We invite you to attend a Delta Rice Workshop on Wednesday, August 23rd from 10:00am to noon on Staten Island (23319 N. Staten Island Rd., Thornton). The workshop is collaboratively supported by Fish Friendly Farming, the Delta Conservancy, Conservation Farms and Ranches, the CA Land Stewardship Institute, the Regional Water Board, and UC Cooperative Extension. Organizers will demonstrate the use of a recirculation pump in rice production, with a discussion of potential financial support programs. Additionally, there will be a presentation on The Nature Conservancy's Bird Returns Program, and I will provide an update on UCCE research in Delta rice.

The agenda is below, and more information is available from the attached flyer. CDFA INMP (1.0) and CCA (1.0 SW, 0.5 CM) continuing education credits have been approved. We hope to see you at the meeting!

Agenda:

Introductions

Fish Friendly Farming and Delta Conservancy/Regional Board funding - Laurel Marcus, FFF

Recirculation Pump System - Jerred Dixon, Conservation Farms and Ranches

Can funding programs such as SWEEP be used for recirculations pumps and pipelines - Laurel Marcus, FFF

Bird Returns Program - Julia Barfield, TNC

Research Activities in Delta Rice - Michelle Leinfelder-Miles, UCCE

Diagnosing problems in the field is never an easy task, but it is one of the most interesting aspects of my job because I usually never encounter the same set of circumstances twice. This summer, I have been called out on a few interesting diagnostics calls, and I wanted to share some observations.

I visited a blackeye bean field that was planted at the end of June. Since June was unusually cool this year, the grower's planting was delayed. Blackeyes shouldn't be planted until the soil temperature reaches at least 65 degrees F, and the cool spring conditions kept the soil cool. About six days after planting, the beans were only sporadically emerged. The plants that had emerged looked healthy, but the overall stand was poor. The grower said that soil moisture was good at the time of planting. I scratched down and found the seed about three inches deep, which is perhaps a little bit deep for blackeyes. Seed had germinated, and the germinated seed looked healthy with no apparent seedling diseases. Seedling diseases include Pythium and Rhizoctonia. Pythium symptoms appear as water-soaked lesions, and the hypocotyl eventually ‘dampens off'. Rhizoctonia symptoms appear as reddish-brown lesions that can girdle the stem. We felt better that it didn't appear to be a disease problem. I reached out to my farm advisor colleague, Rachael Long, to get her take on the situation, and she agreed that this was likely delayed emergence due to cool soil and a deeper planting depth. In the end, we decided to test our patience, wait a few more days, and see what would happen. After another five days, the grower let me know that the plants had emerged, and the stand looked good!

In mid-July, I was walking through a rice field and observed reddish-brown spotting on leaves that were above the water (Figure 1), and older leaves had turned brown and were in the water. I thought about stem rot, which is a disease we have observed on some Delta farms, but I wasn't observing black lesions at the water line. I contacted my colleague, Luis Espino, who has done disease management work in the Sacramento Valley. He didn't think the symptoms resembled a disease, but rather, a nutrient deficiency, like possibly potassium. I think a potassium deficiency is a reasonable hypothesis. We know that soil potassium is low in some Delta soils. Also, potassium is removed from the system in large quantities after harvest, especially in fields where the straw is baled. UC Rice Specialist, Bruce Linquist, has researched this and summarized it in this fact sheet. For a 90-cwt yielding crop, approximately 26 lb K/ac is removed in the grain, but about 28 lb K/ac is removed for every ton of straw. At this field, we advised leaf tissue testing. 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%. Bruce has also created a fact sheet on rice tissue nutrient concentrations. If growers are baling straw, I would advise soil sampling to determine whether soil K concentrations are declining over time.

In late July, I visited a corn field with my new Agronomy Advisor ‘neighbor', Giuliano Galdi. Throughout much of the field, there were plants that were drying up and dying. We didn't have a soil analysis, and what information we had on field history was limited. We noticed that manure had been applied to the field. One of our initial thoughts was salinity injury, but the symptoms didn't seem quite right. With salt damage, we would have expected to see necrosis along the leaf margins. Instead, what we were observing were leaves that were fused and unfurled (Figure 2). We called our colleague, Nick Clark, and Nick noted that he had observed symptoms like this in the southern San Joaquin Valley. He noted that when extreme weather heats up the soil, it can cause these symptoms when the plants emerge. Symptoms will vary based on the amount of plant emergence when the hot weather (i.e. hot soil) occurs. If the growing point of the plant is above the soil at the time of the heat, the plants may only have minimal damage, like a band across the older leaves. However, we suspect that the burned-up plants met their demise because the growing point was at the soil line at the time of the heat. Of course, it wouldn't hurt to get the soil analyzed just to make sure there aren't other conditions impacting the crop.

The UCCE network has a breadth of experience to help identify problems and provide potential management solutions. Please don't hesitate to contact me if you'd like help with diagnosing problems in the field.

UCCE has started its annual monitoring of armyworms in rice. Monitoring involves scouting for damage and deployment of pheromone bucket traps that catch the moths (Fig. 1). I have traps at three Delta locations, and at each location, there are three traps that span adjacent fields. Figure 2 shows monitoring data, expressed as moths caught per day, averaged across all nine traps. Notice the large arrow indicating the 2023 trend line. We are experiencing a very low population year! For comparison, look at the 2022 trend line. During this week last year, traps were averaging about 40 moths per day, and at one trapping location, counts averaged over 70 moths per day. It's hard to pinpoint why populations fluctuate from year to year, but it could relate to winter temperatures (i.e. winter survival) and/or migratory patterns from other western states and Canada.

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. UC IPM provides treatment guidelines that include damage assessment and signs of the worms in the field. Earlier this year, Methoxyfenozide (Intrepid 2F) received full registration, so we now have a new tool in the toolbox when treatment is necessary. 

The monitoring that I do in the Delta is part of a larger effort that is spearheaded by my colleague, Luis Espino, rice advisor in Butte and Glenn counties. Luis writes a weekly blog to provide real-time information on trap counts to help growers and consultants with scouting and decision making. In his blog announcements, he will link to an interactive mapping tool called Ag Pest Monitoring, where you can view counts across trapping locations. Please consider subscribing to Luis Espino's blog, but don't hesitate to reach out to me if you'd like to discuss what is happening in the Delta.

Good luck this season, and I hope to see you in the field!

University of California Cooperative Extension and the UC Davis Department of Agricultural and Resource Economics collaborate on cost of production studies for commodities grown in California. The purpose of the studies is to provide sample costs for producing commodities and expected returns, based on current production practices and economic conditions.

We have recently published a study for Sacramento-San Joaquin Delta rice production, available here. The study is based on a hypothetical 1,100 acre farm, where 1,000 acres are annually planted to rice, and it details the unique production conditions and practices of the Delta. The study assumes the farm's soil has high organic matter and employs drill-seeding (Figure 1). This soil type and planting practice differs from Sacramento Valley conditions, where rice is water-seeded onto mineral soils with high clay content. Nutrient and pest management practices also differ between the regions; hence, the study will more accurately reflect the costs associated with Delta rice cultivation. The study details the operating costs associated with Delta practices and the total costs for farm operation and management. A ranging analysis presents potential returns based on typical yields and recent crop pricing.

The study also details the costs associated with converting land from other annual crops to rice, including levee construction and land leveling. Conversion costs are significant and can inhibit adoption of rice cultivation because they may take years to recuperate.

We thank the growers who contributed their time and expertise to informing this study. Please don't hesitate to reach out to me if you have any comments or questions.