PRODUCTIVITY AND ECONOMICS OF Bt COTTON UNDER DIFFERENT FERTIGATION LEVELS AND WEED MANAGEMENT PRACTICES.
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Date
2019-12-16
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Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra.
Abstract
A field investigation entitled “Productivity and economics of Bt cotton under different fertigation levels and weed management practices” was conducted at AICRP on Weed management farm, Deparment of Agronomy, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during kharif season 2017-18 and 2018-19. The experiment was laid out in split plot design with three replications. There were twenty treatments having four different fertigation levels and five weed management practices. The main plot treatments comprised of different levels of fertilizer in five splits at 75 per cent, 100 per cent and 125 per cent of recommended dose of N and K fertilizers given through fertigation, however P was applied as basal dose and these treatment were compared with 100 per cent recommended dose of fertilizers as soil application. Whereas, sub plot treatments comprised of five weed management practices viz., pendimethalin @ 1 kg a.i/ha PE fb pyrithiobac sodium @ 0.062 kg a.i/ha + propaquizafop @ 0.075 kg a.i/ha 25-30 DAS + 1 hand weeding at 45-50 DAS, pendimethalin @ 1 kg a.i/ha PE fb paraquat @ 0.6 kg a.i/ha at 40-50 DAS, directed spray of paraquat @ 0.3 kg a.i/ha at 30 DAS fb 1 HW 15 days after spraying and paraquat @ 0.6 kg a.i/ha 60 DAS fb 1 HW 15 days after spraying, farmers practice – 3 hoeing 15-20 days interval after sowing fb 3 HW and weedy check.
The soil of experimental plot was vertisol. Low in available nitrogen (170.0 kg ha-1), medium in phosphorus (19.16 kg ha-1), organic carbon (0.41%), rich in available potassium (363 kg ha-1) and slightly alkaline in reaction (7.8). Cotton hybrid PDKV JKAL-116 BG II was sown on June 17, 2017 and June 20, 2018 at a spacing 120 x 60 cm. The experimental site was established with inline drip irrigation system (16 mm) lateral laid out at 120 cm with 60 cm dripper spacing. Irrigation water was applied through drip irrigation on alternate day at the rate of 100 per cent crop evapotranspiration level. As per requirement of cotton crop during rainless period of kharif season.
The major weed flora viz; Dicot weeds comprising six species viz. Ipomea reniformis, Parthenium hysterophorus, Alternanthera sessile, Euphorbia hirta and Euphorbia geniculata was the dominant group with 51% to 58% mean population followed by monocot (grasses and sedges) like Cyperus rotundus, Cynodon dactylon occupying 42% to 49% were found during study.
Experimental results revealed that, in cotton all the growth parameters viz. plant height, leaf area index, chlorophyll content index, dry matter accumulation per plant, sympodial branches and yield attributes viz. bolls picked and seed cotton yield were substantially enhanced by drip fertigation level at 125 per cent recommended dose of N and K ha-1 than lower fertigation levels (75 and 100 per cent) and over conventional soil application with 100 per cent RDNK kg ha-1. As a consequence of better growth and yield attributes, drip fertigation at 125 per cent RDNK ha-1 had recorded higher seed cotton yield of 2640 kg ha-1 and 3156 kg ha-1 during 2017-18 and 2018-19 respectively as well as in pooled mean 2896 kg ha-1.
Invariably higher weed population and weed dry weight were associated with soil application of recommended dose of fertilizers (100 per cent RDNK through soil) compared to fertigation treatments. The more or less indentical values of weed index was recorded under different level of fertigation as compared to 100% RDF through soil application.
Nutrient use efficiency (NUE) was found better in drip fertigation at 75 per cent recommended dose of N and K ha-1 as compared to conventional soil application of fertilizers in cotton crop. The GMR ( 158414 ha-1), NMR ( 95669 ha-1) and B:C (2.46) were also found maximum with drip fertigation at 125 per cent RDNK ha-1 in pooled data during study.
Among the various weed management practices under study farmers practice (3 hoeing 15-20 days interval after sowing fb 3 HW) recorded significantly higher values of major parameters whereas, in herbicidal treatments, directed spray of paraquat @ 0.3 kg a.i/ha at 30 DAS fb 1 HW 15 days after spraying and paraquat @ 0.6 kg a.i/ha 60 DAS fb 1 HW 15 days after spraying recorded significant reduction in weed density, weed dry matter, highest weed control efficiency and lowest weed index. Which ultimately resulted in maximum seed cotton yield of 2531 kg ha-1, 2887 kg ha-1 and 2709 kg ha-1 during 2017-18, 2018-19 and pooled mean respectively. The nutrient uptake by weeds was more in weedy check condition. However, total nutrient uptake by crop was observed maximum with directed spray of paraquat @ 0.3 kg a.i/ha at 30 DAS fb 1 HW 15 days after spraying and paraquat @ 0.6 kg a.i/ha 60 DAS fb 1 HW 15 days after spraying.
The maximum gross monetary return ( 156624 ha-1) was recorded with farmers practice (3 hoeing 15-20 days interval after sowing fb 3 HW) in pooled mean. Whereas, maximum NMR ( 90248 ha-1) and B:C ratio (2.54) were recorded in directed spray of paraquat @ 0.3 kg a.i/ha at 30 DAS fb 1 HW 15 days after spraying and paraquat @ 0.6 kg a.i/ha 60 DAS fb 1 HW 15 days after spraying in pooled data. Lowest GMR, NMR and B:C ratio was found in weedy check.
The highest seed cotton yield (3541 kg ha-1), lint yield (1315 kg ha-1), stalk yield (5188 kg ha-1) and GMR ( 193093 ha-1) were recorded with application of 125% RDNK through drip and weed management by farmers practice which at par with directed spray of paraquat and hand weeding two times. Whereas, highest NMR ( 119220 ha-1) were recorded with 125% RDNK through fertigation and weed management by directed spray of paraquat and hand weeding two times.
On the basis of two year data, it could be concluded that application of 125 per cent recommended dose of N and K in five splits (P as basal) through drip and directed spray of paraquat @ 0.3 kg a.i/ha at 30 DAS fb 1 HW 15 days after spraying and paraquat @ 0.6 kg a.i/ha 60 DAS fb 1 HW 15 days after spraying found to be best for maximizing seed cotton yield, economic returns and weed control efficiency from Bt cotton.
Description
A field investigation was conducted at AICRP on Weed management farm, Deparment of Agronomy, Dr.Panjabrao Deshmukh Krishi Vidyapeeth, Akola during kharif season 2017-18 and 2018-19. The experiment was laid out in Split plot design with three replications. There were twenty treatments having four different of fertigation levels and five weed management practices. When conducting the Bt Cotton (PDKV JKAL-116 BGII) production trial with a view to observed growth, yield, quality, weed density, weed dry matter, weed control efficiency, Weed index, Water use efficiency, Nutrient use efficiency, and economics of Bt Cotton production.
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Citation
THAKARE, SWAPNIL SUBHASHRAO. (2019). Productivity and economics of Bt cotton under different fertigation levels and weed management practices. Department of Agronomy, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. Ph. D. (2019). Print. xxii, 338p. (Unpublished).