Effects of Shading in Summer on Yield and Quality of Tomatoes Grown on a Single-truss System

Abstract

This study was conducted to examine the yield and quality of tomato fruits grown on a single-truss system shaded during the summer. Tomato seeds were sown on the 10th of every month from February to September and the seedlings were grown in NFT. The plants were covered with cheesecloth at the shading level of 0 (control), 30 (light shading), 55 (medium shading), and 83% (heavy shading) from 10 days after the first anthesis. The nutrient solution was cooled to 25°C from July to September. As the shading level increased, total fruit yield decreased with loss of fruit weight. The total fruit yield of each crop was individually correlated linearly with the mean value of daily integrated solar radiation during fruit development. Regression analysis indicated that the decrease of total fruit yield, corresponding to the loss of 1 MJ·m −2 of the daily integrated solar radiation, would increase from 84 to 100 g/plant if the average air temperature increased from 19 to 27°C. Marketable fruit yield in the control plot was highest in the Feb. crop and significantly lower from Apr. crop to Jul. crops, because of the high incidence of cracked fruits. The incidence of cracked fruits was decreased by shading. It was estimated that shading which decreased daily integrated solar radiation to 5-6 MJ·m −2 effectively increased marketable fruit yields when the air temperature exceeded 25°C. Summer harvested fruits had high titratable acidity. Shading was apt to decrease the brix and increase the titratable acidity of fruits.

Effect of Temperature on Photosynthesis Characteristics in the Passion Fruits ‘Summer Queen’ and ‘Ruby Star’

“…However, since the optimal temperature for photosynthesis was 30°C or less in both cultivars, cultivation at 30°C or less is preferable to achieve good tree growth and stable production of high-quality fruit. Some temperaturelowering technologies such as shading (Wada et al, 2006), root-zone cooling (Kinoshita et al, 2012), fogging (Harel et al, 2013), or a water curtain (Iwasaki et al, 2011) of greenhouse, plants, as well as soil under high-temperature conditions have been established. These technologies should be used for the cultivation of passion fruit in the Japanese summer to prevent hightemperature injury which leads to poor flowering and an inadequate peel color.…”

Simulation Model for Predicting Fruit Yield of Tomatoes Grown on a Single-truss System under Shade in Summer

“…Incidence of unmarketable fruits, e.g. blossom-end rot, cracked, cat-faced, or the fruit weight under 50 g, was affected by the month of seeding or shading (Wada et al, 2006). Data of total fruits yield including unmarketable fruit were used for making simulation model in this study.…”

“…The plants planted at both end of each row were not included in replication. Root-zone temperature was cooled to 25°C from July to September following methods described by Wada et al (2006). The lowest air temperature in greenhouse was maintained at 15°C by heating during February to mid-April and the following November.…”

“…In previous paper we reported the effects of shading in summer on yield and quality of tomatoes (Wada et al, 2006). In this study we made a regression analysis of the fruit yield of single-truss tomatoes grown under shade during summer, and tried to make a simulation model for predicting the yield based on integrated solar radiation and averaged air temperature.…”

Irrigation Fuzzy Controller Reduce Tomato Cracking

“…Tomato becomes unmarketable for fresh consumption with losses ranging from 10% to 95% of the total fruit. Summer crack unmarketable tomatoes are caused by high air temperature within the greenhouse [3], so shading becomes an alternative, although tomato yield decreases. Retractable roof shade houses are structures covered with polypropylene, polyethylene, or composite fabrics save up to 30% in energy [4].…”