Comparative Efficacy and Economic Viability of Trichoderma Strains as Bio-Control Agents for the Control of Phytophthora Pod Rot of Cocoa in Nigeria

Abstract

The comparative efficacy and economic viability of Trichoderma species as bio-control agents against Phytophthora megakarya which has been hitherto elusive was determined by field application/evaluation, bean yield and accruable revenue evaluation. The trials followed randomized complete block design (RCBD) with 3 field constituting blocks, 24 treatments with 3 trees per treatment per replicate. The treatments were three fungicides, five bio-agents, fifteen combinations of fungicides and bio- agents while the control consists of unsprayed trees. Data were collected on total pod produced (TP), total number of disease pods (DP) and total number of fermentable pods per tree per treatment (FP) while revenue accrued (RA) and revenue-cost-ratio were also determined accordingly. All the bio-agents significantly reduced the percentage pod-rot on the field. The highest mean pod-rot incidence (16.91) among the treated was significantly lower than the control (30.14). This was observed on BA (NIG-T287) sprayed plots. Funguran 0H + NIG-T289 produced the highest (757) number of pods while the least pod production (312) was observed with Copper Sulphate + NIGT289 (F3BC) treated plots. The highest revenue-cost-ratio (69.45) was obtained from Copper Sulphate treated plots, while the least revenue-costratio (2.85) was obtained from Ridomil Gold + NIG-T288 treated plots. NIGT293 performed better than other bio-agents and most of other treatments when applied sole resulting to 45.90 comparative efficacy and economic viability. These bio-agents were successfully combined with fungicides thereby reducing the frequency of fungicide application from four to one with significant pod-rot reduction on the field, comparatively high yield and more profit (high revenue-cost-ratio).

Keywords: Bio-control agents, comparative efficacy, economic viability,
revenue-cost-ratio.