Determine The Protectively and Curative Efficacy of Aloe Vera Gel and Conocarpus Extracts to Control Nattrassi mangifera Causal Agent of Apple Branches Wilt Disease.

Abstract

Apple trees are grown in different regions, northern and central Iraq. There are several diseases attached tree branches such as branches wilting caused by Nattrassi mangifera. The aim of this study is to test the effectiveness of the Aloe vera gel and Conocarpus leaves extracts in radial growth of mycelium and reduction the disease development by preventive and curative methods by measuring the invasion area and area under disease progress curve (AUDPC). The results showed both extract have inhibitory ability against the radial mycelium growth on PSA 75.41 and 85.75% in Conocarpus leaves extract in consternation 1000 and 2000 ppm respectively, while the inhibition of Aloe vera gel of 1000 and 2000 ppm was 69.58 and 85.41% respectively. The result of the infection on tree branches showed local blotch symptoms area ranging from 19.63 to 50.24 mm². Results showed clear contrast in the invasion area by the pathogen after 28 days of post inoculation , the reduction on the invasion area keep continued to decline in Aloe vera gel and Conocarpus leaves extract in 1000 and 2000 ppm reaching 21.26, 15.63, 17.27 and 15.31 mm² respectively, and significantly differences comparison with control mm² 41.76, which was not significantly different from the treatment of the Beltanol pesticide 16.77 mm², while the Aloe vera gel treatment with concentrate 1000 (21.26 mm²) preventive showed significant reduction. The Results of the AUDPC for Aloe vera gel extract in 1000 and 2000 ppm treatments was 41.61, 30.64, 41.02, 29.33 mm² respectively compared with control treatment 70.24 mm². While excelled treatment of Aloe vera gel and Conocarpus leaves extract concentration 2000 ppm and pesticide treatment 33.91 mm² in preventive method. In curative methods treatments showed high differences in the reduction of invasion area by the pathogen after 28 days, which showed significant reduction for the Aloe vera gel and Conocarpus leaves extract treatments 1000 and 2000 ppm reaching 13.48, 6.86, 6.58, 4.90 mm² comparison with control 36.73 mm² and Beltanol pesticide 12.65 mm². The results reflected of the invasion fungus pathogen N. mangifera area on the AUDPC for treatments Aloe vera gel and Conocarpus leaves extract 1000 and 2000 ppm, was 27.48, 17.09, 16.14, 13.32 mm² respectively, which differed with significant differences in reducing the AUDPC on the control comparison 74.56 mm² and pesticide treatment 38.69 mm².