Impact of sowing periods on incidence of aphid, Hyadaphis coriandri (Das) infesting fennel

Five sowing periods during winter (2nd week of October, 3rd week of October, 4th week of October, 1st week of November and 2nd week of November) was evaluated for its impact on incidence of aphid, Hyadaphis coriandri (Das) infesting fennel at Agronomy Instructional Farm, C. P. College of Agriculture, S. D. Agricultural University, Sardarkrushinagar. Among all the sowing periods, the first two sowing periods viz., 2nd and 3rd week of October sown crop suffered less damage caused by aphid attack, whereas remaining last two sowing periods viz., 1st and 2nd week of November harboured more aphid incidence. Among the five different sowing periods, the maximum seed yield was recorded from 2nd week of October sown crop (14.75 q/ha). The lowest seed yield was recorded when the fennel sown during 1st week of November.