|EVENT:||UC Rice Pest Management Course 2021|
|DAY/DATE:||Friday, Sept. 10, 2021|
|LOCATION:||Hamilton Road Field (on West Hamilton Rd. between Hwy. 99 and Riceton Hwy., Biggs, CA)|
|EVENT TIME:||8:00 AM-3:25 PM (Check-in: 7:30-8:00 AM)|
|COST:||Non-student: $80/100; current student: $40/50|
This year will mark the 4th rice-specific course at the Hamilton Road Field and the Rice Experiment Station in Biggs, CA. The UC Rice Pest Management Course 2021 will begin with an interactive field tour of the research plots (Hamilton Road Field) where attendees can get up close to the weeds and rice (BRING YOUR BOOTS!) The course will include hands-on weed identification sessions on emerging and mature weeds and a disease and pest ID session. In the afternoon, speakers will address several pertinent topics in CA rice, including regulatory updates, new herbicides for resistance management, diseases and pests research updates, and how to construct a weed management program.
The course is a collaborative effort between UC Cooperative Extension (UCCE), UC Davis, and the California Rice Experiment Station (CRES.) “This course provides a strong foundation for weed and pest management in California rice, as well as a chance for interaction and discussion with researchers on the latest pests and pest control options for California rice systems” said Whitney Brim-DeForest, UCCE Rice Farm Advisor. The event is a great opportunity for pest control advisers, growers, industry, extension, and interested students to gain a deeper understanding of pest management topics that affect rice.
Enrollment is limited, so register early. The cost is $80 if received by 9/7/2021 and $100 if received after 9/7/2021 (if there is space.) The cost for current students with proof of student status is $40/$50. Online registration closes on 9/7/2021. If there is space, you can register onsite the day of the event. For more details or to register, visit http://wric.ucdavis.edu and click on RICE PEST MANAGEMENT COURSE.
CA DPR and CCA continuing education units pending approval.
If you have questions, contact Whitney Brim-DeForest [firstname.lastname@example.org or (530) 822-7515.]
Date: August 3, 2021
Location: UCCE Sutter-Yuba Office
142A Garden Highway, Yuba City
Free (lunch provided)
9:00–9:30 am Research Updates 2020-2021 (Whitney Brim-DeForest, CE Rice Advisor)
9:30–10:00 am Weedy Rice Survey 2020 (Luis Espino, CE Rice Advisor)
10:00-10:15 am Weedy Rice Identification (Luis Espino, Whitney Brim-DeForest, CE Rice Advisors)
10:15–10:30 am —BREAK— (plants to view)
10:30–10:45 am Non-conventional Path to Pesticide Registration (Roberta Firoved, California Rice Commission)
10:45-11:00 am Preventing Spread of Weedy Rice with Certified Seed (Timothy Blank, California Crop Improvement Association)
11:00-11:15 am Weedy rice emergence under various environmental conditions (Liberty Galvin, PhD Candidate, UC Davis)
11:15 am —LUNCH—
This project is sponsored with funding from the California Rice Commission.
**CE credits (CCA, DPR) pending**
We came up with a preliminary set of characteristics to distinguish this unknown biotype or species (we are unsure if it is a distinct species) from the typical barnyardgrass and late watergrass found in California rice fields. All were characterized by their seed size and awns (Table 1).
Large size, no awns
Large size, awned (all seeds)
Small size, variably awned (some seeds have awns, some do not)
New biotype/species (unknown)
Small size, awned (all seeds)
In 2018, we collected 8 samples from the field, and used two late watergrass samples from known susceptible populations to use as controls. We conducted a screening in the greenhouse, to see if we could replicate what we were seeing in the field. Field rates of Cerano® (clomazone), Butte® (benzobicyclon+halosulfuron), Granite GR® (penoxsulam), and Bolero® (thiobencarb) were used as the early-season granular applications. Field rates of SuperWham® (propanil), Regiment® (bispyribac-sodium) and Clincher® (cyhalofop) were used to test for the late-season cleanup applications. In the greenhouse, all applications were made at the 1.5 leaf stage of the grass.
Results indicate that 8 of the 8 samples were not controlled (less than 50% by biomass, in comparison to the untreated controls) by Granite GR® or Butte®. 7 of the 8 samples were not controlled by Bolero®, and 6 of the 8 were not controlled by Cerano®. This closely follows what growers were stating had occurred in the field: the watergrass was escaping early-season control, and was then difficult or impossible to control with later-season herbicide applications. SuperWham®, Regiment®, and Clincher® controlled 8 of 8 samples (at least 60% control). However, since the greenhouse application was conducted at an early timing (1.5 leaf stage), it is possible that later applications in the field may be less effective.
For growers, the implications of this preliminary screening are that control of this new biotype/species will need to be prioritized early in the season. Possible treatments (keep in mind that these have not been field-tested and could cause phytotoxicity) could be: a stale seedbed using a non-selective herbicide; pre-plant Abolish® (thiobencarb) followed by Cerano® or Butte® or Granite GR®; Cerano® followed by Butte® or Bolero® or Granite GR®; or Butte® followed by Granite GR® or Bolero®. There is still a strong likelihood that a follow-up application may still be required later in the season, even with these early-season applications.
In 2020, more than 60 watergrass samples were collected from all over the rice-growing region. We will continue working on identification and conduct further herbicide screening this year.
- Author: Whitney Brim-DeForest
- Author: Roberta Firoved
Since 2019, UCCE Rice Advisor Whitney Brim-DeForest has been testing SUPPRESS® herbicide for use in weed control in rice. In 2019, she collaborated with Jim Cook (Colusa County Farm Supply), to spot spray weedy rice in a field containing Type 3 (long awns, straw hulled). The application was made with a handheld backpack sprayer, at the highest labeled rate. The timing was too close to heading, however, and some of the weedy rice plants recovered.
This past season, in 2020, we did further testing in the field, on several different weedy rice types (field was a mix of Types 1, 2, 3, and 5). The application timing for the field testing in 2020 was made with a handheld backpack sprayer, at the highest labeled rate. The timing was approximately at panicle initiation, and at two weeks after application, the weedy rice plants were 100% controlled. At harvest, there was some regrowth, but none of the plants produced viable panicles.
For use in weedy rice spot spraying in 2021, SUPPRESS® could be an option, but the label does not allow for application when there is standing water in the field. Therefore, in order to be used, the field will need to be drained before application. Application timing is after the last grass herbicide has been applied, but before the weedy rice has started to flower (generally no earlier than 60 days after seeding). Reflooding is recommended within 48 hours of application to reduce the germination of additional weeds, unless the field can remain drained until harvest.
Remember to always follow all label instructions when applying any pesticide, as the label is the law. Make sure to pay particular attention to the Use Precautions and Restrictions. Consult your local Agricultural Commissioner's Office regarding buffer zones and aerial restrictions, before making any applications.
For more information, contact UCCE Rice Advisor, Whitney Brim-DeForest (email@example.com), and Roberta Firoved, Industry Affairs Manager for the California Rice Commission (firstname.lastname@example.org)
It's that time again! If you would like to submit seeds for herbicide resistance testing, many weed species will be maturing right about now.
The UCCE Rice Weeds Program tests grower submitted seed samples of potentially herbicide-resistant watergrass species, sprangletop, smallflower umbrella sedge and bulrush. However, we encourage you to submit ANY species that you suspect to be resistant. We keep individual grower information confidential and any reporting of results will not identify individual growers.
Please fill out the form (linked here) for each weed seed sample (each field and/or species). The following tips will ensure that you receive the best possible results:
- The best timing of collection is when the seed easily falls off the seed head by gentle agitation in a paper bag (see video for demonstration):
o For watergrass species, this should be close to rice harvest (seeds should be brownish in color)
o For sprangletop, timing will be earlier, in August or September (seeds will appear greenish)
o For the sedges, timing may be as early as July, all the way through early September
o Smallflower umbrella sedge seed is yellow, with brown hulls (looks like dust)
o Bulrush (roughseed) seeds are black and have small hairs
- Seed should be collected from areas that you know have been sprayed with the suspected herbicide.
- Collect seeds from multiple plants, and the amount should be at least a few handfuls of seed, to ensure sufficient quantity for testing.
- Please do not collect seed from around field margins.
- Allow seed to dry in the paper bag to prevent molding.
Bring the sample and form to your local UCCE Farm Advisor (Whitney, Luis, or Michelle) or send or drop off samples at the Rice Experiment Station (RES) in Biggs. If you need assistance in collection, please contact your Farm Advisor or PCA. Results should be emailed to you in March of 2021.