Avoidance of bird damage on grapes with a simple net and viticulture method

Abstract

In mountainous regions of Japan, some people grow grapes for personal consumption. Damage to grapes caused by birds is serious in many such areas. At present, the only effective method against bird damage is to install physical barriers, such as nets, around or over vineyards. To install nets easily and safely, we designed a new grape cultivation method: the trellis height is equal to the width of a simple commercially available net (1×50 m, 12 g/m 2). Using the new cultivation method, we evaluated its bird damage prevention effect and working efficiency. Results showed that: 1) net installation was easy and safe; 2) nets installed only on the lower edges of the trellis reduced bird damage effectively because brown-eared bulbuls (Hypsipetes amauratis), a main bird that damages grapes, tended to invade the vineyard from under the trellis; 3) nets installed both on upper and lower sides of the trellis perfectly prevented bird damage. These results suggest that this is applicable as an effective method against bird damage to grapes in these areas.