Evaluation of Varying Rates of Mancozeb fungicide and Some Plant Leaf Powders as Seed Treatment and their cost-benefit for the Management of Early Leaf Spot (Cercospora arachidicola Hori) Disease of Groundnut in Makurdi, Nigeria

Abstract

Field experiment were carried out during the first and second cropping seasons (2013//2014) at the Teaching and Research Farm of the Federal University of Agriculture Makurdi, Benue State of Nigeria, the effect of seed treatments with varying rates of Mancozeb fungicide, Pawpaw and Moringa leaf powders on early leaf spot incidence and ground nut yield was studied; and the cost benefit ratios calculated. The seed treatments were: Mancozeb, Moringa leaf powder and Pawpaw leaf powder while the seed treatments rates were 0.0 (control), 2.0, 2.5 and 3.0gm. Groundnut variety Benue AGR seeds were treated with the seed treatment rates replicated 3 times and arranged in a randomized complete block design (RCBD). Results of the first season and second seasons showed that seed treatment with Mancozeb significantly gave the highest plant establishment followed by moringa leaf powder and pawpaw leaf powder respectively. In the first year, 3.0g seed treatment significantly gave the highest plant establishment while the untreated control recorded the lowest plant establishment, but was not significantly difference (P ≤ 0.05) amongst the treatment rates in the second year. In the two cropping seasons, plants grown from seed treated with mancozeb recorded the lowest incidence of early leaf spot disease followed by moringa leaf powder at 40, 47 and 54 DAS respectively. Seed treatment rate of 3.0gm gave the lowest disease incidence from 40 to 54 DAS. At 90 DAS of the first season, seed treatment with Mancozeb significantly lowered the leaf defoliation followed by Moringa leaf powder compared to Pawpaw leaf powder. Similarly, during the second season, seed treatment with Mancozeb also reduced the leaf defoliation compared to the plant powders at 70, 80 and 90 DAS respectively. Mancozeb and Moringa leaf powder gave higher grain yield compared to Pawpaw leaf powder in the first season. Increase in seed treatment rate resulted to higher percentage increment in grain and haulm ............