AlliumNet

2018 State Reports

California: Tom Turini (Cooperative Extension Fresno County, UCANR) and Rob Wilson (UC ANR, IREC, Tulelake, CA)

No major widespread change in the acreage and production of onion and garlic as well as no major issues with foliar pathogens in these crops. White rot was not widespread last year except for one outbreak that led to complete loss of crop in a 60-acre field. Currently, working on white rot issues through a multi-state USDA NIFA funded project (2018-2022). Evaluation of biostimulants were conducted for improving general production issues in onion and garlic.

In addition, there were 3000 to 4000 acres of processing onions for dehydration in CA. Production was stable despite concerns about the smoke. Access to water remains an issue as do onion maggot and white rot. Working on germination stimulants for the management of white rot.

Georgia: Bhabesh Dutta (University of Georgia)

Center rot and sour skin were major concerns in 2018. Center rot issue was more prevalent in field and in storage than sour skin. Botrytis leaf blight (BLB) was widespread but not severe in 2018. Fungicide evaluation was conducted to observe efficacy of individual fungicide for BLB management. Fungicides: Scala, Luna tranquility, Omega 500 and Inspire super provided better efficacy than Rovral. Rovral was moderately effective on BLB. Catamaran is no longer available for sale, hence, Georgia growers were recommended to use K-phite+Bravo. Downy mildew (DM) was observed at the Vidalia Onion and Vegetable Research Center, Vidalia, GA but the spread was limited. Fungicide evaluation for DM control indicated that Bravo and Orondis Ultra are effective compared to Reason, Zampro and Omega 500. Stubby root nematode was first detected on onion in Georgia (2018).

Pennsylvania: Beth Gugino (The Pennsylvania State University)

Spanish sweet onion cultivar cv. Candy is grown. Gave introduction to the onion production system in Pennsylvania which consists of approx. 125 acres and 90 growers for the Simply Sweet Onion Program. The season was wet and losses in sweet onion due to allium leaf miner was minimal. Production is moving north of Lancaster in the state where conditions are cooler and less conducive to bacterial diseases.

Colorado: Mike Bortolo (Colorado State University).

Acreage of Colorado declined from 18,000 acres (1997) to 4,000 acres (2017) in part due to competition for water, labor and hemp production being on the increase. Hail damage was particularly bad this year. Mark Uchanski evaluated the effect of K fertility on IYSV severity in onion. The results will be communicated at the next W3008 meeting. Thad Gourd conducted onion variety trials for yield, flavor and other horticultural attributes. Mike Bortolo stressed that the development of a strong fruit and vegetable grower association in Colorado has been a huge success for the state. They are now working together on a mission to mitigate water and labor issues.

Utah: Dan Drost (Utah State University)

Utah is currently 40% drip irrigated compared to historically being 100% furrow irrigated; however, water management is still an issue. Despite the water challenges, the industry has expanded to 2000 acres along with the addition of couple younger growers. Excessive heat was not observed during onion growing season in 2018 and weather was comparatively better than other years therefore, disease and pest issues were limited.  Yields were high with many colossal and super colossal.  Dan Drost did sabbatical in UK and New Zealand where he shared W-3008 efforts and impact. They were excited how US W-3008 has been a success for our onion researchers and stakeholders which demonstrates international project impact. 

New Mexico: Chris Cramer (New Mexico State University)

No weather issues in general and for most part the conditions were good during onion growing season in New Mexico. It was a good year for onion seed production; not too hot and low-to-moderate rainfall. The USDA-NIFA project on identifying IYSV-resistant germplasms in fields will be performed in 2019. The germplasms to be evaluated will include five pre-identified lines; 4 of the lines will be glossy foliage type. These lines will be compared under stressed and non-stressed conditions. A field trial layout that maximizes IYSV infection was also developed, which is important to the field evaluation of germplasm lines.

Texas: Subas Malla (Texas A and M University)

Evaluated 45 onion lines and among them the line (31028) had the highest yield with less pink root severity. Performance of short day sweet onion germplasm was evaluated and identified some promising ones with thrips tolerance. IYSV not detected at Uvalde, TX. There were issues with Stemphylium leaf blight and Botrytis during seed production that killed the plants. Working to correlate desirable onion traits with NDVI to improve the screening process. Erwinia or other bulb rotting bacteria was reported in farmer’s field at Mission, TX.

Idaho: James Woodhall (University of Idaho)

Generally, little concern on soilborne diseases, Fusarium basal rot, pink root and Pythium, although pink root seems to be the most problematic. Good season for onion production overall with little change in production on the eastern side of Treasure Valley, although yields were down slightly. Later in the season, heavy rain event occurred which was followed by limited outbreaks of blue mold and Botrytis leaf blight.

Oregon: Stuart Reitz (Oregon State University)

It was a good production season for the western side of the Treasure Valley with large onions and high yields. Reports and update on following topics were presented: FSMA-Produce Safety rule (water quality monitoring and variance application), thrips and IYSV (monitoring and management), and, environmental effect on internal bulb rot. FDA requires monitoring of irrigation water that are used for onion production. Growers rely on intensive insecticide spray program for thrips control. Thrips and IYSV monitoring is underway throughout the state by the onion pest monitoring program. The IPM strategic plan for onion in Oregon was recently published. Pesticide resistant management workshops for growers and county agents were conducted. Further, internal bulb quality was a concern in Oregon and occurs when the internal bulb scales do not completely expand (incomplete scale defect) which make the onion more susceptible to opportunistic bacterial infections. Evaluated treatments to reduce losses (e.g. Kaolin and Straw) and found that treatments that increased soil temperatures led to reduced internal bulb quality.

Washington: Tim Waters (Washington State University)

Limited incidence of downy mildew and moderate to low IYSV incidence were observed in onion seed crop, which was not as bad as in 2016-17. Fusarium, pink root and nematode (Stubby root) were also observed in onion. The harvest conditions for onion are currently better in Washington despite the significant amount of wildfire smoke. The WSU onion alerts, modeled off the potato alert system, has 600 subscribers and has been a help for onion growers in Washington. Evaluated organic and conventional insecticides in field trials. Insecticide evaluations for potential resistance of thrips to oxamyl and methomyl were conducted in the field. Fungicides were evaluated for downy mildew management in 2018. Lindsey du Toit is currently leading a Specialty Crop Block Grant to work on arbuscular mycorrhizal fungi (AMF) against soil borne pathogens in onion. Despite conducting trials in over 20 fields over 3 years, there was no benefit found to adding AMF in onion. The application of soil fumigants through center pivot irrigation is becoming increasingly restricted so now evaluating alternative application methods (e.g. chemigation vs shank application) to determine where in the soil profile the fumigant is active and on what pests.

New York: Christy Hoepting (Cornell University Cooperative Extension)

Western New York had a drier than normal spring, and hot temperatures settled in during mid-June. This resulted in mixed results with respect to efficacy of pre-emergent herbicides and an explosive thrips infestation in Western NY, which led to high incidence of IYSV, and pink root problems, especially in red varieties.  The variety ‘Bradley’ was comparatively better than other varieties with regards to root health.  Foliar diseases were generally low, although Stemphylium leaf blight was severe in some small-scale upland productions. Rain events in August aided the crop to produce medium sized bulbs.  Unfortunately, extreme thrips/IYSV/pink root stress along with rain events contributed to higher than normal incidence of bacterial bulb.  The crop in Wayne and Oswego counties did not suffer from such high thrips and IYSV pressure and is of excellent quality. Orange County suffered from remnants of hurricanes in August resulting in delayed harvest and bacterial bulb rot issues.  Overall, yield/bulb size was down (way down on some farms) in New York with quality being highly variable.