Potato Review

www.potatoreview.com POTATO REVIEW MAY/JUNE 2022 41 HERBICIDES P OTATO growers feeling the pinch of price pressures this spring could look at simplifying herbicide mixes for more cost-effective pre- emergence options, according to Syngenta Technical Manager, Andy Cunningham. Greater use of natural regeneration breaks and cover crops in arable rotations means the weed seed burden of some of the more troublesome weeds for potatoes are on the increase. Cleavers, mayweed and shepherd’s Sums add up for potato weed control Getting the right mix ratios can save cash in the long term says specialist. purse, for example, can proliferate rapidly in a single season. “Recent potato herbicide introductions have increased agronomists’ options. In many instances, however, simple mixes can achieve everything growers want, at lower relative cost,” said Andy. “Many of the key weeds that burden early potato emergence can be controlled, using the strength of mixes to widen the specific weed spectrum,” he advised. For example, recent season’s trials had shown a mixture of Defy (prosulfocarb) at 4.0 l/ha + metabromuron at a reduced rate of 1.0 l/ha, for example, achieved full control of assessed broad-leaved weeds, including chickweed, mayweed, cleaver and shepherd’s purse. Untreated weed pressure from these species was more than 70 per m2. That combination, typically costing just £43 per hectare at current prices, was even more effective overall compared to Defy at ➜ Common weeds of potato seedbeds controlled by Defy.