Effect of plant density and foliar nutrient application on seed yield and quality in Asiatic carrot (Daucus carota)

Abstract

A field experiment was conducted to study effect of plant density and foliar spray of nutrients on carrot (Daucus carota L.) seed yield and quality during winter season of 2012-13 and 2013-14. Plant height, days to 50% flowering, number of umbels/plant, number of seeds/umbel, seed yield/umbel, percentage contribution of different order umbel to total seed yield, seed yield/plant, seed yield/ha, 1 000 seed (mericarp) weight, germination (%) and vigour index were recorded. Significant highest average plant height, earliness in days to 50% flowering and seed yield/ha (12.9 q) were observed in high plant density (13 plants/m2). More number of secondary (11.6) and tertiary umbels (30.1) and higher seed yield/plant (25.2g) were recorded in low plant density (4 plants/m2). Per cent contribution of primary umbel to total seed yield was maximum (41.76%) in 13 plants/m2 and minimum (16.89%) in 4 plants/m2. But an increasing trend in contribution percentage to total seed yield by secondary and tertiary umbels was recorded from 13plants/m2to 4plants/m2.Seeds from primary and secondary umbels recorded high quality in plant density of 5 plants/ m2 and 4 plants/m2 respectively.Comparative reduction in pooled seed vigour was observed in 7 plants/m2 and 13 plants/m2. Foliar spray of 0.1% MgSO4at 30 and 60 days after transplanting (DAT) increase the seed quality. Both seed yield and qualityincrease was observed in 0.1% borax spray at 30 and 60 DAT.

Full text

Indian Journal of Agricultural Sciences 87 (3): 419–24, March 2017/Article
Effect of plant density and foliar nutrient application on seed yield and quality
in Asiatic carrot (Daucus carota)
C MANIMURUGAN1, V K PANDITA2, B S TOMAR3, N GUPTA4 and P M SINGH5
ICAR- Indian Agricultural Research Institute, New Delhi 110 012
Received: 22 July 2016; Accepted: 29 August 2016
ABSTRACT
A eld experiment was conducted to study effect of plant density and foliar spray of nutrients on carrot (Daucus
carota L.) seed yield and quality during winter season of 2012-13 and 2013-14. Plant height, days to 50% owering,
number of umbels/plant, number of seeds/umbel, seed yield/umbel, percentage contribution of different order umbel
to total seed yield, seed yield/plant, seed yield/ha, 1 000 seed (mericarp) weight, germination (%) and vigour index
were recorded. Signicant highest average plant height, earliness in days to 50% owering and seed yield/ha (12.9
q) were observed in high plant density (13 plants/m2). More number of secondary (11.6) and tertiary umbels (30.1)
and higher seed yield/plant (25.2g) were recorded in low plant density (4 plants/m2). Per cent contribution of primary
umbel to total seed yield was maximum (41.76%) in 13 plants/m2 and minimum (16.89%) in 4 plants/m2. But an
increasing trend in contribution percentage to total seed yield by secondary and tertiary umbels was recorded from
13plants/m2to 4plants/m2.Seeds from primary and secondary umbels recorded high quality in plant density of 5 plants/
m2 and 4 plants/m2 respectively.Comparative reduction in pooled seed vigour was observed in 7 plants/m2 and 13
plants/m2. Foliar spray of 0.1% MgSO4at 30 and 60 days after transplanting (DAT) increase the seed quality. Both
seed yield and qualityincrease was observed in 0.1% borax spray at 30 and 60 DAT.
Key words: Borax, Carrot, Foliar nutrient spray, MgSO4, Plant density, Seed quality, Seed yield
1,4Research Scholars, Division of Seed Science and
Technology, 3Head (email: bst_spu_iari@rediffmail.com), Division
of Vegetable Science, ICAR-Indian Agricultural Research Institute,
New Delhi 110 012. 2Head (I/c) (email: vndpandita@yahoo.
com), ICAR-IARI, Regional station, Karnal 132 001, 5Head (I/c),
Division of Crop Improvement, ICAR-Indian Institute of Vegetable
Research, Varanasi 221 305.
135
Carrot (Daucus carota L.) is one of the important root
vegetable in umbelliferae family. It covers an area of 62.4
thousand ha in India with the production of 10.7 lakh tonnes
(Saxena and Gandhi 2015). Both Asiatic and temperate type
carrots are cultivated in India but they require different
climatic condition for their seed production. Seeds of
Asiatic type can be produced in plains but that of temperate
types in hilly region only. Carrot inorescence consistsof
many branches and is divided into different order umbels
(primary, secondary and tertiary etc.) based on their position
and developmental stages. This also leads to production of
seeds in different maturity levels. When the primary umbel
reaches maturity the secondary or tertiary umbels may be
in immature or owering stage, respectively. This is one of
major problem in seed production of carrot crop. Highest
contribution by primary umbel to total seed yield in high
density planting in temperate carrot was demonstrated (10
to 80 plants/m2, 2-84 plants/m2and 2-100 plants/m2) by
many authors (Gray et al. 1983, Gray and Steckel 1983
and Mereld et al. 2010). High quality seeds are generally
produced from primary and secondary umbels in carrot
(Pandita et al. 2005). This indicates promotion of primary
and secondary umbel by increasing plant density may
promote uniform maturity and quality of seeds. But there
is a need of ne balance between increase in plant density,
increase in seed yield and maintenance of seed quality. One
should not compromise seed quality for higher seed yield
by increasing plant density. The optimum plant density also
depends upon environment and cultivars. Apart from plant
density, balanced nutrition of macro and micronutrients also
play a vital role in increase and enhancement of seed yield
and quality. In this study an attempt was made to suppress
the side branches of inorescence by increasing the plant
density in carrot and to know the supportive effect off oliar
nutrient for obtaining higher seed yield and quality in carrot.
MATERIALS AND METHODS
The experiment was conducted at Seed Production
Unit of Indian Agricultural Research Institute, New
Delhi during the period of September to May, 2012-
13 and 2013-14. The experimental site was situated at
28°35’N latitude & 77°12’E longitude and at an altitude
of 228.6 m above mean sea level. Seeds of carrot cv. Pusa
Rudhira were sown in the last week of September and
transplanting of uniform size steckling was done in third

420 [Indian Journal of Agricultural Sciences 87 (3)
136
(Abdul-Baki and Anderson, 1973) were calculated. Since
seeds of primary and secondary umbels were combined
together in general seed lot, a pooled vigour index was
also calculated by taking average of seed vigour index one
of primary and secondary umbels. Statistical analysis was
carried out by a software AgRes version 3.01.
RESULTS AND DISCUSSION
Growth attributes
In the present study higher average plant height with
respect to primary (118.7cm), secondary (133.6cm) and
tertiary (139.4cm) umbels were observed in highest plant
density (D1). This may be due to more apical growth and
suppression of side branches. Similar results have also
been reported by Ahmad and Tanki (1997) and Kumar
(2005) in carrot. In case of other crops, increasing plant
density generally reduces the plant height or length due to
competition among plants for space, nutrient and sunlight.
Bahlgerdi et al. (2014) observed highest plant length in
medicinal pumpkin in lowest plant density. Highest plant
density (D1) recorded earliness for days to 50% owering
as compared to other plant densities. Decreasing plant
density showed delay in days to 50% owering. Earliness
in owering may be due to competition between plants in
D1. Andriolo (1999) reported that an optimized leaf area
index (LAI) can be obtained by ideal population density
for better interception of maximum useful radiation for
photosynthesis. Before plants start the reproductive phase,
an optimized LAI can be reached very early on high density
week of January. Split plot design was adopted to conduct
experiments with plant density as main plot treatment and
foliar spray of nutrients as sub-plot treatments. Stecklings
were transplanted with spacing of 15×50cm, 30×50cm,
40×50cm and 50×50cm which gave plant density of
D1-13 plants/m2, D2-7 plants/m2, D3-5 plants/m2and D4-4
plants/m2 respectively. Sub-plot size was 3m×3m and
main plot consists of seven sub-plots for six foliar spray
treatments and one control. Main plots were replicated three
times with all sub-plot treatments. Foliar spray treatments
consist of T1-0.1% borax at 30 DAT, T2- 0.1% borax at 60
DAT, T3- 0.1% borax at 30+60 DAT, T4- 0.1% Magnesium
sulphate (MgSO4) at 30 DAT, T5- 0.1% MgSO4 at 60 DAT,
T6- 0.1% MgSo4 at 30+60 DAT and T7- control (sprayed
with water). Borax used as boron source. All the package
of practices and plant protection measures were carried
out as per recommendation. Days to 50% of owering was
counted from initiation of primary umbel to 50% owering
of primary, secondary and tertiary umbels in individual
treatment. Plant height of 10 randomly selected plants
was measured at the time of 50% of owering. Number
of umbels/plant, percentage contribution of all different
order umbel(s) to total seed yield and seed yield/plant was
estimated from average of observations taken from ten
randomly selected plants at the time of harvest. Number of
seeds/umbel and seed yield/umbel was estimated from 10
randomly selected umbels of different order. Seed yield/ha
was estimated based on average of main plot and subplot
seed yield. Seed quality parameters like 1 000 seed weight,
germination percentage (ISTA 2012) and vigour index
Table 1 Effect of plant density and foliar spray on growth and owering in carrot cv. Pusa Rudhira (Pooled data of two season 2012-
13 and 2013-14)
Treatment Plant height (cm) Days to 50 % owering Number of umbels/plant
Primary Secondary Tertiary Primary Secondary Tertiary Secondary Tertiary
plant density
D1118.7a133.6a139.4a26.5c33.3d40.2c6.2d17.5d
D2112.7b127.7b131.5b27.3b34.1c41.5b9.3c23.8c
D3108.9b123.6c126.6c27.8ab 34.5b43.0a11.3b27.5b
D4104.1c121.5c124.5c28.3a35.0a43.4a11.6a30.1a
CD (P=0.05) 3.96 2.97 3.96 0.60 0.34 1.02 0.12 1.10
Foliar nutrient spray
T1110.0 126.1 129.4 27.1 33.8 41.5 9.6 24.6
T2112.0 127.5 130.6 27.5 34.1 42.0 9.7 25.1
T3113.3 128.6 131.5 27.8 34.6 42.4 9.7 25.7
T4110.4 125.1 130.2 27.1 34.0 41.5 9.5 24.0
T5110.9 126.8 130.9 27.6 34.1 42.0 9.6 24.6
T6111.8 128.1 131.8 28.1 34.8 42.9 9.6 25.3
T7109.2 123.9 129.1 27.1 33.8 41.8 9.5 23.8
CD (P=0.05) NS NS NS NS NS NS NS NS
D×T NS NS NS NS NS NS NS NS
Means followed by different letters are statistically different. Separation done by Duncan’s Multiple Range Test.
MANIMURUGAN ET AL.

421March 2017]
137
of seeds, seed yield/umbel, seed yield/plant (20g) and seed
yield/ha (12.3q). However, T6was on par for number of seeds
and seed yield/primary umbel with T3. These results are in
accordance with results obtained by Sharma et al. (1999),
Vrataric et al. (2006) and Kumar et al., (2012). For all seed
yield attribute, signicant interaction between density and
foliar spray was not observed (Table 2).
Seed quality attributes
Highest 1 000 seed (mericarp) weight with respect to
primary umbel was recorded in D3 (2.489g) followed by D2
(2.446g) and D4 (2.476g). Many authors reported highest
1 000 seed weight of carrot in less plant density (Kumar
2005). In our study maximum seed weight was observed
in D3 instead of D4. Higher number secondary and tertiary
umbel in D4 leads to slight quality reduction in seeds form
primary umbel. Though, only primary umbels promoted in
D1, the reduced seed weight indicate the competition among
the plants for various resources.
Similar kind of results was observed in Cucurbita
pepo. L (Loy 1988) and medicinal pumpkin (Bahlgerdi et
al. 2014). These results indicated requirement of optimum
level of plant density for quality seed production instead of
high or less plant density. Plant density had no signicant
effect on germination per cent of seeds from primary umbels.
Seeds of secondary and tertiary umbels recorded highest
germination at lowest plant density (D4). Highest signicant
vigour index with respect to primary umbel was recorded
in D3 (1134) followed by D2 (1077) and D4 (1087). An
increasing trend of vigour index was observed for seeds of
secondary and tertiary umbel from highest (D1) to lowest
plant density (D4). Foliar spray treatment T3(2.472g) had
maximum test weightfrom primary umbels and was on par
with T2 (2.457g) and T6 (2.458g), 1 000 seed weight was
observed highest with T3 in secondary and tertiary umbel.
Similar results were also observed in chilli (Dongre et al.
2000) and Niger (Paikray, et al., 2001).
Among the foliar treatments, both T3 and T6 recorded
signicantly highest germination percentagein seeds from
primary, secondary and tertiary umbel. T3 followed by
T6 recorded highest vigour index for seeds of all order
umbels. The following may be the reason for seed quality
enhancement by T6. Magnesium is central element in
chlorophyll. It participates in activity of many enzymes and
involved in phosphorous translocation (Curley 1994). Foliar
‘boosting’ of Mg through leaves may deliver the Carbon
and Nitrogen containing compounds to the seeds which
effectively increases the seed quality (Gerendas and Fuhrs
2013). Quality of seeds form primary umbel was always
higher than the other order umbel in all the density and
foliar treatments. Highest pooled vigour index was observed
in D3 (1082), D4 (1071), T3 (1102) and T6 (1089). This
indicates, less plant density and spraying of foliar nutrient
was promoting the seed quality in carrot. Interaction effect
of density and foliar nutrient spray was not signicant for all
the seed quality parameters. Germination per cent of seeds
from tertiary umbel was always less than seed certication
plantings. Thus, planting density in any crop inuences
plant growth, changing the ower initiation and fruit
development and interfering on the biomass distribution
between source and sink.Number of umbels/plant increased
with decrease in plant density and was highest in D4 for
both secondary (11.6) and tertiary umbels (30.1). This
may be due to availability of more nutrient and sunlight
to individual plants in low plant density. These results are
in accordance with Kumar (2005) in carrot. None of the
growth parameters were recorded signicant difference with
respect of foliar nutrient sprays. No signicant interaction
effect was observed between density and foliar nutrient
spray for all growth attributes (Table 1).
Seed yield attributes
Highest number of seeds/primary umbel was observed
in D2 (1742) and D3(1725) followed by D1(1700) and
D4(1702). This indicates both reduction and increase in
plant density affect the seed number in primary umbel.
Lowest plant density (D4) recorded highest number of
seeds in secondary and tertiary umbel. Similar results were
observed in onion by Asaduzzaman et al., (2012). Seed
yield/primary umbel was recorded higher and on par in
D2 (4.24g), D3 (4.30g) and D4 (4.22g) than D1(4.03). Seed
yield/secondary and tertiary umbels were highest in lowest
plant density (D4).
Percentage contribution by primary umbel (41.73%)
to total seed yield was observed highest in high plant
density (D1). But D3 and D4 received significantly
highest contribution from secondary umbels because
increased number of secondary umbel in low plant density.
Contribution of tertiary umbels to total seed yield (10.70%)
was highest in lowest plant density (D4). None of the
foliar spray recorded signicant differences with respect to
percentage contribution in primary and secondary umbels.
Seed yield/plant was highest (25.2g) in lowest plant density
(D4). But seed yield/ha was signicantly higher (12.9q)
in highest plant density (D1). It may be due to increased
plant population in high plant density (D1).These results
are similar with results obtained by Guerrero et al. (1986),
Amjad and Anjum (2001), Lima et al. (2003)and Pandita et
al. (2005) in temperate and tropical carrot cultivars.
Recent studies in watermelon (Edelstein and Nerson
2002), muskmelon (Nerson 2002), onion (Kanwar et al.
2000) and medicinal pumpkin (Bahlgerdi et al. 2014)
showed that relatively high plant densities were required
to obtain the highest seed yield. In contrary, there are few
reports in seed production of winter squash and squash
suggested low plant densities for higher seed yield (Dematte
et al. 1978, Edelstein et al. 1985, Lima et al. 2003). Al
Mamun et al., (2016) also reported that early planting of
potato top shoot cutting with closer spacing (50×10 cm and
50×15cm) was most suitable for breeder seed multiplication.
So optimization of plant density for seed production of
any crop and their different cultivars are very important to
obtain higher seed yield and seed quality.
Among the foliar sprays, T3 recorded higher number
PLANT DENSITY AND FOLIAR NUTRIENT IN CARROT SEED PRODUCTION

422 [Indian Journal of Agricultural Sciences 87 (3)
138
Table 2 Effect of plant density and foliar spray on seed yield parameters in carrot cv. Pusa Rudhir (Pooled data of two season 2012-13 and 2013-14)
Treatments Number of seeds/umbel Seed yield/umbel (g) Percentage contribution to total seed yield Seed yield/
plant (g)
Seed yield/
ha (q)
Primary Secondary Tertiary Primary Secondary Tertiary Primary Secondary Tertiary
Plant density
D11700b389c23d4.03b0.80d0.039d41.73a51.17c7.11c9.7d12.9a
D21742a609b27c4.24a1.33c0.045c24.05b69.94b6.01d17.7c11.8b
D31725a632b37b4.30a1.39b0.064b19.83c72.10a8.07b21.7b10.9c
D41702b692a48a4.22a1.57a0.089a16.89d72.41a10.70a25.2a10.3d
CD (P=0.05) 21.71 26.11 2.74 0.09 0.03 0.002 0.58 0.74 0.34 0.29 0.23
Foliar nutrient spray
T11688c577bc 32c4.14cd 1.25bc 0.059bc 25.78 66.27 7.95abc 18.3cd 11.3bce
T21730b592b36b4.25b1.29b0.062ab 25.52 66.18 8.30ab 18.9b11.5b
T31793a621a40a4.40a1.36a0.066a24.74 66.74 8.52a20.0a12.3a
T41670c556c30cd 4.07d1.23cd 0.055c25.98 66.53 7.49c17.9de 11.2ce
T51723b572bc 32c4.21bc 1.27bc 0.058bcd 25.84 66.36 7.80bc 18.5bc 11.4bce
T61772a588b35b4.35a1.30b0.062ab 25.72 65.96 8.32ab 19.1b11.5bc
T71644d557c28d3.95e1.20d0.053d25.78 66.79 7.44c17.3e11.1e
CD (P=0.05) 26.53 24.29 2.40 0.09 0.05 0.004 NS NS 0.71 0.60 0.30
D×T NS NS NS NS NS NS NS NS NS NS NS
Means followed by different letters are statistically different. Separation done by Duncan’s Multiple Range Test.
MANIMURUGAN ET AL.

423March 2017] PLANT DENSITY AND FOLIAR NUTRIENT IN CARROT SEED PRODUCTION
139
Table 3 Effect of plant density and foliar spray on seed quality of different order umbelsin carrot cv. Pusa Rudhira (Pooled data of two season 2012-13 and 2013-14)
Treatment 1000 mericarp weight (g) Germination (%) Vigour index Pooled
Vigour index
Primary Secondary Tertiary Primary Secondary Tertiary Primary Secondary Tertiary
Plant density
D12.357c2.089d1.778c71 (57.48) 67 (55.20)c40(39.08)c1024c933d507d978c
D22.446b2.162c1.808b73 (58.81) 71 (57.12)b42(40.15)bc 1087b990c555c1039b
D32.489a2.240b1.844a75 (59.88) 72 (57.99)ab 43(41.23)b1135a1030b593b1083a
D42.476ab 2.286a1.858a74 (59.12) 74 (59.00)a50(44.94)a1077b1064a692a1071a
CD (P=0.05) 0.04 0.04 0.02 NS 1.23 1.25 45.26 22.37 34.38 18.62
Foliar nutrient spray
T12.442ab 2.188b1.816bc 72 (57.90)c70 (56.55)bc 42(40.31)bc 1055cde 980ce 559cd 1018cd
T22.457a2.211ab 1.842ab 73 (58.82)bc 70 (57.05)bc 44(41.61)ab 1093bc 1014bc601ab 1054b
T32.472a2.231a1.857a75 (60.15)ab 73 (58.86)a46(42.86)a1140a1064a642a1102a
T42.425bc 2.180bc 1.800cd 72 (58.27)bc 70 (56.47)bc 42(40.40)bc 1049de976ce 546d1013d
T52.445ab 2.193b1.826b73 (58.84)bc 72 (57.78)ab 45(41.87)ab 1077cd 1012bc 591bc 1045bc
T62.458a2.210ab 1.835ab 76 (60.85)a73 (58.62)a46(42.76)a1137ab 1041ab 630ab 1089a
T72.397c2.146c1.779d 70 (56.99)c69 (55.92)c41(39.68)c1015e944e538d980e
CD (P=0.05) 0.03 0.04 0.03 1.93 1.52 1.63 43.63 45.09 41.45 30.62
D×T NS NS NS NS NS NS NS NS NS NS
Means followed by different letters are statistically different. Separation done by Duncan’s Multiple Range Test. Values in parenthesis are arcsine transformed value.

424 [Indian Journal of Agricultural Sciences 87 (3)
140
standard of 60% in all the treatments (Table 3).
Though highest seed yield/ha was observed in 13
plants/m2, we recommend 5 plants/m2 is ideal for breeder
and foundation seed production without quality reduction.
Since seeds form primary and secondary umbels of all the
plant density recorded germination per cent higher than
ISTA seed standard (60%) for carrot, even we can adopt
13 plants/m2 for certied seed production of carrot cv.
Pusa Rudhira. Harvesting seeds from tertiary umbel must
be avoided to maintain higher seed quality.
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