,444; and 66,666 plants ha1) and four rates of Nitrogen (0kg,60kg 120kg and 180 kg N ha1). The treatments were laid out in a split plot design and replicated three times. Result showed that application of sheep manure produced about significant increase in number of branches by 80%, similarly number of fruits increased by more than 600% and fresh fruit yields (Kg ha-1) recorded 57% increase over the control. Plant population was observed to significantly increase in the number of fruits per plant with 22,222 and 44,444plant/ha recording similar values, but higher number of fruits produced per plant than 66,666 plants ha-1 However, fresh fruit yield of Chilli pepper was not significantly influenced by plant population. The use of 120kgN ha1 resulted in increased number of branches, fruit per plant and fresh fruit yields by 57 and 60% respectively over non fertilized plants. Application of sheep manure at 10 t ha1, +44,444plants ha and 120kgN ha could be recommended for the production of chilli pepper under rain fed condition in Northern Guinea savannah.
... Five plants per plot were also harvested to get the fresh pod yield at 120 DAP, and the fresh pods were weighed on a scale, and the average was taken to give the pod weight per plant. Also, the leaf area index was determined at 30, 60 and 90 DAP according to the method of Watson (Watson, 1958). ...
Management efficiency can increase crop productivity through enhanced N2 fixation in the plant-soil system. This study examined soil tillage variants and sulphur fertilization effects on nodulation, N2 fixation effectiveness and yield of Bambara groundnut [Vigna subterranea] in a degraded Ultisol in Agbani Enugu, Southeast Nigeria. Twenty-four experimental units were laid out in a Randomized Complete Block Design (RCBD). The six treatments comprised No-Till+No Gypsum (NTGo), No-Till+Gypsum1 (NTG1), No-Till+Gypsum2 (NTG2), Till+No Gypsum (TGo), Till+Gypsum1 (TG1), and Till+Gypsum2 (TG2). No-till+gypsum2 plots had significantly higher soil N content than each corresponding No-till+no gypsum plot by 15-40 %. At 30 DAP, the plots treated with till+gypsum1 (21 kg/ha), till+gypsum2 (42 kg/ha), no-till+gypsum2 (42 kg/ha), no-till+gypsum1 (21 kg/ha), and till+no gypsum had 62-63 % higher soil sulphur content (P= 0.05) than the control plots. The nodule count per plant in plots treated with no-till+gypsum2 (42 kg/ha) was greater than that in the control plot, plots with no-till+gypsum1 (21 kg/ha), and plots with till+gypsum2 (42 kg/ha) by 72-74 % at 30, 60, and 90 DAP across two seasons. Compared to the untreated plots, nodulation effectivity was raised by 79-89 % in the No-till+gypsum2 plot. The plots treated with no-till+gypsum2 (42 kg/ha) had the highest yield (0.94 t/ha), followed by plots treated with no-till+gypsum1 (42 kg/ha) with 0.93 t/ha dry seed yield and till+gypsum2 (42 kg/ha) with 54-55 % greater yield (P=0.05) than the control plot. Sulphur treatment boosted nodulation by 68 % and nodule effectiveness by about 78 %. The no-till+Gypsum2 application enhanced the average yield of Bambara groundnuts by 56 %. The soil application of S enhanced the amount of accessible S in the soil. Results show that the tillage system and S fertilization impact Bambara groundnut on degraded Ultisols. Dry matter yield was best with a high S supply in both S increments and no-till systems. The number and effectiveness of nodules increased at different S rates and no-tillage. Because of the increased S application rate, there was a considerable increase in N accumulation due to a greater N2 fixation rate. The study recommends using no-till systems and sulphur fertilization practices to enhance crop productivity, especially in degraded Ultisols. The study provides valuable insights into sustainable agriculture practices that boost yields while conserving soils.
... The CGR was worked out between 60 and 90 DAT with the help of the following formula given by Watson (1958). ...
At Sher-e-Bangla Agricultural University’s agronomy field in Dhaka, Bangladesh, a study was carried out from July to December 2019 to determine the suppressing capacity of floating weeds in T. aman rice (Oryza sativa L.). The experiment consisted of two factors, namely, rice varieties (three), including Tulshimala, BR11(Mukta), and Bangladesh Rice Research Institute (BRRI) hybrid dhan6, and weed management (five), including weedy check (control), integrated weed management (IWM) (Pretilachlor 6% + pyrazosulfuron 0.15% and one hand weeding), spreading of Pistia stratiotes, Lemna minor, and Salvinia molesta in 0.5 m2 area in a split-plot design with three replications. The ranking of the relative rate of spreading over the experiment was L. minor > S. molesta > P. stratiotes. A total of six weed species representing five families were found from the transplanting to the later stage of rice growth, where the occurrence of weed infestation related to rice variety and crop growth. BRRI hybrid dhan6 significantly suppressed weeds in related plots. Although weed biomass was significantly reduced, the morphological and biomass characteristics of T. aman rice varieties got disadvantages when grown with P. stratiotes and S. molesta. Cultivation of BRRI hybrid dhan6 and weed control through IWM gave the highest grain yield (5.92 t ha-1). However, the spreading of L. minor facilitated optimal weed control, and good yields were harvested without significant differences, irrespective of varieties. Therefore, competitive weed variety should be considered along with the spreading of L. minor to reduce herbicide loads in the environment and to the evolution of cross-resistant weed populations.
... It is generally expressed in g m -2 day -1 . It is calculated by using following equation (Watson, 1958). ...
An experiment was carried out during the rabi seasons of 2021-22 and 2022-23 to investigate the influence of zinc and boron fortified briquettes on brinjal growth, yield, and economics. There were three levels of recommended dose of nitrogen viz. 100, 80 and 60 per cent through Konkan Annapurna Briquettes (KAB) with and without fertilization of zinc and boron. The recommended dose of straight fertilizers with and without zinc and boron was also included in the experiment. The result revealed that the higher brinjal growth and fruit yield (31.43 and 31.99 t ha-1) Konkan region of Maharashtra obtained with the application of 100 per cent nitrogen through Konkan Annapurna Briquettes (KAB) fortified with 2 kg B and 3 kg Zn per hectare followed by 80 per cent N through Konkan Annapurna Briquettes (KAB) fortified with 2 kg B and 3 kg Zn per hectare.
... Leaf area index (LAI) was determined using the ratio of the total leaf area (LA) to the ground area (GA) of a plant at a data collection time (Williams, 1946). Crop growth rate (CGR) was dry weight accumulation per ground area per unit time (g m -2 day -1 ) (Watson, 1958). ...
Drought stress was a main problem of maize production in Thailand. This study aimed to evaluate the effect of drought stress at different development stages and maize varieties (Zea mays L.) on growth, physiological responses, and grain yield to maintain maize production. The experiment was arranged in split-plot in a Randomized Completely Block Design (RCBD) with four replications. The main plot was control (well-watered) and drought stress at different development stages (the vegetative phase (V5), before the reproductive phase (V12), and the grain filling phase (R3)). The sub-plot consisted of four maize varieties: TS1004, NS3, SW4452, and NK6248. Drought stress during the vegetative phase (V5) and before the reproductive phase (V12) was found to be a susceptible stage for maize because grain yield (GY) was decreased by the loss of crop growth rate (CGR) and total soluble sugar content (TSC) and it accumulated proline content. The NK6248 variety was found to be the most suitable for maize production because it had the highest grain yield (GY) and crop growth rate (CGR). In addition, it had low proline content (PC) under drought stress. In summary, under drought stress, it is advisable to select the NK6248 variety for crop production and avoid drought stress in the vegetative phase (V5) and before the reproductive phase (V12) because a mechanism by which maize could maintain its production of this study was the accumulation of total soluble sugar content to decrease proline content under drought stress condition.
... Change in RGR can be better explained in terms of NAR and LAR (Watson, 1958). The Bradford Method was used to measure the protein content of tissue-cultured plants by comparing the findings to Bonjoch and Tamayo's 2001 BSA standard curve. ...
Bacopa monnieri is an important medicinal and economically useful plant. Its extracts are of primary ingredient in many pharmaceutical goods and are utilized for therapeutic purposes. Due to indiscriminate pharmaceutical demand, it has been obliterated from its natural environment. Therefore, an efficient protocol was developed for rapid micropropagation of Bacopa monnieri. In vitro multiplication method was used for the regeneration of this extremely endangered germplasm. Nodal and shoot tips were explanted on MS media with 3% sucrose, 0.8% agar, and different plant growth regulators. Shoot tip explants on MS media with 1.0 mg/l BAP + 0.25 mg/l Kinetin had the best responses. The best rooting response was on MS media with 1.0 mg/l IAA + 0.2 mg/l NAA.The regenerated and rooted plantlets were acclimatized and successfully transferred to soil for normal growth under field conditions with a 75-83% success rate after primary and secondary hardening. This procedure could be used to preserve and massively multiply economically significant and commercially valuable plants.
... Change in RGR can be better explained in terms of NAR and LAR (Watson, 1958). The Bradford Method was used to measure the protein content of tissue-cultured plants by comparing the findings to Bonjoch and Tamayo's 2001 BSA standard curve. ...
Bacopa monnieri is an important medicinal and economically useful plant. Its extracts are of primary ingredient in many pharmaceutical goods and are utilized for therapeutic purposes. Due to indiscriminate pharmaceutical demand, it has been obliterated from its natural environment. Therefore, an efficient protocol was developed for rapid micropropagation of Bacopa monnieri. In vitro multiplication method was used for the regeneration of this extremely endangered germplasm. Nodal and shoot tips were explanted on MS media with 3% sucrose, 0.8% agar, and different plant growth regulators. Shoot tip explants on MS media with 1.0 mg/l BAP + 0.25 mg/l Kinetin had the best responses. The best rooting response was on MS media with 1.0 mg/l IAA + 0.2 mg/l NAA.The regenerated and rooted plantlets were acclimatized and successfully transferred to soil for normal growth under field conditions with a 75-83% success rate after primary and secondary hardening. This procedure could be used to preserve and massively multiply economically significant and commercially valuable plants.
... Samples were sun-dried and finally oven-dried at 70ºC to a constant weight for estimation of dry matter accumulation. Leaf area was estimated using Sunscan Plant Canopy Analyzer SS1-STD.Crop growth rate (CGR) was computed by the following formula given by Watson (1958): ...
... The CGR was worked out between 60 and 90 DAT with the help of the following formula given by Watson (1958). ...
At Sher-e-Bangla Agricultural University's agronomy field in Dhaka, Bangladesh, a study was carried out from July to December 2019 to determine the suppressing capacity of floating weeds in T. aman rice (Oryza sativa L.). The experiment consisted of two factors, namely, rice varieties (three), including Tulshimala, BR11(Mukta), and Bangladesh Rice Research Institute (BRRI) hybrid dhan6, and weed management (five), including weedy check (control), integrated weed management (IWM) (Pretilachlor 6% + pyrazosulfuron 0.15% and one hand weeding), spreading of Pistia stratiotes, Lemna minor, and Salvinia molesta in 0.5 m 2 area in a split-plot design with three replications. The ranking of the relative rate of spreading over the experiment was L. minor > S. molesta > P. stratiotes. A total of six weed species representing five families were found from the transplanting to the later stage of rice growth, where the occurrence of weed infestation related to rice variety and crop growth. BRRI hybrid dhan6 significantly suppressed weeds in related plots. Although weed biomass was significantly reduced, the morphological and biomass characteristics of T. aman rice varieties got disadvantages when grown with P. stratiotes and S. molesta. Cultivation of BRRI hybrid dhan6 and weed control through IWM gave the highest grain yield (5.92 t ha-1). However, the spreading of L. minor facilitated optimal weed control, and good yields were harvested without significant differences, irrespective of varieties. Therefore, competitive weed variety should be considered along with the spreading of L. minor to reduce herbicide loads in the environment and to the evolution of cross-resistant weed populations.
... Relative weed density, weed control efficiency (WCE), weed control index (WCI), crop growth rate (CGR; mg cm -2 day -1 ), relative growth rate (RGR; mg g -1 day -1 ), and net assimilation rate (NAR; mg cm -2 day -1 ) were calculated following the below-mentioned formula. (Mishra and Tosh, 1979) (iv) Crop growth rate (CGR) = 2− 1 ( 2− 1) (Watson, 1956) Where, P = ground area (cm -2 ), W1 = dry weight per unit area at t1, W2 = dry weight per unit area, at t2, t1 = time of first sampling, t2 = time of second sampling (v) Relative growth rate (RGR) = ...
Weed management plays an important role in obtaining target yield. A field experiment was carried out at the Agronomy field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, from July to December 2019 to get the most effective weed control strategy for transplanted Aman rice. The soil of the study field was silty clay loam in nature. The study consisted of two factors i.e., variety (4: Chinigura, BR11(Mukta), BRRI dhan56, and BRRI hybrid dhan6) and herbicide (4) viz., Bispyribac-sodium WP @ 150 g ha-1, Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1, Pretilachlor 6% + pyrazosulfuron 0.15% WP @ 9.88 kg ha-1, and weedy check as a control. The experiment was laid out in a split-plot design with three replications. Thirteen weed species were found in the experimental plots, mostly broadleaf and sedge. Monochoria vaginalis was the most dominant weed species. The study noticed that the application of mixed herbicides offered better weed control over single herbicide application. Application of Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1 significantly reduced weed density and biomass and was the best way of controlling complex weed flora. The study marked out BR11 (Mukta) as the most potential aman rice variety to produce the highest yields at applying Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1. This treatment gave the highest gross return (Tk. 1,46,010), net return (Tk. 88,699), and benefit-cost ratio (2.55). Therefore, the study suggests the application of mixed herbicides and BR11 (Mukta) to get the optimum yield of transplanted Aman rice and maximum economic benefit. Bangladesh Agron. J. 2023, 26(1): 56-74
... Five plants per plot were also harvested to get the fresh pod yield at 120 DAP, and the fresh pods were weighed on a scale, and the average was taken to give the pod weight per plant. Also, the leaf area index was determined at 30, 60 and 90 DAP according to the method of Watson (Watson, 1958). ...
... The leaf area was measured with the help of LI-3100 leaf area meter by passing detached leaves, and leaf area index was calculated by dividing the total leaf area by ground area. Crop growth rate was (CGR) calculated from dry weight of the whole plant using the formula suggested by Watson (1958). Oil content in seeds of each treatment was estimated by Nuclear Magnetic Resonance (NMR) spectrometer as suggested by Tiwary et al. (1974). ...
A field experiment was conducted to evaluate the effect of integrated nutrient management (INM) practices on growth, yield parameters and yield of sunflower grown under neem (Azadirachta indica) and melia (Melia azadirach) trees during kharif 2009 at Student's Farm, College of Agriculture, Hyderabad. Dry matter production, crop growth rate, leaf area index, yield components and yield of sunflower was higher in sole cropping of sunflower compared to sunflower grown under neem or melia trees. Higher sunflower yield was recorded under sole cropping (560 kg /ha) compared to sunflower grown under neem and melia trees with yields of 461 and 317 kg /ha respectively. Application of subabul (Leucaena leucocephala) green leaf manure at 5 t / ha + 30 kg N/ha produced more growth, yield parameters, and yield of sunflower compared to other nutrient management practices. The studies suggested that sunflower was compatible with neem trees. However, melia trees had severe impact on growth, yield and yield parameters. Application of green leaf manure with half of recommended dose of nitrogen recorded better yield than recommended dose of nitrogen alone.
... [218][219][220] Overall, the increase in leaf area index (ratio between the area of one leaf to plant ground coverage) leads to more efficient light capture up to a certain point, after which self-shading reduced the plant's overall light use efficiency. 221,222 As reduction of leaf size is typically associated with reduced overall light capture and yield, and is not exhibiting high phenotypic plasticity, it has thus far not been utilized in breeding programs. ...
Plant architecture develops post-embryonically and emerges from a dialogue between the developmental signals and environmental cues. Length and branching of the vegetative and reproductive tissues were the focus of improvement of plant performance from the early days of plant breeding. Current breeding priorities are changing, as we need to prioritize plant productivity under increasingly challenging environmental conditions. While it has been widely recognized that plant architecture changes in response to the environment, its contribution to plant productivity in the changing climate remains to be fully explored. This review will summarize prior discoveries of genetic control of plant architecture traits and their effect on plant performance under environmental stress. We review new tools in phenotyping that will guide future discoveries of genes contributing to plant architecture, its plasticity, and its contributions to stress resilience. Subsequently, we provide a perspective into how integrating the study of new species, modern phenotyping techniques, and modeling can lead to discovering new genetic targets underlying the plasticity of plant architecture and stress resilience. Altogether, this review provides a new perspective on the plasticity of plant architecture and how it can be harnessed for increased performance under environmental stress.
... The Sugar Crop Research Institute's recommendations for growing sugar beet were adopted. As shown in Table (2), soil samples (0-30 cm depth) from the experimental location were collected to evaluate its physical and chemical characteristics using the techniques outlined by The recorded data At 110 days after seeding, five plants were randomly collected from the middle ridges of each sub-plot to determine the following: 1. Leaf area index (LAI): Leaf area was determined by the disk method using ten disks of 1.0 cm Watson (1958), the equation was used: LAI = Leaf area per plant (cm 2 )/plant ground area (cm 2 ). Ten guarded plants were selected at random from each subplot's middle ridges at harvest, uprooted, topped, and weighed to determine the following traits: 1. Root diameter/plant (cm). ...
... Dry matter remobilization efficiency (%) and dry matter conversion rate (%) was calculated by using the formulae suggested by Ntanos et al., (2002) and Xiong et al., (2013). The crop growth rate (CGR), Relative growth rate (RGR) and Net assimilation rate (NAR) were calculated as suggested by Watson (1958), Radford (1967) and Vernon and Allison (1963), respectively. For recording grain yield, the grains obtained after threshing net plots were sun dried, winnowed, cleaned and weighed on an electronic balance. ...
Salicylic acid (SA), a signaling molecule is known to affect various physiological processes like growth and development, photosynthesis, absorption and translocation of assimilates etc. Therefore, an experiment was conducted to study the effect of salicylic acid on assimilate partitioning and yield of rice. The experiment comprised of 14 treatments replicated thrice in Randomized Complete Block Design (RCBD). Foliar application of SA @ 50, 100, 150 & 200 µg ml-1 was done at boot leaf stage (BL), one week after boot leaf stage (1WABL) and at BL + 1WABL. Treatment of water spray and unsprayed (control) were also included. Findings reveal that application of 100 µg ml-1 SA at BL + 1WABL resulted in the highest grain yield, which was statistically similar to 150 µg ml-1 SA at BL + 1WABL. The higher productivity under respective treatments can be ascribed to higher crop growth rate, relative growth rate, net assimilation rate and improvement in partitioning of dry matter from vegetative parts to grains due to improved vascularization. Also there was improvement in photosynthetic efficiency in terms of total chlorophyll content; carotenoid content and Hill reaction activity under SA treated plots. Thus, the productivity enhancement in rice can be achieved through 2 foliar sprays of salicylic acid @ 100 µg ml-1 each at boot leaf stage + one week after boot leaf stage.
... The remaining quantity of 10 % N and 20 % K were applied from 24 th to 28 th weeks. The crop growth rate was analyzed from the procedure given by Watson (1958), chlorophyll by Yoshida et al. (1971) and soluble protein by Lowery et al. (1957). The third youngest leaf was used as the standard leaf for physiological parameters estimation (Saifudeen, 1981). ...
A field experiment to study the influence of fertigation of N and K fertilizers on physiology and yield of turmeric (Curcuma longa L.) cv. BSR 2 was carried out during June 2007 to February 2008. The experiment consisted of seven treatments replicated four times in a randomized block design. The physiological parameters viz., crop growth rate, chlorophyll a, chlorophyll b, total chlorophyll, soluble protein and yield parameters viz., number of mother, primary and secondary rhizomes, length and girth of mother, primary and secondary rhizomes, weight of mother, primary and secondary rhizomes, fresh, cured rhizome yield plant-1 and estimated cured rhizome yield hectare-1 were recorded. The study revealed that the fertigation treatments were significantly superior over the control. Among the treatments, N + K @ 100 % level (150 : 108 NK kg ha-1) by fertigation using water soluble fertilizers viz., Urea and Multi 'K' registered the highest values for the above parameters.
... Total leaf area of plant Leaf Area Index = Leaf area occupied by plant (Williams, 1946) (L 2 + L 1 ) Leaf Area Duration = × (t 2 -t 1 ) 2 (Power et al., 1967) L 1 = Leaf Area Index at time t 1, L 2 = Leaf Area Index at time t 2 (t 2 -t 1 ) = Time interval in days (w 2 + w 1 ) Crop Growth Rate = (g m -2 day -1 ) (t 2 -t 1 ) (Watson, 1956) Where W 1 and W 2 are the dry weight of the whole plant at times t 2 and t 1 and are the ground area on which W 1 and W 2 are noted. ...
A field experiment was conducted during Kharif 2021 at ZARS, V.C. Farm, Mandya to study the influence of split application of potassium on rice under different establishment methods viz., dry direct seeded rice (DDSR), wet direct seeded rice (WDSR), system of rice intensification (SRI), alternate wetting and drying (AWD) in comparison to conventional method of transplanting as standard check. The experiment was laid out in factorial randomized complete block design and replicated thrice. Among the different rice establish- ment methods, system of rice intensification (SRI) recorded significantly higher growth and yield param- eters viz., higher plant height (137.7 cm), number of tillers (583.0 m-2) and dry matter production (81.2 g hill- 1), higher number of panicles (359.4 m-2), grains per panicle (270.5), filled grains per panicle (233.5), grain yield (6412 kg ha-1) and straw yield (7483 kg ha-1) as compared to other methods. The growth and yield attributes differed non-significantly by split application of potassium and the interaction among the treat- ments. However, numerically three split application of potassium recorded higher values as compared to two split applications.The wet DSR recorded significantly higher content of available N, P2O5 and K2O (178.7,
39.3 and 160.6 kg ha-1, respectively) as compared to other methods of establishment. The lower N, P O and
2 5
K O (140.0, 26.5 and 147.2 kg ha-1, respectively) and potassium forms in the soil was recorded in SRI with
three split application of potassium.The higher benefit cost ratio (B:C) (2.40) was recorded with three split applications of potassium in SRI method and hence considered as best establishment method with timely supply of potassium for achieving higher yield and net returns.
... Such substances are, therefore, potentially useful in agriculture. Suitable concentrations applied at appropriate time can increase yield either by altering dry matter distribution in the plant or by regulating growth (Watson, 1958). Microenvironment plays a vital role in production of quality seeds besides increasing productivity. ...
An investigation was undertaken to study the effect of foliar sprays of NAA, triacontanol and boron on vine growth, seed quality and storability in bitter gourd cv. Pusa Visesh. Results revealed that NAA at 50mg/l produced the longest vines (192.33 and 260.67cm), maximum leaf area (1.890 and 2.965cm2/vine), leaf area index (1.969 and 2.760) and leaf chlorophyll content (39.23 and 38.90 SPAD value) at 85 and 100 days after sowing (DAS), respectively. As for seed quality attributes, treatment with boron at 4mg/l recorded lowest seed moisture content and highest seed germination percentage (9.16% and 85.5%, respectively), followed by NAA at 50mg/l (9.21% and 85.25%, respectively) whereas, Control recorded highest seed moisture and lowest seed germination percentage (9.84% and 74.5%, respectively) recorded at the end of storage.
... The number of branch was estimated by counting the number of branches per plant and The mean number of branches per plant was recorded. Leaf area index was determined at 6, 8, 10 and 12 weeks after emergence using the method described by (14), i.e LAI was calculated as the ratio of leaf area to the ground area covered by the plant, multiply by a factor (0.75) to the unit ground area covered by each plant. LAI = leaf area per plant (cm) x 0.75 ...
This study was conducted to investigate the effect of intercrop on quality and forage yield of maize (Zea mayz L.) and groundnut (Arachis hypogea) in Northern Guinea Savannah at the National Animal Production Research Institute Shika, Zaria, Nigeria. The experiment was laid in a Completely Randomized Design (CRD) replicated 3 times. The treatments consist of five intercropping pattern (sole maize (M), sole groundnut (G), 1:1 M-G, 1:2 M-G and 2:1M-G). Forage yield, proximate composition, and mineral concentrations were determined at 14 weeks after sowing (WAS). Intercropping significantly (P<0.05) affected fresh forage yield of maize and dry forage yield of maize and groundnut. The highest fresh forage yield of maize and dry forage yield of maize and groundnut (20.33, 8.63 and 6.53 t/ha, respectively) were obtained at 1:2 M-G intercrops. The percentage proximate composition and fibre fractions were significantly (P<0.05) affected by intercropping. The crude protein and crude fibre ranges between 6.60-7.30 % and 19.46-22.81 %, respectively. Mineral concentration for Ca, Mg, P and Cu were significantly influenced (P<0.05) by intercropping pattern. This study reveals that intercropping maize and groundnut at 1:2 M-G ratio produced the highest forage yield and improved percentage composition of DM, CP and CF. Therefore, intercropping of maize and groundnut at 1:2 M-G planting pattern is recommended for farmers and livestock producers in Northern Guinea Savanna of Nigeria.
... Need-based plant protection measures were given whenever pest incidences are more than economic threshold level. Crop growth rate (CGR) and Relative growth rate (RGR) were computed by using the standard procedure suggested by Watson (1958) and Williams (1946) respectively. The data was statistically analyzed by following the method of Gomez and Gomez (2010). ...
A Field experiment was carried during rabi, 2016-17 at the Department
of Agronomy, Agricultural College and Research Institute, Tamil Nadu
Agricultural University, Madurai to find out the residual effect of slow release
herbicide formulations on weed and bhendi in the rice-bhendi crop sequence.
Among weed control treatments, the residual effect of butachlor at 1.25
kg/ha on 3 DAT fb HW on 40 DAT recorded significantly lower total weed
density of 21.33/m2 and 51.17/m2 at 20 and 40 DAS respectively. It was on
par with the residual effect of oxadiargyl loaded in zeolite applied at 3 DAT,
whereas, at 60 DAS and at harvest stage, the residual effect of oxadiargyl
encapsulated with water-soluble polymer and loaded in zeolite applied on 3
DAT recorded lower weed density. Significantly, lower weed dry weight was
recorded in butachlor at 1.25 kg/ha on 3 DAT fb HW on 40 DAT + HW twice
at 20 and 40 DAS which was on par with residual effect of oxadiargyl loaded
in zeolite at 3 DAT and oxadiargyl loaded in biochar at 3 DAT compared to all
other treatments at 20 DAS. The same pattern was observed in total weed
dry weight at 40, 60 DAS and at harvest stage except oxadiargyl loaded in
biochar at 3 DAT. Slow release formulation of oxadiargyl recorded higher
germination percentage of bhendi as compared to commercial formulations
and weedy check. Weed-free check, butachlor at 1.25 kg/ha fb HW on 40
DAT, oxadiargyl loaded in zeolite applied to previous rice crop on 3 DAT has
recorded higher bhendi fruit yield of 6.40, 3.70, 1.53 times against weedy
check.
... The Leaf area index (LAI) was then calculated using the area-weight relationship (Watson 1947). Crop growth rate (CGR) was calculated according to equation (1) according to Watson (1958), ...
Indiscriminate application of inorganic chemicals has resulted in soil health deterioration and decline in crop produce in nutrient poor Alfisols of India. We conducted an experiment to find out the influence of different level of inorganic fertilizer and bio-formulations on nutrient uptake, crop growth and productivity of kharif groundnut in the Red and Laterite soils during 2018, 2019 and 2020. It was hypothesized that judicious application of inorganic fertilizer and bio-formulation would result in better nutrient uptake, improving nut yield and net income. We found that higher dose of inorganic fertilizer along with liquid bio-formulations yielded better results in terms of nutrient uptake, crop growth, yield and quality in groundnut. An increase of 43.2% and 57.5% in haulm and kernel N uptake; 67.6 and 98.1% in haulm and kernel P uptake; 47.4% and 57.6% in haulm and kernel K uptake was recorded, respectively, when 100% recommended dose of NPK (F 4) was coupled with liquid NPK bio-formulation + Zn-solubilizing bacteria (B 2) over control and was most economical (higher B:C ratio, 2.73). Groundnut being an exhaustive crop, responded well to higher levels of inorganic fertilizer and bio-formulations.
... Chlorophyll content of the leaves on a relative basis was measured by SPAD chlorophyll meter readings which measures the green colouration. Leaf area index is the total leaf area present for unit land area and was calculated by using the formula of Watson [82]. ...
Rice is an important cereal crop, is mostly grown as a staple food in developing nations. One of the main causes restricting rice productivity is drought, which has a detrimental effect on global food security. Silicon increases antioxidant activity and lessens plant oxidative damage. In the current study, eight rice cultivars were subjected to foliar silicon spray to evaluate its effectiveness in reducing water stress. The plants were foliar sprayed with silicon under well-watered and drought-stressed circumstances. The collected data showed that drought stress significantly reduced physiological parameters, growth, and yield. In comparison with control, silicon application (T2) has increased LAI by 50.13%, RWC by 0.24%, total dry matter by 18.86%, productive tiller number by 30%, number of panicles m-2 by 26.10%, number of grains panicle-1 by 24.60%, test weight by 29.26% and grain yield by 10.60%; water stress alone (T3) reduced LAI by 38.06%, RWC by 21.02%, total dry matter by 38.88%, productive tiller number by 30%, number of panicles m-2 by 33.45%, number of grains panicle-1 by 42.85%, test weight by 34.87% and grain yield by 40.88%; while silicon + water stress (T4) reduced LAI by 3.41%, RWC by 16.89%, total dry matter by 8.45%, productive tiller number 0.00%, number of panicles m-2 by 13.97%, number of grains panicle-1 by 18.25%, test weight by 24.50% and grain yield by 19.24% only. Overall, silicon application has ameliorated the negative impacts of drought stress on rice and improved the growth, physiological traits and yield under both well-watered and water stress conditions. To increase the quality of the yield and to generate rice cultivars that can withstand drought stress, silicon should be incorporated into breeding programmes.
... Leaf area index (LAI), the ratio of the surface area of a plant leaf to the surface area of land LAI, is used to quantitatively describe changes in leaf growth and density at the community level (Watson, 1958). LAI is an important input parameter for simulating the carbon and water cycles in forest ecosystems (Weiss et al., 2004;Wang et al., 2005); Zhao et al. . ...
Analyzing the physiological response of trees to climate change in the Qilian Mountains region is key to studying the impact of global change on forest ecosystems in the semiarid alpine region of Northwest China. The leaf area index ( LAI ) of the canopy of a forest is an important input parameter for simulating carbon and water cycles in forest ecosystems. Studying the relationship between LAI and environmental factors can provide a scientific basis for accurately describing the structure, function, and ecohydrological processes of forest ecosystems and theoretically guide for sustainable management of water conservation in forests. Methods: In this study, the LAI of the Picea crassifolia canopy was monitored for 2 years (2015–2016) by field observations, and its dynamic changes were analyzed. The relations between LAI and air temperature ( AT ), precipitation ( P ), soil temperature ( ST ), and soil water content ( SWC ) were studied using Pearson's correlation and multiple regression analyses. The results were as follows: seasonal variations in LAI showed a single-peak curve, which first increased, reached a maximum, remained relatively stable, and then decreased. The maximum value was 4.02 and 4.18 relatively observed in mid-August 2015 and 2016. The LAI of the P. crassifolia canopy in different months was positively correlated with AT and P . It was correlated between the LAI of the canopy with ST 40−60 in May and June ( p < 0.05) and was also highly positively correlated between the LAI of the canopy with ST 60−80 , ST mean , and SWC 60−80 in July and August ( p < 0.01). There was a positive correlation between the LAI of the canopy with SWC 0−60 and SWC mean in July and SWC 0−60 and SWC mean in August ( p < 0.05). The LAI of the canopy was affected by AT and ST in May and July, AT and P in June, P in August, and P and ST in September. Our study implied that the rapid increase period of the LAI of the canopy was from late May to early July. The LAI of the canopy was more influenced by temperature and water in July and August. In addition, the LAI of the canopy has significant seasonal variation although it is evergreen coniferous tree species.
... Five plants were randomly collected from the middle ridges of each sub-plot at 110 days from sowing to determine the following: 1. Leaf area index (LAI): Leaf area was measured and determined by the disk method using ten disks of 1.0 cm diameter according to Watson (1958), and then the following equation was used: LAI = Leaf area per plant (cm 2 )/plant ground area (cm 2 ) was measured at 120 days from sowing using the leaf area meter, model: 3000 A. 2. Photosynthetic pigments i.e., chlorophyll a, b, and carotenoids (mg/g leaf fresh weight) were determined according to the method described by Wettstein (1957). At harvest, a random sample of ten guarded plants was taken from the middle ridges of each sub-plot to determine the following traits: 1. Root diameter/plant (cm). ...
... The computation of the mean net assimilation rate was performed using Equation 3, as provided by Watson (1958): ...
The major challenge of growing soybean, other than unfavorable weather and small farm size, is the non-availability of quality inputs at the right time. Furthermore, in soybean growing regions, crop productivity and soil environment have deteriorated due to the use of traditional varieties and conventional methods of production. Soybean crop intensification or system of crop intensification in soybean (SCI) is an agricultural production system that boosts soybean yields, improves the soil environment, and maximizes the efficiency of input utilization, although the contribution of SCI to crop productivity is not well understood as different genotypes of soybean exhibit different
physiological responses. Therefore, a field study was conducted in 2014–2015 and 2015–2016 using three crop establishment methods (SCI at a 45 cm × 45 cm row spacing, SCI at 30 cm × 30 cm, and a conventional method at 45 cm × 10 cm) assisted in vertical strips with four genotypes (Pusa 9,712, PS 1347, DS 12–13, and DS 12–5) using a strip-plot design with three replications. Compared with standard methods of cultivation, the adoption of SCI at 45 cm × 45 cm resulted in a significantly higher stomatal conductance (0.211 mol H2O m−2 s−1), transpiration rate (7.8 mmol H2O m−2 s−1), and net photosynthetic rate (398 mol CO2 m−2 s−1). The implementation of an SCI at 30 cm × 30 cm had significantly greater intercepted photosynthetic active radiation (PAR) (1,249 mol m−2 s−1) than the conventional method system, increasing crop yield from 9.6 to 13.3% and biomass yield from 8.2 to 10.7%. In addition, under an SCI at 30 cm × 30 cm, there were more nodules, significantly larger root volume and surface density, and increased NPK uptake compared with the other methods. Significantly greater soil dehydrogenase activity, alkaline phosphatase activity, acetylene-reducing assay, total polysaccharides, microbial biomass carbon, and soil chlorophyll were found with SCI at 45 cm × 45 cm (13.63 g TPF g−1 soil hr.−1, 93.2 g p-nitro phenol g−1 soil hr.−1, 25.5 n moles ethylene g−1 soil hr.−1, 443.7 mg kg−1 soil, 216.5 mg kg−1 soil, and 0.43 mg g−1 soil, respectively). Therefore, the adoption of an SCI at 30 cm × 30 cm and/or 45 cm × 45 cm could provide the best environment for microbial activities and overall soil health, as well as the sustainable productivity of soybean aboveground.
... The computation of the mean net assimilation rate was performed using Equation 3, as provided by Watson (1958): ...
The major challenge of growing soybean, other than unfavorable weather and small farm size, is the non-availability of quality inputs at the right time. Furthermore, in soybean growing regions, crop productivity and soil environment have deteriorated due to the use of traditional varieties and conventional methods of production. Soybean crop intensification or system of crop intensification in soybean (SCI) is an agricultural production system that boosts soybean yields, improves the soil environment, and maximizes the efficiency of input utilization, although the contribution of SCI to crop productivity is not well understood as different genotypes of soybean exhibit different physiological responses. Therefore, a field study was conducted in 2014-2015 and 2015-2016 using three crop establishment methods (SCI at a 45 cm × 45 cm row spacing, SCI at 30 cm × 30 cm, and a conventional method at 45 cm × 10 cm) assisted in vertical strips with four genotypes (Pusa 9,712, PS 1347, DS 12-13, and DS 12-5) using a strip-plot design with three replications. Compared with standard methods of cultivation, the adoption of SCI at 45 cm × 45 cm resulted in a significantly higher stomatal conductance (0.211 mol H 2 O m −2 s −1), transpiration rate (7.8 mmol H 2 O m −2 s −1), and net photosynthetic rate (398 mol CO 2 m −2 s −1). The implementation of an SCI at 30 cm × 30 cm had significantly greater intercepted photosynthetic active radiation (PAR) (1,249 mol m −2 s −1) than the conventional method system, increasing crop yield from 9.6 to 13.3% and biomass yield from 8.2 to 10.7%. In addition, under an SCI at 30 cm × 30 cm, there were more nodules, significantly larger root volume and surface density, and increased NPK uptake compared with the other methods. Significantly greater soil dehydrogenase activity, alkaline phosphatase activity, acetylene-reducing assay, total polysaccharides, microbial biomass carbon, and soil chlorophyll were found with SCI at 45 cm × 45 cm (13.63 g TPF g −1 soil hr. −1 , 93.2 g p-nitro phenol g −1 soil hr. −1 , 25.5 n moles ethylene g −1 soil hr. −1 , 443.7 mg kg −1 soil, 216.5 mg kg −1 soil, and 0.43 mg g −1 soil, respectively). Therefore, the adoption of an SCI at 30 cm × 30 cm and/or 45 cm × 45 cm could provide the best environment for microbial activities and overall soil health, as well as the sustainable productivity of soybean aboveground.
... If we consider that the fruit represents a major sink for carbohydrates (DeJong and Grossman 1995), it is likely that a higher yield efficiency related with lower leaf to fruit ratio may further compete with the vegetative growth. Total leaf area is an important determinant of photosynthetic gain and overall growth (Watson 1958). Differences in the relative proportion of leaf area were anticipated between low versus high vigor trees as a consequence of architectural changes during canopy development. ...
Size-controlling rootstocks have been one of the major innovations facilitating high-efficiency fruit production; however, biological mechanisms responsible for their size-controlling effect remain unclear. In this study we investigated if apple and pear trees grafted on dwarfing and invigorating rootstocks differ in the size and dynamics of non-structural carbohydrate (NSC) storage pools. Seasonal dynamics in NSC concentrations were assessed in current-year shoots, coarse roots, trunks, and leaves. These measurements were then upscaled to whole-organ and whole-tree NSC pools and mutually compared. Because of the small variation in the relative biomass partitioning and generally similar organ-level NSC concentrations, the size of the NSC pools scaled tightly with the overall tree biomass with vigorous trees having greater absolute storage pools compared to dwarfing trees. The magnitudes of the seasonal fluctuation in NSC pools (i.e., November to May difference) were in the range from 0.55 to 3.93 kg per tree and 20 to 50 g per kg of tree’s dry weight. In absolute terms, the seasonal fluctuations in NSC pools were higher in vigorously growing trees but in relative terms and also when scaled by the tree’s biomass the differences between the low and high vigor trees became negligible, suggesting that the low and high vigor trees rely on their NSC reserves to a similar extent during their annual growth cycle. Thus, our results provide no support that the observed differences in growth vigor are driven by the availability of C-reserves.
... The photosynthetic efficiency of pearl millet leaves in terms of net gain of assimilate per unit leaf area per unit time, that is, mean NAR value was estimated for vegetative phase to flowering phase (30-60 DAS) by the expression suggested by Watson, (1958): where, W1 and W2 are the dry weights (g plant -1 ) and LA1 and LA2 are leaf area (m 2 ) per plant at time T1 (days) and T2 (days), respectively. Ln denotes natural logarithm. ...
The study was undertaken to evaluate the effect of foliar sulphur (S) nutrition through Ammonium Thiosulphate (ATS) under conservation management on the growth, photosynthetic efficiency and productivity of rainfed pearl millet in dryland and rainfed ecologies of New Delhi in 2021 and 2022 crop years. The pearl millet established under conservation management (ZTCRret) achieved significantly higher crop growth rate (CGR) and relative growth rate (RGR) as a result of improved photosynthesis efficiency in terms of net assimilation rate (NAR) and a higher rate of productive tiller production (RPTP). The productivity of rainfed pearl millet under ZTCRret was improved by 26.6 and 13.5 % during 2021, and by 27.6 and 12.7 % over zero tillage (ZTCRrem) and conventional tillage (ConTil), respectively. The application of a recommended dose of S at 30 kg ha-1 resulted in a dramatic improvement in growth indices and photosynthetic efficiency over control and ATS doses upto 0.5% twice. Foliar application of ATS at 0.5% once and successively higher doses were found to improve the growth and productivity of pearl millet over S control, however, the dose of ATS at 1.0% twice could only achieve statistically similar levels of CGR and RGR to RDS that led to the higher RPTP with higher photosynthetic efficiency which resulted in non-significant yield difference. Therefore, the pearl millet established under zero tilled and crop residue retained plots supplemented with foliar feeding of ATS at 1.0% at 20 DAS (4-6 leaves stage) and 50 DAS (flowering stage) can be practiced under rainfed ecologies without significant yield loss.
The present investigation was conducted to study the integrated use of microbial enriched organic manures with inorganic fertilizers on the physiological attributes of chickpea in the School of Agricultural Science, Karunya Institute of Technology and Sciences, Coimbatore, India. The experiment was laid out in Randomized Block Design (RBD) with three replications, during the late rabi season of 2023. The outcome of the study delineates the substantial efficacy of treatment T5 (100% N: P2O5: K2O + Microbial enriched vermicompost @ 6 t ha-1) and T4 (100% N: P2O5: K2O + Microbial enriched FYM @12.5 t ha-1) in significantly augmenting the physiological growth and development of chickpea crop, resulting in an improved yield of 12.76 q ha-1 and 12.59 q ha-1 respectively.
"Effect of Neem coated Urea on growth and yield of Barley (Hordeum Vulgare L.)" Investigates the application of neem-coated urea as a means of enhancing agricultural productivity while addressing modern agricultural challenges, by focusing on the impact of this specific nutrient management technique on barley growth and yield, the study likely aimed to contribute to the adoption of advanced agricultural practices.
Neem-coated urea is known for its slow-release properties, which can lead to more efficient nutrient uptake by crops and reduced nutrient losses through runoff or leaching. By optimizing nutrient cycles through the use of this technology, the thesis likely aimed to mitigate issues such as soil degradation, nutrient imbalances, and environmental pollution associated with traditional fertilizer application methods.
Ultimately, the research likely provided valuable insights into the potential benefits of adopting neem-coated urea as part of a modern agricultural strategy, with implications for sustainable agriculture and environmental stewardship. It likely contributed to the ongoing efforts to develop innovative solutions to contemporary agricultural challenges, promoting both productivity and environmental sustainability in the agricultural sector.
Fly ash (FA) is a waste byproduct produced in large quantities by coal-fired power stations. Its accumulation causes environmental issues, so it needs safe disposal of FA to reduce its accumulation. Herbal medicines like Mentha arvensis are being investigated worldwide for the prevention and treatment of a wide range of disorders because of their remarkable therapeutic benefits and absence of side effects when compared to current medications.
The aim of the study was to determine the effect of different concentrations of fly ash on growth, biochemical parameters, and constituents of essential oils of M. arvensis.
The findings demonstrated that FA improved some important physical and chemical properties of soil. The use of FA-amended soil (10%) significantly improved the growth performance, photosynthetic pigments, protein, proline, antioxidant activity, and mineral contents. Conversely, the higher fly ash doses (25%) resulted in oxidative stress by increasing lipid peroxidation and electrolytic leakage levels, which negatively affected all of the aforementioned parameters. A confocal microscopic examination of the roots of M. arvensis revealed that fly ash at concentration of 25% resulted in membrane damage. In addition, alcohols, phenols, allenes, ketenes, isocynates, and hydrocarbons were among the functional groups found in the control and 10% of fly ash. Gas chromatography–mass spectrometry analysis of essential oils of M. arvensis treated with 10% fly ash revealed the presence of 32 bioactive components.
It is possible to use the 10% FA concentrations to increase plant growth and decrease the accumulation of FA that pollutes the environment.
A field experiment was conducted during the rainy (kharif) season of 2018 at Jobner, Rajasthan, to study the ef- fect of sulphur and zinc fertilization on growth, yield attributes and grain yield of sesame (Sesamum indicum L.). The experiment, comprising 4 levels each of sulphur (0, 15, 30 and 45 kg/ha) and zinc (0, 10, 20 and 30 kg zinc sulphate/ha), thereby making 16 treatment combinations, was laid out in factorial randomized block design and replicated thrice. Progressive increase in level of sulphur up to 30 kg/ha significantly increased the most of the growth and yield-attributing characters of sesame, viz. plant height, dry-matter accumulation, crop growth rate (CGR), relative growth rate (RGR), branches/plant, chlorophyll content, leaf-area index, capsules/plant, seeds/ capsule and test weight, over preceding levels. It also recorded significantly higher seed yield (712 kg/ha) of sesame over the control and 15 kg/ha. However, it was found at par with 45 kg/ha, wherein the maximum values of growth and yield attributes as well as yield were obtained. Results further showed that an increase in level of zinc sulphate up to 20 kg/ha by and large significantly improved the most of the growth and yield-determining charac- ters of sesame over lower levels. It also recorded significantly higher seed yield (725 kg/ha) over the control and 10 kg/ha and found at par with 30 kg/ha. Application of 30 kg S/ha in conjunction with zinc sulphate at 20 kg/ha (S Zn ) was the most effective treatment combination for obtaining higher seed yield (802 kg/ha) and net returns 30 20 ( 48,970/ha) in sesame.
Long‐term weather patterns (environmental conditions or stresses exceeding 10 days in length) have the potential to influence corn (Zea mays L.) growth, development, and yield. This review summarizes the current knowledge (with emphasis placed on the Midwestern U.S. production environment) on how long‐term weather conditions affect corn growth and yield, including (i) drought and heat stress, (ii) solar radiation, and (iii) distribution of heat unit accumulation during the season. Each section contains summaries of how these environmental factors influence corn growth and yield and provides context into past events experienced. The focus of the review is on dent corn grown for grain production, though relevant issues related to other types (i.e., silage corn) are included. This review also discusses agronomic recommendations or considerations to help alleviate the negative effects of stress conditions and identify areas where future research would be beneficial to continue improving the resiliency of corn cropping systems. Periods of high heat and water deficit as well as limited light availability challenge the ability to maximize yield production in corn. Temperature affects crop growth and development through the season, and accurately describing phenological progression using heat unit accumulation is a challenge. Advances in corn breeding and genetics, hybrid selection, and agronomic management practices will be key to ensuring long‐range productivity and fully leveraging possible benefits from the shifts in long‐range weather patterns.
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