A network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests.
PestNet is a network that helps people worldwide obtain rapid advice and information on crop protection, including the identification and management of plant pests. It started in 1999. Anyone with an interest in plant protection is welcome to join. PestNet is free and is moderated, ensuring that messages are confined to plant protection.
Pests > Pest Management > Chemical control > Herbicides > Withholding periods for herbicides? PNG
December 2002. Papua New Guinea asked an interesting question about the withholding period for herbicides. The Ramu Sugar Limited use Fusilade (0.75 litres product/ha) to control grass weeds in cowpea fallows. Is it likely that there will be any chemical residues left on or in the plant after a week before the plants are used as a vegetable. There are withholding periods for insecticides, but what about herbicides?
In response, PestNet members advised that Meister publications (US) recommends a maximum application rate of 0.375 lb a.i./acre for fluazifop-P-butyl, the active ingredient in Fusillade (as distinct from Fusillade 2 which has half the concentration of a.i.). The rate used in Papua New Guinea (0.165 lb a.i./acre for Fusillade) is much less than the above.
Yes, there are withholding periods for herbicides too. These vary according to the compound, concentration, application frequency and crop. It is best to check the manufacturers’ information on each product. In the case of Fusilade this is provided at: