المستخلص:
This study was carried out in the laboratories of Plant Protection Department / Agriculture College / University of Basrah, while the field experiment has been done at the fields of wheat in, Qurna, North of Basrah during the season of 2013 - 2014. in orderd to know the causal agent of the wheat death and stunting phenomena. The results of isolation, identification and pathogenicity test revealed that Rhizoctonia solani was the causal pathogen agent of wheat bare patch disease. The evaluation of efficiency of Trichoderma harzianum and Moncut fungicide and their interaction were done. The study showed that bare patch disease spread in all fields in Qurna and some fields in Mudainah. The highest percentage of disease incidence was recorded in Jurf - Alsakher which was 7.9%, while the lowest percentage was recorded in Nahr Salih fields which was 2.1% . Pathogenicity test showed that the isolate Rs1 which was isolated from Qurna - Mzeraa was more virulent than Rs2 isolate which was isolated from Jurf - Alsakher. Results also explained that 25ºC and pH 5 were the best temperature and pH values for the growth of the fungus. On the other hand it was found that both isolates RS1 and RS2 were able to grow at high salinity ranges from 6 - 16 ds.m - 1.The results also showed that the bioagent T. harzianum has a high antagonistic ability against isolates of R.solani (Rs1 and Rs2) with antagonism degree reached (1) according to Bell scale . It's also found that both isolates give positive detection for cellulase , protease and polyphenol oxidase enzymes, while they gave negative detection for lipase . It is also noticed that culture filtrate of Rs1 and Rs2 treated or non - treated with heat effected on seed germination and reduced the percentage to 0% compared to 100% in control treatment.BThe laboratorial experiments revealed that Moncut fungicide was the most effective among all tested fungicides , the growth inhibition reached 50.55 and 42.22% for Rs1 and Rs2 isolates respectively, and 7.33% for T. harzianum . On the other hand the concentrations of 150 and 200 ppm of Moncut fungicide were most effective among all concentrations to inhibit growth of RS1 and RS2 isolates on PDA, which reached 62.2, 66.3, 75.7 and 80.9% for both isolates and concentrations respectively.Pot experiment elucidated that the treatment of T. harzianum + Moncut + RS1 or RS2 increased wheat seeds germination up to 74.7 and 60.35% respectively compared to 41 and 29.6% for R1 and R2 alone respectively. It is also found that T+M+R1 and T+M+R2 reduced seed decay to 26.3 and 31.6 respectively compared to 59 and 71.33% for treatments R1 and R2 respectively, also they increased the number of offshoots, plant height, fresh and dry weight for shoot and root systems.Field experiment results revealed that the treatment T+M+R1 and T+M+R2 led to increase seed germination percentage and reduced seed decay percentage to 89.67, 10.33, 82.0 and 12.0% respectively compared to 50, 45.33, 50 and 54.67 for treatments R1 and R2 alone. It's also observed that T+M+R1 and T+M+R2 increased off shoot number , plant height , fresh and dry weight for both shoots and root system which reached 7.2, 6.6, 59.66, 55.89, 25.16, 22.56, 2.76, 2.42, 6.49, 6.37, 0.59, 0.66 respectively in comparison with the treatments of R1 and R2 alone which were 4.4, 4.1,41, 38.33, 10.86, 9.51, 1.28, 1.02, 2.67, 2.55, 0.29,0.23 respectively. Also, these treatments gave best number of spikes which was 476.4 and 461.3 spike/m2 respectively. From other hand the number of seeds also increased it reached 39.67 and 34.7 seed/spike respectively, These treatments also led to increase the weight of 1000 seeds up to 41 and 39.27 gm respectively compared to the pathogen treatments R1 and R2 alon
اسم المشرف:
يحيى عاشور صالح
اسم المؤلف:
ابتهال رياض مكطوف المعارج
