Seed Health Management for Better Productivity - Govind Ballabh ...

(Seed Health Management for Better Productivity)nutrition owing to high microbial activity. The value of organic manuring for fungal disease control,and in particular the use of compost has been confirmed during last few decades. In some soilshigh levels of organic matter and biological activity are directly associated with low levels ofdisease incidence. Such soils have higher populations of bacteria and actinomycetes. Mycorrhizaeplay a particular role in plants defense mechanism. They assist in disease control by forming aprotective fungal jacket around the plant root. Plants with roots affected by mycorrhizae known tobe less disease susceptible than without, and are also more resistant to nematodes.Natural Rhythms and optimal planting seasonAn outbreak of diseases is usually associated with a particular stage of development ofhost plant. This should be observed locally to reach right decision.Crop RotationIt is believed that species diversity leads to a greater stability in the agro ecosystem andtherefore reduces risk from sudden outbreaks of specific diseases.Host Plant Resistance and TolerancePlants in natural environments depend entirely on their own defenses. In traditional farmingsystems farmers have long been familiar with a wide choice of land races/ local cultivars which areappropriate to their needs.Field SanitationSanitation includes removal and destruction of plants affected by seed borne diseases, andof the plant residues infected by diseases.Other Disease Control Measures (Supplementary Measures)At organic farms, frequently natural controls may be all that is required. Once all steps tocreate an optimal environment for plant growth have been taken, and there are circumstanceswhere the disease incidence is significant to cause economic damage supplementary interventionmay be necessary. The organic standards permit the use of physical methods, including the use ofheat; and the use of products that are prepared at the farm from local plants, animals andmicroorganisms, subject to conditions imposed, if any (Table 1).Table 1 Crop Protectants and Growth RegulatorsSubstances, Description, compositionalrequirementsPANT AND ANIMAL ORIGINAlgal preparationsAnimal preparations and oilsBeeswaxChitin nematicides (natural origin)Coffee groundsDairy products (milk, casein, buttermilk etc.)GelatineLecithinNatural acids (vinegar)NeemPlant oilsConditions for use- 47 -