Seasonal occurrence and response of maize ibred lines to pink stem borer in the Northwest of Spain

Open Access

Abstract

6 Pags., 5 Tabls. ; The most important pest of maize (Zen mays L.) in North America and Europe is the European corn borer (Ostrinia nubilalis Hbn). However, in southern Europe another corn borer species, the pink stem borer (Sesamia nonagrioides Lef.), also causes significant damage to maize. The damage caused by the pink stem borer in the northwest of Spain was not important a few years ago, but today this damage has increased considerably. Few studies about this pest have been made thus far. The first objective of this work was to study the population quantify and seasonal appearance of Sesamia nonagrioides in this area. Two trials were carried out in two years under natural field conditions with different sowing dates, thus covering the damage at different stages where the plant-insect relationship could change. The results showed that the attacks varied in intensity depending on the year and sowing date. Early sowing could be a good method for cultural control of Sesamia nonagrioides because the material is too mature and escaped borer attack. Although cultural control could be effective in preventing or reducing the damage, genetic resistance is another alternative that could be used alone or joined with other control components for integrated pest management. The first step in this insect-resistance breeding program is to identify sources of resistance. Consequently, the second objective was to study the resistance/tolerance of twenty maize inbred lines under artificial infestation conditions with Sesamia nonagrioides. The inbred lines were evaluated for resistance and other agronomic traits. Significant differences were found for all traits. The inbred lines were divided according to maturity groups: early and late. Early maturing inbreds had the greatest damage. The early inbreds EP37, W153R and CM105 and the late inbreds Va26 and W64A showed the best resistance to the pest. Thus, they could be promising sources of resistance or tolerance to pink stem borer. These lines may be suitable far use directly in the formation of resistant hybrids and new resistant inbred lines. Further, they and others could be used for the development of resistant synthetics, which could become the base material to obtain resistant varieties to Sesamia nonagrioides. ; This work was supported by the Committee for Science and Technology of Spain (project AGR89-0537) and the Autonomous Government of Galicia (project XUGA40301A90). ; Peer reviewed