Nature and management of selected pathogens and diseases of onions and other vegetable crops grown on muckland soils in New York

2007 Impact statement
  • Lorbeer, James W

abstract

The project develops 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 are undertaken as needed and requested and that have been emphasized in past years. Onion diseases are currently being emphasized.

submitted by

issue being addressed

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 appliable minor) diseases as well as methods for their control in order to maintain a competitive and prosperous onion industry in New York.

response

Research focused on the nature of a bacterial disease new to New York in 2006. The studies centered on proving the bacterial disease is center rot caused by the bacterium Pantoea ananatis. Center rot, first described in South Africa, occurred in Georgia some 10 years ago. Research at Ithaca during 2007 (1) established, based on PCR Primer Pairs supplied by Georgia researchers, as well as other tests and procedures, that P. ananatis occurs in New York and (2) the new disease experimentally is characterized by a dark staining and water soaking 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. Rejections of onion shipments at market occur when infected bulbs are detected by inspectors; this has caused onion growers in New York significant economic losses. The research 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 Actigard, products like Actigard that induce defense mechanisms in plants, and different copper compounds on onion plants tested under controlled environmental conditions during 2008 to determine if P. ananatis can be managed in New York using those approaches.

impact assessment

The occurrence in 2006 of a bacterial onion disease new to New York and now believed to be caused by Pantoea ananatis has resulted in the initiation of a major research effort to characterize all 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 bacterial canker and 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 control procedures have been developed. However, it is now apparent that other bacterial diseases (such as center rot) by their unique form of pathogenesis can cause significant losses to New York onion growers. An effort now will be made to make Cornell the national center of study for bacterial diseases of onion. During 2008 it is anticipated that a collection of cultures of bacterial pathogens of onion contributed from other researchers throughout the US and elsewhere will be 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 presently in New York, the nature of the diseases they cause under New York growing conditions, and ultimately develop strategies and procedures for their control.

academic priority area

has geographic focus

funding source description

  • Smith-Lever 3(b) & (c)
  • Agricultural Nonpoint Source Abatement and Control Program
  • Hatch
  • Unrestricted funds

collaborators

  • CCE
  • Department of Horticulture, NYSAES, Geneva
  • Department of Plant Breeding and Genetics
  • Guelph University

key personnel

  • Jan vander Heide
  • Christy Hoepting
  • Dr. Alan Taylor
  • Dr. Martha Mutschler
  • Eric Carr
  • Carol McNeil
  • Maire Ullrich
  • Dr. Alison Seyb

mission focus

From CALS annual faculty reporting. Imported on August 5, 2008