近年来,各地都在大面积推广早稻旱育秧技术,春季在育秧过程中,常发生青枯死苗,对培育早稻壮秧威胁很大,现将其发生情况及防止方法介绍如下,供各地参考。一、症状及发生原因。早稻旱育秧中常见的死苗大致有两大类型:一是黄枯型死苗。多发生于立针到2叶期,发生时病苗心叶枯黄,基部变褐,幼苗基部生有霉层。用手提苗,通常易与种子脱离。此类型死苗,发展缓慢,危害较为轻。二是青枯型死苗,二至三叶期发生,特别是早春寒流 In recent years, all over the large area to promote early rice drought nursery technology, spring seedling nurturing in the process of spring and autumn, nuisance breeding strong seedlings of early rice, now its occurrence and prevention methods are described below for reference. First, the symptoms and causes. Early rice dry nursery seedlings in the common dead seedlings generally have two major types: First, yellow dead seedlings. Occurred in the needle to the 2 leaf stage, the heart of the disease occurred when the leaves of yellow, brown base, seedling base with mold layer. Seedlings with hand, usually easy to break away from the seeds. This type of dead seedlings, slow development, more harmful. Second, the green dead dead seedlings, two to three-leaf period occurs, especially in early spring cold