Damage of Maize Borer and Maize Weevil on the Yield of Transgenic Phytase Maize

Abstract

The recent Chinese government approval of transgenic phytase maize for field experimentation is vital for its development of biotech maize for improved maize production. Phytase maize can potentially improve the efficiency of feed utilization by livestock and reduce environmental pollution from animal manure. Plant growth, phytochemistry, and economic characteristics of phytase maize were compared with non‐transgenic maize in field conditions. Population abundance and growth physiology of the maize borer (Ostrinia furnacalis) and the maize weevil (Sitophilus zeamais) were investigated during maize growing season and grain storage period, respectively, to assess insect pests’ occurrence and economic damage. Agronomic traits of phytase maize were generally superior to those of non‐transgenic maize, but the yield of phytase maize was only 5.5% higher than that of non‐transgenic maize. No significant difference in population dynamics of the maize borer was observed between them, while phytase maize significantly enhanced pupal weight and female fecundity of the maize borer. The length of the maize borer feeding tunnels in the stems was significantly greater in phytase maize. Moreover, significant increases in adult weight and population abundance of the maize weevil resulted in additional 2.98% losses for transgenic grains compared with non‐transgenic grains. Upon commercialization of transgenic maize in China, it will likely alter the arthropod population dynamics in the maize agroecosystem, increase plant susceptibility to lodging, and increase grain yield loss. Nevertheless, the increased insect‐induced loss (∼8%) in transgenic maize would likely be more than offset by enhanced phosphate utilization efficiency of livestock, when fed transgenic maize containing diet, and reduced environmental pollution from lower phosphate animal waste.