M Sc

The study entitled “Eco-friendly weed management in okra (Abelmoschus
esculentus (L.) Moench) was carried out during the period 2019-2021, at College
of Agriculture, Vellayani, Thiruvananthapuram, Kerala with an objective to find
out a cost -effective ecofriendly weed management practice for okra.
The field experiment was conducted at Coconut Research Station,
Balaramapuram, Thiruvananthapuram, Kerala during Rabi 2020 (November
2020- March 2021). The experiment was laid out in randomized block design with
12 treatments replicated thrice. The treatments were combinations of two factors,
first factor being seedbed preparation (S), viz., stale seedbed (S1) and normal
seedbed (S2) and second factor, weed management practices (W) viz., dried
banana leaf mulch @ 10 t ha-1
alone (W1), dried banana leaf mulch @10 t ha-1
fb
mechanical weeding (MW) with wheel hoe weeder (WHW) at 30 DAS and 45
DAS (W2), dried banana leaf mulch @10 t ha-1
fb hand weeding (HW) at 30 and
45 DAS (W3), MW with WHW at 15, 30 and 45 DAS (W4), HW at 15, 30 and 45
DAS (W5) and weedy check (W6). The variety used for the study was Anjitha.
Results of the experiment revealed that seedbed preparation had
significant influence on growth parameters, physiological parameters, yield
attributes and quality parameters in okra and higher values were recorded in SSB.
At 15, 30 and 60 DAS, lower total density of weeds (30.44, 90.67 and
35.67 no. m-2
), weed dry weight (0.139, 4.57 and 7.81 g m-2
) and higher weed
control efficiency (WCE) (80.20, 89.46 and 81.33%) were recorded in SSB
compared to normal seedbed.
The highest nutrient uptake by crop, dehydrogenase enzyme activity at 60
DAS and urease enzyme activity at 15, 30 and 60 DAS and the lowest nutrient
removal by weeds at 30 and 60 DAS were recorded in SSB.
Higher net income (54,520 ₹ ha-1
) and B:C ratio (1.69) were recorded in
SSB compared to normal seedbed (non-stale).
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Higher values for growth parameters viz., plant height, number of branches
per plant, number of leaves per plant, dry matter production and physiological
parameters such as LAI, total chlorophyll content at 60 DAS and CGR at 30-60
DAS time interval were recorded in MW with WHW at 15, 30 and 45 DAS (W4).
However, the treatment W5 (HW at 15, 30 and 45 DAS) resulted in the highest
total chlorophyll content at 30 DAS and W2 (dried banana leaf mulch @ 10 t ha-1
fb MW at 30 and 45 DAS) resulted in the highest CGR during 60 DAS-final
harvest.
Mechanical weeding with WHW at 15, 30 and 45 DAS recorded greater
number of fruits per plant (38.8 no. per plant), higher fruit girth (6.36 cm), fruit
length (15.20 cm), fruit weight (6.98 g), dry haulm yield per plant (63.51 g), dry
haulm yield per hectare (2353 kg ha-1
), fruit yield per plant (0. 270 kg) and fruit
yield per hectare (4412 kg ha-1
) and the lowest weed index.
Quality parameters such as crude protein and ascorbic acid content was
higher in treatment W2 (dried banana leaf mulch @ 10 t ha-1
fb MW at 30 and 45
DAS).
The lowest total weed density at 60 DAS (26.67 no. m-2
), the lowest total
weed dry weight at 30 and 60 DAS (2.48 and 2.54 g m-2
, respectively) and the
highest WCE at 30 and 60 DAS (92.28 and 93.86 %, respectively) were recorded
in MW with WHW at 15, 30 and 45 DAS (W4).
The highest nutrient uptake by crop and the lowest nutrient removal by
weeds was recorded in the treatment W4.
The highest net income (97,804 ₹ ha-1
) and B: C ratio (2.24) were recorded
in W4 (MW with WHW at 15, 30 and 45 DAS).
Interaction between seedbed preparation and weed management practice
was significant only for plant height at 60 DAS and final harvest, DMP at 30 and
60 DAS, LAI at 60 DAS and CGR at 30-60 DAS and total weed density, weed
dry weight, WCE and nutrient removal by weeds at 30 and 60 DAS. Stale
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seedbed fb MW with WHW resulted in the lowest total weed dry weight and the
lowest nutrient removal by weeds.
Considering the growth, yield, weed control efficiency, nutrient removal
by weeds, nutrient uptake by crop and economics, it could be concluded that in
SSB or in normal seedbed (non-stale), mechanical weeding with wheel hoe
weeder at 15, 30 and 45 DAS could be adjudged as the best ecofriendly weed
management practice for higher yield and net income in okra.