EVALUATION OF DEFOLIANTS ON YIELD AND HARVESTING OF COMPACT COTTON VARIETIES IN HIGH DENSITY PLANTING

Loading...
Thumbnail Image
Date
2020
Journal Title
Journal ISSN
Volume Title
Publisher
PROFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY
Abstract
A field experiment was conducted at College Farm, College of Agriculture, Rajendranagar, Hyderabad during Kharif 2017-18 to study the “Evaluation of defoliants on yield and harvesting of compact cotton varities in high density planting ” The experiment was conducted in a factorial randomized block design with Treatments consisted of 18 combinations comprising of three genotypes viz., ADB-39, WGCV-48 and Suraj as main plots six chemical defoliaters (S1-Drop ultra @ 250ml ha-1 , S₂-Etherel @ 1.25 l ha-1 , S₃ - Paraquat @ 1.0 l ha-1 , S₄ - Urea @ 10%, S₅ - Drop ultra @ 200 ml ha-1 and S₆ - Control (No defoliant application)) as sub plots and replicated thrice. The experimental soil was sandy loam in texture, neutral in reaction, non-saline, low in organic carbon, available N, high in available P and K. WGCV-48 cultivar recorded significantly higher plant height, LAI, Leaf area, dry matter production, dry matter partitioning to stem, leaf and reproductive parts, number of monopodial branches plant-1 , number of sympodial branches plant -1 (17.8), SPAD chlorophyll meter reading (33.8) and number of square plant -1 (23.4) at 80 per cent boll opening as compared to ADB-39 and Suraj cultivars. Similar tread was noticed at square initiation, boll initiation and boll opening stages. Results revealed that genotype WGCV 48 recorded higher seed cotton yield with gross returns, net returns and B: C ratio over other varieties. The similar trend was observed in yield attributes viz., number of picked bolls plant-1 , number of seeds per boll. Quality parameters viz., Lint index and GOT not varies with varieties while fibre fineness and bundle strength 2.5 % span length were more with Suraj. Per cent defoliation was significantly influenced by different defoliant treatments, there was significant increase in per cent defoliation with Drop ultra @ 250 ml ha-1 at 20 days after defoliant spray which is at par with Drop ultra @ 200 ml ha-1 and lowest per cent defoliation was observed in urea @ 10 %. However, defoliation with Etherel @ 1.25 l ha-1 resulted in higher number of picked bolls plant-1 , boll opening percentage and seed cotton yield. The yield enhancement in case of Etherel @ 1.25 l ha-1 further lead to significantly better net returns and B:C ratio over other treatments. Quality parameters were not influenced by defoliants except fibre fineness which was highest with Etherel @ 1.25 l ha-1 . Per cent inert matter in mechanised picking was minimum with Drop ultra @ 250 ml ha-1 . However, Drop ultra @ 250 ml ha-1 was on par with Drop Ultra @ 200 ml ha-1 , Etherel @ 1.25 l ha-1 and urea @ 10%. Whereas, the time and cost of mechanical picking were minimum with both the levels of Drop ultra (@200 ml ha-1 and @ 250 ml ha-1 ). Hence, genotype WGCV -48 along with defoliant spray of Etherel @ 1.25 ha -1 at 80 per cent boll opening stage can be recommended for achieving higher seed cotton yield in single picking with mechanical harvesters.
Description
Keywords
Citation
D10,505
Collections