Effect of Weed Management Practices on Weed Dynamics, Yield and Economics of Sweet Potato ( Ipomoea batatas L.)

Abstract

An experiment was conducted to find out the most suitable weed management practice for weedmanagement in sweet potato during 2015-16 at Agricultural Research Farm, Dholi of Dr. RajendraPrasad Central Agricultural University, Pusa (Bihar) under sandy loam soil. It was found that theherbicide Quizalofop-p-ethyl alone or in combination with other herbicides performed better than allother herbicides tested. It may be due to its better efficacy towards controlling narrow leaved weedsparticularly against the most dominant weed of the fieldSorghum halepanse. The most effectivecombination of herbicides was pendimethalin followed by quizalofop-p-ethyl (T7) which may be due toweed control right from the early stage up to about a month by the application of pendimethalin andthereafter control of most dominating and vigorous weedSorghum halepanseby the application ofquizalofop-p-ethyl. Although lowest weed population and weed dry matter at 30 and 60 days afterplanting were recorded under T10(Hand weeding twice at 20 & 40 days after sowing) and was significantlysuperior than all other treatments, it could not achieve highest net return and B : C ratio even afterrealizing highest tuber yield (20.3 t ha-1). Best weed index (9.36 %) was recorded by the treatmentcombination of pendimethalin (T1) followed by quizalofop-p-ethyl (T7) and it was equally good withhand weeding twice (T10)with respect to tuber yield. Significant highest net return (`115226 ha-1)was recorded by T7than all other treatments but was found on par with T10(`111826 ha-1). B : C ratiorecorded by T7(3.60) was significantly superior than the other treatments. Highest weed population,weed dry matter, weed index and lowest tuber yield, net return and B : C ratio were recorded undercontrol treatment.