The effect of three resistance inducers, i.e. chitosan, citrien and potassien were studied under both greenhouse (2009/2010) and field condition in 2010/2011 and 2011/2012 growing seasons to control powdery mildew disease caused by Sphearotheca fuliginea in chamomile (Matricaria chamomilla). Results showed that all used inducers had decreased disease severity compared to non-treated control. In this respect, chitosan showed the highest effect on decreasing disease severity followed by citrien. Meanwhile, potassien gave the lowest effect. The decrease in disease severity of powdery mildew was positively expressed by an increase in crop parameters, i.e numbers, inflorescences weights, fresh, dry weights of plants and the principal components of chamomile essential oil.

hizoctonia solani (Kuhn), Macrophomina phaseolina (Tassi) Ashby, Sclerotium rolfsii (Sacc.) and Fusarium spp. were found to be the most associated fungi with damping-off and charcoal-rot of sunflower plants in Behera Governorate. Rhizoctonia solani was the most pathogenic fungus, causing pre-emergence damping-off on sunflower (cv. Vedok). Meanwhile, M. phaseolina caused less disease incidence 15 days after sowing. In contrast, S. rolfsii was the most pathogenic fungus, causing post-emergence damping-off, 15 to 45 days after sowing. However, M. phaseolina was most effective to cause charcoal-rot , 45 to 90 days after sowing. Soil amendments with sulphur, compost and gypsum, either alone or in combination, recorded the highest reduction of pre-, post-emergence damping-off and charcoal-rot when compared with check (control) treatment in field experiments. Also, results indicated that the soil amendments improved growth characteristics and increased yield as well as oil contents of sunflower.

Biological and physiological assays have been used to evaluate garlic cultivars for their resistance to the pink root disease. Biological methods using artificial media amended with Pyrenochaeta terrestris and/or its toxins or using soil infested with the pathogen P. terrestris were tested to evaluate the resistance of seedlings of various garlic cultivars against the pink root disease. Results showed that the assay using the fungus-free Pyrenochaeta toxins was more reliable than using the fungus itself, in which determination of the disease resistance of garlic seedlings was possible in 7 days without the problems of contaminations. Physiological assays indicated that histones and RNA contents in garlic plants play a role in their resistance to the pink root disease.

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Organic solvent extracts of lemon grass leaves were more effective than those of rhubarb roots in inhibiting mycelial growth of F. solani and R. solani , two fungi pathogenic to pothos plants causing root and basal stem rots. Superiority was realized as for ethanolic extracts than those extracted using hexane and ethyl acetate as organic solvents. Dipping root system of pothos cuttings in 20 % concentration of ethanolic extracts of lemon grass or rhubarb for 15 min. just before planting in soil infested with either of F. solani and R. solani recorded the lowest percentages of diseases incidence by (5 % & 10 %) and (15 % &20 %) , respectively , relative to those of their controls (40 % & 60 %). Values of physical characteristics of lemone grass essential oil such as specific gravity (0.89 %) , optical rotation (-1.6) , refractive index (1.4875) and acid number (8.3) were estimated. Also , chemical main compounds quantitatively determined by chromatography which confirmed that volatile matter of lemon grass oil represents 100 % of its composition. However , citral and myrecene constituted 77.0 % and 6.5 % of the total composition of that oil. Lemon grass essential oil at concens. of 10 % and 20 % could completely inhibit mycelial growth of the aforementioned two fungi , respectively .Besides , citral (2.5 concen.) realized the same effect , whereas, myrecene only minimized mycelial growth of these fungi by 40% and 28.6 % .