The effect of adjusting fruit loading by pruning on the yield and quality of sweet pepper in low light conditions

Abstract

Pruning and light quality and quantity can affect the fruit load, fruit shape, nutritional value, and quality of sweet pepper. The experiment was arranged as a split-plot conducted in a randomized block design. Treatments consisted of keeping 3, 5, and 7 fruits on the bush, and having un-pruned (P3, P5, and P7 Pnon=without pruning) sweet pepper (Capsicum annuum L., cv. Lumos) with 3 replications. Two greenhouses including 14,000 for the full-light one and 6000-Lux for the low one were designed. The results showed that carotenoid biosynthesis and accumulation were highly related to light, with a significant effect in the full light greenhouse, as compared with the low one. Leaves carbohydrate content was raised in P3 and P5 for both greenhouses and this was more significant in the full light greenhouse, as compared with the low one. TSS was higher in full light with pruning (P3, P5, P7); the highest TSS in the low-light greenhouse was seen in P3. Phenol, antioxidant, vitamin C, and organic acid were higher in the full light greenhouse, as compared with the low one. Conclusively, pruning was more effective on weight after increased growth of bush in the second or third harvest. Longer shape and less flushing are favored by pepper producers. This can be achieved in the full light greenhouse with P3 and then P5 pruning.