tailieunhanh - Development of prediction equations for tomato leaf curl virus on tomato at different dates of planting using Logistic and Gompertz model

Tomato leaf curl virus (ToLCV) has become a major threat of Tomato (Solanum lycopersicum) production in the world including tropical and subtropical tomato growing regions due to its the endemic presence. The aim of this study is to develop a forewarning strategy for the farmers. The components included in the experiment were, a susceptible tomato variety “Patharkuchi” planted at 15 days interval starting from16th August to 29th December during both the experimental year 2012-13 and 2013-14 under field condition. Different dates of planting also allowed the plants to interact with the different weather factors prevailed through out the growing period. Here, six independent weather variables like maximum and minimum temperature and their differences, maximum and minimum relative humidity and rainfall were considered and natural epiphytotic conditions were permitted. Disease severity was measured and expressed as AUDPC. Prediction equations were developed for each treatment separately through step down multiple regression analysis which showed that different meteorological factors having different influence on disease severity and these were explained after logistic and gompertz transformation of the realized observed value of the disease severity (expressed as AUDPC). Logitic and gompertz are the two transformation models through which the disease progress curve move over time and its comparative expression are also presented graphically in this study. Different dates of planting showed differences in disease severity. | Development of prediction equations for tomato leaf curl virus on tomato at different dates of planting using Logistic and Gompertz model