Planning for pre-em weed control in maize crops

Article taken from Farmers Guardian Newspaper

Timely weed control in maize crops will be key this season, with weeds likely to grow rapidly post drilling as moist soils warm up. Cheshire-based Agrovista agronomist Phil Campion has been advising growers to delay drilling due to low soil temperatures. Once crops are in, he recommends using a pre-emergence spray as soon as possible. He says: ""Small maize plants are sensitive to competition, so early weed growth must be kept in check. Pendimethalin at 1,200g per hectare is good on meadow-grass and it will hold black nightshade, polygonums and fumitory. ""It also takes the pressure off post-emergence products - you can use lower rates to lessen the risk of crop damage.""
Timing At the key post-emergence timing of three leaves onwards, where broad-leaved weeds such as black bindweed, nightshade, fat hen and redshank are a problem, he favours at least 70g/ha and 300g/ha respectively of mesotrione plus terbuthylazine. Mr Campion says he would increase the rate to 1.5 litres/ha if the pre-emergence spray was missed. This also boosts annual meadow-grass activity. Mesotrione plus nicosulfuron has also given good results where wild oats, rye-grass or couch are a problem. ""I will use at least one litre/ha and up to 1.5 litres/ha on big weeds," says Mr Campion.