Viral Diseases in Banana Next

Major Viral Diseases in Banana  Kootaivazhai in Poovan  Bract Mosaic  Bunchy Top  Streak Next Previous End

Kootaivazhai Symptoms in poovan In Tamil Nadu, the banana cv. Poovan is characterized by conical and ill filled fruits with prominent central core having many under developed non viable seed structure rendering the fruits inedible. Reasons Insufficient growth hormones (Auxin) for the redevelopment of fruit and hence the fruits are forced to produced seeds. Next Previous End

Management practices This disorder can be overcome by spaying 2, 4- D 20 ppm when the last hand of bunch is opened. The same chemical at same dose stage result in increased bunch weight and uniform grade especially in cvs. Nendran and monthan. Next Previous End

Bract Mosaic Virus Banana bract mosic virus (BBrMV,) - locally known as kokkan. Symptom develops in primarily transmitted through infected suckers. Transmission Primary: Infected Sucker Secondary: mealy bugs Next Previous End

Symptoms Yellow streaks on leaves. Splitting of the pseudo stem. Abnormal emergence of the bunch from the middle of the pseudo stem. Produce fewer fruits of smaller size. Dark reddish-brown mosaic symptoms, which are especially obvious in bracts. Spindle-shaped chlorotic streaks running parallel to the veins. Distinctive dark colored mosaic patterns, stripes or spindle-shaped streaks are visible. Next Previous End

Green or reddish-brown(depending on cultivar) streaks or spindle shaped lesions on the petioles and a tendency towards a congested leaf arrangement. Management Practices: Transmission by mealy bugs. Requires early detection, and immediate eradication of infected plants. Effective control of the disease, similar to that of other viral diseases. virus-free propagating materials should be planted. Next Previous End

Symptoms The presence of dark-green spots on the petioles, midribs, and leaf veins of the newly emerging leaves. The infected leaves are erect, narrow, stunted, and often have yellow leaf margins. The leaves become smaller as the disease progresses. Bunchy Top Next Previous End

Eventually, the crown of the plant is composed of only stunted leaves, producing a "bunchy top", hence the name. The infected plant does not produce any fruit or the bunch does not emerge from the pseudo stem. Next Previous End

Mode of Spread  Banana aphids (Pentalonia nigronevosa)  Infected planting materials  Volunteer plants that serve as alternate hosts like  Bird of paradise,  Ginger, and  Wild ban  Weeds Next Previous End

Management Practices  Using diseased-free planting materials controlling of aphids, using soapy water or insecticidal soap.  Spray the Plants thoroughly, importantly on petioles, furled leaves, whorls, or on young sucker removing and rouging of infected banana plants. Chop, dry, and bury the infected plants.  Control vector by spraying methyl demoton 1 ml/l. or Monocrotophos, 2 ml/l. or Phosphomidon 1 ml / lit. or Injection of Monocrotophos 1 ml / plant (1 ml diluted in 4 ml). Infected plants are destroyed using 4ml of 2, 4, D (50g in 400 ml of water). Next Previous End

Banana Streak Virus Banana streak virus (BSV) is an important disease of Musa and affecting the productivity of both bananas and plantains. Reported in nearly all countries where this crop is grown including Mauritius, India and many countries of the African continent. Symptoms Disease severity is very variable, and probably depends on environmental conditions, as well as on host and virus genotypes. (Cont).. Next Previous End

The most characteristic foliar symptoms of infection are chlorotic streaks, which become necrotic with time. The leaf lamina may also be narrower, thicker and become torn. Next Previous End

Stunting of the plant, constriction of the bunch on emergence (choking), altered phyllotaxis (leaves arranged in a single vertical plane instead of the normal spiral pattern), and detachment and splitting of the outer leaf sheaths of the pseudo stem. Next Previous End

Management Practices  The eradication of infected plants.  The use of BSV-free planting materials.  BSV can be carried in in-vitro plantlets, as it is not eliminated by shoot-tip culture.  Virus particles can only be detected in areas of leaf tissue with symptoms.  Parts of leaves with pronounced symptoms should be used for serological indexing. Next Previous End

To sum up: Viral diseases are mostly transmitted through vectors. It affect the quality and vigour of the plant. Kottavazhai in banana – ill filled development of fruits with unviable seedy structure it can be overcome by application of 2, 4 – D 20ppm at the last hand of bunch opened. Banana bract mosaic – This disease transmitted through aphids it caused symptom of dark reddish brown mosaic it may be avoided using free propagating materials. Bunchy top – Stunted growth of plant with bunchy appearance. This disease transmitted through aphids. The disease controlled application of monocrotophos 2 ml/ lit. Banana streak virus - Chlorotic spots on leaf lamina. Use virus free planting material. Previous End