【生態】農薬の使用削減がコムギの収量に与える影響を評価する

The yield losses resulting from a reduction of pesticide use for winter wheat in France are quantified in a study published this week in Scientific Reports.

As populations grow, crop yields become increasingly important. Between 1960 and 1990 worldwide cereal crop yield increased by an average of 98%, partly due to an increase in pesticide use. However, given the potential threat to human health and the environment, recent policies have sought to reduce pesticide use.

Laure Hossard and colleagues investigated the effect of halving pesticide use on winter wheat production using 176 experimental plots across four study sites in France. The study used cropping system experiments in three conditions: conventional (using pesticides), integrated (reduced pesticide use) and organic (no pesticide use). The authors then applied a statistical model to estimate the yield losses resulting from either a 50% or 100% reduction in pesticide use. Since pesticide type and dose can vary, the authors used a treatment frequency indicator that allowed them to consider general pesticide use in the statistical model.

The model predicted that a 50% reduction in pesticide use would reduce winter wheat production by 2-3 million tons in France, representing 15% of the country’s wheat export. This potential loss is much smaller than the loss attributed to a 100% reduction in pesticide use. Further research is needed to investigate how specific pesticide types (for example, fungicides, herbicides and insecticides) affect crop production and how pesticide reduction could affect crops other than winter wheat.