Impact of Commercial Beauveria bassiana Application on Cucumber (Cucumis Sativus L.) Insect Pests, Pollinator Densities and Some Growth and Fruit Parameters

Abstract

A field trial was conducted in 2021 and 2022 at the Experimental Farm, Federal University of Agriculture, Abeokuta to establish the bio-efficacy of Beauveria bassiana on the abundance of pests, beneficial insects, agronomic characteristics, storability and fruit quality of cucumber. The experiment was designed using a 4 x 3 factorial arrangement in a Randomized Complete Block Design and replicated three times. The treatment comprised four Beauveria bassiana (FIXITGA ™) concentrations (8.00, 6.00, 4.00 and 2.00 kg/ha) applied at three different spray frequencies (spray once a-week, once in two-weeks and once in three-weeks) along with the untreated control. The results indicated that the densities of Aulacophora hilaris, Epilachna chrysomelina, and Bactrocera cucurbitae were significantly reduced in B. bassiana-sprayed plots compared to unsprayed ones in both seasons. Higher densities (6.33 and 5.33) of Apis mellifera were observed in plots sprayed at 8.00 kg/ha once a week than the unsprayed plots (2.00 and 0.33). The agronomic traits significantly increased when B. bassiana was sprayed once a- week at a concentration of 8.00 kg/ha compared to other treatments. At 8.00, 6.00, and 4.00 kg/ha of B. bassiana applied once a week, cucumber fruits showed an extended shelf life, lasting between 13 to 15 days before deterioration. In contrast, cucumber fruits sprayed at 2.00 kg/ha and untreated plots deteriorated faster, within 1 to 3 days. Furthermore, the nutritional composition of fruits from the untreated plots was comparable to that of fruits from the treated plots.