Fungicide Spray Programs for Defender, A New Potato Cultivar with Resistance to Late Blight and Early Blight.

Defender (A90586-11) is a new late blight-resistant potato cultivar which was released from the Tri-State Potato Variety Development Program in 2004. Conventional and reduced fungicide spray programs were compared on Defender and Russet Burbank (3 years) and Ranger Russet (1 year) in Wisconsin experimental field trials. Useful levels of field resistance to both late blight and early blight were observed in Defender in the absence of fungicide sprays and reduced fungicide input programs. Disease progressed slowest on Defender regardless of fungicide program, relative to Russet Burbank and Ranger Russet. Organic, conventional, and reduced fungicide spray programs also were compared on Defender and Russet Burbank in experimental greenhouse and field tests in Washington. Fungicide spray programs performed similarly on both Defender and Russet Burbank; however, area under the disease progress curve values for no-fungicide treatments were either three times (greenhouse) or six times (field) lower on Defender compared with Russet Burbank. Regardless of the fungicide program, total yield was higher for Defender than Russet Burbank. Mean economic returns associated with Defender also were higher than for Russet Burbank ($6,196 versus $4,388/ha). Fungicide and nonfungicide treatment programs generated similar returns on Defender whereas conventional and reduced fungicide programs generated comparable but higher returns than the nonfungicide program on Russet Burbank.

The Occurrence of PVYO, PVYN, and PVYN:O Strains of Potato virus Y in Certified Potato Seed Lot Trials in Washington and Oregon.

Totals of 960 and 286 certified potato seed lots from locations across North America were planted in trials in Washington and Oregon, respectively, in 2001 to 2003 and tested for strains of Potato virus Y (PVY). The incidence of PVYO-infected lots averaged 16.4 and 25.9% in the Washington and Oregon trials, respectively. There was a general trend of increasing incidence of the PVYO, PVYN:O, and PVYN strains during this period, as evidenced by more infected cultivars, sites of seed origin, and number of seed growers providing infected seed lots. In particular, there was a dramatic increase in seed lots with the PVYN:O strain from 2002 to 2003. PVYN:O, in contrast to PVYO, which only causes yield reduction, also causes internal and external damage to tubers, making them unmarketable. In 2003, PVYN:O occurred in seed lots originating in eight states and three Canadian provinces. The increased incidence of PVYN:O was likely due to the difficulty in differentiating this strain from PVYO. The prevalence of PVY in potato seed lots documented herein poses a threat to potato production in the United States and suggests that current measures to reduce the incidence of this virus are inadequate.

First Report of the Necrotic Strain of Potato virus Y (PVYN) on Potatoes in the Northwestern United States.

More than 50 isolates of Potato virus Y (PVY) with characteristics of strains that cause tobacco veinal necrosis (PVYN) were obtained from potatoes (Solanum tuberosum L.) grown in the northwestern United States. These isolates are being characterized at the biological and molecular levels. Isolate RR1 was obtained from leaves of potato cv. Ranger Russet showing distinct mottling and leaf deformity, which is in contrast to the leaf-drop and necrosis usually observed with ordinary strains of PVY (PVYO) in this variety. Isolate AL1 was obtained from tubers of potato cv. Alturas showing distinct internal light brown rings and blotches. When RR1 and AL1 were transmitted to tobacco (Nicotiana tabacum L. cvs. Samsun NN and 423), they caused systemic veinal necrosis, including stem and petiole lesions typical of PVYN strains (2). Symptoms induced by RR1 and AL1 on tobacco appeared 9 to 11 days after inoculation, whereas some other isolates caused delayed veinal necrosis. All isolates that produced veinal necrosis on tobacco were detectable with PVY polyclonal antisera. Potato virus X was not detected by enzyme-linked immunosorbent assay in tobacco plants showing veinal necrosis. Some isolates, including AL1, failed to react in serological tests using PVYN-specific monoclonal antibodies obtained from three commercial sources. Other isolates, including RR1, were detectable with these monoclonal antibodies. Reverse transcription-polymerase chain reaction (RT-PCR) products obtained with primers specific for the coat protein (CP) open reading frame (ORF) were cloned and sequenced. AL1 possesses a CP more closely related to PVYO type isolates, which would account for its failure to react with PVYN monoclonal antibodies. In this regard, AL1 is similar to the PVYN-Wilga isolate (1). Other isolates that are detectable with the PVYN monoclonal antibodies possess a CP more consistent with N strains of the virus. Results of RT-PCR tests using primers derived from the P1 ORF sequence (3), and the restriction enzyme analysis and sequencing of the RT-PCR products, all suggest that AL1 and RR1 are related to European-type members of PVY tuber necrotic (NTN) or N strains. However, other isolates under investigation appear to be more closely related to previously reported North American NTN types (3). The symptomatology of these viruses on tobacco and potato, and the serological and molecular data clearly show that at least two distinct variants of PVYN have been found for the first time in a major potato production area of the United States, and pose a potential threat to the potato industry. References: (1) B. Blanco-Urgoiti et al. Eur. J. Plant Pathol. 104:811, 1998. (2) J. A. de Bokx and H. Huttinga. Potato virus Y. Descriptions of Plant Viruses. No. 242, CMI/AAB, Surrey, England, 1981. (3) R. P. Singh et al. Can J. Plant Pathol. 20:227, 1998.

Chiropractic care of a patient with vertebral subluxations and unsuccessful surgery of the cervical spine.

OBJECTIVE: The chiropractic care of a patient with vertebral subluxations, neck pain, and cervical radiculopathy after a cervical diskectomy is described. CLINICAL FEATURES: A 55-year-old man had neck pain and left upper extremity radiculopathy after unsuccessful cervical spine surgery. INTERVENTION AND OUTCOME: Contact-specific, high-velocity, low-amplitude adjustments (i.e., Gonstead technique) were applied to sites of vertebral subluxations. Rehabilitation exercises were also used as adjunct to care. The patient reported a decrease in neck pain and left arm pain after chiropractic intervention. The patient also demonstrated a marked increase in range of motion (ROM) of the left glenohumeral articulation. CONCLUSION: The chiropractic care of a patient with neck pain and left upper extremity radiculopathy after cervical diskectomy is presented. Marked resolution of the patient's symptoms was obtained concomitant with a reduction in subluxation findings at multiple levels despite the complicating history of an unsuccessful cervical spine surgery. This is the first report in the indexed literature of chiropractic care after an unsuccessful cervical spine surgery.

Potato Late Blight in the Columbia Basin: An Economic Analysis of the 1995 Epidemic.

The cost of managing late blight in potatoes during a severe epidemic caused by new, aggressive strains of Phytophthora infestans in the Columbia Basin of Washington and Oregon in 1995 was documented. The mean number of fungicide applications per field varied from 5.1 to 6.3 for early- and midseason potatoes, and from 8.2 to 12.3 for late-season potatoes in the northern and southern Columbia Basin, respectively. In 1994, a year when late blight was not severe, the mean number of fungicide applications per field made to early- and midseason potatoes was 2.0; whereas late-season potatoes received a mean of 2.5 applications. The mean per acre cost of individual fungicides applied varied from $4.90 for copper hydroxide to $36.00 for propamocarb + chlorothalonil. Total per acre expenses (application costs plus fungicide material) for protecting the crop from late blight during 1995 ranged from $106.77 to $110.08 for early and midseason potatoes in different regions of the Columbia Basin and from $149.30 to $226.75 for lateseason potatoes in the northern and southern Columbia Basin, respectively. Approximately 28% of the crop was chemically desiccated before harvest as a disease management practice for the first time in 1995, resulting in an additional mean cost of $34.48/acre or $1.3 million for the region. Harvested yields were 4 to 6% less than in 1994. The total cost of managing late blight in the Columbia Basin in 1995 is estimated to have approached $30 million.

Preliminary studies of urinary hydroxyproline levels in rodents and in smokers.

Groups of rats were exposed to four dilutions of cigarette smoke over a period of our weeks. Compared to the control (untreated) group of animals, the 24-hour hydroxyproline output (relative to creatinine) was lower for all dilutions of smoke and showed a negative dose-response relationship. In human smoking studies, in which groups of 20 male subjects and 20 female subjects were switched between various cigarettes for periods of 2 weeks, hydroxyproline output (relative to creatinine) for each sex did not change with increasing nicotine uptake although the outputs for men and women were significantly different.