INFLUENCE OF COMPOST, EFFECTIVE MICROORGANISMS (EM) AND POTASSIUM ON STRAWBERRY PRODUCTION IN SANDY SOILS

A field experiment was carried out during the 2008-2009 season at Salah Alden farm, which belongs to the modern agriculture company Pico and is located at 30°37’60”N, 30°42’03”E in south Altahrir district, Elbehira governorate, Egypt. A split plot design with three replicates was used to study the influence of two application rates of compost (with or without EM) and potassium on fruit yield and quality of strawberry (Fragaria × ananasa) ‘Festival’ grown in sandy soil. Main plot treatments included: control; compost A (8.3 kg m^-2); compost B (12.5 kg m^-2); EM (5 cm³ m^-2); compost A + EM; compost B + EM. Subplot treatments included: control (K₀); 265 kg K₂O fed^-1 (K₁); 200 kg K₂O fed^-1 + foliar spray from K-biopota (42% K₂O) at a rate of 2.5 cm³ L^-1 (K₂). The results indicated that application of compost A + EM resulted in the highest strawberry yield and quality (1023 g plant^-1), although fresh and dry weight as well as nitrogen, phosphorus and potassium uptake were significantly increased in plots that received compost B + EM. The potassium treatment (K₂) significantly increased marketable and total fruit yield (1048 g plant^-1) as well as total soluble solids (10.65%) and firmness (96 g. force), while the potassium treatment (K1) significantly increased potassium concentration in leaves and fruits. The interaction between compost and potassium treatments didn’t give any significant increase in fruit yield of strawberry. Also, this study indicated that the application of EM increased the efficiency of both organic and mineral nutrient sources but alone was ineffective in increasing yield.