凉山州大蒜煤斑病的发生规律

THE OCCURRENCE PATTERN OF HETEROSPORIUM ALLIUM IN LIANGSHAN PREFECTURE

大蒜煤斑病由葱煤斑瘤蠕孢菌HeterosporiumalliumElletMare.侵染所致。病原菌耐寒,不耐高温,发生在冷凉高湿的环境,不能在凉山大蒜主产区越夏。其初侵染源来至周围海拔2000m以上地区。洛水蒜较抗病。高密度种植和偏施氮肥病害流行加重。此病对大蒜叶片危害大,但只要植株顶部4～5叶发病轻微,即能达到较高产量。

Heterosporium allium Ell et Mare, infecting garlic, cannot oversummer in Liangshan Prefecture of Sichuan as it is winter hardy but intolerant to high temperature. The primary pathogen comes from the surrounding areas with an altitude of over 2 000 m. Of the local garlic varieties, the Luoshui variety is the most resistant to the disease. High plant population and excessive application of N fertilizer will aggravate the epidemy of the disease. The pathogen mainly infects the leaves of the garlic plant. However, if only the top 4 or 5 leaves are not severely infected, satisfactory yield may be harvested.