RESEARCH, ACQUISITION, MANAGEMENT, AND DOCUMENTATION OF PLANT GENETIC RESOURCES
Location: Plant Germplasm Introduction and Testing
Title: Managing diseases in seed garlic: What are the options?
Submitted to: Garlic Press
Publication Type: Trade Journal
Publication Acceptance Date: November 25, 2008
Publication Date: December 1, 2009
Citation: Dugan, F.M., Hellier, B.C. 2009. Managing diseases in seed garlic: What are the options?. Garlic Press. newsletter note.
Interpretive Summary: There are four kinds of organisms that cause disease in garlic: fungi, bacteria, viruses and nematodes. Seed garlic is garlic whose cloves will be planted as "seed" (since garlic is a clonal, or vegatitive crop, generally lacking true seeds). All these organisms affect garlic grown for seed, and many have the potential to cause disease in the subsequent crop of table garlic. The mere presence of these organisms does not necessarily result in significant disease problems because the growing or storage environment may not be conducive to disease development, arthropod vectors (essential for some viral diseases) may be relatively scarce, or the disease itself may usually be restricted to minor effects such as blemish. But in the long run, virtually all pathogenic microorganisms present potential problems, and both producers and users of seed garlic should be aware of management options. General recommendations for disease management are provided, as are more comprehensive references for pest and disease identification and managment.
Organisms (fungi, bacteria, viruses and nematodes) causing diseases of seed garlic are discussed in terms of their pathogenic abilities, aggressiveness, management constraints and management options. Management options for vectors (for viral diseases) are placed in context. Concise and general management options are provided with the caveat that professional level management requires use of comprehensive identification and management guides, for which citations are provided. Hot water treatments, thermotherapy, tissue culture, and chemical treatments (including biostimulants) are discussed, as are disease-resistant varieties and fungicide resistance. The feasibility of tissue culture for small scale garlic producers is discussed in the context of previous biotech ventures and of economies of scale.