The occurrence in 2006 of a bacterial onion disease new to New York and now proven to be caused by Pantoea ananatis resulted in the initiation of a major research effort to better characterize the bacterial onion diseases which presently occur in the state. Research done in the past at Ithaca has resulted in considerable knowledge on the nature and control of Burkholderia cepacia which causes the bacterial sour skin disease. That disease generally occurs annually at different levels of outbreaks and undoubtedly is the most important of the bacterial diseases that occur in New York. It has received much research attention in past years and a potential control procedure was developed. However, it is now apparent that other bacterial diseases (such as center rot) can cause significant losses to New York onion growers.
An intensive effort has been underway since 2007 to better understand the biology of center rot in New York and make Cornell a center of study for bacterial diseases of onion. During 2009 a collection of cultures of Pantoea ananatis and other bacterial pathogens of onion contributed from other researchers throughout the U.S. and elsewhere was developed at Ithaca. By using these cultures for comparisons in traditional and molecular tests, it will be possible to characterize those bacterial pathogens of onion that are currently present in New York, the nature of the diseases they cause under New York growing conditions, and ultimately develop strategies and procedures for their control. Since the retirement of Dr. J. W. Lorbeer on June 30, 2010, Dr. S. V. Beer is continuing and expanding the research on bacterial diseases of onion.
impact statement issue
Onions are one of the major commercial vegetable crops grown in New York. The state's onion industry is economically competitive on both a national and international basis. Onions are stored and marketed throughout the year; this enables a continued relationship with buyers which, in turn, enhances sales. There is a significant number of diseases from which onions grown in New York must be protected. A continuously expanding in-depth understanding of the nature of these diseases, and the biology of their pathogens is critical for developing new programs and revising existing traditional programs for effective control of the diseases. Therefore, a strong continuing research program on onion diseases and their pathogens is needed to provide a continuing flow of new information on the nature of each of the major (and applicable minor) diseases as well as methods for their control in order to maintain a competitive and prosperous onion industry in New York.
impact statement response
Research in recent years has focused on the nature of a bacterial disease new to New York in 2006. The studies presently are centered on the bacterial disease center rot caused by the bacterium Pantoea ananatis. Center rot first occurred in Georgia some 10 years ago. Research at Ithaca during 2007-10: (1) has established, based on PCR Primer Pairs supplied by Georgia researchers, as well as other molecular tests and procedures, that P. ananatis occurs in New York, and (2) the new disease experimentally is characterized by a dark staining of the fleshy scales of onion bulbs. These symptoms differentiate the disease from those caused by other bacteria attacking onion. Since bulb tissue is not macerated, it is difficult to detect affected diseased bulbs on grading lines. Rejection of onion shipments at market occur when infected bulbs are detected by inspectors; this has caused significant economic losses to onion growers in New York. The research has resulted in new effective techniques for isolating P. ananatis from diseased onion bulbs. The research has established new techniques for successfully inoculating onion leaves and bulbs with P. ananatis. These advances will allow the testing of products like Actigard that induce defense mechanisms in plants. In future years, different copper compounds and other materials could be tested on onion plants under controlled environmental conditions to determine if P. ananatis can be managed in New York using those approaches. From January 2009 to December 2010 experimentation indicated that P. ananatis is resident on a number of different weeds which occur in and near onion fields and that strains of the bacterium isolated are pathogenic and non pathogenic to onion. This compounds understanding the biology of the bacterium and has resulted in the need for a quick molecular technique to differentiate the two types of the bacterium. Studies to develop such a technique are currently being emphasized.
impact statement summary
For five decades, the project has developed new fundamental and application knowledge on the nature and management (IPM) of the pathogens and diseases of onions grown on the muckland (organic) soils of New York. Studies on the nature and management of pathogens and diseases affecting other vegetable crops grown on the muckland soils also were undertaken as needed and that growers requested. Such studies were emphasized for the time durations required for problem resolution. From 2007 to the present (2010) an intensive research program on the center rot disease which is new to New York and caused by the bacterium Pantoea ananatis has been underway and presently is being continued by Dr. S.V. Beer following the retirement of Dr. J.W. Lorbeer on June 30, 2010.
Other private funding
New York Onion Research and Development Program administered by NY Ag. and Markets
