Herbicides for Gentians

Abstract

Gentians are a small but expanding flower crop in New Zealand. Few herbicide recommendations are available for gentians. A range of pre-emergence herbicides were tested, with application in August when the buds on the crown were still dormant. Established crops appeared to tolerate herbicides better than newly planted crops. Herbicide mixtures with low rates of simazine or terbuthylazine combined with low rates of alachlor or diuron gave good weed control without damage to an established crop. Post-emergence application of haloxyfop at 0.25 kg/ha gave good control of summer grasses and did not damage the crop.