Effect of sowing and jute varieties on the incidence of yellow mite (Polyphagotarsonemus latus Banks) and jute semilooper (Anomis sabulifera Guen.) under terai region of West Bengal

Infestation of yellow mite (Polyphagotarsonemus latus Banks) on jute decreased with delayed sowings; highest being on 1^st sowing during 3^rd week of April (32.40% in terms of % leaf damage). Intensity of infestation was more on olitorius jute (24.78%) than capsularis one (21.97%). On the contrary the infestation of semilooper (Anomis sabulifera Guen.) increased with delayed sowings and the highest percentage of leaf damage was observed on crops sown during 1^st week of May (31.56% and 23.56% for olitorius and capsularis jute respectively). Similar to yellow mite, the intensity of leaf damage due to semilooper was more on olitorius varities (27.34%) than capsularies (21.21%). The fibre yield of both the species of jute decreased with delay in sowing time. Although the difference in decrease in yield with time was highly significant in olitorius (42.10–24.44 q/ha) but in capsularis there was no difference between first two sowings viz. 3^rd week of April (36.48 q/hal and 1^st week of May (36.47 q/ha). However, significant difference in yield was observed between last two sowings during 1^st and 3^rd week of May.