Ecology, Environment and Conservation Paper

RADIANT AND THERMAL EFFICIENCIES OF COTTON CULTIVARS UNDER DIFFERENT GROWING ENVIRONMENTS

Premdeep Ram Niwas and M.l. Khichar

Abstract

A field experiment was conducted at the research farm of department of Agricultural Meteorology CCS Haryana Agricultural University, Hisar, during kharif 2013-14. Three cultivars were sown in four date of sowing in split plot design with four replications. Daily weather data was used for computation of energy indices of cotton cultivars in four growing environments. Efficiency of thermal and radiant enegy utilization for dry matter conversion of cotton cultivars was computed at different phenological stages. The 2nd week of April (G1) sown crop consumed highest thermal and radiation indices and its efficiency of conversion into dry matter was also highest in this growing environment as compared to 4th week of April (G2), 2nd week of May (G3) and 1st week of June (G4) sown cotton crops, The transmitted photosynthetically active radiation was recorded lowest in G1 as compared to G2, G3 and G4 environments. All growth parameters yield and yield attributes were found highest in 2nd week of April sown crop. Cotton hybrid RASI 134, consumed maximum heat units (HU), heliothermal units (HTU) and photothermal units(PTU) as compared to H 1098 and HD 123 under different growing environments. The efficiency of PAR utilization for dry matter production was highest in RASI 134 at all phenophases. The efficiency of heat utilization was also maximum in RASI 134 as compared to H 1098 and HD 123. The correlation and regression analysis were carried out to study the relationship between agrometeorological and crop parameters. Among the phenophases, the weather parameters during 50 per cent flowering were better associated with the crop parameters than those during other phenophases. Maximum temperature, minimum temperature and vapour pressure deficit showed a strong positive correlation with seed cotton, cotton seed, cotton lint and bolls per plant during boll opening stage, whereas morning and evening relative humidity showed negative correlation with seed cotton, cotton seed, cotton lint and bolls per plant during vegetative, flowering and boll opening stages. Among the agrometeorological indices, HTU were highly correlated with seed cotton, cotton seed, cotton lint and bolls per plant followed by PTU and HU. The model based on maximum temperature, morning relative humidity, vapour pressure deficit during boll opening and sunshine hours during flowering stage was best fit for prediction of seed cotton yield and explained upto 82 per cent variability in seed cotton yield.