MSc

The research was entitled with “Foliage and grain yield optimization in cowpea
(Vigna unguiculata (L.) Walp.) through foliar nutrition in homestead” was conducted at
College of Agriculture, Vellayani during 2020 - 2022. The objective of the study was to assess
the effect of foliar nutrition and percentage of foliage harvesting in growth, foliage yield and
grain yield in cowpea (Vigna unguiculata (L.) Walp).
The experiment was undertaken at Farming Systems Research Station,
Sadanandapuram, Kottarakkara during summer season (February to May 2022) in
randomized block design with 12 treatments and 3 replications. Treatments were (Factor A-
Foliar nutrition (F) and Factor B - leaf harvesting intensity (I)), and treatment combination
comprised f1l1- urea 2% spray at vegetative stage + 20% leaf harvest , f1l2- urea 2% spray at
vegetative stage + 40% leaf harvest, f1l3 - urea 2% spray at vegetative stage + control (no leaf
harvest), f2l1 - urea 2% spray at flowering stage + 20% leaf harvest, f2l2- urea 2% spray at
flowering stage + 40% leaf harvest, f2l3- urea 2% spray at flowering stage + control (no leaf
harvest), f3l1- urea 2% spray at vegetative stage and flowering stage+20% leaf harvest, f3l2 -
urea 2% spray at vegetative stage and flowering stage + 40% leaf harvest, f3l3- urea 2% spray
at vegetative stage and flowering stage+ control (no leaf harvest), f4l1- control (water spray)
+ 20% leaf harvest, f4l2 - control (water spray) + 40% leaf harvest , f4l3- control (water spray)
+ control (no leaf harvest). The variety used in the study DCS 47(1) was raised as per KAU
POP recommendations. Fully expanded cowpea leaves from the top were harvested prior to
flowering.
Among the foliar nutrition management treatments, f3 showed significantly the
tallest plants (91.97 cm), more number of branches (15.13), leaves (34.76), leaf area/ plant
(884.29 cm2), leaf area index (1.96) dry matter production (42.39 g) and chlorophyll content
(3.544 mg/g) and on par with f1. The treatment f3 was on par with f1 (88.22 cm) and f2 (87.98
cm) with regard to plant height. The nodule parameters such as nodule number (37.44) and
effective nodule number (32.11) were the highest in treatment f3 and was on par with f1. In
contrast, the highest fresh weight of nodule (966.72 mg) was attained with f1 and it was on
par with f3 and f2. Further, days to 50 per cent flowering (53.65 days), pod length (17.27 cm),
100 seed weight (12.40 g), pod number (24.58), foliage yield (1484.57kg ha-1), grain yield
(925.85 kg ha-1) and haulm yield (2722.70 kg ha-1) were the highest in treatment f3 and was
on par with f1 except for pod weight (21.19 g). The number of leaves harvested per plant
(10.07) was significantly highest with f1 and was on par with f3. The lowest response was
observed in the treatment f4 in terms of growth parameters, nodule parameters and yield
attributes.
Quality parameters i.e., highest seed crude protein (23.05%), phosphorus (P) (0.44%)
and potassium (K) (2.41%) were observed in the treatment f3. The lowest crude fibre content
(CF) was observed in treatment f3 (15.37%), whereas highest CF was obtained in f2. Content
of calcium (917.47 mg/100 g dry weight), iron (54.37 mg/100 g dry weight), zinc (116.82
mg/100 g dry weight) and nitrate (940.20 mg/100 g dry weight) were observed highest in f3.
With regard to above all quality parameters f3 was found to be on par with f1. However, the
leaf crude protein (22.11%) and nitrogen content (N) (3.54%) were higher in f1 and were
found on par with f3. Highest NPK uptake was observed with treatment f3 and it was on par
with f1. With respect to N uptake f2 was also found to be on par with f3.
Among the leaf harvest intensity, treatment l3 recorded the tallest plants (92.45 cm),
leaf area per plant (902.71cm2) leaf area index (2.01), less days to 50% flowering (47.60
days) and haulm yield (2754.85 kg ha-1). It was on par with l1 pertaining to plant height. The
number of branches (15.03), dry matter production per plant (40.78g), pod weight/plant
(19.43 g), pod number/plant (23.59) and grain yield (925.85 kg ha-1) were the highest in
treatment l1. Number of leaves (35.05), number of leaves harvested (11.93) and foliage yield
(2519.25 kg ha-1) was recorded highest with l2. The lower plant height (81.21 cm), leaf area
per plant (679.39 cm2), leaf area index (1.51), dry matter production per plant (38.25 g), pod
weight per plant (16.02 g), pod number per plant (19.83), grain yield (824.91 kg ha-1), haulm
yield (2225.95 kg ha-1) and more days to 50% flowering (50.46 days) was recorded with l2.
Number of branches (12.56), number of leaves (29.02), number of leaves harvested/ plant
(0.0) and foliage yield (0.0 kg ha-1) were the lowest in treatment l3.
Among the interactions, treatment f3l1 was superior with respect to number of
branches/ plant (15.97), dry matter production/ plant (43.62 g), pod weight/ plant (22.91 g),
pod number/ plant (25.45), grain yield (961.36 kg ha-1), leaf crude protein content (22.55%),
leaf nitrogen content (3.61%) and leaf K content (2.55%). In contrast, leaf area per plant
(971.07 cm2), LAI (2.16), haulm yield (3018.26 kg ha-1) and uptake of NPK (78.58, 9.74 and
57.34 kg ha-1) were the highest in f3l3. Treatment, f3l2 recorded the highest number of leaves
harvested plant-1 (13.47), foliage yield (2807.67 kg ha-1) and leaf P content (0.46%). The
lowest content of crude fibre was recorded in the treatment f1l1 (15.15%) and it was on par
with f3l2, f3l1, f3l3 and f1l2.
With the above findings, it is recorded that high foliage yield was attained with the
treatment f3l2 with high net income (₹. 54522/ha) and B:C ratio (1.85). Significant
enhancement of growth parameters resulted in high grain yield was recorded in the
treatment f3l1 (i.e., urea 2% spray at vegetative stage and flowering stage+20% leaf harvest)
(grain yield 961.36 kg/ha) which was comparable with f3l2 (urea 2% spray at vegetative stage
and flowering stage + 40% leaf harvest) (grain yield 925.88 kg/ha).
Therefore, it can be concluded that RDF (20:30:10 NPK) combined with foliar urea
treatment @ 2 per cent during both vegetative and flowering stages with 40 per cent leaf
harvest (f3l2) might be a feasible choice for increasing growth, productivity, quality and
generating economic returns.