Agroclimatic requirement of large cardamom (Amomum subulatum Roxb.) for the state of Sikkim

Abstract

The present study was carried out to identify the cause of major yield losses of large cardamom in the state of Sikkim.  For this purpose three years meteorological data from two stations viz. Gangtok and Tadong and the potential evapotranspiration data from two adjacent stations located in the sub-Himalayan West Bengal were used for computation of heat unit (GDD) and agroclimatic rainfall index (ARI).

The study  revealed that rainfall availability and potential evapotranspiration followed the same trend with the highest value at vegetative stage and the lowest value at lag phase of the crop.  The total heat unit requirement of the crop was very high; its value increased from nursery seedling to transplanting stages and then reduced sharply during lag phase; afterwards the peak was attained at vegetative growth stage, which sharply reduced at later growth stages. Very high ARI values were recorded at transplanting and flowering stages for both the stations. The postmortem study suggests that the crop requires well distributed, plentiful rainfall with high relative humidity and cool temperature, which were not available during 1998-99, affecting the crop severely  at secondary flowering stage.