论文部分内容阅读
旱育秧是水稻栽培新技术,优点很多,广大农民十分欢迎.然而,农民又非常担心旱育秧发生病害,严重的可导致无秧可插.由于旱育秧是一项新技术,大部分农户对旱育秧病害缺少识别能力.在稻麦两熟制的黄淮稻区,旱育秧的三种主要病害.“恶苗病”、“立枯病”和“黄(白)化病”都有“黄”的表现,分别表现为“瘦黄”、“枯黄”和“嫩黄”,不少农业技术人员也不能辨认,只笼统地称为“黄苗、死苗”.正确识别病害类型,了解其发生原因,采取恰当的防治措施十分必要,现简介如下.1.在气温达到30℃～35℃左右时,看到苗床上一些秧苗迅速长高,比普通秧苗高出1/3以上,在苗床上很显眼.叶色与假茎均为淡黄色,瘦而长,不卷叶,根数少,除少数发病早且重的植株外,至移栽时一般不死苗.病苗在苗床上均匀分布.该病属于苗期徒长恶苗病.其病原由串珠镰孢菌侵染而引起,该菌为好气菌,喜欢高温高湿.旱育秧苗床透气性好,苗床覆盖地膜所致的膜下高温高湿,都有利于该病菌的生长.所以,旱育秧恶苗病比水育秧重.此外,粳稻发病比籼稻普遍.
However, farmers are also very worried about the disease of dry seedlings, which can lead to serious seedlings can not be inserted.Because dry seedling is a new technology, most of the farmers on the dry Nursery diseases lack of identification ability in the rice and wheat double cropping Huang-Huai rice area, dry nursery seedlings of the three main diseases. “Bakanae”, “blight” and “yellow (white) disease” are yellow “, The performance of” thin yellow “,” yellow “and” bright yellow “, many agricultural technicians can not identify, only generally referred to as” yellow seedlings, dead seedlings. "Correctly identify the type of disease to understand its occurrence Reason, take appropriate prevention and control measures are necessary, are summarized as follows.1.When the temperature reaches 30 ℃ ~ 35 ℃ or so, see some of the seedlings on the seedbed grow quickly, higher than the average seedling more than 1/3, in the seedbed Very conspicuous.The leaf color and pseudostem are yellow, thin and long, do not roll leaves, the number of roots is small, except for a few early onset and heavy plants, to transplant generally undeveloped seedlings in the seedbed evenly distributed . The disease belongs to the growth of nursery sickness seedlings. The pathogen caused by Fusarium moniliforme infection caused by the bacteria Aerobic bacteria, like high temperature and humidity. Dry seedbed seedbed permeability is good, the seedbed coverage of the membrane under the high temperature and humidity caused by the film are conducive to the growth of the bacteria, so dry seedling nursery disease than watering seedling weight. In addition, japonica rice The incidence is more common than indica rice.