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CORRELATION BETWEEN
HUMID THERMAL RATIO AND EPIDEMICS OF CERCOSPORA LEAF SPOT
OF PEANUT IN POTHWAR
MUHAMMAD IJAZ1*,
M.I. HAQUE2, C.A. RAUF, FAYYAZ-UL-HASSAN2, ABID RIAZ2
AND S.M. MUGHAL2
Abstract:
The
epidemic of Cercospora leaf spot (CLS) frequently led to yield
losses on unsprayed peanuts in Pakistan. During 3 successive years of
field trials under medium rainfall conditions of Pothwar at Chakwal, it
was observed that CLS incidence epidemic differed significantly during
crop seasons. Genotypes exhibited significantly different disease
response to CLS incidence provided suitable environmental conditions
prevailed during crop growth cycle. Among crop seasons, year 2003 was
most conducive due to frequent and early rains making humid thermal
ratio (HTR) quite favorable for most of the time for disease initiation
and development resulting in higher values of AUDPCs and incidence. Six
fortnights from July to September were the most critical and risky for
crop as the HTR values 2.01 to 3.84 are most likely conducive for
significant increase in CLS incidence.
1Plant
Pathologist Barani Agricultural Research Institute, P.O. Box 35 Chakwal,
Pakistan
2PMAS
Arid Agriculture University Rawalpindi, Pakistan
*E-mail:
ijazabneatta@gmail.com
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