Sunday, May 18, 2014

Diseases of Apple: White Root Rot Management

This is in continuation to my earlier post on Diseases of apple: White Root Rot Pre-Disposing Factors. This disease is generally appear in clay laom or loam soil having neutral pH. Mainly characterized by white thread like mats in the feeder root and bark that has rotten completely. Always get it diagnosed from an expert eye or one must consult some experienced farmers or a plant pathologist. Since it’s a soil borne disease, it should be managed in holistic way

1.     Phytosanitation: Free water or flood irrigation high moisture content in basin is major pre-disposing factors for the disease to spread. So keep the cultivation area free of diseased material like diseased bark and roots, etc. The cleanliness reduces the primary inoculum of the disease causing agents. This simple principle should be followed even if we don’t see primary symptoms. This is the best way to manage the diseases on small farms and helps in reducing the costs.

2.     Cultural Practices: Alter the environment in which disease is appearing i.e. high moisture level in the basin and nearby trunk. Improve drainage from the basin area. The basin area should be enriched with organic matter in the form of FYM or vermicompost, mulching with dry grass etc. This helps in building up saprophytes that in-turn act as biological control agents. These practices remove the primary inoculum as well as modify the environment for disease proliferation again without enhancing the cost to a greater level.

3.     Biological Control: Introduction of biological control agents in the soil is always being a good idea. Trichoderma viride, and its variants help the plant in fighting with plant pathogen and grow healthy with a little cost. If consortium of different soil inhabiting biocontrol agents is available it will help better in managing the disease.

4.     Chemical Control: Agrochemicals should be the last priority to manage the disease and that too after the proper diagnosis. As the application of a wrong chemical will not only worsen the situation but also pollute the soil and soil microflora. i.e. soil health. In turn increase the cost without preventing the damage caused by the insect-pests or disease. Since the disease caused by Dematophora necatrix this can easily be checked by carbendazim.

In my coming post I shall be discussing about pre-mature leaf fall of apple.