"Some growers who did sow untreated seed have been forced to replant, with associated additional costs and disruption to production schedules," he said. "Where they have re-sown with Force-treated seed, the results have been fine."
Force ST, containing the insecticide tefluthrin, is a seed treatment that some growers have forgone after recent dry springs, Norman explained.
The problem has been especially severe in soils with high levels of organic matter, or where large volumes of organic residue from previous vegetable crops or weeds have been incorporated, he added.
He said of overall yield prospects this season: "At this stage, yields look to be below average, and quality is under threat. That could be better news for prices after last season's oversupply, particularly where growers can deliver the required quality."