Broomcorn [sorghum bicolor (l.) Mocnch]panicle yield as affected by environmental variables and agro-technological traits

Abstract

The aim of this study was to access the overall effects of genotype, environment and genotype x environment interaction (GEI), as well as the importance of individual agro-technological traits in the broomcorn [Sorghum bicolor (L.) Moench] panicle yield formation. The performances of 11 broomcorn cultivars grown in eight different seasons are discussed in this paper. The restricted maximum likelihood (REML) variance component estimates model revealed that panicle yield was for the most part dependent on GEI (47.5%), which allowed identification of best genotypes for specific environments. The partial least squares regression (PLSR) model revealed that the most important climatic variables for optimal yield are precipitation in vegetation period and maximum air temperature in vegetation, followed by difference between maximum and minimum temperature in vegetation, growing degree days and sum of precipitation. Generally, lower temperature and higher precipitation parameters had beneficial effect on yield. Considering the individual agro-technological traits, the most important for panicle yield were weight of threshed and unthreshed panicle, as well as grain weight per panicle. As directly related to yield; length of the panicle, fibre length and number of fibres per panicle were also important. The best yield (Sava, 11.75 t ha(-1) ) and stability (Jumak, Prima) performances were recorded for locally adapted cultivars. The knowledge obtained in this study is valuable for the identification and understanding of key environmental and agro-technological factors that contribute to the yield of broomcorn panicle.