- Groundnuts Aphids
- These spread the groundnut rosette disease which in severe cases may cause up to 100% damage.
- The pests should be sprayed with menazon, endosulfan and phosphamidon.
- Thrips, potato leaf hoppers and bollworms also attack groundnuts and can be controlled in a similar manner to the aphids. Sprays should be directed towards the base of the plant.
2. Leaf miner
- Groundnut leaf miner is a very serious pest of groundnuts attacking in both the rainy and post rainy season crops is regarded as the most important pest threatening groundnut production whenever outbreaks occur.
- It is more damaging during the short rainy cycle when long drought precedes rains.
- In Uganda, total crop losses have been reported by some farmers.
- No resistant variety is yet available in Uganda through tolerant variety Serenut 10R was released in 2011.
- Leaf miner larvae mine the leaves and feed inside the leaflets. Eggs are singly on the underside of the leaves of groundnut, soybean and other leguminous plants.
- Young larvae mine the leaves and later instars exit the mine to web together several leaflets.
- Damaged leaves become brownish, rolled and dissected which results in early defoliation and affects the growth and yield of the crop.
- Spraying with Monochrotophos 36SL at 600ml/ha or Dimethoate 30 EC at 650ml/hha in 600l water.
- Growing groundnut-cereal rotation reduces the leaf miner incidence
- Growing resistant genotypes such as Serenut 10R
- Peanut bruchid beetle
Groundnut bruchid caryedon serratus is also known as peanut bruchid beetle, groundnut borer, seed beetle is a serious pest of stored groundnuts, particularly when these are still in their shells.
The damage caused is particularly significant when the groundnuts are desired for confectionary purposes.
The translucent milky-white eggs are attached to the pod wall.
After hatching, the larva burrows straight through the eggshell and the pod wall, and start eating the seed.
The first sign of attack is the appearance of ‘windows’ cut into the pod wall by the larva to allow the adult to leave the pod after emerging from the pupal cocoon.
Fully grown larvae sometimes come out through the exit holes made by the previous generations.
Treatment and Control
- To prevent the primary infestation from alternative hosts (Tamarind, Acacia, and Pongamia) avoid drying groundnuts near these host trees.
2. Red Flour Beetle
- Fumigate with methyl 1 bromide 4 followed by chlorpyriphos at 3-g/kg seed.
- Groundnut Rosette Disease
- This virus is the most serious disease. It is spread by aphids.
- The groundnuts should be sprayed with Rogor (Dimethoate) two weeks after emergence and at 10-day intervals for a total of 4 times.
- The use of resistant types such as Igola-1 eliminates costs on chemicals.
- Recommended spacing must be followed because wide spacing increases disease incidents.
- Leaf Spots Disease
- Cercospora leaf spots should be sprayed with Dithane M-45, Benlate, and Brestan.
- Crop rotation should be practiced and crop debris should be burnt.
Root and Stem wilt also affect the crop. The control can be achieved by crop rotation, use of clean planting materials and burning of crop debris.