Efficacy of a certified organic herbicide based on pine essence

Abstract

Six trials were conducted to evaluate a new certified organic herbicide Organic Interceptor (680 g/litre pine essence) which is the only weedkiller approved for use by BIO GRO NZ This herbicide was trialled on both newly emerged and established weeds On newly emerged weeds in freshly cultivated soil pine essence at rates of 50 100 kg/ha was as effective as traditional systemic herbicides such as glufosinateammonium or glyphosate Larger established weeds required higher rates per hectare to achieve good control Pine essence is a contact weedkiller which causes rapid plant dehydration through cuticle damage and finally resulting in cell rupture For best results full plant coverage must be achieved Therefore optimum application volumes are dependent on weed canopy density and height On a dense pasture sward mown to 50 mm optimum application volumes ranged from 1600 to 3200 litres/ha