INFESTATION STATUS AND MANAGEMENT OF OKRA SHOOT AND FRUIT BORER, EARIAS VITTELLA F.

Abstract

A series of studies were undertaken to determine infestation status, varietal preference of okra shoot and fruit borer. Lai•ias ri/tel/a and also to develop their management tactics in the Entomology Division Experimental field. BAR!. Gazipur during 2005 cropping season. Shoot infestation started from 30 (lays after seed sowing (DAS) and infestation gradually increased thereafter. At 51 DAS the shoot infestation reached to the peak and 32.41% shoot infestation was recorded during that time. On the oilier hand fruit infestation started three weeks later than the shoot infestation. Fruit infestation ranged from 1•93% (51 DAS) to 1 7.49% (107 DAS). Shoot infestation was severe during the early part and fruit iniCstation during the later part of the crop cycle. Both shoot or fruit infestations of okra by OSFI3 were positively correlated with temperature and rainfall. This indicates that okra shoot and fruit borer like hot and humid climate for its growth and development. Atnoiig the three varieties/lines tested against OSFB, BARI Dheros I. consistently and significantly showed higher shoot infestation than the other two okra lines. Gazipur local I and Gazipur local 2 in all the observations. Mean percent shoot infestation in B,\Rl Dheros I was 29.81 while that was 14.93% in Gazipur local I and 17.29% in Gazipur local 2. Among the management treatments significantly lowest shoot infestations were observed in the neem oil and neem seed kernel extract treatments. Highest shoot infestations were recorded in untreated plots. The overall mean shoot infestations were 7.85%. 6.95%. 13.62% and 21 76% in neeni seed kernel extract, neem oil. dimethoate and untreated control plots. respectively. Fruit infestation almost followed the same trends of result due to the efThct of those treatments. However chemical pesticide. Diniethoate performed better in the reduction of fruit infestation than shoot infestation. Significantly lowest fruit infestations were observed in the neem oil and neem seed kernel extract and dimethoate treatments. Highest fruit infestations were recorded in untreated plots. Average reduction of 60.94%. 65.21% and 53.16% fruit infestation were happened over untreated control due to the effect of neem seed kernel extract. neem oil and Tafgor 40 EC treatments, respectively. As okra is quick harvestable vegetable so it is not wise to spray toxic pesticide at every one week interval. This study revealed that neem seed kernel extract and neem oil spray at 10 days interval can control the pest yen' much effectively.