Modeling the association of weather and black pepper yield

Abstract

The knowledge on the role of climate in crop production is essential precondition for sustainable agriculture and crop-weather analysis model (CWAM) helps to understand the crops association with weather. Black pepper is an important spice grown in rainfed under tropical humid and sub-tropical climate and the present study was undertaken to establish crop-weather relationship in black pepper by using second-degree polynomial equation. Readily available weekly meteorological data such as maximum temperature (oC) (TMAX) and minimum temperature (oC) (TMIN), maximum relative humidity (%) (RHMAX) and minimum relative humidity (%) (RHMIN), rainfall (mm) (RAIN), evaporation (mm) (EVPN), wind speed (WIND) (km h-1) and bright sunshine hours (SUNS) data and black pepper fresh spike yield for six years (1992-93 to 1997-98) were used in this study. The association between black pepper yield and weather indicated that effects of change in weather variables in successive weeks were not an abrupt or erratic change but an orderly one. The regression models developed in this study brought out the magnitude of association of weather parameters with black pepper yield in the order, i.e., RHMAX > RAIN > TMIN > TMAX > SUNS > WIND > RHMIN > EVPN. All the weather parameters studied had significant relationships with black pepper yield except RHMIN (R2 = 0.4697) and EVPN (R2 = 0.3913). Crop-weather relationships developed in this study provides information on the response of black pepper to weather and would help further studies in this direction particularly in the context of changing climate.