- Author: Michelle Leinfelder-Miles
UC Cooperative Extension will host a Healthy Soils Program field demonstration day on cover cropping in rice systems. The meeting will take place on Thursday, February 29th, from 9:30am to noon, on Staten Island in San Joaquin County (23319 N. Staten Island Road, Thornton). Presentations will describe field trials to evaluate winter cover cropping, incentive programs for growers, and weed management topics ahead of the 2024 growing season. There will also be an opportunity to view different cover crop species for performance. Attendance is free, and registration is not required. CCA continuing education credits will be offered (0.5 PM, 1.0 CM, 0.5 PD). The agenda is pasted below, and a downloadable version is attached. Thanks for your interest in UC Cooperative Extension programming, and we hope to see you later this month!
9:30am Arrive at Staten Island grain silo to sign in (See yellow star on the map)
9:45am Depart to field location – Don't be late!
10:00am Welcome and Introductions: Michelle Leinfelder-Miles, UCCE Delta Region
10:05am Winter Cover Cropping in Rice Systems – Field Demonstrations: Michelle Leinfelder-Miles, UCCE Delta Region
10:20am Cover Crop Variety Evaluations: Sara Rosenberg, UC Davis
10:35am A Grower's Perspective on Cover Crops: Jerred Dixon, Conservation Farms and Ranches
10:55am Healthy Soils Program – Block Grant Pilot Program: Chris Kelley, CA Land Stewardship Institute
11:10am What's New in Rice Weed Management: Whitney Brim-DeForest, UCCE Sutter/Yuba
11:25am Weedy Rice Updates: Whitney Brim-DeForest and Michelle Leinfelder-Miles, UCCE
11:40am Discussion, Viewing of Field Plots, Evaluation
2024 Rice Cover Crop Field Day Agenda FINAL
- Author: Michelle Leinfelder-Miles
Rice production in the Sacramento-San Joaquin Delta region has been steadily increasing in recent years. While Delta acreage is only a fraction of that in the Sacramento Valley, Delta yields are consistent with statewide averages. I estimate that in 2023, the Delta had around 10,000 acres of rice. In this seasonal recap, I'll overview UCCE research in Delta rice, as well as provide some observations about the 2023 season.
Armyworm Monitoring: I have been monitoring armyworm populations in the Delta since 2016, in collaboration with my UCCE colleague, Luis Espino. Monitoring involves scouting for damage and deployment of pheromone bucket traps that catch the moths. We can use trap counts and Growing Degree Day modelling (i.e. a temperature measure of time) to determine whether and when to treat fields. In 2023, we were thinking we might get away with minimal pressure because the population stayed low through early July. Then, the population spiked in mid-July, later than we had ever observed (Fig. 2). We surmise this was due to the cool, wet spring and later planting season. This year, Methoxyfenozide (Intrepid 2F) was available for use under full registration.
Disease Observations: We have identified diseases like stem rot, aggregate sheath spot, and rice blast on some Delta farms. It is important to scout for these diseases at late-tillering and early-heading because treatment timing is critical for management. Fungicide treatments are most effective when applied between late-boot and early-heading. Rice blast may be exacerbated by too much nitrogen, and stem rot and aggregate sheath spot by low potassium (K). K can be limiting in some Delta soils, especially where the straw is baled. There is a loss of approximately 28 lb K/ac for every ton of straw removed. Consider leaf tissue sampling for K between tillering and panicle initiation. The Y-leaf should have a K concentration of at least 1.5%. At heading, the flag leaf should have a K concentration of at least 1.2%. On-farm consultations are a service provided by UCCE. Please reach out if I can help identify pests and provide management guidelines.
Weedy Rice: We should continue to keep weedy rice on our radars because we have observed it in the Delta. In-season management includes rogueing or spot spraying before viable seed is produced. The organic herbicide Suppress is registered for spot spraying. Post-harvest management should include straw chopping, but not incorporation, and winter flooding. This will keep seed on the soil surface, where it can potentially deteriorate over the winter.
Variety Trial: UCCE collaborates with the California Rice Experiment Station to evaluate commercial varieties and advanced breeding lines. The San Joaquin County Delta location was one of ten locations in the 2023 statewide trial. The Delta is a test site for very-early maturing varieties because it has cooler growing conditions than other rice growing regions of the state. Variety trial results will be made available in the February 2024 newsletter.
Cover Cropping: With funding from the CDFA Healthy Soils Program and CA Rice Research Board, I am collaborating with Sara Rosenburg (UC Davis graduate student) and Whitney Brim-DeForest (UCCE rice advisor) to evaluate winter cover crops. We are interested to learn whether cover cropping improves soil carbon and nitrogen dynamics in the rice system. Since rice may be grown over multiple seasons without rotation, cover crops may provide an opportunity to introduce plant diversity, including nitrogen-fixing legumes. Trials will occur from 2022-2025, and the Delta site is one of three (also in Butte and Colusa counties). The 2022-2023 winter season presented several challenges for cover cropping. At the Delta location, seasonal rainfall exceeded 25 inches, and in the ten days after planting, the site received nearly 3.5 inches of rain. In addition to saturated soils, bird predation was severe. This fall, our aim is to plant earlier, if conditions allow.
Thank you to all the growers who collaborated with us on these projects. I wish everyone a good end to the year and a great 2024.
- Author: Michelle Leinfelder-Miles
Mark your calendar with these upcoming meetings brought to you by UC Cooperative Extension, USDA-NRCS, and the California Rice Experiment Station. See the links or attached flyer for more information.
1. UCCE Rice Production Workshop
Tuesday, August 7, 2018
8:30am - 3:00pm (lunch included with registration)
5311 Midway, Richvale, CA 95974
Registration is required. Visit http://ucanr.edu/rice2018 to register, or see this post for more information.)
2. USDA-NRCS Warm Season Cover Crops Field Day
Wednesday, August 22, 2018
10:00am-12:00pm
Lockeford Plant Materials Center, 21001 N. Elliott Rd., Lockeford, CA 95237
No registration required. See agenda in the attachment (below).
3. UC Davis Dry Bean Field Day
Thursday, August 23, 2018
10:00am-12:00pm
UC Davis Agronomy Farm: Take Hutchison Dr. approximately 1.5 miles west from Hwy 113, in Davis. Turn south on Hopkins Lane, and then take the first left turn (heading east) onto a gravel/broken pavement road with a row of olive trees; park along the fence. The field is located north of the Bee Biology Center.
4. Rice Experiment Station Annual Field Day
Wednesday, August 29, 2018
7:30am-12pm (lunch included)
Rice Experiment Station, 955 Butte City Hwy, Biggs, CA 95917
No registration required. For more information, visit http://www.crrf.org/.
4. UCCE Alfalfa and Forage Field Day
Wednesday, September 19, 2018
7:30am-12:30pm (lunch included)
Kearney Agricultural Research and Extension Center, 9240 S. Riverbend Ave., Parlier, CA 93648
More information will be forthcoming.
NRCS Warm Season Cover Crops Field Day Flyer