露期對稻熱病發病之影響
Other Title
Studies on the Effect of Dew Period on the Severity of Rice Blast
Journal
中華農業研究
Journal Volume
33
Journal Issue
1
Pages
59-64
Start Page
59
End Page
64
Date Issued
1984-03-08
Date
1984-03-08
Author(s)
簡錦忠
C.C. Chien
Abstract
稻熱病菌分生胞子著落於稻葉表面後，經發芽、產生附著器、侵入及病斑之形成，在此過程中，與氣象環境因子具密切關係。氣象因子中，除溫度外，露期（包括露水、雨水及點泌液等）之短久，直接影響病菌之侵入。在田間測定不同插秧密度間之罹病程度，顯示插秧密度愈密，即單位面積內稻叢數多（密）時，葉稻熱病愈早期發生，且其罹病程度亦愈嚴重。為進一步明瞭，各不同密度的稻叢內露期及露量之實際變化情形，利用dew dynamicst 測定水膜相對厚度（Relative wetness）在自然狀態測不出露水之環境下，行距與株距為5 × 5 公分之小區葉面露期維持13.0 小時，10 × 10 公分區10.5 小時，20 × 20 公分區在上半夜具有水膜，此可能受微風之影響所以水膜厚度很低，40 × 40 公分區就測不出露期。在露水箱內保持露期12 小時比8 小時者每支苗平均病斑數高出很多，而保持時間愈長，每支苗平均病斑數有愈增加的趨勢。由此可知稻熱病之發生，須要露水之存在，始能完成侵入之行動，同時露期最好保持12 小時以上。
The infection of Pyricularia oryzae on rice is closely related to dew period. Therefore, the dew dynamics was used to study the varying relationship between rice blast severity and dew period and/or dew quantity. The dew periods on the leaf surface were controlled by plant densities. Thirteen hours of dew period were observed in the plant density of 5 x 5cm, 10 hours in the density of 10 x 10 cm, and the relative wetness was very low in the density of 20 x 20 cm at late right. No dew was recorded in the density of 40 x 40 cm.
It comes to the conclusion that dew period which favored the infection of P. oryzae had better maintain more than 12 hours and dew period is positively correlated with the severity or lesion number of rice blast.
Publisher
農業試驗所
Type
journal article
File(s)![Thumbnail Image]()
Loading...
Name
journal_arc_33-1-8.pdf
Size
681.4 KB
Format
Adobe PDF
Checksum
(MD5):bf8e169aba41aa5dbefee8a90d02c229