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The influence of sunshine and rain on tea blister blight, Exobasidium vexans Massee, in Ceylon
Author(s) -
VISSER T.,
SHANMUGANATHAN N.,
SABANAYAGAM J. V.
Publication year - 1961
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1961.tb03616.x
Subject(s) - biology , germination , blight , horticulture , spore , sunshine duration , fungicide , relative humidity , botany , agronomy , toxicology , meteorology , physics
SUMMARY The germination of spores of blister blight of tea ( Exobasidium vexans Massee) requires moisture, but 0.1 in. of rain in a day provides sufficient for a high percentage of germination to occur; more rain does not materially increase germination. Spores are killed by sunshine of a few hours' duration, even if there is adequate rain on the same day. An average of about 3 3/4 hr. of sunshine per day over 5 days is enough to reduce the blister‐blight disease to subeconomic levels. Ten‐day spraying rounds with copper fungicide usually give adequate control of the disease but add to the cost of production. A method is put forward of using recorded sunshine hours as the criterion in deciding on the frequency of spraying; spraying is postponed, by successive 5‐day periods, until the average sunshine for the previous 5 days has dropped below 3 3/4 hr. A reduction approaching one‐half of the number of spray applications can be made in this way.