Lettuce is one of the
top ten vegetables consumed by Canadians. About 60 percent of lettuce grown in the country is head lettuce, while the
remaining 40 percent is leaf lettuce. It is produced either in the field or in greenhouses. Greenhouse lettuce is grown
year-round, with most of the production in Quebec and Ontario, close to major markets. Lettuce is consecutively planted
throughout its 50-75 day growing season, so growers need to stay on top of pest management for a successful crop throughout
Manage disease inside and out
Botrytis stem rot is the
most prevalent disease in lettuce, and can cause grey-green shrivelled leaves. For best control, a fungicide should
be applied preventatively. Sclerotinia, or white mould, is primarily an issue for head lettuce. It’s a growing concern
as the spores that cause the disease can overwinter in the soil for many years. Downey mildew is more severe in greenhouse
lettuce, but it does attack field lettuce as well especially when humid conditions persist.
Start out weed-free
Lettuce can be sensitive to herbicides, so much of the weed control work is done upfront. A pre-seed clean up is often done
to make sure the soil is weed free. Plastic coverings are used to control weed growth. Tilling between the rows can also
help stop the spread of weeds.
Insect control difficult on large-surface lettuce leaves
Controlling insects on lettuce can prove challenging because there is such a large plant area to protect. Insects are therefore
a major threat for lettuce growers. Lettuce aphids can cause stunted, discoloured foliage on the plant. Researchers are
looking at how biologic controls can work alongside chemical controls to eliminate aphid concerns. Leafhoppers are dangerous
because they carry the aster yellow disease. When aster yellows are high, growers can see anywhere from a
15-50% reduction in yield.
Sivanto Prime works fast to target the pests that have the potential to do the most damage to your lettuce crop including aphids and whiteflies.