Title:

Impact of Ergot in Kentucky Bluegrass and Nematodes in Perennial Ryegrass on Seed Production in Sustainable Nonthermal Grass Cropping Systems

Objective 1:

Evaluation of resistance to Kentucky bluegrass cultivars to ergot

Investigators:

Steve Alderman, plant pathologist, USDA-ARS NFSPRC, Corvallis
Reed Barker, USDA-ARS NFSPRC, Corvallis

Progress:

One Hundred and four cultivars of Kentucky bluegrass were established in a randomized replicated trial at Hyslop field station during 1993. During the spring and summer of 1996, data was collected and included date of beginning of flowering, ending of flowering, and of seed maturity. Ergot ascospore populations were monitored with a Burkard 7-day recording volumetric spore trap. At harvest, 20 seed heads were removed from each plant and evaluated for ergot incidence. Each set of heads were hand threshed, cleaned, and ergot removed and counted. Remaining seed was weighed. One thousand seeds were removed using a seed counter and weighed to determine 1000 seed weight. Data will be subject to analysis of variance and means separated by Duncan multiple range test.

Two years of data have been collected (1994 and 1996). A third year of data collection is planned for 1997.

Objective 2:

Evaluation of impact of ergot in Kentucky bluegrass seed production.

Investigators:

Steve Alderman, USDA-ARS NFSPRC, Corvallis
Fred Crowe, superintendent, OSU-COARC, Madras
Marvin Butler, extension agent, OSUCOARC, Madras

Progress:

During 1991-1994, combine-run samples of Kentucky bluegrass were obtained from seed companies in eastern and central Oregon. Samples were cleaned with a combination of hand screens and air column to remove debris and lightweight material but retain ergot. A 10 gram subsample from each seed lot was examined for ergot under 5X magnification. Sclerotia were counted and weighed. Percent ergot, based on weight and number of seeds were determined. Percent seed lost during re-cleaning was estimated. Results from eastern Oregon were published (see below). Data collected from Central Oregon is under analysis and publication of results is planned for 1996-1997.

Objective 3:

Plant pathogenic nematode species and populations in perennial ryegrass seed production fields.

Investigators:

Steve Alderman, plant pathologist, USDA-ARS NFSPRC, Corvallis
Jack Pinkerton, nematologist, USDA-ARS HCRL, Corvallis
Russell Ingham, nematologist, OSU, Corvallis
Nanci Adair, technician, OSU, Corvallis

Progress:

During February 24-March 30, 1995, soil cores were taken from 51 perennial ryegrass seed production fields within the Willamette Valley. Fields were selected at random from a list of fields registered with OSU Seed Certification. Nematodes were identified to genera (see 1995 report).

During March-May, 1996, 32 fields were sampled. Soil was collected from two sites in each field. Species identification to date has been completed for four of the fields. Pratylenchus pratensis, Xiphinema americana, and Meloidogyne naasi were found in 4, 2, and 1 of the four fields, respectively. Meliodogyne naasi is of particular concern because it has been recorded on more than 60 host plants, including cereals. Cereal crops may be at risk as a rotational crop in grass cropping systems if M. nassi. Additional field sampling and species identifications will continue during the fall, 1996 and spring, 1997.