Experiments were conducted in the farmers orchard of Gazipur district and in the laboratory and Fruit farm of Bangladesh Agriculture Research Institute, Gazipur during January, 2005 to August, 2005 to study Biology, Pest status and management of Jackfruit borer, Diaphaniacaesalis Walker.Among them biology and management of the pest were conducted at Fruit orchard of Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh, while survey on the fruit infestation through direct count and through farmers’ interview at four locations of Gazipur district. On the other hand incidence of fruit infestation was also studied at 10 different Jackfruit orchards of Gazipur district. All the studies were done during January 2005 to August 2005.
Infestation status
Infestation status through direct count: One hundred plants were randomly selected from each location of Sreepur, Joydebpur and Kapasia of Gazipur district. A total of 4 observations were made per fruiting season from each location. The first observation was made at 30 days after fruit setting (DAFS), the second at 60 DAFS, the third at 90 DAFS and the fourth at 120 DAFS. Data of four observations were pooled and the mean was calculated. Percent fruit infestation was also calculated.
Infestation status through farmers’ interview: A total of randomly selected 25 Jackfruit growers were interviewed from each location
Incidence of fruit infestation
Numbers of healthy and infested fruits were counted and recorded from 25 randomly selected plants of each location by observation each plant carefully at 15 days interval from the first fruit setting till last harvest.
Management
Five treatments were evaluated to find out the effective management tactics against jackfruit borer. The treatments were as follows:
1) Neem oil: Three sprayings of neem oil @ 10 ml/L of water + soap solution 5 g/L were done at 30, 45 & 60 days after fruit setting (DAFS).
2) Dimethoate (Tafgor 40 EC): Three sprayings of dimethoate (Tafgor 40 EC) @ 2.5 ml/L of water were done at 30, 45 & 60 days after fruit setting (DAFS).
3) Cypermethrin (Ripcord 10 EC): Three sprayings of Cypermethrin (Ripcord 10 EC) @ 1.0 ml/L of water were done at 30, 45 & 60 days after fruit setting (DAFS).
4) Bagging: Three plants are selected for fruit covering.
Data collection and analysis
Data on healthy and infested fruits were recorded from each plant and percent infestation was calculated according to the following formula:
% fruit infestation = Number of infested fruits/plant ÷ Total Numberof fruits/Plant X 100
All the data were analysedstatistically followed by MSTAT programming.