Abstract

Nemafric-BL phytonematicide, produced from fermented fruit of wild watermelon (Cucumis africanus), had been consistent in suppressing root-knot (Meloidogyne species) nematode population densities. However, due to the biological nature of Nemafric-BL phytonematicide, quality could be compromised during increasing storage period. A study was, therefore, conducted to determine the response of cucurbitacin B concentration in Nemafric-BL phytonematicide over a six-month storage period. The product, in 50 ml hermetically-sealed plastic containers, was stored in a dark room at room temperature (±25°C), with 10 samples being analysed monthly for cucurbitacin B concentrations using Shimadzu High Performance Liquid Chromatography (HPLC). Cucurbitacin concentrations over increasing storage period exhibited density-dependent growth patterns, which were characterised by increases in cucurbitacin B during the initial period of storage and followed by gradual decreases. Relative to the initial storage time (T₀), at the end of the storage period, cucurbitacin B concentration was still more than three-hundred times that at T₀, suggesting that the product was still suitable for use in managing nematode numbers.

Key words: Cucumis africanus, effective microorganisms, product quality, phytonematicide, shelf-life.