CONTROL OF BROOMRAPE (OROBANCHE-CRENATA FORSK) IN BROAD BEAN (VICIA-FABA L) WITH IMIDAZOLINONES AND OTHER HERBICIDES

Field experiments were conducted at two locations for 2 years to study the effects of pre-emergence and post-emergence herbicide treatments on: (a) control of crenate broomrape (Orobanche crenata Forsk.) in broad bean (Vicia faba L.) and (b) crop yield response under weed-free conditions. Twelve herbicides belonging to the imidazolinone, sulphonylurea, glyphosate-analogue and substituted amide families were tested. In general, the effectiveness of any herbicide treatment was largely dependent on the duration of crenate broomrape infestation. For late planting/low-yield cropping systems, which normally face short and slight crenate broomrape infestations, crop pre-emergence treatments of imazethapyr at 75-100 g ha-1 and imazapyr at 12.5-25 g ha-1 resulted in efficient control without damaging the crop. Imazaquin at about 80 g ha-1 and chlorsulfuron at about 6 g ha-1 applied pre-emergence were also active, but their performance was likely to be affected by soil conditions. Applied after crop emergence, imazethapyr at 40 g ha-1 and Mon-8000 at 60 g ha-1 gave similar results to the standard treatment of glyphosate at 60 g ha-1. Early planting/high-yield cropping systems which are normally subject to heavy and lasting parasite infestations would normally require a combination of pre-emergence and post-emergence treatments.