Analysis and Hierarchization of Factors Explaining Strawberry Cultivation Yield Gap in Southern Uruguay

Abstract

Average yield of commercial strawberry crops in southern Uruguay is below the attainable yield for production conditions, according to experimental results and the best yields of commercial crops, which determines the existence of a yield gap (YG). Furthermore, there is a wide variability between farmers. The aim of this study was to identify, hierarchize and analyze the environmental and management factors explaining yield gap in strawberry fields in southern Uruguay. We evaluated 76 strawberry crops in two production harvests in a sample of 13 farms representative of the area. We developed a method combining principles from Regional Agronomic Diagnosis and Yield Gap Analysis. We measured variables related to crop growth, development, management, yield, and environment. The statistical analysis combined path analysis, boundary lines, clusters, and regression trees. The average commercial yield was 16.9 ± 12.1 and 24.9 ± 8.1 Mg.ha^-1 and the average YG was 65 and 46 % for the 2012 and 2013 harvests, respectively. Crop vegetative growth and development at early spring, measured as soil cover (SC), was the main variable explaining crop yield, affected by the date of planting, the date in which the final crop density was reached, and plant density. The commercial yields of groups with low, intermediate and high SC at early spring were of 8.7 ± 6.1, 20.0 ± 8.1 and 28.9 ± 8.5 Mg.ha^-1, respectively. The relative YG for groups with intermediate and high SC was mainly explained by soil pH, crop water balance and fertilization management. Yield gaps were explained by management variables that can be improved without increasing production costs.