EFFICACY OF SOME ORGANIC COMPOUNDS AGAINST ROOT ROT WILT DISEASES OF OLIVE TRANSPLANTS AND THEIR GROWTH RESPONSE IN NEW VALLEY GOVERNORATE, EGYPT

Abstract

Root rot and wilt disease complex were detected during disease survey carried out through two successive seasons (2011 & 2012) in several olive transplants nurseries and new orchards at ElKharga, Baris, Balat, El-Dakhla and El-Farafrah districts of New Valley governorate. Percentage of disease incidence and severity on olive transplants in surveyed districts varied. The highest means either in disease incidence or severity (60.8 and 48.7%, respectively) were recorded at El-Dakhla district followed by ElKharga (52.1 and 43.6%). Fusarium oxysporum was the most frequently isolated fungus at the five locations tested, followed by F. solani and Rhizoctonia solani, while Macrophomina phaseolina was the least one. Efficiency of seven organic compounds and one fungicide, as soil drench treatment, varied in reducing disease incidence and severity under greenhouse conditions. All organic compounds tested reduced the diseases severity than the control. Humic acid, Inicium, Fulvital and Bio-Health compounds gave the highest protection compared to untreated transplants (control). Humic acid, however, was significantly superior than the other, whil EMI was the least. All treatments significantly increased plant height, number of leaf plant -1, leaf area and fresh & dry weights