الفهرس 
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Abstract
Isolation trials carried out from naturally diseased chickpea plants suffering from root rot, stem rot diseases resulted in securing 5 Fusarium isolates identified as Fusarium solani (isolates C1,C2 and C3) and F. oxysporum (isolates C4 and C5), three isolates of Chaetomium sp (isolates C6,C7 and C8) and four isolates of Sclerotinia sclerotiorum (isolates C9,C10,C11 and C12). In pathogenicity test carried out in pots showed that all isolates were pathogenic to chickpea plant (cv. Giza 3). The highest pathogenic isolate was S. sclerotiorum (isolate C11) caused damping-off and stem rot at percentage 63.02% followed by F. solani isolate C2 (52.83%), while the lowest disease severity was obtained in case of Chaetomium sp isolate C7 (13.37%).
In host range study, the obtained data could be summarized as follows, in case of F. solani isolate C2, faba bean, pea, lupine and fenugreek were highly resistant, lintel, common bean and alfalfa were moderate resistant, but Egyptian clover was susceptible. In case of Chaetomium sp isolate C6, pea, fenugreek and barley were resistant, faba bean, lupine and wheat were moderate resistance, but lentil, alfalfa and Egyptian clover and common bean were susceptible or highly susceptible. As for S. Sclerotiorum, while lupine only was highly resistance, pea, wheat and barley were moderate resistant, and the other plant species showed different degrees of susceptibility.
The physiological activities of three pathogenic isolates, one from each of F. solani, Chaetomium sp and S. sclerotiorum were studied. Fusarium isolate grew and sporulated at temperatures from 5-35 oC and the optimum temperature for growth and sporulation was 25oC. However, 25 oC and 20 oC were the optimum temperature in case of Chaetomium sp and S. sclerotiorum but no growth existed at 35 oC or 30 oC for both fungi, respectively. No sclerotial formation of S. sclerotiorum happened at 15 oC, As for Chaetomium sp the fungus did not sporulate at any temperatures tested.
F. solani grew and sporulated at a wide range of pH 3-9. The optimum pH for growth and sporulation was 5. In case of Chaetomium sp , the optimum pH was near 5. but no growth at pH 3 or 9 and no sporulation existed at any pHs. On the other hand, the optimum pH was at 5 for growth of S. sclerotiorum and sclerotial formation but at pH 9 nether growth and nor sclerotial formation took place.
In test of cultivar response, six local cultivars reacted differently towards infection with isolates C2, C6 and C11 belonging to Fusarium solani, Chaetomium sp and/or Sclerotinia sclerotiorum, respectively. Giza 2, Giza 3 and Giza 4 were all susceptible towards all tested isolates, while Giza 1 was the highest resistant to all isolates.
Sowing date of 1 st December was more suitable to minimize disease severity by the three pathogens tested.
Effect of fungicides on isolate growth each of F. solani, Chaetomium sp and S. sclerotiorum in vitro was studied. Homi-80 was highly effective against all tested isolates as it caused complete inhibition to F. solani at 100 ppm, but 25 ppm was sufficient to cause complete to both Chaetomium sp and S. sclerotiorum. Vitavax / Captan caused complete inhibition to F. solani and Chaetomium sp at 25 ppm but less effective on S. sclerotiorum. Also, Rhizolex-T at 100 caused complete inhibition to Chaetomium sp. Mancober, Moncerien and Benzamidazole were less effective to all the tested isolates. Homi, Vitavax/ Captan and Rhizolex-T the most effective fungicides in plate treatment were subsequently tested for their efficacy as seeds protectants against three the pathogens in bags trails containing sterile soil infested with each of which. The three chemicals showed various degrees of plant protection, Homi-80 proved the most effective fungicide towards infection with all isolates. It proved the highest effective fungicide towards F. solani as it decreased the infection from 85.75% in control to 8.89% in treated seeds. On the contrary Rhizolex- T was the lowest fungicide towards all isolates.
Potassium or calcium salts were used against the three fungi at different concentrations in vitro an in vivo. Chickpea plants emerged from seeds previously soaked in solution of K2HPO4 at 4000 ppm caused the highest protection against F. solani and Chaetomium sp (11.93% and 10.0% infection, respectively) compared to the chemically untreated plants. However, CaSO4 at 4000 ppm proved the best inducer for resistance against S. Sclerotiorum.
Effect of the six chemical compounds was studied on chickpea yield/plant under field condition. The results obtained showed that all these tested compounds increased the average yield/plant of the tested chickpea cultivar Giza 3. Ca(H2PO4)2 proved the most effective compound as it achieved an average of 14.288 gm/plant whereas in case of untreated plants the average was 9.285 gm/plant.
The obtained data indicated that, all tested salts inhibited dry weight of F. solani and Chaetomum sp but were less effective on the linear growth. K2HPO4 proved the most inhibitory salts on growth of F. solani at 4000 ppm while CaSO4 at 4000 ppm was the most effective inhibitor on growth of Chaetomium sp. On the other hand, CaCl2, KCl, K2HPO4 reduced dry weight of S. sclerotiorum, whereas other salts did not affect the dry weight of S. sclerotiorum, whereas other salts did not affect the dry weight of S. sclerotiorum.
The activity of peroxidase, polyphenol oxidase and phenylalanine ammonia lyase enzymes and total phenol content increased as a result of treatment with either K2HPO4 or CaSO4 in healthy or inoculated plants. K2HPO4 treated plants resulted in enzyme activity more than those treated with CaSO4 except total phenol content. However CaSO4 proved superior than K2HPO4. Also, activity of pectinase and cellulase in culture filtrates the three tested fungi decreased as result of adding K2HPO4 or CaSO4 in the cultivated medium.