EFFECT OF NET SHADING TECHNOLOGY AND HARVEST TIMES ON YIELD AND FRUIT QUALITY OF SWEET PEPPER

Shading effects on yield and fruit quality (sunscald, total carotenoid content and ratio of red and yellow pigments) were examined in 'Karpex' red colored sweet pepper hybrid (Capsicum annuum L.). The sampling was performed at two different harvest times; 27th of August and 1st of October in 2013. The photo-selective shading nets were CN red from Israel, and yellow, red, green, and white from Hungary, all with 40% shade factor. We found a significantly higher yield under the yellow and red net compared with the unshaded control. The yield was more than 50% higher under the yellow net (33.6 t ha(-1)), than in the control plot (15.5 t ha(-1); F-5,F-12=10.761, p<0.001). All shading nets had a significantly positive effect against sunburn at the first harvest (F-5,F-12=12.403, p<0.001), except for the white shading net. In addition, no sunscald fruit were observed under CN red net and green net, compared to 4 t ha- 1 losses due to sunburn in the control plot. No sunscald pepper fruit were detected at the second harvest. The total carotenoid content ranged between 163.4 and 338.9 mu g g(-1) fw. Regarding the net shading, we could determine significant difference in total carotenoid content, between white net and the control treatment (F-5,F-12=4.372, p=0.017) at the second harvest. The unshaded control contained more than 50% less carotenoid than that under the white net. Peppers under the yellow and red nets contained the lowest amount of carotenoids. Overall, significantly more carotenoids were detected at the second harvest, than at the first harvest (F-1,F-24=220.035, p<0.001). In contrast, the ratio of red and yellow pigments was higher at the first harvest. Hence, the earlier harvest is recommended in order to produce pepper fruits with attractive red color. In conclusion, the use of net shading technology resulted in increased yield, reduced sunscald, and can be tailored to improve fruit color.