Soil-fertility management and host preference by European corn borer, Ostrinia nubilalis (Hübner), on Zea mays L.: A comparison of organic and conventional chemical farming

• Published in: Agriculture, ecosystems & environment ecosystems & environment, 1995-11, Vol.56 (1), p.1-8
• Main Authors: Phelan, P.L., Mason, J.F., Stinner, B.R.
• Format: Article
• Language: English
• Subjects: AGRICULTURA ORGANICA; AGRICULTURE BIOLOGIQUE; Biological and medical sciences; CHEMICALS; Control; CONTROL DE INSECTOS; Crop resistance; Cultural control; Fundamental and applied biological sciences. Psychology; Host selection; HOSTS; HOTE; HUESPEDES; INSECT CONTROL; Lepidoptera; LUTTE ANTIINSECTE; MANEJO DEL SUELO; MISE EN VALEUR DU SOL; ORGANIC FARMING; OSTRINIA NUBILALIS; Ovipositional preference; PEST RESISTANCE; Phytopathology. Animal pests. Plant and forest protection; PRODUCTOS QUIMICOS; PRODUIT CHIMIQUE; Protozoa. Invertebrates; RESISTANCE AUX ORGANISMES NUISIBLES; RESISTENCIA A LAS PLAGAS; SELECCION; SELECTION; SOIL MANAGEMENT; ZEA MAYS
• ISSN: 0167-8809; 1873-2305
• DOI: 10.1016/0167-8809(95)00640-0

It has long been argued by proponents of organic agriculture that crop losses to insects and diseases are reduced by this farming method, and that reduced susceptibility to pests is a reflection of differences in plant health, as mediated by soil-fertility management. These reports although widespread are mostly anecdotal and largely without experimental foundation. In this study, the effects of two parameters of soil fertility on the host-preference behavior of an insect pest were measured: (1) the immediate effect of organic vs. inorganic fertilizers and (2) the long-term effect of soil-management history. Soils were collected from three pairs of neighbouring farms, each pair matched for soil type and comprising organic and conventional chemical production systems. Each soil was potted and amended with mineral fertilizers, animal manures, or left amended. After planting the amended soils with maize ( Zea mays L.) in a greenhouse, European corn borer females (ECB), Ostrinia nubilalis (Hübner), were released to determine egg-laying preferences. For each of the three farm comparisons, there was a significantly higher level of ECB oviposition on plants in conventional soil. In two comparisons, there was also a significant amendment effect; however, the specific fertilizers leading to greater egg laying were not consistent among farm comparisons. Thus, the form of the fertilizer did not have consistent effects on maize susceptibility to ECB, but soil-management history did. Moreover, there was significant variation in egg laying among fertilizer treatments within the conventionally managed soil, but for plants in the organic soils, egg laying was uniformly low. Pooling results across all three comparisons, variance in egg laying was about 18 times higher among plants in conventional soil than among plants in organic soil. It is suggested that this difference is evidence for a form of biological buffering characteristic of organically managed soils. Also significant, ECB ovipositional preference did not correlate with plant biomass. Thus, these results suggest that soil-management practices can significantly affect the susceptibility of crops to pests, and do so without adversely affecting plant productivity.