Development of leaf spot of safflower (Alternaria carthami) in relation to weather parameters Murumkar D.R., Gud M.A., Indi D.V., Shinde S.K., Kadam J.R. All India Coordinated Research Project on Oilseeds (Safflower), Zonal Agricultural Research Station, Solapur-413 002, M.S., (India). Abstract A field experiment was conducted successively for 4 years (2004–05, 2005–06, 2006–07 and 2007–08) with an objective to study the effect of different weather parameters viz., rainfall, temperature and humidity on the development of Alternaria leaf spot of saffiower caused by Alternaria carthami. The correlation studies indicated that in early sowing rainfall, minimum temperature and relative humidity (RH-I and II) had a positive correlation with the disease development whereas, the maximum temperature had a negative correlation. The weather conditions during 36 to 42 MW were observed to be the most congenial for the crop infection and further rapid build-up of the disease. In normal sowing, the disease had a positive correlation with rainfall, maximum and minimum temperature and relative humidity-II, whereas the relative humidity-I had a negative correlation. The results of regression analysis stated that, if the rains received coupled with high humidity above 80% and temperature in the range of 21 to 33°C favour the primary infection of the crop. Top Key words Carthamus tinctorius L., Alternaria carthami, correlation, weather parameters. Top |