PEST MANAGEMENT DECISION GUIDE: GREEN AND YELLOW LIST
Stem borer in maize
Buseola fusca, Chilo partellus, Sesamia calamistis
- Remove infested stems and stubbles from the previous harvest and destroy by composting or shred for mulch and use in plantain farm away from maize.
- Rotate maize with cassava, root crops or legumes and come back to plant maize after 2 years.
- Remove leftover maize, sorghum, millet and/or alternate hosts (elephant grass, guinea grass) to reduce carry over of larvae from one growing season to next.
- Modify sowing periods by planting early in the major and minor rain seasons to avoid periods of heavy infestation.
- Intercrop with legumes such as cowpea, or cassava to reduce the incidence of stem borer infestation on maize.
- Monitor 3 weeks after planting.
- Larvae are creamy-white to yellowish-brown, with dark-brown spots on the back. They can grow up to 25 mm long.
- The larvae are found in the leaf funnels, causing scars and holes by feeding.
- They later feed at the growing point, which may be killed (death of the growing point of the plant = dead heart); especially seen in young plants.
- Look for older larvae burrowing into stems and into cobs, weakening the stems, which may break and lodge. Then, direct control is too late.
- Early control can be considered when 5-10% of young plants are damaged, meaning having feeding holes in leaves.
- When young larvae have not yet entered stalks consider spraying hot pepper solution (50g/L) onto young plants every 10 days until tasseling.
- Pour ash dust (half matches box) into leaf-funnel of knee-high young plant.
- Spray Neem extract 50-60ml per 15 litres of water onto young plants every 10-14 days until flowering if threshold is reached.
- Apply products onto young plants particularly onto or into leaf sheath funnels when larvae are still on leaves. When larvae are inside stems or cobs, spraying has no effect
- When using a pesticide or botanical, always wear protective clothing and follow the instructions on the product label, such as dosage, timing of application, pre-harvest interval, maximum number of sprays, restricted re-entry interval. Do not empty into drains and water sources.
- Always consult the most recent list of registered pesticides of EPA, Ghana.
Apply Deltamethrin-based products (check product label for dosage). It is a Pyrethroid with a contact and stomach poison (2-3 weeks persistence in field). IRAC mode of action 3A
WHO toxicity class II (Moderately hazardous); restricted re-entry interval r.e.i. ½ day; pre-harvest interval p.h.i. 3 days. High risk to predators, pollinators; to fish and other aquatic organisms. Do not contaminate surface waters or ditches; do not apply to plants suffering from drought or other physical distress; do not spray within 6m of field boundary.
Chlopyriphos ethyl-based products (e.g. Dursban 4E, Pyrinex 48EC, Conpyrifos). Usually at a rate of 60-70mls per 15L knapsack sprayer, but check labels as product differs. A contact and ingested organophosphorus insecticide; IRAC mode of action 1B
WHO class II (Moderately hazardous). Repeat application twice if the pests persist and reaches threshold. Apply early morning or late afternoon, maximum two times per planting season. p.h.i. 35 days; r.e.i. 3 days.
CREATED/UPDATED: May 2016
PRODUCED BY: Plantwise
©CAB International. Published under a CC-BY-SA 4.0 licence.