Ecology, Environment and Conservation Paper

EFFICACY OF PRE AND POST EMERGENCE HERBICIDES ON GROWTH AND YIELD OF SUNFLOWER (HELIANTHUS ANNUUS L.)

K. Ashok Kumar, S. Neelima and P. Munirathnam

Abstract

To study the effect of pre and post emergence herbicides on growth and yield of rabi sunflower, a field experiment was carried out at Regional Agricultural Research Station, Nandyal, Andhra Pradesh during 2009-10 and 2010-11. The experiment consisted of eight treatments comprising of application of pre emergence herbicide (pendimethalin @1.5 kg a.i ha-1) fb handweeding at 30 DAS, post emergence herbicides (quizalofop-p-ethyl@50g a.i ha-1, fenoxa prop-p-ethyl @56 g a.i ha-1 and cyhalofop butyl @ 50g a.i ha-1) at 20 DAS, sequential application of pre mergence herbicide fb post emergence herbicides at 20 DAS and unweeded check were laid out in randomized block design with three replications. The results revealed that application of fenoxaprop-p-ethyl@ 56 g a.i ha-1 at 20 DAS resulted in maximum reduction in dry matter from 20 to 30 DAS (7.0 to 3.5 g m-2 and 7.3 to 3.2 g m-2 during 2009-10 and 2010-11 respectively). However, higher mean seed yield (1399 kg ha-1), net returns ( 39,083 ha-1) and B:C ratio (3.5) were recorded with application of pendimethalin @ 1.5 kg a.i ha-1 fb HW at 30 DAS followed by application of pendimethalin @1.5 kg a.i ha-1fb fenoxaprop-p-ethyl@56 g a.i ha-1 at 20 DAS.