The study of bud break percentage and aberrant fruit shape incidence in some Hayward kiwifruit vineyard in Guilan Province

Kiwifruit is one of the main exportable agricultural products, during which large quantity of kiwifruit was annually exported from Iran. Low percentage of winter bud break and malformed fruits incidence is the main factors for low productivity in Hayward Kiwifruits. Because the exportable fruits quantity was positively correlated with bud break percentage, flower number and normal fruits percentage. Therefore, the main objective of current study is to evaluate bud break and malformed incidence percentage in some kiwifruit vineyards in Talesh and Rudsar in West and East of Guilan province respectively.

This experiment was conducted as a completely randomized design in nine kiwifruit vineyards in both east (Rudsar) and west (Talesh) of Guilan province. Three uniform Hayward kiwifruit vines with four canes were selected in each vineyard. Climate conditions in two regions were also studied. Bud break percentage, flower number per winter bud, aberrant fruit percentage (flat and fan fruit percentage) and bud index for aberrant fruits was investigated.

The results of orthogonal test showed that there is a significant difference between two regions for bud break percentage, flower number per bud and malformed fruits percentage (flat and double fruit percentage) and bud index for flat and fan fruits. Bud break percentage varied (45.5-58.76%) in Talesh vineyard and (30.7-45.39%) in Roodsar. Furthermore, aberrant fruits percentage was (2.04-5.85%) in Talesh and (2.1-5%) in Roodsar. There were significantly different in terms of the number of flowers per kiwi winter bud in different vineyards. This value varied between (1.81-2.59) and in Rudsar (1.78-1.18). There was a significant difference between different vineyards in terms of cane diameter, average number of buds in cane, percentage of flowering buds, number of flowers in winter buds, percentage of flat and fan fruits. The incidence place of flat and fan fruits on the canes was the same independently to vineyards, but double fruit formation place was dependently to vineyard. The most flat and fan shape fruits was found on node 2 and 3 of current season shoot, however, double and triple fruits incidence was found in node 1 and 2.

Overall, the results showed that bud break percentage and aberrant fruits incidence was varied to environmental condition and orchard practices. These conditions caused disorders incidence in Hayward kiwifruit by affecting on vine physiology