Indicators for evaluating the resistance of tomato genotypes to low light.

Low light is one of the most important factors limiting tomato (Solanum lycopersicum L.) production. In this experiment, tomato genotypes under low light (winter planting), and adequate light (summer planting) were evaluated in the same greenhouse condition for other environmental conditions where 11 tolerance and susceptibility indices were evaluated in terms of fruit weight per plant produced. Using the rank of each genotype for the calculated indices, the mean rank index was calculated. The highest yield under adequate light was in genotypes "9318," "9314," "2216," "324," and "5239." Under low light, genotypes "321," "9318," "9314," "523," and "324" had the highest fruit yield per plant, respectively. Evaluation of tolerance and sensitivity indices indicated that tolerance indices, geometric mean productivity index, mean relative performance index and relative efficiency index had a positive, significant, correlation with fruit weight per plant in low light and adequate light are the best indicators for selecting genotypes tolerant to low light. Based on these indices, genotypes "9318," "9314," "321," "324," and "523" had the highest ranks and more tolerance to low light, and might be successfully cultivated in low light areas. [ABSTRACT FROM AUTHOR]