Vol. 71 No: 1

Title:
Effects of Different Day and Night Salinity Levels on Vegetative Growth, Yield and Quality of Tomato

Author:
W. VAN IEPEREN

pp: 99-112

Abstract:
Tomato plants were grown in nutrient film technique at constant, and different, day and night salinity levels to investigate whether salinity could be used to control vegetative growth, fruit yield and quality (size, dry matter percentage, and incidence of blossom-end rot (BER)). Greenhouse experiments were conducted with the following salinity treatments: 5/5, 9/9, 1/9 and 9/1 (day/night salinity levels in dS m^-1). The salinity treatments influenced fruit yield clearly: Yield was increased greatly at 1/9. It was decreased at 9/1, although not as much as at 9/9. Yield differences were mainly due to differences in average fruit size, except at 9/9, where after 12 weeks of harvesting, the number of harvested fruits was decreased too. Considering the number of unripe fruits on the plants, in the near future a lower number of harvested fruits was expected at 9/1, and a slightly higher number at 1/9 as compared with 5/5. These differences in the numbers of harvested fruits were partially due to differences in plant development, and partially to differences in fruit setting and fruit abortion between the EC-treatments. Before the fruit harvesting phase was reached, vegetative growth of young tomato plants was decreased at 9/9, and to a lower extent also at 9/1 as compared with 5/5. It was not altered by the 1/9 treatment. Similar results were found for leaf area. Plant development and dry-matter distribution in the young plants were not influenced. After 12 weeks of fruit harvesting, comparable responses of the salinity treatments were observed on vegetative growth and leaf area. The number of trusses was decreased at 9/9 and 9/1, and within the vegetative plant parts dry-matter distribution towards the roots increased to the disadvantage of the leaves. Dry-matter distribution towards the fruits was increased at 1/9 and decreased at 9/9 as compared with 5/5. Fruit quality was influenced considerably by the salinity treatments: Dry-matter percentage of the harvested fruits was higher at 9/9 and slightly lower at 1/9 as compared with 5/5, whereas at 9/1 it was intermediate between 5/5 and 9/9. Differences in yield were not only due to differences in fruit water content: dry weight per fruit was also changed. These changes were comparable with changes in fresh weight yield, but less pronounced. The incidence of BER was influenced greatly by the salinity treatments: it was almost absent at 1/9, while it was increased at 9/1 and 9/9 as compared with 5/5.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 835766 bytes)

Translate:

Go back to previous page