Influence of weed control practices on nutrient uptake in cotton plant

Abstract

A field experiments was conducted at Professor Jayashankar Telangana State Agricultural University, Rajendranagar during <em>kharif</em> 2017 for the evaluation of diuron in two different soils. The treatments consisted of diuron 80% WP at 0.5, 0.75 and 1.0 kg ha^-1 along with registered formulation of pendimethalin 38.7% CS at 677 g ha^-1, intercropping with green manure crop, mechanical weeding thrice at 20, 40, 60 days after sowing and unweeded control. The experiment was carried out in a randomised block design replicated thrice. The weed flora of the experimental field in red soil was dominated by <em>Cynodon dactylon</em>, <em>Rottboellia exaltata, Parthenium hysterophorus,</em> <em>Trianthema portulacastrum</em> and <em>Commelina benghalensis</em>. While in case of black soil predominant flora was <em>Cynodon dactylon, Cyperus rotundus, Parthenium hysterophorus</em>, <em>Euphorbia geniculata</em>, <em>Tridax procumbens</em>, <em>Cyanotis cristata</em>, <em>Digera arvensis</em> and <em>Celosia argentea.</em> The macronutrient contents in cotton crop were higher in polymulch, mechanical weeding thrice at 20, 40 and 60 DAS and this was comparable to pre emergence application diuron at 1.0 kg ha^-1 followed by post emergence application of pyrithiobac sodium + quizalofop <em>p</em> ethyl in red soil and post emergence application diuron at 1.0 kg ha^-1 followed by post emergence application of pyrithiobac sodium + quizalofop p ethyl and diuron at 0.75 kg ha^-1 black soil. The minimum weed competition facilitated higher DMP and nutrient uptake by the plant. The nutrient removal by weeds also was minimal in polymulch, mechanical weeding thrice at 20, 40, 60 DAS, diuron at 1.0 kg ha^-1 pre emergence application of pyrithiobac sodium + quizalofop p ethyl followed by post emergence application of diuron at 0.75 kg ha^-1in both red and black soil.