EFFECT OF INOCULATION BY SOME PLANT GROWTH PROMOTING RHIZOBACTERIA (PGPR) ON PRODUCTION OF 'MANZANILLO' OLIVE TREES

This investigation was carried out during two growing seasons, 2008 and 2009, to investigate the effects of two plant growth promoting rhizobacteria (PGPR) on morphological and productivity characteristics of olives (Olea europaea ‘Manzanillo’), grown in sandy soil under drip irrigation system in a commercial orchard in Egypt. PGPR treatments (Bacillus polymyxa as Biovine and yeast strain Saccharomyces cereivisea) were added in addition to the standard (100%) and a reduced (50%) farm fertilization program. 50 ml of Biovine and yeast were added per tree every fifteen days during the period from 1 February until the end of fruit set (June). Results showed that standard farm fertilization either with Biovine or yeast or Biovine + yeast recorded high shoot length in first season. Adding Biovine to 100% farm fertilization led to increased density of leaves, surface leaf area, and number of flowers per inflorescences. Percentage of sex expression ratio of ‘Manzanillo’ trees were significantly affected by treatments applied and it varied from (43.20 to 71.81) in 2008 season and (52.40 to 77.92) in 2009 season respectively, fruit set, yield per tree, and fruit dry weight in both seasons compared with the unamended control. Addition of Biovine in a reduced (50%) fertilization regime increased fruit length and width, stone length and width, fruit and stone weight, average flesh weight and flesh/stone ratio in both seasons. Biovine + yeast treatment with 100% farm fertilizer increased the oil content in olives, and also macro (N, P) and micro nutrient (Mn, Zn, Fe) levels in the fruit in both seasons.