Impact of Rhodopseudomonas palustris on Fruit Yield and Quality of ‘Keitt’ Mango

Using microorganisms can develop into a promising strategy for increasing photosynthetic activity and greater accumulation of assimilates in crops. This study aimed to evaluate the effects of Rhodopseudomonas palustris on fruit yield and quality of ‘Keitt’ mangoes grown under semi-arid environmental conditions. The experiment was carried out simultaneously in two mango orchards in Petrolina, Pernambuco, Brazil. The study comprised a randomized block design with treatments distributed in 7 treatments, 4 replications, and 3 plants per plot. The treatments consisted of different strategies for applying R. palustris. These treatments were T1) control treatment; T2) 1.43 × 107 CFU/plant via fertigation; T3) 2.85 × 107 CFU/plant via fertigation; T4) 4.27 × 107 CFU/plant via fertigation; T5) 5.70 × 107 CFU/plant via fertigation; T6) 1.43 × 107 CFU/plant via fertigation + 1.43 × 107 CFU/plant via leaf spray; T7) 2.85 × 107 CFU/plant via fertigation + 1.43 × 107 CFU/plant via leaf spray. The treatments were a pplied monthly, totaling seven applications. We evaluated fruit yield (Mg ha-1), longitudinal diameter, ventral diameter and transverse diameter, fruit mass, pulp firmness, pulp percentage, soluble solids (SS), pH, titratable acidity (TA), SS/TA ratio, and dry pulp mass. R. palustris improved mango yield and fruit quality characteristics regarding longitudinal and transversal diameters and the SS/TA ratio. Mango plants treated with R. palustris at 1.43 × 107 CFU/plant via fertigation (T2) produced 10 Mg ha-1 more than the control group, without loss of fruit quality while considering the European market demand.