Insecticidal Activities of Allium sativum and Capsicum annum extracts in field against thrips (Megalurothrips sjostedti) damage on cowpea plant in Kano State-Nigeria

摘要

The insecticidal activities of Capsicum annum fruits and Allium sativum cloves methanolic crude extracts were assessed on field against M. sjostedti damage on cowpea plants. Two genotypes IAR-48 and IT97K-499-35 were planted separately in a randomized block design, for a cowpea genotype four plots each measured 5mx3m with 1.5m space between plots replicated three times given the total of twelve plots were formed. Within the plots are three pairs of ridges (70cm apart) tallied with the three different concentrations (200, 600 and 1000ppm) for the plant extracts treatments application. Plant extract treatments along side with synthetic chemical insecticide (Magic force) as control check were applied to the plots using Knapsack sprayer 33 days after sowing. The results showed that the damage rates of M. sjostedti on susceptible cowpea genotype IAR-48 was significantly (p>0.05) higher as expected when compared with resistant genotype IT97K-499-35. The least significant (P 0.05) M. sjostedti damage rate was recorded on IT97K-499-35 genotype treated with A. sativum at 1000ppm concentration level which is similar to control check (synthetic chemical). Also the genotype IAR-48 had the lower damage rate on plant treated with A. sativum at 1000ppm which differed significantly (p>0.05) with untreated control. Although the least significant (p>0.05) damage rate was recorded in control check (synthetic chemical). For a safe crop production, there is the need to boost the use of plant extracts technically in field as segment of integrated pest management.