The Effects of Four Clonal Rootstocks on Growth Indices, Yield, Fruit Quality, and Quantity of `Golden Smoothee' Apple in Iran's Climate Conditions

Abstract

In this research the effect of four clonal rootstocks (B9, M9, M26, and MM106) on growth characteristics, flowering and fruiting, and fruit quality and quantity of `Golden Smoothee' apple (Malus × domestica Borkh.) were studied during 2001 and 2003. Trees were 8 years old at the beginning of study. Experiments were planned in randomized complete-block design with four treatments (four rootstocks) and four replications. Rootstocks had significant effects on all growth characteristics. The highest tree height, shoot growth, and tree cross-sectional area were found on MM106; with B9 was the least and M9 and M26 were intermediate. The effect of year, and interaction of year on rootstocks were nonsignificant. Rootstock has highly affected flowering and fruiting characteristics. The highest flowering efficiency related to M9 and B9. The highest primary and secondary fruit set and fruit set efficiency found with M9 and M26. The highest preharvest fruit abscission observed with M26. The M9 had the least preharvest fruit abscission. Yield of M9 was the highest and B9 was the least. The M9 has the most yield efficiency and MM106 had the least. Effect of year was significant in many characteristics related to flowering and fruiting. Generally, trees had better conditions in first year. Among fruit quantitative treatments, rootstock only affected fruit weight significantly. Fruit harvested from B9 had the least weight and other rootstocks had similar fruit weight. Generally rootstock had no noticeable effect on fruit quantity and quality.