STUDIES ON SEQUENTIAL APPLICATION OF HERBICIDES IN COTTON (Gossypium hirsutum L.)
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Title |
STUDIES ON SEQUENTIAL APPLICATION OF HERBICIDES IN COTTON (Gossypium hirsutum L.)
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Creator |
MADHU GUMMADI
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Contributor |
SRINIVASULU, K
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Subject |
bacteria, meat, livestock, biological phenomena, sampling, diseases, enzymes, poultry equipment, polysaccharides, eggs
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Description |
A field experiment entitled “Studies on sequential application of herbicides in cotton (Gossypium hirsutum L.)” was conducted during kharif, 2011 on clay loam soils of Agricultural College Farm, Bapatla. The experiment was laid out in a randomized block design with eleven treatments comprising of T1- Weedy check; T2- Hand weeding twice at 30 and 60 DAS; T3- Pendimethalin @ 1.5 kg a.i. ha-1 as pre-emergence; T4- Pendimethalin @ 1.5 kg a.i. ha-1 as preemergence followed by interculture at 40 DAS; T5- Pendimethalin @ 1.5 kg a.i. ha-1as pre-emergence followed by fenoxaprop ethyl @ 56 g a.i. ha-1 as postemergence at 40 DAS; T6-Pendimethalin @ 1.5 kg a.i. ha-1as pre-emergence followed by quizalofop @ 50 g a.i. ha-1 as post-emergence at 40 DAS; T7- Pendimethalin @ 1.5 kg a.i. ha-1as pre-emergence followed by pyrithiobac @ 63 g a.i. ha-1 as post-emergence at 40 DAS; T8- Interculture at 20 DAS followed by fenoxaprop ethyl @ 56 g a.i. ha-1 at 40 DAS; T9- Interculture at 20 DAS followed by quizalofop ethyl @ 50 g a.i. ha-1 at 40 DAS; T10- Interculture at 20 DAS followed by pyrithiobac @ 63 g a.i. ha-1 at 40 DAS and T11- Farmer’s practice (four times at 15 days interval). The treatments were replicated three times. The weed species which infested the experimental plot were grasses like Cynodon dactylon, Dactyloctenium aegyptium, Digitaria sanguinalis (L.) Scop., Echinochloa colonum, Panicum repens Linn., sedge Cyperus rotundus Linn. and broad leaved weeds like Acalypha indica Linn., Acalypha ciliata, Achyranthes aspera, Aristolochia bracteata Retz., Cleome viscosa Linn., Commelina benghalensis Linn., Corchorus trilocularis Linn., Cynotis cucullata Kurtz., Digera arvensis Forsk, Euphobia hirta, Euphorbia geneculata, Merrimia emerginata Hallier., Physalis minima, Phyllanthus maderaspatensis Linn., Trianthema portulacastrum, Linn. and Tridax procumbens. Among the weed flora identified in the experimental plot, Cynodon dactylon, Cyperus rotundus, Panicum repens, Digera arvensis, Cynotis cucullata, Phyllanthus maderaspatensis, and Trianthema portulacastrum were predominant. Weed density was significantly reduced by all weed management practices over the weedy check. The minimum weed density was recorded with farmer’s practice (T11). Among the weed management practices, pendimethalin @ 1.5 kg a.i. ha-1 fb interculture at 40 DAS (T4), pendimethalin @ 1.5 kg a.i. ha-1 fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T7) and interculture at 20 DAS fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T10) treatments were comparable with that of hand weeding twice at 30 and 60 DAS (T2). The lower dry weight of weeds and higher weed control efficiency was recorded with farmer’s practice (T11). Among the weed management practices, pendimethalin @ 1.5 kg a.i. ha-1 fb interculture at 40 DAS (T4), pendimethalin @ 1.5 kg a.i. ha-1 fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T7) and interculture at 20 DAS fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T10) treatments were comparable with that of hand weeding twice at 30 and 60 DAS (T2). The minimum uptake of nutrients by weeds and lower weed index were recorded with farmer’s practice (T11). Among the weed management practices, pendimethalin @ 1.5 kg a.i. ha-1 fb interculture at 40 DAS (T4), pendimethalin @ 1.5 kg a.i. ha-1 fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T7) and interculture at 20 DAS fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T10) treatments were comparable with that of hand weeding twice at 30 and 60 DAS (T2). Plant height, number of monopodial and sympodial branches per plant, dry matter accumulation and uptake of nutrients by the crop were found to be higher with farmer’s practice (T11). Among the weed management practices, pendimethalin @ 1.5 kg a.i. ha-1 fb interculture at 40 DAS (T4), pendimethalin @ 1.5 kg a.i. ha-1 fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T7) and interculture at 20 DAS fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T10) treatments were comparable with that of hand weeding twice at 30 and 60 DAS (T2). Yield attributing characters and seed cotton yield was significantly higher with farmer’s practice (T11) than all other treatments studied. Among the weed management practices, pendimethalin @ 1.5 kg a.i. ha-1 fb interculture at 40 DAS (T4), pendimethalin @ 1.5 kg a.i. ha-1 fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T7) and interculture at 20 DAS fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T10) treatments were comparable with that of hand weeding twice at 30 and 60 DAS (T2), whereas, in weedy check an yield reduction of 56.8 per cent was recorded. The higher seed cotton yield, net returns and returns per rupee of investment were found to be higher with the farmer’ practice. Among the weed management practices, even though higher seed cotton yield and gross returns were recorded with hand weeding twice at 30 and 60 DAS but the net returns and returns per rupee of investment were low due to high cost of manual weeding. Therefore, pendimethalin @ 1.5 kg a.i. ha-1 fb interculture at 40 DAS (T4), pendimethalin @ 1.5 kg a.i. ha-1 fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T7) and interculture at 20 DAS fb pyrithiobac @ 63 g a.i. ha-1 at 40 DAS (T10) found to be more profitable than hand weeding twice at 30 and 60 DAS. |
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Date |
2016-06-22T12:06:42Z
2016-06-22T12:06:42Z 2012 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/67695
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Language |
en
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Relation |
D9415;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
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