Effect of rootstock type, fruit growth pattern and cell intensity of peel on pre-harvest fruit splitting in citrus

Pre-harvest fruit splitting each year causing a significant reduction in yield and the prevalence of fungal rot in citrus fruits. In this research, effect of rootstock and also, physical traits of fruits on the severity of pre-harvest fruit splitting were investigated. For this purpose, a research was performed in 2016-17 based on RCBD statistical design with three blocks of three mandarin cultivars (Page, Kara and Cadoux) grafted on four rootstocks (Sour orange, Citrange, Citrumelo and Cleopatra mandarin) under dry farming condition in Tonekabon city (private orchard). Obtained results showed that, both two investigated factors had significant effects on this disorder. According to results, sour orange and citrumelo caused the highest and lowest fruit splitting respectively and two other rootstocks with no significant difference were at an intermediate level in this regard. The significant role of growth pattern, thickness and cell density of peel at the stylar end of fruits on pre-harvest fruit splitting, caused that Page and Cadoux have the highest and lowest percent of fruit splitting respectively. Results also showed that cell density on the peel of the split fruits was lower than healthy ones.