hite rot of onion is still one of the most destructive diseases in Egypt causing significant losses in bulb yield. The causal organism produces abundant amount of sclerotia in the soil and therefore, it has been established in many parts of Egypt particularly in upper and Middle Egypt. Different methods of disease management were applied; however, the disease is still the main problem of onion in Egypt. Plant extracts, i.e. neem and datura, as well as salicylic acid and sodium benzoate antioxidants were tested to control the disease under either greenhouse or field conditions. Obtained results were compared to a fungicidal treatment (Folicur) at different concentrations using the onion (cv. Giza 20). A field experiment was carried out for two seasons (2011 and 2012). Application of plant extracts of neem and datura reduced the rot incidence accompanied by high amount of free phenols and reducing sugars which were higher in the treated plants. Moreover, application of antioxidants reduced the rot incidence.

he inhibitory effect of potassium, calcium and sodium silicate was assessed, in in vitro at different concentrations (0.1, 0.5 , 1, 2, 4 and 8ml /l) against Sclerotium cepivorum the causal of onion white rot . The results indicated that potassium and calcium silicate at 0.5 ,1,2,4 and 8ml/l inhibited the mycelial growth and sclerotia formation of S. cepivorum, but at 0.1ml/l concentration, the mycelial growth decreased to (2.4cm and 5.0 cm) respectively compared with control treatment . On the contrary sodium silicate resulted in low effect on the mycelial growth and sclerotial formation. Our results also showed that, potassium and calcium silicate increased the pH of the PDA medium from 8.8 to 11.4 by increasing K 2 SiO 3 and from 8.7 -11.5 by increasing CaSio 3 concentration from 0.1to 8 ml/l. Under greenhouse conditions, the incidence of white rot disease was significantly decreased when onion plants were treated with potassium silicate(2,4 and 8ml/l) only or with VAM fungi, as soil drench in potted soil infested with S. cepivorum compared with the control. Adding 4ml/l potassium silicate as soil drench showed high reduction to the disease incidence by 71.43%. On the other hand, onion plants treated with different concentrations of potassium silicate as soil drench and VAM fungi or Folicur 25%, increased apparently healthy survived plants at harvest under field conditions of Kalubiya Governorate during 2015/2016 and 2016/ 2017 seasons, since they decreased disease infection percentages. The highest reductions of onion white rot were observed when onion plants were treated with Folicur 25% followed by potassium silicate at (2 ml/l +VAM fungi). Regarding the yield of onion bulbs, our results indicated that all treatments showed significant increase to bulb yield in contrast to the non-treated plants. Spores count and percentage of root colonization with VAM fungi were increased by increasing potassium silicate concentration, in contrast to the percentage of hypha which was increased by decreasing potassium silicate concentration. In addition, VAM fungi and VAM+ 2ml/l potassium silicate treatments were considered the T 126 EFFECT OF INTEGRATION BETWEEN VASCULAR ARBUSCULAR ……..

reenhouse experiments were conducted in Ismailia governorate (El-Kassassine county), Egypt, during 2017/2018 growing seasons to determine the effect of both water salinity or water deficit at different treatments consisted of four levels of salinity (10, 15, 20 and 25 mM NaCl/L) and 3 rates of water stress (80, 60 and 40% W.H.C.) on pink root incidence and yield of garlic (Allium sativum L.) cv. (Sids-40), as well as the garlic plant responses. Irrigation with saline water increased pink root incidence in garlic inoculated with Pyrenochaeta terrestris, and yield was decreased. Irrigation of garlic until 20 mM NaCl/L did not affect cloves germination, plant height, leaves dry weight, cell sap concentration and proline concentration, but partial effect was observed at 25 mM NaCl/L of garlic grown in soil uninfested with the tested pathogen. Garlic plants exposed to 80% rate of W.H.C. weren't significantly affected, disease incidence, cloves germination, plant height, leaves dry weight, cell sap concentration and proline concentration and yield produced from infested or uninfested soils showed insignificant variation in comparison with 100 % W.H.C. At 60 and 40 % rates of W.H.C., noticeable increases in pink root incidence were found on plants inoculated with P. terrestris, and their yield was decreased. Cloves germination, plant height and leaves dry weight values were significantly reduced, whereas cell sap concentration and proline concentration values were significantly increased under water deficit of plants grown in uninfested soil comparing to the check. In this respect, 40% of W.H.C. highly affected the disease incidence and crop yield compared to the other tested rates.

ncidence of Fusarium wilt disease of sesame caused by Fusarium oxysporum f.sp. sesami was successfully controlled under greenhouse and field conditions through enhancing systemic resistance by soaking sesame seeds in concentrations of chemical inducers. Most of the tested treatments were effective in controlling disease under greenhouse conditions. Salicylic acid (2 and 4mM), Bion (4mM), CoSO4 (1 and 2ppm) and IBA (100 and 200 ppm) were the most effective treatments for controlling the disease because they maximized the percentage of healthy plants compared with the untreated controls. Under field conditions, most of the treatments were also effective in controlling the disease and increasing seed yield. Salicylic acid (2 and 4mM), Bion (4mM), CoSO4 (1 and 2ppm) and IBA (200 ppm) were the most effective treatments in controlling disease while, salicylic acid (2 mM), Bion (4mM), CoSO4 (2ppm) and IBA (200 ppm) were the most effective treatments in increasing seed yield. Relationship between induced systemic resistance and some biochemical changes like increases in activity of oxidative enzymes (peroxidase and polyphenoloxidase), phenolic compounds, sugars and total free amino acids was observed in root tissues of healthy sesame plants that grown from treated sesame seeds compared with those grown from untreated seeds. Cobalt sulphate at 2ppm, salicylic acid at 2mM and IBA at 200 ppm were the most effective treatments for stimulating these defense mechanisms with few exceptions.

he microelements boron, iron and zinc were tested for their effect on the incidence of onion basal rot caused by Fusarium oxysporum f.sp. cepae (FOC) and Fusarium solani (FS). The tested microelements inhibited mycelial growth and spore germination of the causal pathogens and their counts in the soil and rhizosphere of onion plants. In field experiments, the results of the two seasons indicated that spraying of microelements resulted in significant reduction to the disease during stoage with significant increas to bulbs yield and their diameter. Generally, spraying with the tested microelements at the rate of 50 g/ 100L.water was more effective in reducing onion basal rot than 100 g/100L.water. The percentages of onion basal rot after five months of bulb storage were determined. In storage experiments, results indicated that boron was the least effective in reducing the disease, which resulted in 19.75% disease infection, on the average at the rate of 50 g/100L.water. On the other hand, iron treatment was the most effective one in this respect 10.0%, on the average followed by zinc 11.25%, on the average during 2008/2009 and 2009/2010 growing seasons. The activity of the oxidative enzymes, i.e., peroxides and polyphenol-oxidase and phenolic compounds were higher in treated onion plants by the microelements compared with control.