Agricultural Biodiversity for Crop Disease and Pest Management

Abstract

Agricultural producers regardless of their location need to determine what strategies best fit with their local needs. In order to manage their local ecosystems in a sustainable way, three main aspects have to be considered: genetic diversity, species diversity, and ecological diversity. This chapter aims to demonstrate that biodiversity has the potential to be an effective means of disease and pest management. This chapter systematically elaborates on the key technologies and successful examples of the application of these principles of the three levels of biodiversity to disease and pest control. Rational rotation of resistant rice varieties implies to utilize diversity of resistance genes in time, that is, novel resistant variety carrying different resistance genes replaces the varieties that were susceptible to the pathogen in the field. Many studies to date have assessed the efficacy of such rotation on controlling the rice blast disease. The results of in-depth research on controlling rice blast disease by using rice genetic diversity is reported. By analyzing the genetic diversity structures of a large number of rice varieties, the optimum combination of different rice varieties was screened. These optimum combinations were deployed in the field, and to analyze the effects of combination of different varieties and different cultivating patterns on rice blast disease in an in-depth fashion. The main principles of techniques controlling rice genetic diversity are reported in this chapter. Crop species diversity can significantly increase the number of insect species that are natural enemies in a given area. The chapter further deals with intercropping patterns with different crop species to control pests and diseases, protective effects of landscape mosaic patterns on rice germplasm resources in different rice-fish systems, and chemical and resistant relationships between crops, microbes, insects and natural enemies.