Kanjarai leaf spot management in banana

July 30, 2014 11:35 pm | Updated 11:35 pm IST

The disease is caused by a fungus mycospharella musicola. Occurrence of the disease is severe in Tiruchi, Tirunelveli, Kanyakumari, Tuticorin, Erode, Coimbatore, Theni and Dindigul districts of Tamil Nadu.

The varieties susceptible to this disease are robusta, gros michale, sandana valai, nali poovan, rasthali, karpooravali, monthan and grand naine.

The infestation initiates as narrow spindle shaped light yellow or brown coloured streaks on the leaf lamina parallel to the veins.

Yellow halo The streaks enlarge into linear, oblong brown to black spots. The central portion becomes necrotic and greyish surrounded by a dark brown band which in turn is surrounded by a yellow halo.

Several such spots coalesce to cause drying of entire leaves. This leads to the reduction of photosynthetic area which eventually reduces the yield.

Weather Humid weather and rainfall favour the spread of the disease. The conidia of the fungus are carried by wind and rain water aiding to the spread of the disease.

Fields without proper drainage are severely affected. The weed hosts help in the perpetuation and spread of the disease.

Closer spacing, heavy weed or grasscover, frequent irrigation and failure to remove suckers increase the relative humidity in the plantation, favouring rapid buildup of the disease.

Affected leaves should be removed immediately and destroyed. This helps in reducing the population of the fungus.

Spraying Depending on the severity of the disease three to four sprays with any one of the following fungicides viz., carbendazim at l gm per lit or propiconazole at 1 gm per lit or mancozeb at 2 gm per lit or chlorothalonil at 2 gm a lit at 20 days interval may be done.

Wetting agents viz., teepol or sandovit at one ml / litre of water should be added to the fungicide before spray.

Spraying on the lower surface of the leaves is effective for control of leaf spot disease.

(Dr.M.Theradimani and Dr.A.Vijaysamundeeswari are Professors, Department of Floriculture and Medicinal crops, Horticultural College and Research Institute, TNAU, Periyakulami 625 604, Tamilnadu, E mail : mtheradi@gmail.com)

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in

Comments

Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.