Bio-Control Of Cercospora Leaf Spot Disease Of Groundnut (Arachis Hypogeae) Using Extracts Of Moringa Oleifera Lam. And Jatropha Curcas L.

ABSTRACT

The study was conducted in the School of Agriculture and Agricultural Technology (SAAT) research farm. The Experiment was laid out in a RCBD form. Extracts from roots and seeds of Moringa oleifera and Jatropha curcas were tested at 10% concentration and sprayed after 2,3 and 4 weeks in three different growing periods of groundnut; 2, 3 and 4 weeks. Some plant extrated were mixed with 3ml of an emulsifier made from castor oil known as RIMULGAN and then separately added to each of the 150ml of the four different plant extracts. Neem oil at 0.6ml, hexaconazole material (6% EC) at 0.3ml and mancozeb (80% WP) at 0.4g/plot were equally used. The test materials significantly reduced the disease severity at 2, 4 and 6 Weeks spray in two, three and four weeks After Sowing (WAS) plots when compared with untreated plots. When the plots were treated after 2 weeks, all the plots showed no severity of the disease (0.00), except plots sprayed with Hexaconazole 6% E.C (0.333), Neem oil (0.667) and RIMULGAN alone which recorded highest severity of the disease (1.00). In three weeks after sowing plots, all the treated groundnuts showed no severity of the disease (0.00), except Hexaconazole 6% E.C and Mancozeb 80% WP (0.333) and untreated plot (0.667), while plot treated with RIMULGAN alone recorded the highest severity of the disease (1.00). In four weeks after sowing plots, the untreated plot recorded highest severity of the disease (1.333), while the groundnuts in other treated plots recorded the same severity of the disease (1.00). At 4WAS, plot treated with RIMULGAN + M. oleifera seed extract, RIMULGAN + M. oleifera root extract, RIMULGAN + J. curcas seed extract, RIMULGAN + J. curcas root extract and Neem oil recorded lowest incidence of the disease (0.00%) after two weeks spray, followed by Mancozeb 80% WP (0.333%), while untreated plot recorded the highest (1.667%). In three weeks after sowing, the test materials showed no significant differences on severity of Cercospora disease of groundnut after 4 and 6 weeks spray when compared with untreated plot. In four weeks after sowing,  untreated plots (control) recorded highest severity of the disease (2.333) followed by RIMULGAN (2.00). While plots treated with Neem oil and Mancozeb 80% WP recorded lowest (0.333). After 6 weeks spray, plot treated with RIMULGAN + J. curcas root extract recorded lowest incidence of the disease (0.00%) in two weeks after sowing, followed by RIMULGAN + J. curcas seed extract and Neem oil (0.333%), and while plot treated with RIMULGAN and untreated plot recorded highest (2.00%). In four weeks spray, plots treated with RIMULGAN and control recorded the highest severity of the disease (2.333), followed by M. oleifera seed extract (2.00) while groundnut in plots sprayed with Neem oil and Mancozeb 80% WP recorded the least (0.333). Treatment materials showed significant differences on Cercospora disease incidence at 2, 4 and 6WAS. It also showed significant differences on overall seed yield and on incidence and severity of non Cercospora diseases (late leaf spot, rust, Alternaria leaf disease and anthracnose diseases) at 2 and 6 weeks after spray, in two, three and four weeks after sowing when compared with the untreated plot. The summary of this study shows that the plant extracts were able to control both the Cercospora and other folia diseases of groundnut. However, the RIMULGAN + seed extracts (Jatropha and Moringa) were more effective and comparable with Neem oil and synthetic fungicides (Hexaconazole 6% E.C and Mancozob 80% WP) than the root extracts and spray test plant after 2 WAS gave a better result than 3 and 4 WAS.