Setting up crops for the best possible start
Weeds cause problems, whatever the cropping situation. Failure to adequately control them may result in lost yield, reduced quality and harvesting issues.
It is important to plan your herbicide strategy carefully. Consider using cultural control methods such as delayed drilling, crop rotation and ploughing to reduce the reliance on chemicals. Herbicide resistance is an increasing problem, so consider adopting cultural controls within your programme.
The use of pre-emergence herbicides can form a part of an integrated strategy to deal with resistant weeds and sets up the crop for the best possible start.
Fodder beet herbicides
Beet crops are sensitive to weed competition in the early stages of development. Weeds that emerge within eight weeks of crop emergence, and those that grow above the crop and shade it, cause large yield reductions, in part due to harbouring pests and viruses.
Overseas work from the British Beet Research Organisation (BBRO) has demonstrated in sugar beet, one tall weed, such as fathen, in each one metre² area can reduce the beet’s yield by 10 percent.¹ Whilst this research was carried out in sugar beet, there is no reason to suggest it is not applicable to fodder beet.
A good, evenly established crop will assist with weed control with a beet canopy contributing to suppression. It is imperative to control the most competitive weeds including wireweed, cornbind, fathen and volunteer potatoes, early in the spray programme. Grass weeds need to be considered and removed separately from broadleaf weeds. Uncontrolled grass weeds, like couch, can become a problem in subsequent pastures following winter crops. Remember to always use a decent spraying oil with your grass herbicide. The best approach is to kill weeds slowly whilst allowing the beet plants to flourish.
As with fodder beet, it is essential to provide brassica crops with as weed-free an environment as possible. To do so, pay attention to the previous crop or pasture spray-out, seedbed preparation, seed rate, weed control and early nutrition given. Consider too, the frequency of pest monitoring as slugs can severely damage a crop in the right conditions.
It is vital to apply a pre-emergence herbicide, if ground conditions allow, as weed competition can be intense in spring. The brassica crop may need a follow-up application of a post-emergence herbicide, so continue monitoring the crop in the weeks that follow. Remember to remove grass weeds; if they seed, they will become a problem for future crops.
All weeds are better controlled early, giving your crop the greatest chance of achieving its potential.
To plan an effective integrated strategy for managing weed pressure in fodder beet and brassicas crops, contact your local PGG Wrightson Technical Field Representative.