الفهرس | Only 14 pages are availabe for public view |
Abstract This study was proposed to reduce the production costs of perennial sweet pepper plants that grown in the greenhouses for two consecutive years through maintaining a balance between vegetative and fruit growth, to obtain the highest productivity and quality of fruit yield, Marvel F1 variety. Two field experiments were carried out at the Experimental Station Farm of the Faculty of Agriculture, Alexandria University, Abies, Alexandria, Egypt, during the seasons of 2018/2019 and 2019/2020. The experiments were conducted in four greenhouses; the area of each greenhouse was 240 m2 (3 rows x 2 m width x 40 m long), under a drip irrigation system. Each experiment included 48 treatments, which were the combinations of four CMS rates (0.0, 1.0, 2.0 & 3.0 l m-3 ) under three potassium silicate concentrations (0.0, 0.5 and 1.0 gl -1) under four combined treatments of NK ; 25, 50, 100, 125% of the recommended dose from each fertilizer. Nitrogen doses were 47.5, 71.25, 95.0 and 118.75 kg N fed-1 added through irrigation water (fertigation) while K doses were 0.5, 0.75, 1.0 and 1.25 g K2O l -1, which was added by spraying on the leaves of sweet pepper plants. The design used was the split-split-plot system in a Randomized Complete Blocks Design, with three replications. The NK fertilizers were random, arranged in the main plots (four greenhouses), while three potassium silicate concentrations were, randomly, distributed within each greenhouse (the sub-plots) and each sub-plot was contained two rows having an area of 80 m2 . In addition, concentrations of condensed molasses soluble, in sub-sub-plots, were randomly distributed under each concentration of potassium silicate. Each sub-sub-plot contained two rows having an area of 20 m2, and the number of plants in the sub-sub-plot 50 plants. The transplants of sweet pepper (Marvel F1) were transplanted, on September 20th, in the first season of 2018/2019 only, in two lines on each row. The row spacing was 40 cm between the plants and 50 cm between the two lines. At the end of the first season 2018/2019, in August 2019, peppers plants were pruned at 30 cm above the ground, to encourage initial vegetative growth in the second season of 2019/2020, which was beginning on September 20th, 2019, and then all the previous treatments that were executed during the first season are applied. The obtained results could be summarized as follows: 1. Fresh and dry mass characters The results showed that increased levels of NK fertilizers from 50% to 125% of the recommended dose lead to significant and gradual increases in the fresh, dry biomass of roots, stems, leaves, fruits and whole plant of sweet pepper plants, in the both seasons. The results revealed that the spraying of sweet pepper plants with potassium silicate at a concentration of 0.5 g l-1 achieved the highest significant average of the fresh and dry biomass to all organs of sweet pepper plants, in the two growing seasons. The results indicated that raising the rate of addition of condensed molasses soluble up to 3.0 l m-3 lead to successive and significant increases in the fresh and dry biomass of roots, stems, leaves, fruits and whole plant of sweet pepper plants, in the two seasons. |