VARIATION OF SPIKE HARVEST INDEX IN WHEAT (Triticum aestivum L.)

Abstract

Spike harvest index (SHI) can be an indicator of partitioning assimilation into seeds vegetative biomass and wheat productivity. The aim of this study is estimation of spike harvest index variation in wheat varieties grown under different environmental conditions. Twenty genetically divergent winter wheat cultivars were included in two years which characterized different weather conditions. On the field experiment in randomized block design in three replications, the seeds of varieties were sown at the distance of 0.10 m in rows of 1.0 m length with the distance of 0.2 m. For analysis of spike harvest index determined in proportion of seed mass spike-1/mass of spike, 60 plants in full maturity stage (20 plants per replication) were used. The results showed differences of spike harvest index among varieties and between years of experiment. In the first year the variety Pobeda had the highest value of spike harvest index (80.93%) and the Evropa 90 had the lowest SHI (75.67%), while in second year of experiment, the variety Zadruga had the highest value of spike harvest index (85.00%) and the Šumadinka had the lowest SHI (75.50%). Differences of SHI in wheat varieties are due to response of genotypes to environmental factors as well as interaction of genotype/environment.