July 6, 2014. Rhizobium vitis cause the crown gall disease of grapevines resulting in  considerable economic losses. Recent reports have revealed that the water-based crude extracts from hairy vetch (Vicia villosa) and ryegrass (Lolium perenne) act as a deterrent to antimicrobial activity against R. vitis. Researchers now  have shown that in a greenhouse experiment they are able to induce defense-related genes in grapevines (Vitis spp.).

A total of 100 ml of each extract concentration (125, 250 and 500 g/L) was prepared from fresh and pounded shoots and roots. These extracts were then applied to grapevine cuttings once every 10 days. The extracts displayed remarkable antibacterial effects.  Gall formation was considerably less in treated grapevines compared to the controls.

The expression of several defense-related genes was observed. The results have revealed that the extracts of hairy vetch and ryegrass brought into play the activity of defense-related genes. Based on these results, extracts from tested crops can act as efficient biological plant-defense inducers and therefore capable of serving as an alternative control strategy for grapevine crown gall protection.