The largest herbaceous perennial plants in the world are Banana trees (Musa spp.). Cultivated for their fruit, banana plantations are meticulously managed and the trees can produce for up to 25 years. Any number of banana pests and diseases can derail a successful plantation, however, not to mention environmental banana plant problems such as cool weather and high winds. Any of the problems affecting bananas may afflict the home gardener as well, so it’s important to learn to identify banana pests and diseases so you can nip them in the bud.
Banana Tree Insect Pests And Insecticides To Use
Several banana tree insects can cause minor damage to a single plant or wreak havoc through an entire plantation. Some of these banana pests act as vectors of disease as well. Sometimes, banana plant diseases are transmitted via insect pests but not in every case. Control of pests on bananas requires early identification.
#1. Banana aphids
Banana aphids are an example of a pest that acts as a vector of disease. These pests are soft-bodied, wingless, and almost black. An infestation of these aphids causes curled shriveled foliage. The pest may also transmit the banana bunchy top disease to the plant, resulting in chlorotic leaf margins, brittle leaves, and, as the name suggests, a bunchy top.
The aphid population is often tended to by ants, so control of the disease involves treating for ants. Insecticides, soapy water, and horticultural oil can help mitigate the population of aphids, but if the plant already has a bunchy disease, it is best to destroy the plant. There are no chemical controls to protect against the transmission of the banana bunchy top, so the only control method is to prevent the transmission by ridding the plant of the aphids. That or plant less susceptible cultivars. Aphids can also transmit banana mosaic disease.
This disease also presents with chlorotic mottling or stripes on foliage. Fruit will be distorted, sometimes with chlorotic streaking as well. If the banana becomes afflicted with banana mosaic, it is best to destroy it. Plant virus-free material next time, control aphids, and remove susceptible host plants including weeds from around the tree.
#2. Banana weevils
Banana weevils are nocturnal pests that slow plant growth and reduce fruit yields. They tunnel through the corms, which can cause plants to wilt and topple over. Eventual destruction and the plant’s death follows. The population of Banana weevils can be controlled by treating the plant with neem powder.
Several different types of thrips are known to infest banana trees and can be controlled using insecticides, soapy water, and oil. Use chlorpyrifos insecticide once a month to kill thrips if they are present.
Nematodes are a major problem amongst banana growers. There are many different types of nematodes, but they all love to feed on banana plants. When nematicides are properly applied, they can protect the banana tree for a long period. Otherwise, the land must be left fallow for up to 3 years. Control banana nematodes with Nemacur using 45kg/ ha (20g/plant). Compost, kraal manure and chicken manure applied in ample quantities will also suppress nematodes. Tissue culture plants are free of nematodes, which is one of the reasons that this is the preferred method of cultivation.
Some Plantain Diseases and Control
#1. Coconut scale
Coconut scale isn’t just common to banana plants alone; it attacks many hosts, including coconuts. Coconut scale is observed by the presence of scales on the underside of leaves as well as other areas of the banana tree which causes tissue discoloration and yellowing of foliage. Biological control of the coconut scale can be achieved by the introduction of ladybugs, is the most effective control method.
#2. Banana bacterial wilt
Banana bacterial wilt may be transmitted by insects, farm equipment, other vertebrate pests, and infected rhizomes. The first symptom of banana bacterial wilt is yellow leaves that later turn brown and dies. If infection occurs late in fruit production, the buds get dried and become blackened. Fruit ripens early and unevenly and fruits infected become rusty brown. It is important to sanitize garden equipment to prevent the spread and remove excess male buds. Infected plants should be destroyed and replaced with disease free specimens.
#3. Black leaf streak
Banana black leaf streak, also called black sigatoka, is a fungal disease that is fostered by high humidity. Spores are spread by the wind. The first signs of black sigatoka are red/brown spots on the underside of leaves and dark or yellow bordered spots with a gray center. Leaf surfaces eventually die and fruit bunches do not develop properly. Plantations use fungicide application to control black sigatoka, increasing the space between trees reduces the circulation and leaves that show any signs of infection should be removed. Plants with leaves damaged by the disease may have up to 50% lower fruit yield. Control banana black leaf stray with Dithane and mineral oil. The mineral oil facilitates the penetration of the fungicide in the leaves and reduces leaching from rain. Lastly, dip the banana hands into Benlate solution at a rate of 5g/10l water to prevent post-harvest decay.
#4. Cigar end rot
Cigar end rot is another fungal disease caused by either Verticillium fungi or Trachysphaera. In the foremost signs are, the tips of the banana (fingers) observed to be wrinkled and darkened; the portion begins to rot. In the latter case, the rotted areas become covered with white spots, which make the fingers look like the ash end of a smoked cigar. Commercial banana growers remove infected flowers, bag banana bunches with perforated polyethylene, and when necessary utilize chemicals.