A tightly planned fire spray is the best recipe against problem weeds later in the season, says Syngenta crop advisor Steven Dorrestijn. Intensive monitoring of turnout is therefore necessary. In this article he explains his weed strategy, including the possibilities for earlier use of Boxer®.
In particular, the number of products with contact action has decreased in recent years, making soil herbicides more important. But the importance of pre-emergence spraying has also increased, says Dorrestijn. "We can make less corrections after emergence. Spraying with Stomp immediately after sowing is standard, but a good timing of burning down is especially crucial. You have to do this as soon as possible before emergence because the weeds that emerge first after burning down are the hardest to combat. After all, shortly after emergence we have little choice of means and we spray with low doses. So the shorter before emergence you burn, the longer clean after emergence. You will always spray a few onions away, but that also happens, and probably worse, when you try to spray the largest weeds later in the season with higher doses." Dorrestijn recommends intensive sampling of the plot from day 10 after sowing to determine the timing of the burn-off. "Walk zigzag across the plot and look in several places. And do your round in the middle of the afternoon. When you find the first seedlings, they have already hardened off a bit and you can spray immediately." Where sowing has been done very shallowly, up to a maximum of one and a half centimetres, the inspection must be done two to three days earlier.
More possible with Boxer
The good news in weed control is Boxer's wider range of applications. Dorrestijn: "In the past, Boxer only came into the picture with the first pipe, but we have discovered that it can already be used at a low dose in the staple stage in combination with Stomp. Then you benefit from the contact effect of the Boxer at an early stage ."
The cultivation advisor does add that there is a risk of plant failure in certain circumstances. See also the box at the bottom of this article. Dorrestijn recommends the following strategy for the continuation of weed control:
Regularity very important
When implementing weed control in onions, the regularity of spraying is also very important, in addition to the choice of means. "If possible, just spray on the same day of the week," advises Dorrestijn. "And if that doesn't work due to circumstances, always spray earlier and especially not later." Dorrestijn's last tip is about the dosage: "Adjust it to the weeds. Some growers look too much at the onion plants. Of course they do this with the best intentions, but then there is a chance that you will underdose for the weeds. As a result, you don't spray the weeds to death, but spray them sick. And a sick plant does not absorb anything during the next spraying. But an onion that has stood still for a while will recover."
When there are risks in early deployment Boxer (staple stage) The deployment of Boxer in the staple stage can give rise to risk in the following circumstances:
Design: Check your field carefully to determine the right herbicide mix, timing and doses.