No abstract

Attempts are being made to minimize the use of synthetic chemicals such as fungicides. There is an interest toward the use of environmentally-friendly products to minimize impact of toxic residuals on human, animals, and environment. Two-season field experiments were conducted in 2018 and 2019to investigate the effectiveness of foliar sprayings of three products [potassium silicate (PS), perbicarbonate (PB), and peroxyacetic acid (PAA)] as singular or sequential treatments (totaling 10 treatment combinations) on growth (plant height, number of leaves, number of branches, leaf area), yield, yield attributes (number of pods plant-1 , pod length, pod weight), chlorophyll a, b, and carotene contents, and resistance of okra plants (cv. Baladi) to powdery mildew disease. All treatments were significantly reduced powdery mildew infection with highest resistance observed with PAA+PS or PAA+PB, or PB+PAA treatments. Growth characteristics were enhanced by most treatments with the highest increases detected with singular PS or PAA treatments and with sequential PB+PS treatment. PS was superior in increasing the number of leaves, branching number, and leaf areas. The only treatments that significantly increased total yield were PAA+PB, PAA, PS, PS+PAA, and PAA+PS with the former two treatments giving the highest total yield. In conclusion, foliar spraying of okra with singular or sequential treatments with PS, PAA, and PB significantly improved plant resistance to powdery mildew infection. Nevertheless, singular PS or PAA treatments as well as sequential PB+PS, PAA+PS, PS+PAA, and PAA+PB treatments were the most effective in improving growth and yield while controlling powdery mildew disease.

This study was conducted to evaluate the potential effect of foliar spray with different doses of two bio-stimulants Chitosan (CS) and Royal Jelly (RJ) on growth and yield and quality of two garlic cultivars (Egaseed1 and Balady i.e(Egyptian) at two winter seasons of 2017/2018 and 2018/2019.Generally, the foliar spray of all tested biostimulates treatments considerably improves almost all plant growth traits of garlic cultivars which reflected on plants yield and quality. Data showed that spraying Ega1 plants with different doses of CS and RJ considerably increased total yield (TY) in both seasons as compared with control (13.39 and 14.64 tons). The highest values of TY were found in Ega1 plants treated with 0.1g/l RJ (15.29 and 15.80 tons) and 0.3g/l RJ (15.08 and 16.61 tons) at both seasons respectively. On the other side, there was clear increase in TY of Egy plants treated with different CS and RJ doses at both seasons as compared with control (7.57 and 8.69 tons, respectively). The highest values of TY were found in Egy. plants treated with 0.2g/L RJ (9.23 and 8.53 tons) at both seasons respectively as compared with all other treatments. As compared to control, foliar spray with CS and RJ reduced weight loss % and deterioration of bulbs during storage. In general, foliar application of chitosan (1000 and 1500 ppm) and Royal Jelly (0.2 and 0.3 g.L -1 ) could be recommended to improve productivity, quality and storability of the two garlic cultivars grown under Minia Governorate conditions.

Producing new transformants phosphate bio-stimulate (PBS) bacterial inoculates in addition to study their potential effect on growth, yield and quality of kohlrabi plants at two successive seasons 2017/2018 and 2018/2019 were studied in this present work. The obtained results revealed that using the three tested phosphate bio-stimulate inoculates (PBS1, PBS2 and PBS3) alone or combined with different doses of phosphate mineral fertilizer PMF (calcium superphosphate) increase considerably growth, yield and quality of kohlrabi plants as compared to control. Among all tested PBS inoculates treatments, plants treated with PBS2 was superior and gave the best results in all studied traits when used alone or in combination with PMF doses at both seasons. Applying PBS (1,2 and 3) inoculates alone or combined with PMF doses improved the quality of kohlrabi knobs by increasing the values of total soluble solid TSS%, carbohydrates% and Lascorbic acid% content in the same time, it decreased significantly the fiber% and nitrate content in knob as compared to the control in both seasons. So it could be recommended that to reduce the actual hazard of mineral fertilizer on soil and human health and to produce safe and healthy vegetable for local market and exportation it should be used PBS inoculates alone or combined with low PMF doses.

Potassium plays a pivotal role in improving potato quality and yield. Field experiment was conducted during fall seasons of 2018/2019 and 2019/2020 at the experimental facilities of Minia University, Egypt, in order to study effects of different organic and inorganic sources of potassium (Potassium Sulfate -Potassium Humate -Potassium Nitrate -Potassium Silicate) on growth and yield performance of potato cultivars of (Lady Balfour and Cara). After 75 days from planting, maximum plant height and number of branches was obtained with cultivar Lady Balfour fertilized with potassium humate. Use of potassium humate with Lady Balfour gave superlative results in terms of length of branches, number of stems and weight of branches, while the leaf area was increased in the Lady Balfour with potassium silicate treatment. The greatest amount of tubers/plant in both seasons were achieved by Cara fertilized with potassium silicate, while the weight of tubers/plant was recorded by Lady Balfour with potassium humate treatment in the second season. The greatest tuber yields for both seasons were achieved by Cara with potassium silicate and Lady Balfour with potassium humate. Tuber's texture, TSS and contents of chlorophyll a, b and carotene were higher with Cara cultivar fertilized potassium humate and potassium silicate. The results of experiment showed that the highest contents of nitrogen, phosphorous and potassium in potatoes leaves obtained by humic acid with both cultivars. Positive impacts of potassium humate followed by potassium silicate over other examined potassium sources on potato growth and quality were confirmed.