Potato Review

www.potatoreview.com POTATO REVIEW MAY/JUNE 2020 43 WEED CONTROL as Shark for weed control uses, and Spotlight Plus as a desiccant, while Gozai has both uses on the same label. As a result, using Gozai as a herbicide will limit the amount of pyra ufen- ethyl available for desiccation, if the maximum permitted dose of 1.6 L/ha is to be observed,” he said. “For crops that are expected to be vigorous at the point of burn down, it is prudent to use Shark at pre-emergence to maximise desiccation options.” While the loss of diquat is promoting growers to review contact herbicides, the bigger change will be to force growers towards greater use of residual herbicides at the early post-planting stage. “Residuals still o er best weed control” While many herbicides have been lost in recent seasons, two agronomists advocate carrying out a post-planting weed control programme. Spraying pre emergence residual herbicide onto potatoes - Lincolnshire ➜ W eed control used to be a simple a air, but despite the loss of some established products the recent introductions mean good control is still achievable. Agronomists say it just requires a little more thought. e most recent change to programmes has occurred with contact herbicides. Following the loss of diquat, which was more valued as a desiccant than a contact herbicide, growers are left with either pyra ufen-ethyl or carfentrazone-ethyl. Scottish Agronomy’s Eric Anderson says the choice of which contact to use as a desiccant at the end of the season will in uence which is used as a contact at the start of the season. “Carfentrazone-ethyl is registered separately