Effect of Herbicides, Seed Dressing Chemicals and Spray Regimes on Germination, Insect Infestation and Yield of Cowpea (Vigna Unguiculata (L) Walp) (Report‪)‬

Introduction Cowpea (Vigna unguiculata (L) Walp) is a leguminous crop, native of the drier regions. Jefferson (2005) and Davis et al (2005) confirmed that cowpea is an ancient crop that originated in central Ghana, Africa, being carbon dated to 1450-1400 BC (Flight, 1976). Cowpea was domesticated about the same time with pearl millet and sorghum some five to six thousand years ago (Davis et al, 1999). It is commonly referred to as southern pea, black eye pea, Crowder pea, lubia, niebe or frijole, marble pea or ponna. Cowpea is a primary source of plant protein; the grain, shelled/dried peas, leaf green pods and fresh shelled green peas are great sources of food and vegetables for human diets, as much as a fodder for farm animals. The percentage nutritional value of cowpea indicated its protein content to be 23%, fats 1.3%, 1.8% fibre, 67% carbohydrate and 8-9% water (Jefferson, 2005). Cowpea also serves as a cover crop important for soil nitrogen fixation. Davis et al (2005) recently reported that the improved dual purpose cowpea intercropped with sorghum or millet can fix between 25-45kg per hectare of nitrogen (N) capable of reducing the N fertilizer requirements for cereals by half. Cowpea is adoptable to hot weather, drought, less fertile soil conditions and widely cultivated across the globe (Fery, 2002). Despite its adoptability to stringent conditions, still insects pose a great threat to achieving its optimum yield. The crop usually suffers serious pest and disease infestation which constitute a major limitation to its production (Singh et al. 2000). Damage from pest such as beetles, leaf hoppers and birds could lead to poor plant stands (Singh et al, 1997). Field pest of cowpea appears to be the major constraints in both field and storage conditions (Singh et al, 1990). According to Raheja (1976) and Singh and Allen (1980), losses of cowpea grains due to pest infestation range from 20 to 100%, annually. Amatobi et al (2005) also opined that field insect pests could even cause colossal loss in yield of cowpea. The use of plant materials, synthetic chemicals and biological controls have been experimented by many researchers to control insects in cowpea production in recent years. Seed treatment with chemicals such as insecticide dusts or slurry are applied as toxic barriers on seeds or growing crops in order to provide protection against infestation by pathogenic organisms (Breniere, 1967). Getting a good crop stand is paramount to getting good yields. Other seed treatments were popular in the past; these include Fernasan-D[R] (25% Thiram, 20% Lindane) and Aldrex-T[R], which are no longer recommendable. Current findings accounted dust formulation such as Apron star[R] (20% w/w Thiamethoxam, 20% w/w Metalaxyl-M and 20% w/w Difenoconazole) or Carbosulfan as quit effective seed dressing chemicals against insect pest infestations. Proper use of seed dressing ensures good initial plant stands, which are characteristic of successful farming (Singh et al 1997). The problem of insect pest infestation on cowpea continues to surface annually, there by affecting the quality and quantity of yields. In light of this problem, the present research intends to asses the effect of Apron star[R] spray regimes on insect infestation, germination and yield of cowpea in the study area.