Delta Region Areawide Aquatic Weed Project

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midge popping out of a consumed rice kernel
Article

The Usual Suspects

July 9, 2025
By Luis A Espino
Time to round up the usual suspects! When talking about arthropod control in California, the usual suspects are rice seed midge, tadpole shrimp, and armyworms. I will focus on rice seed midge and tadpole shrimp in light of recent pyrethroid exceedances detected in the Sacramento Valley. The challenge…
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bakanae rice plant in a rice field
Article

Chlorine Seed Treatments

July 2, 2025
By Sarah Marsh Janish
 In the last month, I’ve had more frequent calls about how to cut costs, with several people mentioning cutting their chlorine seed soak treatment in an attempt to bring down their input costs. This seed soak is used to eliminate bakanae spores from rice seed and is one of the most effective methods to…
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Article

Blanking potential in forecast

June 27, 2025
By Bruce A Linquist
Blanking (floret sterility) can occur during meiosis (pollen formation) when nighttime temperatures drop below 58 oF. Blanking can cause reduced yields. The cooler it is and the more nights during this period with low temperatures have an increasingly negative effect.  You can see in Figure 1, where in…
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Summary of the 2024 Variety Trails

June 26, 2025
By Bruce A Linquist
In 2024 we had eight variety trial locations. Four locations were in what we refer to as warmer locations (north of Hwy 20) and four in the cooler locations (south of Hwy 20 and into the Sacramento Delta region). These trails are funded by the Rice Research Board and fulfill at least two purposes. First,…
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Defoliation
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Don't let your guard down against armyworms

June 25, 2025
By Luis A Espino
I've been looking at some fields this week and I'm seeing high worm populations. These are fields where armyworms have been a problem in the past. I would say this year the numbers I am seeing are much higher than the last three years. In one field in particular, defoliation is close to threshold (25%). …
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Bakanae field
Article

Bakanae still showing up after bleach treatment

June 18, 2025
By Luis A Espino
In the past few years there has been a steady increase in the incidence of bakanae in the field. Fortunately, the levels of infection we have seen have not resulted in yield reductions. However, talking to those that worked on developing the bleach treatment after bakanae was identified in California, there…
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Shrimp or Midge: What is Affecting the Rice?

June 9, 2025
By Sarah Marsh Janish
When it comes to early season seedling injury, the damages wrought by rice seed midge and tadpole shrimp can be difficult to differentiate. Both are invertebrate pests that feed on young rice seeds and inhibit or terminate rice growth, and both can leave a field devoid of plants. However, taking a closer…
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2025 Rice Production Workshop - Save the Date!

June 5, 2025
 2025 Rice Production WorkshopAn in-depth workshop that covers the principlesand practices of rice production in CaliforniaJuly 23-24, 20258:30 am - 3:30 pmUCANR Building, 2801 2nd St, Davis, CA 95616Please click here for the agenda: Agenda** Registration required ($200 registration fee includes manual…
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To topdress or not to topdress?

May 30, 2025
By Luis A Espino
Given the current economics of rice, you may be planning on not topdressing. If there is enough N up front as aqua, this should be fine. The question is how to determine if you have enough. One easy, practical way to confirm that you do not need a topdress is to set up a small overfertilized area. To do this…
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2025 No-Till Rice Field Day - Save the Date!

May 12, 2025
No-Till Rice Field Day  An in-depth discussion that explores no-till drill-seeded rice planting and management strategies June 10, 2025 9:00 am – 11:00 am694 Watson Road, Biggs, CA 95917Please click here for the agenda: Agenda Program8:30 am    Registration  9:00…
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QR code for survey
Article

Survey on Weed Control Technologies for Tree and Vine Crops

May 6, 2025
By Brad Hanson
Note: I'm sharing a survey request related to grower and industry needs related to novel weed control technologies in orchards, vineyards, and other perennial specialty crops.  Our team of research collaborators is developing this information as a first step towards a future coordinated national…
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Article

The best soil P test for rice: Olsen-P vs Bray-P

April 18, 2025
By Bruce A Linquist
This year, with high input costs and low rice prices, a lot of growers are testing their soil to determine if they need to apply P and K fertilizer.  I have received a number of calls this week asking about interpreting their soil P test for rice soils. I have recommended using the Olsen-P test (or a…
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Four men in weedy area. One is holding a measuring container while another sprays liquid into it from a wand attached to a backpack sprayer. A third person holds a clipboard and the furth holds a stopwatch.
Article

New Online Course: Calibrating Herbicide Applications for Non-Agricultural Areas

April 14, 2025
By Cheryl A Reynolds
Calibration might sound intimidating, but it’s critical for safe and effective herbicide application. Proper calibration ensures that the correct amount of pesticide is applied to an area while achieving the desired level of pest control. To support land managers and pesticide applicators, the UC Statewide…
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Late Rains, Small Plants, Fast Phenology

April 4, 2025
By Chris J McDonald
Originally Posted April 1, 2025. This year in Southern California the rainy season got off to a late start. Southern California has received about one half of the average precipitation total as of this writing (and that's not an April fool's joke). Last year we had over 50% more rainfall than the…
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webinar video on electric weed control in organic perennial crops

April 2, 2025
By Brad Hanson
A quick repost to share a link to a recent January 14, 2025 webinar on Electric Weed Control in Organic Perennial Crops. The webinar was part of a multi-state research and extension project that includes researchers from Oregon State University, Cornell University, and UC Davis and outreach support from…
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WeedCut: BMPs for herbicide application techniques

April 2, 2025
By Brad Hanson
Sharing a recent post from the California Invasive Plant Council (Cal-IPC) about a new page on the WeedCUT online decision support tool. -Brad--------------------------------------------------------------------New WeedCUT Feature: BMPs for Herbicide Application Techniques   Confused about…
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field map of the hedgerow and control plot area
Article

Hedgerows in Rice Update

February 26, 2025
By Whitney B Brim-Deforest, Taiyu Guan, Luis A Espino, Sarah E Light, Consuelo B Baez Vega
Incorporating hedgerows in rice could provide growers with an alternative method for managing field margins without relying on pesticide applications to control the pests along the edges of rice fields.
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Welcome

Participants
NASA Ames Research Center
USDA-ARS Invasive Species and Pollinator Health Research Unit 
California Dept of Parks & Recreation - Division of Boating & Waterways
California Dept of Food & Agriculture
Sacramento-San Joaquin Delta Conservancy
University of California, Davis
Local mosquito vector control districts
 
General areas of study
Weed mapping tools
Management techniques and strategies
Weed effects on ecosystems, native plants, and water quality
Biological control agents
Effects of weeds on mosquito populations
Bio-economic modeling of weed control costs and project benefits

 

Announcements

As of September 2021, a special issue of the Journal of Aquatic Plant Management features participants in DRAAWP. Individual papers can be seen under the "Journal Articles" tab to the left.

We have posted a new 2020 Areawide Report under the Products tab to the left.

This year's Aquatic Plant Management Society annual meeting is planned for July 12-14, 2021, in New Orleans.

The Western Aquatic Plant Management Society (WAPMS) recently participated in a virtual conference jointly with the Western Society of Weed Science. The 40th annual meeting of WAPMS is scheduled for March 7-11, 2022. 

Our DRAAWP informational brochure is available from the Site Navigation tab at the left.

 

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