Growth, yield and fruit quality of ‘Marisol’ clementine grown on four rootstocks in Egypt

Abstract

To evaluate the most appropriate rootstocks for mandarin production in Egypt, vegetative growth, yield and fruit quality of ‘Marisol’ clementine (as newly introduced cultivar in Egypt) grafted on Sour orange (the common rootstock), Cleopatra mandarin, Carrizo citrange and ‘Swingle’ citrumelo were evaluated under the Egyptian conditions during 2004/2005 and 2005/2006 seasons. Trees were grown in a private farm at ‘Wady El-Mullak’ region, Ismailia Governorate (Latitude, 30°36′ N; longitude, 32°14′ E; Altitude, 10 m above sea level). ‘Marisol’ clementine trees budded on Sour orange showed higher vegetative growth parameters (canopy circumference and diameter, tree volume, scion trunk girth) than trees on Carrizo citrange, ‘Swingle’ citrumelo and Cleopatra mandarin rootstocks, except the tree height which was shorter than those on Carrizo citrange and ‘Swingle’ citrumelo (in the first season) or similar (in the second season), while the trees budded on Cleopatra mandarin were the shortest. The highest affinity was found with the Sour orange, followed by Cleopatra mandarin and Carrizo citrange, while the lowest affinity was found with ‘Swingle’ citrumelo. Trees on Sour orange produced the higher yield than those on Cleopatra mandarin, ‘Swingle’ citrumelo and Carrizo citrange rootstocks. The trees on Sour orange had the highest average yield of two seasons (26.36%, 19.51% and 17.6% over those on Cleopatra mandarin, Carrizo citrange and ‘Swingle’ citrumelo, respectively); however, those budded on Cleopatra mandarin had the lowest one. Trees on all rootstocks exhibited relatively little alternate bearing index, and the trees on Carrizo citrange significantly showed lower alternate bearing index. Fruit weight, volume, dimensions and shape, peel thickness and percentage, rag percentage and juice content were not significantly affected by rootstock. However, fruit gravity, colour, firmness and juice TSS, acidity, TSS/acid ratio and ascorbic acid contents were significantly affected by rootstock. Sour orange produced fruits with high gravity, firmness and acidity and low fruit colour, TSS and TSS/acid ratio, indicating that Sour orange retarded fruit maturity and, therefore, it is not recommended as a rootstock for this cultivar (whereas its fruit maturation is extra early), despite of its high fruit production. While, Carrizo citrange produced fruits with low gravity, firmness and acidity and best colour, high TSS and TSS/acid ratio, followed by Cleopatra mandarin and ‘Swingle’ citrumelo rootstocks. Carrizo citrange, Cleopatra mandarin and ‘Swingle’ citrumelo can be considered as suitable rootstocks for ‘Marisol’ clementine under the Egyptian conditions.