Comparison of Soil Nutrition, Tree Performance, and Insect and Disease Occurrence between Organic and Conventional Asian Pear Orchards

Abstract

A conventional and an organic orchard each with 12-year-old ‘Niitaka’ pear ( Pyrus pyriforiaNakai) trees were compared in terms of soil nutrition, tree performance, and insect and disease occurrence in the warm, humid environment of South Korea from 2008 to 2010. The organic orchard management system had higher weed species diversity compared to that of the conventional system. The conventional orchard had higher soil pH, organic matter, [T-N], [P ₂O ₅], [K ₂O], [MgO], and CEC than the organic orchard on average over the three years but this did not result in higher foliar [T-N], [P], and [Ca]. Overall fruit shape index, soluble solids concentration, and color were similar under both management systems, but individual fruit size and fruit yield were both higher and fruit firmness was lower in the conventional orchard. Fruit from the organic trees were more damaged by diseases and insects. Estimated fruit production income was not significantly different between the two management systems in the first two years, but income was 69% higher for the conventional system in year 3 than for the organic system as a consequence of yield loss from severe pest problems due to an extended period of precipitation in that summer production season.