Berber orchardgrass tested as cover crop in commercial vineyard

Abstract

Berber orchardgrass [Dactylis glomerata cv. Berber] was sown as a cover crop between rows of grapevine cv. Cabernet Sauvignon plants in a commercial orchard of low rainfall. No effect due to the cover crop was seen in the first growing season after sowing (1988) as it was still becoming established. However, in the next season (1989), the cover crop reduced pruning weight/vine by 54% compared with controls, and in 1990 it reduced pruning weight/vine and fruit yield by 58 and 53%, respectively. Vines in the cover crop treatment showed greater water stress (i.e. lower leaf potential, stomatal conductance and transpiration) in the early part of the season than controls. Some nematode and, possibly as a result of reduced vine vigour, some insect pest populations were significantly lower in the cover crop plots than in control plots, but after 2 years cane borer (Polycaon confertus [Melalgus confertus]) populations were higher in the cover crop treatments.