Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: D. D. Gull x
Clear All Modify Search

Tomatoes (Lycopersicon esculentum Mill.) were grown on a sand and loamy sand to evaluate the effects of K source, K rate, and Ca rate on plant nutrient uptake, fruit yield, and fruit quality. The K was applied at 200 and 400 kg K·ha-1 from KCl and K2SO4. Gypsum was applied at 0, 450 and 900 kg Ca·ha-1. On the sand, tomato N leaf tissue concentrations were higher with K2SO4 than KCl. Leaf K concentrations were higher and Ca contents were lower with the higher than lower K rate. At first fruit harvest, leaf Ca concentrations were linearly increased with an increase in Ca rate. Early and total fruit yields, however, were not influenced by K source, K rate, or Ca rate at both locations Marketable fruit were more firm with K2SO4 than KCl and with 200 than 400 kg K·ha-1 on the sand. Fruit were less firm on the sandy loam than sandy soil but was not affected by K source or rate on the former soil. Ca rate had no effect on fruit firmness on either soil. Fruit citric acid contents were higher with KCl than K2SO4 and with 400 than 200 kg K·ha-1, Fruit color and percentage dry weight were not affected by treatment.

Free access


Ten fresh-market tomato (Lycopersicon esculentum Mill.) genotypes were evaluated for stability of fruit firmness, citric acid, soluble solids, β-carotene and ascorbic acid concentrations, sugar : acid ratio, color, N content, and dry weight when grown in nine environments. Linear relationships between the genotype means for a given trait and the mean for the trait in each environment were used as an indicator of stability. A stable genotype for a given trait was considered to possess a regression coefficient (b1) ⩽ a coefficient of linear determination (r2) > 0.50, a genotype mean above the grand mean (mean of all genotypes), and a nonsignificant deviation from regression mean square (S2d). Using these criteria, stability in the nine environments was shown by the fruits of the various cultivars as follows: ‘Flora-Dade’, ‘FTE-12’, and D76I27 for firmness; ‘Castlehy 1035’ and ‘Sunny’ for citric acid; ‘Walter’ for soluble solids concentration; ‘FTE-12’ for ascorbic acid concentration; ‘Hayslip’, ‘Walter’, and ‘Burgis’ for sugar : acid ratio; ‘FTE-12’ and ‘Hayslip’ for β-carotene concentration: ‘Flora-Dade’ and 827115-IBK for color a/b; ‘Castlehy 1035’ and ‘Hayslip’ for dry weight; and ‘Walter’ for N content. Stable genotypes are less sensitive to environmental changes and are more adapted to favorable and unfavorable conditions than unstable genotypes. No genotype was found to be stable for every fruit quality trait in the nine environments. Stability of fruit quality characteristics should be considered in tomato breeding programs to develop genotypes adapted to diverse environmental and management conditions.

Open Access