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POPULATION DYNAMICS AND DEVELOPMENT OF WEATHER BASED FOREWARNING MODELS FOR THRIPS IN GROUNDNUT

KrishiKosh

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Title POPULATION DYNAMICS AND DEVELOPMENT OF WEATHER BASED FOREWARNING MODELS FOR THRIPS IN GROUNDNUT
 
Creator REVATHI, M
 
Contributor VIJAYA LAKSHMI, K
 
Subject crops, groundnuts, environmental degradation, diseases, land resources, sowing, fruits, developmental stages, sowing date, necrosis
 
Description The present studies on “Population dynamics and development of weather based
forewarning models for thrips in groundnut” were carried out at Agricultural Research
Institute, Hyderabad during kharif, 2010.
To study the effect of sowing dates and age of the crop on groundnut thrips and
Bud Necrosis Disease incidence, the crop was sown in four different dates. The first
sowing was taken up on 19th June 2010 and the remaining three sowings were taken up
at 15 days interval i.e. on 4th July, 19th July and 4th August. The results indicated the
prevalence of high incidence of thrips and PBND in late sown crop (August 4th), while
early sown crop (June 19th) escaped from both thrips and PBND incidence in the initial
stage and recorded high yield.
Species composition of thrips identified in groundnut indicated the presence of
two species of thrips Scirtothrips dorsalis Hood, and Thrips palmi Karny in leaf
terminals while three species of thrips viz., Megalurothrips usitatus Bagnall,
Frankliniella schultzei Trybom and Thrips palmi Karny inhabited the groundnut
flowers. S. dorsalis was the dominant species in groundnut leaves while M. usitatus
was found in greater proportion in flowers. The dominant species of thrips existing in
leaves (S. dorsalis) and flowers (M. usitatus) were found throughout the crop growth
period with their peak population occurring at 34 and 41 days age of the crop,
respectively.
The correlation studies conducted between thrips incidence and preceding one
week weather had more significant relation than preceding two weeks weather. Among
the weather parameters minimum temperature, morning and evening relative humidity
showed significant positive correlation, while sunshine hours played a significant
negative role. For PBND incidence preceding two weeks weather had more significant
relation. Leaf wetness showed significant positive correlation while evaporation and
morning relative humidity showed significant negative correlation with PBND
incidence.
Linear and non linear models developed for thrips incidence with crop and
observatory parameters (preceding one week) together predicted the thrips incidence to
an extent of 32 per cent with linear and 69 per cent with non linear models than used
individually. For PBND incidence also the crop and observatory weather parameters
(preceding two weeks) together played a major role in predicting the incidence to an
extent of 93 per cent with linear and 96 per cent with non linear multiple regression
models.
 
Date 2016-06-09T14:20:32Z
2016-06-09T14:20:32Z
2011
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/67131
 
Language en
 
Relation D8852;
 
Format application/pdf
 
Publisher ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY