Occurrence of pests and stem rot on various oil crops
Jõgeva Plant Breeding Institute, Aamisepa 1, Jõgeva, 48309, Estonia;e-mail: Lea.Narits@jpbi.ee
The purpose of this study was to find an oil crop with no serious problems with pests and diseases, making it suitable for organic farms.The spring oilseed rape is the most important oil crop in Estonia. Winter turnip rape andwinter oilseed rape are alternatives to spring rape.In the present exploration the following were investigated: incidence of flea beetles,pollen beetles and cabbage seed weevils, and the number of blind stalks and infection of stem rot on spring oilseed rape, winter oilseed rape and winter turnip rape.In winter oilseed rape and winter turnip rape trials no pesticides and fungicides were usedduring the growing period, but there was a variant of seed treatment by ‘Rapcol’ (phurathiocarb + matalaxil + fludioxonil) in comparison with the non-treated variant. Spring oilseed rape trials were treated by ‘Rapcol’ before sowing and sprayed by ‘Fastac’ (alpha-cypermethrin) at the beginning of flowering (stage of development – 61).The following results were obtained: flea beetles appeared most on winter oilseed rape,least on winter turnip rape. Pollen beetles appeared most on spring oilseed rape, least on winter turnip rape. Most pods damaged by pollen beetles’ larvae were found on winter oilseed rape, least on winter turnip rape. Damage by cabbage seed weevil was minimal in all the oil crop trials. Stem rot infection was high on spring oilseed rape, least on winter turnip rape.By the results of exploration it can be concluded that winter turnip rape had the lowestinfection by pests and disease and therefore has good potential for sustainable agriculture.