EVALUATION OF NEEM SEED EXTRACT AND VARIETY ON THE CONTROL OF CERCOSPORA LEAF SPOT OF COWPEA (Vignaunguiculata L.) IN SOKOTO, SUDAN SAVANNAH

Abstract

ABSTRACT This research work was conducted at Usmanu Danfodiyo University Teaching and Research Dry land Farm Sokoto during 2018 rainy season, with the aims of evaluating the effect of Neem seed extract and variety on the control of Cercospora leaf spot of cowpea. Randomized Complete Block Design (RCBD) was used in the experiment. Three cowpea varieties (IT288, Dan Zafi and Sampea 15),with four control measures (Neem seed extract at 500 and 750g/10 litres of water, a fungicide check and a control), were combine to give 12 treatment combinations and were replicated 3 times. Parameters assessed include; establishment count, disease incidence and severity, pod yield, seed yield, 100 seed weight and haulm yield. Disease incidence and severity were found to be significantly higher in the control compared with Neem seed extract treatments.Sampea 15 had the highest disease incidence and severity both at 9WAS and at harvest. Lowest disease incidence and severity was observed both at 9WAS and at harvest on IT288 and Dan Zafi. However, the variety and doses interaction yield significant result. Also there was significant difference between the two Neem seed extract doses. Highest pod and seed yield were recorded on IT288 treated with 500g NSE, IT288 treated with 750g NSE, Dan Zafi treated with 500g NSE,IT288 treated with Mancozeb and finally Dan Zafi treated with Mancozeband are due to the treatments applied in controlling the disease. Lowest pod and seed yield are recorded on IT288-control, Sampea 15-control, and Dan Zafi controlbecause no control measures was taken to prevent its establishment, while that of haulm are recorded on Dan Zafi treated with Mancozeb, Dan Zafi treated with 500g NSE. Lowest haulm yield was recorded onSampea 15- control. This research finding shows that Neem seed extract is effective in the control of Cercospora leaf spot of cowpea and can compete with fungicide (Mancozeb) in the disease management.