A new use for the maize herbicide Calaris, to control weeds when the crop is grown under degradable plastic, will help push back the physical boundaries for the crop in marginal areas, and enable growers in less favourable areas to benefit from higher yielding, high-dry matter varieties, according to Mark Palmer of Agrovista.
The Maize and Alternative Forage Group of the Ulster Grassland Society, in conjunction with Agri-Food and Biosciences Institute of Northern Ireland, has obtained the Specific Off-Label Approval (SOLA) for the use of Calaris under plastic this season. Over the past 10 years the area of forage maize in Northern Ireland has increased to over 3000 hectares, most of it grown using the plastic mulch system. Hitherto the region was considered on the periphery of the viable maize cropping area.
"Independent research has shown that establishing maize under a degradable plastic film gives the crop a valuable two week kick-start and can bring forward flowering date by three weeks, enabling the higher yielding varieties to fulfill their potential at harvest," advises Dr Palmer. "With the cold start to the spring and more of the specialist Samco drills available through contractors, we have seen an upsurge in interest in the technique this year," he reports.
However, the plastic film, laid down as the crop is drilled, creates an ideal microclimate for weeds. "You have to get complete weed control first time, as there's no post-emergence option. Following the withdrawal of atrazine, we had to look for options to partner pendimethalin; Calaris will increase the spectrum and reliability of weed control, with added residual activity."
Dr Palmer cites results of the company's trials last year, where the addition of Calaris components, mesotrione and terbuthylazine, overcame poor redshank control of pendimethalin alone, and boosted control of both Black Nightshade and Ochre to completely control all weeds. The herbicide mixture, including the adjuvant, Grounded, is applied by a specialist machine designed to cultivate, drill, spray and lay down the film in one pass.
Agrovista have developed the agronomy package in conjunction with the maize growing technique's developers - Irish equipment manufacturers Samco and maize variety breeders, Pioneer Hi-Bred.
