Effect of Nitrogen Doses and its Application Time on Leaf Blight Disease Severity on Wheat

摘要

The first section of the present investigation was to study the effect of nitrogen doses and application time on durum wheat variety WH896. It contained three main plot treatments and five subplot treatments. The second section of study Was to investigate the same effect on a bread wheat variety UP2338. It contained three main plot treatments and four subplot treatments. The variety WH896 (durum) was applied wi{h three doses of nitrogen i.e. 120 kg ha~(-1),150 kg ha~(-1) and 180 kg ha~(-1), each with five different dates of applications. However, bread wheat variety UP2338 was applied with same three doses of nitrogen, each with four different dates of application. Two disease ratings were recorded. First rating was according to 0-9 scale and second was taken in percentage of flag leaf area covered with leaf spots. Lower doses of nitrogen were associated with reduced severity of leaf blight in bread as well as durum wheat. In durum wheat 120 kg N/ha in split application i.e. 1/2 N at sowing + 1/2 N at first node or 1/3 N at sowing + 1/3 N at CRI + 1/3 N at flowering produced minimum disease. Whereas in bread wheat, 120 or 150 kg N/ha with split application i.e. 1/2 N at sowing + 1/2 N at crown root initiation produced minimum leaf blight disease.