INFLUENCE OF CHLORMEQUAT CHLORIDE ON FIVE WINTER BARLEY CULTIVARS

A field experiment was undertaken to examine the effects of foliar application of chlormequat chloride (2-chloroethyl-trimethyl ammonium chloride, CCC) on growth, development and yield of five winter barley (Hordeum vulgare L.) cultivars (Arass, Victoria, Alger-Seres, Probest Dwarf and Valfajr). The results indicated that despite the concomittant start of reproductive phase in all cultivars, timing and duration of developmental stages were significantly different among the cultivars. Chlormequat chloride increased the survival of tillers and therefore, the number of ears, and despite partial decrease in individual grain weight, the grain yields of CCC-treated plots were significantly higher than the untreated controls due to higher spikelet survival per spike. Chlormequat chloride increased phytomass production in all cultivars except Probest Dwarf, with no significant effect on harvest index. Alger-Seres produced the highest grain yield and Valfajr the lowest. This was associated with the highest phytomass production in Alger-Seres with no significant difference in harvest index. Also, the grain number per plant was the highest in Alger-Seres while there was no significant difference in mean kernel weight with the other cultivars. Better understanding of the responses of widely grown barley cultivars to chlormequat chloride needs further investigation.