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Growth and performance of rubber trees (Hevea brasiliensis) during the immature phase were studied in a tropical humid climate. Monthly girth growth of the main stem from 25 clones, between ages three and eight years, was monitored. Monthly girth increments, seasonal and annual absolute and relative girth rates were the analysis parameters. Three s...
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... The end of the immature period of rubber trees is currently determined empirically, by measuring the trunk girth (Compagnon et al. 1986;Webster and Baulkwill 1989). Depending on the country, a tree is considered as mature when its trunk reaches a girth of 45 to 50 cm at a height of 100 to 150 cm above ground level, while a plantation is considered mature when 50 to 70% reach this girth (Compagnon et al. 1986;Chandrasekhar et al. 2005;Gunasekara et al. 2007;Nhean et al. 2020). Reaching this trunk girth takes generally 6 to 7 years. ...
Perennial cropping systems begin their cycles with a pluriannual immature period. Appropriate management, including the inter-rows, is essential for the long-term viability, and productivity of the plantation while reducing the length of the unproductive period. Despite its significant economic and environmental impacts, the immature period is still poorly characterized and rarely included in the assessment of perennial cropping systems sustainability. Rubber plantations are an interesting case, as a major perennial system in the tropics. Here we conducted a systematic review to identify (1) management practices in inter-rows of immature rubber plantations; (2) the variables used in the literature to analyze the adoption drivers of these practices and to assess their effects on plantation functionalities and performances; and (3) the main effects of diversification practices on plantation functionalities and performances. The major results showed that (1) different inter-row management practices, including a diversity of crops, are possible during the immature period; (2) adoption of diversification practices is driven by few global factors but mostly depends on the specific socio-economic and agroecological context; (3) diversification practices are usually assessed with respect to agronomic and economic performances, and their impacts are generally positive. We identified missing knowledge required for a comprehensive view on current inter-row management practices in immature rubber plantations. First, technical operations should be included in the characterization and assessment of inter-row management practices. Second, a multicriteria assessment framework is required to cover all the sustainability dimensions to guarantee the diffusion of more performant management practices. In order to include the diversity of perceptions of sustainability in rubber plantations, this multicriteria assessment should be based on relevant criteria that combine farmers’ and scientists’ points of view. Detailed characterization of current immature rubber plantations merged with multicriteria assessment will be essential for the design of more sustainable rubber tree cropping systems.
... Kalam et al. [21] also observed that the fertilizer treatments in their experiment had an effect on girth 4 YAP but not 5 YAP. Analysis of rubber tree growth during the immature phase showed that the highest annual increments were found during the 3rd and the 4th YAP [22,23]). Our results confirmed these observations ( Fig. 4a and Table 4b) and showed significant differences in annual increment at the 3rd YAP only. ...
Nutrient management is critical for the development and growth of rubber trees during the immature phase. We present the
results of a fertilizer trial during the immature phase of a rubber plantation setup in Cambodia. The main objective of this
study was to analyze the response of a specifc clone, PB330, in the specifc conditions of one of the most important rubber�growing areas of Cambodia. The experiment was arranged in a randomized complete block design with 4 treatments and
4 replications. The four treatments consisted of 3 fertilization treatments with an increasing dose of fertilizers (respectively
T1, T2 and T3) compared to a non-fertilized control (T0). The girth of trees was measured every six months from the end of
the frst year after planting (YAP) to the end of the 6th YAP. Results showed that fertilization had a signifcant efect on tree
girth. At the end of the 6th YAP, fertilization had a signifcant efect on the number of tappable trees, and stand basal area
but not on average tree girth. The most pronounced efect of fertilization was observed from annual increments in girth and
stand basal area during the 3rd and 4th YAP. The efect of fertilization on tree growth was evident from all three treatments,
although T3 gave the most signifcant increase compared to T0, increasing doses of fertilizer did not signifcantly improve
the growth parameters. Hence, this study confrmed the importance of mineral nutrition on rubber tree growth during the
immature phase even at T1, the lowest level of nutrient inputs. These results can be used to improve the standard fertilizer
recommendations for immature rubber trees in Cambodia. We recommend setting up similar trials in diferent edaphic
conditions of the country with the aim to establish nutrient management practices tailored to local biophysical constraints.
Keywords: Rubber tree · Immature period · Fertilizer · Tree growth analysis · Stand basal area
... During the breeding procedure, both girth and yield parameters are widely used as attributes of growth and good harvesters. Girth is the key factor taken into consideration for evaluating growth and attainment of crop maturity for harvesting (Chandrasekhar et al., 2005). Average yield is an important factor for Hevea clonal selection (Reju et al., 2016). ...
... This study may provide information on which regions will be best for planting rubber and estimate its growth performance in Peninsular Malaysia. Growth analysis can provide useful insights into the influence of biotic as well as abiotic factors on rubber tree (Shorrocks et al., 1965;Chandrasekhar et al., 2005). ...
... Mann et al. (1934) suggested there exists a very close relationship between the characters of girth, yield and the number of latex vessel rows. Growth can be measured in various parameters but girth or circumference measurement of the main trunk remains the most significant (Chandrasekhar et al., 2005). Girth and girth increment of trees are used in experimental work to assess the growth performance of new planting materials and the effects of cultural treatments on growth (Shorrocks et al., 1965). ...
... But then, premature tapping is limited by the effects on the long-term vigor of the tree and created new problem (Hunt, 1983;Xiao et al., 2003). Planters and smallholders still using conventional tapping system where the girth at least must 45 cm measured 170 cm height from ground or 150 cm from the bud union (Rayong, 2003;Chandrasekhar et al., 2005). Recent experience indicates that trees which have reached a girth of 43 cm and above can be brought into tapping, if required, with mild stimulation (Kadir, 1988). ...
Climate change directly alters climate conditions and indirectly impacts land suitability for cultivating rubber. The Malaysian tropical rainforest climate with regular rainfall of about 2000–2500 mm per year and the average temperature of 26–28 °C provide a suitable condition for planting rubber commercially. There is doubt about how well rubber plants will perform in the future because of climate change. The main question of whether rubber is still appropriate for planting in Peninsular Malaysia must be answered conclusively as rubber requires an approximately 30 year investment in one cycle. This question is particularly relevant in Malaysia as its rubber production is dependent on smallholders. Smallholders contribute approximately 93% of natural rubber production and furthermore, 93% of the rubber land area in Malaysia is owned by smallholders. An agroclimatic map produced in this study will help smallholders in deciding whether to proceed with rubber or change to other valuable crops based on their specific location. In this study, we evaluate 21st century land suitability for cultivating rubber and assess its growth based on climatic data for the Historical (1970–2000), Early (2010–2040), Middle (2040–2070) and End (2070–2100) projections periods. We use the Hevea 1.0 static model for rubber tree modelling to calculate the agroclimatic indices and estimate 30 years’ of actual rubber growth (girth) for all study periods. We find that climate change is predicted to have a positive impact on rubber-suitability in tropical rainforest in Malaysia climates at least until 2100. The End period, where the precipitation and temperature are projected to experience significant increases, becomes more favourable to rubber. The Perak region shows the highest increase in estimated rubber growth in the Early, Middle, and End periods by 16.3%, 31.9% and 39.4%, respectively. Among all regions, Kelang is predicted to be the most suitable area to plant rubber during the Early period as it has a potential estimated girth of up to 94.5 cm. Meanwhile, Johor is predicted to be the best place to cultivate rubber during the Middle and End periods with growth estimations of 97 cm and 99.5 cm, respectively. We indicate that about 32% of existing planted rubber area in Peninsular Malaysia is in Class 6 of land suitability to cultivate rubber.
... During the breeding procedure, both girth and yield parameters are widely used as attributes of growth and good harvesters. Girth is the key factor taken into consideration for evaluating growth and attainment of crop maturity for harvesting (Chandrasekhar et al., 2005). Average yield is an important factor for Hevea clonal selection (Reju et al., 2016). ...
... Malaysia is the third largest rubber producer in the world, after Thailand and Indonesia (Heru & Andus, 2010). Rubber or its scientific name Hevea brasiliensis is one of the first commodity crop planted in large scale in Malaysia, besides cocoa, palm oil and tobacco (Chandrasekhar et al., 2005). Rubber trees are a major producer of natural latex (Wongcharoen, 2011). ...
Rubber prices are influenced by several factors including supply and demand especially from countries who are major rubber producers and consumers as well the growth rate of the world economy. High rubber prices increase the incidence of rubber theft, thus forcing the owners to build hut and camp in their rubber estates to prevent such occurrence. Rubber theft becomes prevalent not only at night but also in the broad daylight as the commodity price increases. From the survey, it has been noted that more than 10 incidents of theft have been reported within 15 days. Plated Rubber System (PRESS) was developed to imprint an identification entity on rubber that leads to identifying the ownership. With the invention of this system, the stolen number of rubber can be reduced because each rubber smallholders has their personal serial identification plate. The main objective PRESS is to establish an identification of rubber, helping to reduce the theft of rubber at farm level as well as to curb the sale of stolen rubber. In addition, it can be used to regulate the quality of rubber produced by smallholders and developing a database profile of rubber smallholders. The finding shows that the respondent agreed that the innovation of PRESS may help them to reduce the prevalence of rubber theft and increase the good practice of plantation management that leads to greater efficiency and productivity.
... Malaysia is the world's fifth largest producer of natural rubber after Thailand, Indonesia, Vietnam and China. Moreover, rubber is one of the first commodity crop planted in large scale in Malaysia, besides cocoa, palm oil and tobacco (Chandrasekhar et al., 2005). ...
National Key Economic Area (NKEA) for rubber involves three (3) Entry Point Projects (EPPs) and one of the targets is to ensure the sustainability of the upstream rubber industry in Malaysia. This EPP aims to increase the area of replanting and new planting of rubber by independent smallholders to 24,000 hectares. More replanting exercises can also be expected following the government's rubber incentive to aid rubber smallholders suffering from weak commodity prices. Rubber smallholders produce 94% of the Malaysian rubber production. Nowadays, rubber smallholders need to face many challenges, especially in rubber price fluctuation. The unstable prices of natural rubber could affect the income and socio-economics of the rubber smallholders. This paper employed survey data to identify smallholders' social adaptation level towards unstable rubber prices among Malaysian smallholders. 400 respondents who are rubber smallholders in four (4) districts area (Baling, Kulim, Gua Musang, and Kuala Krai) were involved in this study. The results show that 76.5% of respondents are male and the rest of 23.5% are female. The most predominant age group of the respondents are more than 56 years old which is 42.0%. For the marital status of the respondents, there were 90.0% are married, 1.5% are single and 8.5% are widows and widowers. 35.0% of respondents went to primary schools while about 38.5% went to secondary schools. Meanwhile, only 4.0% had s college/university education and 22.5% did not get any formal education. In general, the income level of smallholders is still low (68.5% less than RM1000). The main factors affecting the income of the smallholders are the current rubber price and the old age of the trees. The overall mean for social adaptation level of smallholders towards the impact of unstable rubber price is 2.501 considered as a moderate level of perception.
... Malaysia is the third largest rubber producer in the world, after Thailand and Indonesia (Heru & Andus, 2010;Sabah Rubber Industry Board, 2011). Rubber, Hevea brasiliensis is one of the first commodity crop planted in large scale in Malaysia, besides cocoa, palm oil and tobacco (Chandrasekhar et al., 2005). Rubber trees are a major producer of natural latex (Wongcharoen, 2011). ...
Sabah is recognized as the poorest state in Malaysia, whilst having numerous rural communities categorized as a hardcore poor especially in the rural district, Pitas. The Kanibongan project involving rubber smallholders in the Pitas district has been developed by the State Government for the purpose of socioeconomic development. The main objectives of this study were to determine the effectiveness of the project implementation in addressing the poverty level in the area involved; and to determine the factors driving the smallholders to participate in the project and the problems faced by these smallholders. This study involved five villages, namely, Kampung Masin, Kampung Kutoyon, Kampung Sulakulong, Kampung Simpang Empat and Kampung Simpang. Data was collected with 100% sampling comprising of 195 respondents by using questionnaires and interviews. Based on the results of this study, the average monthly income of the smallholders showed significant improvement up to 30% since its implementation. The main driven factors for smallholder participation in this project were self motivation (94.3%), subsidy incentives programme by LIGS (93.3%), poverty level (92.9%), good rubber prices (90.3%), and family encouragement (88.2%). Whereas the main problems faced by the smallholders were the unstable price of rubber (84.6%) and theft of latex (74.4%). The Kanibongan rubber planting project is considered successful in reducing poverty among the smallholders involved.
Tree diameter and circumference measurements are important metrics that should be monitored periodically and which can be used to determine rates of plant growth, timber production (wood), rubber tapping time, and to estimate the nutrient content of the soil in agroforestry especially for rubber and Albizia sp. trees. In this study, we evaluated the use of optical sensors, including a smartphone camera, which were analyzed by an image processing technology to estimate tree circumference of homogeneous and production forests especially rubber and Albizia forest plantations, through a real-time tree diameter measurement approach. Camera measurements were carried out for the diameter at breast height (DBH) and a certain distance of each tree (with the diameter of tree range of ∼6–50 cm). The results show that the use of smartphone camera measurements is highly correlated with manual measurements obtained using a tree caliper or meter tape in estimating tree circumference with coefficient of determination (R ²) and RMSE of 0.95 and 7.9 cm, respectively. Thus, this tool can be employed as an alternative method for measuring tree diameter and circumference.
Adaptation of rubber tree clones to water-limited areas and maintenance of trunk radial growth are important keys for performance of genetic material. The rubber farmers need to shorten the interim phases to produce latex, which is considered “immature” phase, i.e. the time without income. The objective of this study was to compare the performance of three important rubber tree clones: GT1, the elder clone as control, which is still widely used in Cambodia and West Africa; RRIM600, the “all-round” clone, the most planted clone in Thailand, the first world producer; and RRIT251, the expanding clone, recommended by the Rubber Authority of Thailand, all in the field condition. The investigation was conducted in a drought-prone area of Northeast Thailand, where the dry season lasts 5 to 6 months. The cumulated growth and the annual growth were analyzed 4.5 years after planting. The trunk girth and height were measured monthly. Main climatic variables were hourly recorded. The year was separated in three periods: the leaves-shed season from January to April, the wet season from May to September, and the dry season with canopy maintenance from October to December. The results showed significant clonal effect on both trunk girth and height; however, with relatively low differences. The trunk girth of clone RRIT251 was about 29 cm and 10% higher than GT1. The difference was not significant in RRIM600. The annual girth increment was mainly located in wet season (63%) without clonal effect. The clonal difference was occurred in the dry season, where RRIT251 was better performed particularly in the leave-shed period preceding wet season. On a monthly basis, the relative trunk girth increment rate was highly negatively related to the vapor pressure deficit. We hypothesized that rubber clones shared a common strategy of dehydration avoidance, while RRIT251 expressed a little less degree of avoidance.
