Tomato genotype in relation to nitrogen utilization and yield

Twelve different tomato (Lycopersicum esculentum Mill.) genotypes were grown in a controlled greenhouse to determine the influence of genotype variation on the efficiency of nitrogen utilization and fruit yield. The results showed that the variation of genotype in tomatoes influences the utilization and assimilation of foliar NO3-. The genotypes that proved highly efficient in this utilization were G7, G9, G11, and G12. These genotypes had the highest foliar NO3- concentrations, greatest nitrate reductase activities, and highest protein and organic nitrogen contents. Genotype also influenced marketable and nonmarketable yields. Genotypes G2, G3, G6, and G8, which ranked intermediate in the efficient utilization of N, had the highest marketable and lowest nonmarketable yields.