Welcome to the Monsanto website
Quick Links
Broad-leaved Weeds
The Broad-leaved weed Problem
Cleavers is the most competitive broad-leaved weed in cereal crops. It grows rapidly, using the crop for support, and starts to impact upon yield during tillering, continuing throughout the spring and summer eventually causing combining difficulties. Just one cleavers plant per square metre of crop can reduce yield by up to 3%.
Volunteer Oilseed Rape and Charlock are not only a threat to the yield of cereals, but they can contaminate the seed of broad-leaved crops, which may reduce saleability. They have a low tolerance index, with anything over 20 plants per square metre is considered damaging to profits.
Another species falling into this category is Mayweed, while Chickweed and Forget-me-not have a slightly higher tolerance index. However, it is sensible to control any weed species that could reduce yield, worsen lodging and complicate harvesting.
Risk assessment
Walk a ‘W shaped’ line through wheat crops from the early spring to check for weed emergence. Once weed populations reach threshold numbers, or start to compete for space, apply Monitor.
The threshold for spraying Cleavers is just one plant/square metre.
Broad-leaved weed management
The best time to control most broad-leaved weeds is as soon as possible after emergence, once they have two true leaves. This usually coincides with crop tillering in the spring.
Top up autumn herbicide activity with an appropriate spring treatment. Prevent the development of herbicide resistance by choosing products from groups with different modes of action, and using effective mixtures. Do not rely solely on one mode of action, eg ALS-inhibiting herbicides, over several seasons.
Adopt a zero tolerance approach in fields with Cleavers, since the seed bank declines fairly quickly. Monitor offers 97% control of Cleavers across a range of crop growth stages from GS 23 to GS 33, when applied to cleavers seedlings no greater than the 3 whorl stage. It also effectively controls Volunteer Oilseed Rape, Charlock, Mayweed and Shepherds Purse.
For improved control of only moderately susceptible, resistant weeds or Cleavers greater than 3 whorls, tank-mix Monitor with an appropriate herbicide, check Tank Mix sheet for compatibilities. The following weeds fall into this category: Speedwell, Scentless Mayweed, Black Bindweed, Common Fumitory, Knotgrass, Field Pansy, Common Poppy, Fat Hen, Red-Dead/Hemp-nettle, Cranesbill and Corn Marigold.
