Ajithkumar, BAswini HaridasanKAU2020-03-032020-03-032016http://krishikosh.egranth.ac.in/handle/1/5810144141PGYard long bean is an important leguminous vegetable crop cultivated in Kerala. It is a highly relished vegetable crop which can be cultivated throughout the year. However, weather and climate are considered to be the most limiting factors in crop production. Since weather conditions experienced by a crop play a major role in its growth and yield, the study of the influence of weather on crop is very much important. The present investigation on “Crop weather relationship of Yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Walp) was carried out in the Department of Agricultural Meteorology, College of Horticulture, Vellanikkara during 2013-2014 to determine the crop weather relationship and to study the effect of date of sowing on the growth and yield of yard long bean. The experiment was laid out in randomized block design with three replications at Instructional farm, Vellanikkara from September 2013 to August 2014. The treatment comprises of twelve dates of sowing at monthly intervals from September 2013 to August 2014. Yard long bean variety lola was used for the experiment. The different growth and yield characters like plant height, biomass, number of pods per plant, number of seeds per pod, hundred seed weight, length of pod, pod yield per plot, pod yield per plant and duration of different growth phases were recorded along with monitoring of major pests and diseases. The daily weather parameters like maximum and minimum temperature, forenoon and afternoon relative humidity, forenoon and afternoon vapour pressure, rainfall and rainy days, bright sunshine hours, evaporation, wind speed and soil temperature were also recorded. The maximum temperature was found highest in February 2014 sowing and was recorded lowest in July 2014 sowing whereas the highest minimum temperature was recorded in March and April 2014 sowing. The crops sown during December 2013 and January 2014 received no rainfall and those sown during June 2014 received the maximum rainfall. The bright sunshine hours was recorded more in December 2013 sowing and was low in June 2014 sowing. Plant height, biomass, phenological stages, yield and yield attributes were highly variable among the different sowing dates. The March 2014 sown crops took more number of days to attain 50% flowering followed by February 2014 sown crops. The crop duration was also observed more for March sown crops which was on par with December 2014 sown crops. Yield and yield attributes were influenced by various weather parameters experienced during the different crop growth stages. Pod yield was highest from September and October 2013 sown crops and lowest from May and July 2014 sown crops. Yield attributes such as number of pods per plant, number of seeds, length of pods and hundred seed weight were also recorded more in September and October 2014 sown crops. Pests such as aphids, pod borer, pod bug and diseases such as mosaic, rust and anthracnose were observed in the crop during the study. To determine the critical weather elements affecting the crop growth, correlation analysis was done and it was found that maximum temperature, diurnal temperature range, soil temperature at 10cm depth, wind speed and bright sunshine hours exhibited positive influence on the pod yield, whereas increase in minimum temperature, growing degree days, relative humidity, vapour pressure, rainfall and rainy days negatively influenced the yield. Multiple linear regression models were fitted, to predict the pod yield based on the weather variables..ennullThesis