Effect of Soil Moisture Content on Seedling Emergence and Early Growth of Some Chickpea (Cicer arietinum L.) Genotypes

At the crop level, the drought stress accounts for most variations in yield. A controlled glasshouse investigation at day/night temperatures of 22/15 degrees C based at Perth City, Western Australia was performed (in 2006) to assess the influence of different soil moisture contents (field capacity percentage basis) on emergence as well as early plant growth in twenty chickpea genotypes. The experiment was laid out in split plot design with soil moisture content as the main treatment and genotype as sub-treatment. Significant differences (P < 0.001) as regards plant emergence and early growth were observed among different soil moisture contents (from 100 to 50, then to 25% field capacity). This brought about a quadratic reduction in mean emergence percentage, delayed the first day to emergence and suppressed the early growth in all the chickpea genotypes. Highly significant differences were also noticed among the genotypes for mean emergence percentage, first day to emergence, plant height, leaf area, total above-ground biomass (plant size) as well as specific leaf area. Significant interaction effect of soil moisture contents and genotypes were observed only for some of the characteristics. Inverse relationship between first day to emergence with plant height (r=-0.87**) and above-ground biomass (r=-0.84**) were observed, indicating that the chickpea genotypes which emerged sooner produced greater plant size. Seed size and density were found to have no relationship with plant size. Although the Kabuli types on average germinated faster and produced larger plants as opposed to the Desi types under the limited soil moisture content, but there was no consistency observed among the chickpea genotypes. Susceptibility of the genotypes to limited soil moisture condition was shown through relatively longer delays in time to emergence (lower germination rate) and reduction in seedling parameters as compared to the resistant genotypes. Final average above-ground biomass (plant size) and plant height under the limited soil moisture content, as opposed to adequate moisture level (F. C. 25% vs. 100%), were reduced 79-85% in Kabuli and 77-79% in Desi types, respectively.