Mycorrhizal Fungi and Rock Phosphate Application to Mitigate Soil Salt Stress and Its Effect on Productivity of ‘Picual’ Olives and ‘Wonderful’ Pomegranates

Abstract

Field experiments were carried out to determine the effect of times and rates of mycorrhizal fungi and bacteria mixture applications for rock phosphate inoculation to mitigate the impacts of soil and water salt stress for enhance the productivity of ‘Picual’ olive trees in a private orchard at Cairo-Ismailia desert road, Ismailia governorate and ‘Wonderful’ pomegranate trees in a private orchard at Cairo-
Alexandria desert road, Alexandria governorate, Egypt. Experiments included applications of rock phosphate (RP) at 1 kg / tree and 25 cm3 of bacteria mixture were applied once at the end of January and inoculated with mycorrhiza fungi (MF) at 100 g/ tree divided at different rates and times as the follow; (T1) application of mycorrhiza fungi at 100 g/ tree on the end January, (T2) application of
mycorrhiza fungi at 50 g/ tree on the end January and 50 g/ tree on mid-March, (T3) application of mycorrhiza fungi at 50 g/ tree on the end January and 25g/ tree on mid-March and 25 g/ tree on mid- May and (T4) control trees (untreated with mycorrhiza fungi). The results showed that the inoculation of rock phosphate with microbial stimulant (mycorrhizal fungi + bacteria mixture) had an obvious effect in enhancing the studied parameters, leaf mineral content, yield and fruit quality of ‘Picual’ olive and ‘Wonderful’ pomegranate trees and water productivities as compared with control. As a result, it can be recommended to inoculate the rock phosphate with bacteria mixture and mycorrhizal fungi at rate of 1 kg of rock phosphate +25 cm3 of bacteria mixture + 50 g of mycorrhizal fungi / tree on the end of January and 25 g of mycorrhizal fungi each in mid-March and mid-May for ‘Picual’ olive trees. However, application of mycorrhiza fungi was 50g of mycorrhizal fungi / tree on the end January and 50 g/tree on mid-March for ‘Wonderful’ pomegranate trees to mitigate the impacts of soil and water salt stress on the trees under the same conditions, thus enhancing productivity.