Vegetable production: Pest and weed control for your bell peppers

Here’s some expert advice on weed and pest control for your bell peppers.


  • Aphids (mainly Myzus persicae or green peach aphids) are small, soft bodied insects that can be green, black, yellow or pink.
  • They are found on the terminal growth ends or underneath the leaf of the plant.
  • Once established, an aphid colony can increase rapidly.
  • Aphids cause direct damage to plants by sucking the plant fluid or sap from them, causing stunting, yellowing or curling.
  • The insects cause indirect damage due to the secretion of honeydew, a sticky substance.
  • Honeydew is a growing medium for certain black sooty moulds that can inhibit plant growth or make the fruit unmarketable.
  • Aphids are carriers (or vectors) of certain viruses.
  • The best control is early detection, so regular scouting is important.
  • Their natural enemies include ladybugs, but the reproduction rate of the aphid can outnumber the impact of these predators.
  • Applying insecticides as control can kill these natural predators, so keep that in mind when applying chemical control.
  • When applying chemical control, keep in mind that the aphids live underneath the leaves and are protected from aerial spray.
  • Infestation in a greenhouse can be controlled by good sanitation.
  • Weed control around your fields can aid to the control of the aphids.
  • Destroy infested crop debris soon after harvesting.


  • The European corn borer (Ostrinia nubilalis) causes damage to a variety of agricultural crops, including sweet peppers.
  • The worm causes direct damage to the fruit by feeding or boring into the fruit, leading to premature ripening and fruit rot.
  • The wound caused by the worm is an entry point for other pathogens.
  • Their presence can be indicated by small egg masses on leaves or holes in the fruit.
  • The damage might not always be visible from the outside.
  • Plant your peppers as far away as possible from maize fields to lower chances of infestation. Weed control around the edge of your field is important.
  • Chemical control after infestation is difficult since the worm is shielded inside the fruit.
  • It is better to apply preventative control.
  • The overuse of pyrethroid insecticides as control can lead to problems with aphids, due to the reduction of their natural enemies.
  • It is advised to use it in rotation with other insecticides.
  • Applying insecticides to control the worm during bloom is harmful and deadly to foraging bees and is not advised.
  • It should otherwise be administered when the bees are not active, during the early morning or late afternoon.
  • Infested crop residue should be destroyed and ploughing during the fall can destroy most of the overwintering larvae.


  • Feeding broad mites causes downward curled leaves.
  • Affected leaves develop a bronze colour, especially on the lower side where they become thick and brittle.
  • The surface of affected fruit becomes russeted and corky and may become distorted.
  • Weeds, like nightshade that serves as hosts for mites, should be controlled to reduce infestation.
  • Spotted spider mites reduce the chlorophyll content of the plant, with damages leaves appearing bleached and stippled with small silver-gray or yellow speckles.
  • Heavy infestation causes leaves to die off and webbing can be visible on the plant.
  • Mites are difficult to control and biological control in the form of the predatory mite Phytoseiulus persimilis is the best form of control.
  • Mites don’t like high humidity, so regular watering of plants should reduce infestation.


  • Feeding damage from thrips cause distortion and the upward curling of leaves. Leaves become crinkled, and develops a silvery sheen that later turns bronze.
  • Signs of damage on the fruit include distortion and russeted streaks.
  • The Western flower thrip is a vector for the tomato spotted wilt virus.
  • The virus causes yellowing and browning of young leaves, that eventually die off.
  • Long streaks of dead tissue appear on the stems extending to the growing tips.
  • Large dead streaks of tissue and spots appear on the fruit after infection, while young fruit can completely die off.
  • Disease infected plants must be destroyed immediately.
  • Thrip resistant cultivars are the best control, as well as mulching with plastic.


  • Weeds in your pepper fields negatively affect the yield of peppers in several ways.
  • Weeds compete for moisture and nutrients and are hosts to several pests and diseases that can be carried over to the pepper plants.
  • Peppers are very sensitive to weed competition, especially 12 to 48 days after transplanting.
  • It is therefore important to control weeds in and around your sweet pepper field.

Also read:
Vegetable production: An introduction to planting healthy bell peppers
Vegetable production: Getting your soil right for bell peppers


share this