Susceptibility of some mango varieties to the bud mite Eriophyes mangiferae (Sayed) and malformation disease and the relation of mite infestation to malformation disease.
Mahgoob A. E. A.
Author Affiliation: Department of Plant Protection, Faculty of Agriculture, Ain Shams University, Shoubra El-Kheima, Cairo, Egypt.
Arab Universities Journal of Agricultural Sciences 14 : 491-507
Abstract : A field study was conducted during 2002-03 with 11 mango cultivars at Sharkia, Ismailia and Fayuom Governorates (Egypt) to estimate the population fluctuation of the bud mite E. mangiferae [Aceria mangiferae], their susceptibility to mite infestation, the relation between mite infestation and chemical contents of mango buds, and the correlation between the bud mite and malformation disease (caused by Gibberella fujikuroi). The highest mite population occurred during September-January or February, and the lowest during March-June. Temperature and relative humidity had no significant effect on mite population. The highest level of mite infestation was recorded at Sharkia, followed by Fayuom and Ismailia Governorates. The mango cultivars differed in their susceptibility to E. mangiferae infestation. Zebda, Taimour, Ewais and Arnaba were the most susceptible, while Mabrouka, Company, Excellent Succari and White Succari were the least susceptible. Mesk, Geolck and Alphonse showed moderate susceptibility to mite infestation. Buds of some highly mite-susceptible cultivars had lower values of total carbohydrates and total soluble sugars than some moderate or susceptible cultivars. Phenol contents were higher in most of the susceptible cultivars, and lower in most of the moderate and low susceptible cultivars. The total soluble proteins and amino acids were higher in some susceptible cultivars. The susceptible characteristic was positively correlated with the total soluble proteins and amino acids, while negatively correlated with the total carbohydrates and total soluble sugars. The phenol content showed no clear trend. The mango cultivars had varying degrees of floral malformation, Company, Alphonse and Geolck were the most susceptible, while Zebda was the most resistant. Statistical analysis showed a negative correlation between the eriophid bud mite and the incidence of malformation disease. Zebda harboured the highest number of mites but exhibited the lowest percentage of malformation, whereas the opposite trend was observed with Company.