Control can be through use of pesticides such as imidachroprude, Jackpot or Aabamectin. You can grow strong-scented plants such as onions, garlic or parsley at the boundaries of the garden. These attract aphids such that you trap them there and thereafter spray them. Avoid excessive application of nitrogen fertilisers as these attract aphids.
Leaf miners: These are black or yellow small flies of about 2mm long when adult. They lay eggs on the leaves that hatch into larvae, which feeds by mining the lower and upper parts of the leaf making long tunnels as they move.
Natural control can be through placing a yellow basin in the garden filled with water. The adult leaf miners are attracted to bright colour. When they fall in the basin, they can be trapped and killed.
Use chemicals that are systemic in nature. These are able to pass through the leaf layers into the plant sap. They include abamectin, thiamethoxam, cyromazine. Other pests that affect passion fruits include bugs, root nematodes, snakes and termites to mention but a few.
Fusarium wilt (Fusarium oxysporum fsp): This disease is also referred to as colar rot. This is because it affects the stem (colar) much more than any other part of the plant.
This disease may be spread through infected planting materials such as seedlings and seed. Farm tools and animals from infected sites can also carry the disease.
It deforms the xylem vessels that are responsible for the movement of water and nutrients in the plant system. This leads to the yellowing of leaves.
If the colar (stem) is attacked, it becomes brown, peels off and cracks vertically. This makes the vine wilt.
For a control measure, graft weak passion fruit varieties on to yellow root stock. This is because yellow root stock is resistant to the disease. Fields that are already affected with fusarium wilt should be left to rest from passion fruit for about six planting seasons.
During this period; other crops can be planted to break the cycle. Keep the orchard clean and free from plants that are affected. In case, there are affected plants, pruning should be done, the plants removed and disposed of. Avoid excessive use of fertilisers.
For chemical control, paint the colar with macozeb mixed with metalyxl to prevent further development of the fungus. Copper-based fungicides are also very effective.
Passion fruit blight (phytothora nicotiamea var parastica): This usually affects the leaves, which become thin, water-soaked, light brown in colour and eventually fall off. The stem turns brown, weak, wilt and later collapse and die out.
Good field practices can help reduce the disease drastically. All weeds should be kept low by slashing, plants should be pruned regularly and the pruned materials should be disposed of properly. Fruits that fall on to the ground should be picked and disposed of. Avoid vines touching the ground.
Chemical control includes use of macozeb, macozeb + metalyxl to spray on the crop. Farmers should spray at least once a week in case the prevalence of the disease is high, and once after every two weeks in case the disease incident is low.
