Pre- and post-harvest strategies in the production of high quality tomato fruit
Applied agricultural research(5): 282-287
Salinity as a means of restricting growth and improving quality by modifying tomato fruit composition has been investigated. For tomatoes grown in peat-loam, the effects of a daily application of sodium chloride, or diluted seawater as an alternative, were assessed. The possible protective action of polyethylene glycol (PEG) against widely varying salinity levels was examined. The main effect of salt treatment was to increase the acidity and the uptake of sodium and potassium by the fruit; PEG did not alleviate the uptake of these ions. Cv. Ed Kawy apparently do not resist salt uptake better than unadapted lines. In a further trial, cherry tomatoes were grown in nutrient-film culture at two salinity levels. At the higher level, an improvement in composition and a reduction in fruit size was found. The ability of the crop to resist grading simulation was tested; a widely varying increase in CO2 and increased ethylene was detected with high salinity fruit compared with normal fruit. Overwrapping ripening tomatoes with plastic film, or the incorporation of nonripening mutant material into selected genotypes are additional possibilities for maintaining quality. By combining moderate, stable salinity levels with appropriate post-harvest treatment, the marketing of flavorful, long-life tomatoes from plants having an acceptable yield could become a reality.