Influence of tillage systems and herbicides on weed control and yield of cotton in wheat-cotton system

Abstract

Wheat–cotton system is a major production system in Pakistan, however, cotton yield is declining in the system most likely due to weeds infestation and intensive tillage practices. Conservation tillage such as reduced and zero tillage in combination with appropriate herbicide may have the potential to enhance cotton yield on sustainable basis. The objective of this study was to determine the effect of herbicides under different tillage systems on weed control and cotton yield in wheat-cotton system. A field experiment was conducted at Cotton Research Station, Ratta Kulachi, Dera Ismail Khan, Pakistan, during 2017 and 2018. In the experiment, post-emergence herbicides, i.e. floxyfop-R-methyl 10.8 EC (108 g a.i. ha-1), lactofen 24 EC (168 g a.i. ha-1), floxyfop 10.8 EC + lactofen 24 EC, hand weeding, weedy check and three tillage systems (zero tillage, reduced tillage and conventional tillage) were evaluated in randomized compete block design (RCBD), with split plot arrangements, replicated 4 times. Tillage was allotted to main plots while herbicides were applied to subplots. The results revealed that hand weeding and floxyfop as post emergence alone or in combination with lactofen reduced weed density to the minimum irrespective of the tillage systems. Maximum dry weed biomass was recorded in control. Interaction effects revealed that reduced tillage in combination with broad spectrum herbicides had maximum weed population reduction percentage. Reduced tillage with broad spectrum herbicides had seed cotton yield compared to zero and conventional tillage. In conclusion, broad-spectrum herbicides under reduced tillage were more productive in wheat based cropping system on silty clay soil of D.I.Khan.