212: Effects of Soil Applied Biopesticides on Postharvest Quality of Camino Real Strawberries Grown in Southeast Texas

Introduction

Developing effective and safe methods of producing organic strawberries is necessary for meeting local consumer demand. However, local climatic conditions pose a high risk of insect problems and fungal diseases, and hence effective pest and disease management strategies are needed. Our objective was to study the effects of selected commercially available soil-applied biopesticides on quality characteristics of Camino Real strawberries grown in southeast Texas.

Methods

Strawberries were grown under plastic mulch covered-beds with drip irrigation using bare roots at the Prairie View A&M University Research Farm, Prairie View, Texas. Ten biopesticide treatments were applied in the soil system and a completely randomized design was used for the field experiment with three replications. The berries used for this study were subsampled from harvest made in mid-April 2019. Biometrical characteristics, and physicochemical analyses (pH, acidity, total soluble solids, sugars and organic acid contents, firmness, and instrumental color) of samples were determined. Experimental data were analyzed using the PROC Mixed model procedure of SAS. The effects of biopesticide treatments on physicochemical characteristics of strawberries were carried out by one-way ANOVA and Least Significant Difference post hoc test was used (p < 0.05).

Results

The fruit length, major diameter, sucrose content, internal lightness, and internal chroma were not affected (P > 0.05) by the biopesticide treatments in the strawberries compared to the control. The ranges of total soluble solids (TSS) and titratable acidity (TA, % citric acid) in the strawberries were 6.32-8.08°Brix and 0.65-0.77%, respectively. For an acceptable strawberry flavor, a maximum of 0.8% TA and/or a minimum of 7% TSS is recommended. The TSS/TA ratio values ranged from 9.61-11.47 in the fresh fruits. The ratio of TSS to TA is crucial for assessing fruit quality. In this study, we observed an adequate relationship between the sugar content and acidity of strawberries.

Significance

The biopesticides showed no negative effects on the fruit quality, hence they could serve as alternatives to conventional products.

Authors: Maryuri Nuñez de González, Peter Ampim, Rahmat Attaie, Eric Obeng, Adela Mora-Gutierrez, Selamawit Woldesenbet, Russell Wallace, and Yoonsung Jung