No abstract

A filed experiment was carried out during the two successive seasons of 2016/2017 and 2017/2018 at the Experimental Farm of El-Kassasein, Hort. Res. Station, Ismailia Governorate, Egypt, to investigate the effect of foliar spray with amino acids, citric acid, some calcium compounds and mono-potassium phosphate (MKP) on vegetative growth, early and total yield, yield components, storability and gray mould disease reduction of strawberry Festival cultivar under sandy soil conditions. The obtained results showed that, spraying strawberry plants with CaCl 2 at 20 ml/l, amino acids at 10 ml/l, citric acid at 2 g/l, calcium amino acids chelate at 20 ml/l and calcium citric acid chelates at 20 ml/l and mono-potassium phosphate (MKP) at 20 ml/l increased yield, yield components and decreased incidence and severity of gray mould disease compared to control. Spraying with amino acids or calcium amino acids chelate increased plant height, number of leaves/ plant, shoot dry weight/ plant, average yield/plant, total yield/fad., and decreased weight loss (%) and decay (%) during cold storage periods. Spraying with MKP recorded minimum incidence (12.6 and 18.3 %) and severity (13.9 and 13.2%) of gray mould disease in fruits at the 1 st and 2 nd seasons, respectively, followed by spraying with calcium amino acids chelate. In addition, incidence and severity of gray mould disease decreased with increasing TSS and vitamin C in strawberry fruits.

hizoctonia solani is a major problem causing damping-off of seedlings and root rot in mature plants and thus reducing nutrient uptake and plant stand. The aim of this study is to evaluate the effect of some bioagents in combination with the lowest doses of macronutrients on management of R. solani in cucumber plants. Four cucumber hybrids, i.e. hybrid 6, hybrid 9, hybrid 14 and Beit-Alpha F1 were tested for their susceptibility to the pathogenic fungi. Data indicated that Beit-Alpha, was highly susceptible to infection by all the pathogenic fungi and R. solani isolate No.1 was highly aggressive. The double recommended dose of each of potassium and phosphorous was the most effective treatment. Half dose of phosphorous gave the lowest reduction of damping-off. T. harzianum, T. viride, a mixture of them, Bacillus subtilis and Pseudomonas fluorescens, as well as arbuscular mycorrhizal fungi (AM), were used. The maximum reduction in disease incidence was recorded due to using P. fluorescens followed by AM fungi. They significantly reduced damping-off and enhanced the vegetative growth of cucumber plants and the levels of oxidative enzymes compared to control.

he efficiency of foliar spray with potassium sulphate, potassium silicate, calcium chloride and calcium citrate gel formula was evaluated in controlling early blight disease (caused by Alternaria solani), improving growth and yield quality of potato (cv. Lady Rosetta). A field experiment was performed during two successive seasons, 2018/2019 and 2019/2020. Foliar applications of potassium and calcium compounds were compared to Copperal Max (8 % copper as a positive control) and water as a control treatment. All treatments were sprayed twice on the plants at 45 and 60 days post-planting. The results proved that all foliar spraying treatments significantly decreased the disease incidence and severity of early blight, improved vegetative growth parameters and nutrients content (N, P and K) of potato plants as well as increased yield and tuber quality of potato compared with untreated plants. In this respect, the lowest disease severity was achieved by Copperal Max (9 and 11.05%) followed by potassium silicate (9.95 and 12.77%) and calcium chloride (9.66 and 12.92%), finally, untreated control recorded the highest disease severity (22.07 and 26.71 %) respectively at both tested seasons. On the other hand, potassium silicate and calcium chloride in gel formula was superior to other treatments in increasing the total and marketable yield of potato tubers, also reducing the weight loss and decay of tubers stored on a shelf. These results suggest that one of the main alternatives to controlling potato early blight is using potassium silicate or calcium chloride.