Caterpillars: soybean lopper, leaf miners, leaf rollers

• These insect pests feed on the foliage
• They reduce the plant photosynthetic area thereby affecting final yield
• Once insecticide application is usually enough to control insect attacks
• can also be controlled by applying Tephrosia Vogelii (Fish bean) seeds and leaves which are a good local insecticide

Termite

• Can attack soybean plants at any stage of development from seed to mature soybean plant particularly when there is prolonged dry spell
• First sign of termite attack is wilting leading to death or falling over of plants
• Pull out affected plants to examine roots and lower stem for live termites and/or tunneling
• Plant roots and stems may be completely hollowed out and soil-filled
• Damage by termites is greater in rain-fed than irrigated crop, dry periods than periods of regular rainfall, lowland rather than highland areas, and in plants under stress rather than in healthy and vigorous plants
• Plants can be under stress from weeds competing with crops for nutrients, light and water, hence increasing susceptibility to termite attack.
• Crop rotation and removal of other debris from the field reduces build-up of termites, reduces potential termite food supplies, thus reducing termite number and subsequent attack

Pod-sucking buds - Attack crop from flowering onwards

• Insect pests can be controlled with a single spray of Cypermethrin + Dimethoate 10 EC. Read the chemical label for instructions.

Soybean Rust

• The only disease of economic importance
• Other diseases such as frogeye, bacterial pastule, red lead blotch occur but are less important economically
• Asian soybean rust, caused by Phakapsora pachyrhizi, is one of the notable foliar soybean diseases in Malawi
• Infected leaves have small tan to dark brown or reddish-brown lesions on which small raised pustules (or bumps) occur on the lower surface of the leaves
• Pustules produce a large number of spores
• Brown or rust-colored powder falls when severely infected leaves are tapped over a white paper or cloth
• Severe infection leads to premature defoliation and yield losses up to 80%
• Soybean rust is of great economic importance where humidity and rainfall are high
• Late planted soybean is prone to soybean rust infection

Soybean cyst nematode (SCN), Heterodera glycines

• It can be present in the field without causing obvious above-ground symptoms
• In heavily infested fields, SCN can cause yield losses of more than 30%
• “yellow dwarf” describes the symptoms that are commonly caused by SCN
• Infested plants become stunted, canopy closure does not occur, leaves become chlorotic; however, these symptoms may also be caused by other crop stresses such as nutrient deficiencies
• Severely infected plants may die before flowering, especially during dry periods where soils have poor water holding capacity

Control of SCN:

• Ensure good soil fertility and adequate moisture increase tolerance and reduce the severity of above-ground symptoms in fields
• Employ good crop production practices to reduce severity of nematode infestation; for instance, a 1 to 2-year rotation with Maize or cotton (non-hosts) has proven effective for many soybean growers
• Use resistant varieties such as Ocepara 4

Virus diseases:

• Commonly transmitted by insects such as whitefly
• Symptoms range from mosaic and mottling, leaf curling, green vein banding, and stunting
• Soybean is also susceptible to several viruses transmitted by aphids and beetles prevailing in Malawi
• Foliar symptoms of virus infection include mosaic and mottling, thickening or brittling of older leaves, puckering, leaf distortion, severe reduction in leaf size, and stunting of plants
• Remove and burn infected plants

• Use certified seed to avoid seed-borne infection
• Use varieties resistant to prevailing diseases of the area
• Plant early to escape diseases that come late in the season and to encourage good establishment of soybean plant to withstand disease attack
• Avoid planting seeds obtained from mosaic affected plants
• Uproot and destroy symptomatic plants
• Do not use seed that is cracked or broken; take care during harvesting and handling to reduce mechanical damage
• Rotate soybeans with non-host crops such as Maize or sorghum
• Eradicate weeds and voluntary plants in the vicinity of soybeans sites  as weeds act as these act as host agents.