Effect of Top-fertilizing of Raw Protein and Glucosinolates Content of Winter Turnip Rape

L. Narits

Jõgeva Plant Breeding Institute, J.Aamisepa 1, EE48309 Jõgeva, Estonia;
e-mail: Lea.Narits@jpbi.ee

Abstract:

Rapeseed is a major oil–yielding crop, ranking third place after soybeans and oil palm in the world. Rapeseed contains as average 36–38% crude protein and content of anti–nutritional compounds, among which glucosinolates have received the major attention. The object of the present study was to evaluate the effect of the nitrogen rate and different application times to the crude protein and glucosinolate content of winter turnip rape. The trials were carried out at the Jõgeva Plant Breeding Institute in the 2007–08, 2008–09 and 2009–10 growing seasons. Ammonium sulfate (nitrogen content 21%, sulphur 24%) was used as top–fertilizer. Three different nitrogen rates, 120, 140 and 160 kg N ha−1 and three different application times were used: A) once at the beginning of spring growth (oilseed rape growing code 26), B) A + when the main stalk was 10 cm (code 33), C) B + start of flowering (code 60) (a total of nine different variants) in equal portions. The results indicate that the quantity of the fertilizer has not as strong an impact as application time on the glucosinolate content. The lowest glucosinolate content was obtained from the variant of one N application. The highest protein content was obtained from the variant of three times split-N.

Key words:

Occurrence of pests and stem rot on various oil crops

L. Narits

Jõgeva Plant Breeding Institute, Aamisepa 1, Jõgeva, 48309, Estonia;e-mail: Lea.Narits@jpbi.ee

Abstract:

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.

Key words:

cabbage seed weevil, flea beetle, pollen beetle, spring oilseed rape, stem rot, winter oilseed rape, winter turnip rape