6.1. Stalk-borer or stem-borer
- Feeds on the growing points and then the cob
- Best control is by: early planting, remove and destroy all the infected growing plants
6.1.2. Army worm
- It feed on maize leaves and they attack in large numbers (army worm) and very serious under dry condition
- Control is by spraying carbarlyl 85%wp (sevin) dissolved in 14litres of water and providing training to farmers
6.1.3. Maize Weevil
- This is a post-harvest insect which eats stored maize grain. It is more destructive on dent maize.
- Control is done by dusting Actellic dust or other recommended chemicals by extension officers
6.1.4. Termites
- They attack maize stalks causing lodging. Fallen cobs are also attacked in the process.
- To reduce the damage, banking should be done when the plants are still young
6.1.5. Rodents
- These are very common in storage. They feed on the maize grain from the storage
6.2.1. Leaf Blight
- Caused by a fungus. It is seldom seen before tasselling. There are boat-shaped, greyish lesions on the infected spots. The lower leaves are infected first and those heavily infected may die
- The younger the plant, the greater the reduction in yield.
- Control is by use of improved certified seed. At a larger scale spray of some fungicides might be necessary
6.2.2. Rust
- Maize is susceptible to several rust diseases but the most common one is called Pucciniasorghi.
- Greyish lump but turns black and releases the spore as they mature
- They attack every part of the plant
6.2.3. Smut
- Common smut caused by fungus
- Symptoms are stunting, distorted leaves, excessive branching, yellowing of vines and dark, brown to blackish corky spots in the roots.
- Use disease free planting materials coupled with field sanitation
- Control virus vectors, aphids and white flies
- Use resistant varieties
6.2.4. Root-rot: fungus such as diplodia and Gibberella
- The affected plants tend to lodge. This is more common in compacted, poorly-drained soils.
- They can be controlled by use of resistant varieties or use of chemicals in treating seed before sowing
6.2.5. Stem rots – also caused by fungi such as Diplodia and Gibberella
- Gibberella stem rot causes plants to break at the internodes (joints)
- Diplodia stem rot causes breakage at the nodes ( between joints)
- When the attack occurs at an early stage, there are small ears with shrunken kernels
- Control by planting hybrid seed which are resistant to lodging.
6.2.6. Ear rot
- A wind-borne disease. The spores are trapped between the husks of the ear. When moisture conditions are favourable, they penetrate into the developing ear on which develops greyish-white mould.
- Can be controlled by rotation and seed treatment.
