With planting season coming up, thinking about appropriate variety selection is key, and one of the first steps towards ensuring a good 2021 crop. Each year the California Rice Research Board funds a statewide variety trial testing program. Here I summarize some of that data.

These trails are on grower managed fields in eight locations around the Sacramento Valley as seen in the map. One major difference in the locations selected is nighttime temperatures in mid to late July when most of the rice is booting. Cold temperatures during this period can cause blanking and lower yields. On the map, locations in red are where cold nighttime temperatures are usually not a problem. These locations are generally north of highway 20. In yellow are locations where growers need to be concerned about low nighttime temperatures; while they may not occur every year, they are common. In blue (South Yolo) is a location where cold temperatures occur almost every year. Importantly, in each of these regions may be micro-climates where temperatures vary from the “average”.

Map showing variety trial locations in the Sacramento Valley. Dot color refers to nighttime temperatures in the last half of July (during booting). Red dots refer show locations where cold nighttime temperatures are not normally a concern for blanking. Yellow dots are those locations where cold temperatures more common, and the blue dot location is where cold temperatures occur almost every year. Temperatures are a concern when they drop below 58^oF.

Some varieties are more tolerant of cold than others. Therefore, it is important to select varieties that are suitable for the location you are farming. In the tables below, are yield data from the past five years for each location in the variety trial. Only the main medium grains varieties are shown (M-105, M-206, M-209, M-210 and M-211). This data will allow for a more informed decision when it comes to variety selection. 

The warmer locations are north of Hwy 20,in Glenn, Butte and Colusa counties. At these locations, M-211 consistently outperforms the other medium grains by 4 cwt/ac, on average, over the five years and four locations. Among the other varieties shown, there were no consistent differences among them.  

In the cooler locations, M-209 performed the worst in general. In the moderately cool locations (yellow dots on the map), M-105 and M-211 both did consistently well. In the coldest location (South Yolo), M 105 performed the best; while M-209 and M-211 performed poorly. Both M-209 and M-211 have similar days to maturity (about 5-7 days later than M-206). This data suggest that M-211 may have a broader adaptability range than M-209 because it appears to be slightly more cold tolerant. However, in the coolest location even M-211 did not perform well. 

M-206 versus M-210: M-206 has been the most broadly adaptable variety available. While it may not always be the highest yielder, it generally does well across all locations.  M-210 is a new variety which has blast resistance. It is basically M-206 with genes for blast resistance and has similar time to heading.  Based on these data M-206 and M-210 have almost identical yields in both the warm and cooler regions. 

Thoughts on M-211: As seen in the data provided, M-211 is a tremendously promising variety in terms of yield potential. Furthermore, its sensory qualities are similar to premium grain varieties such as M-401. However, one draw back is that for good milling quality, M-211 needs to be harvested at 20-22% moisture. Harvesting below this moisture can result in low milling quality. Given this, it may not be a variety that is suitable for large acreage planting and this should be tested by growers. 

Considerations for choosing the right medium grain rice variety

                        With planting season coming up, thinking about appropriate variety selection is key, and one of the first steps towards ensuring a good 2021 crop. Each year the California Rice Research Board funds a statewide variety trial testing program. Here I summarize some of that data.

   

       

Map showing     variety trial locations in the Sacramento Valley. Dot color refers to nighttime     temperatures in the last half of July (during booting). Red dots refer show     locations where cold nighttime temperatures are not normally a concern for     blanking. Yellow dots are those locations where cold temperatures more     common, and the blue dot location is where cold temperatures occur almost     every year. Temperatures are a concern when they drop below 58oF.

These trails are on grower managed fields in eight locations around the Sacramento Valley as seen in the map. One major difference in the locations selected is nighttime temperatures in mid to late July when most of the rice is booting. Cold temperatures during this period can cause blanking and lower yields. On the map, locations in red are where cold nighttime temperatures are usually not a problem. These locations are generally north of highway 20. In yellow are locations where growers need to be concerned about low nighttime temperatures; while they may not occur every year, they are common. In blue (South Yolo) is a location where cold temperatures occur almost every year. Importantly, in each of these regions may be micro-climates where temperatures vary from the “average”.

Some varieties are more tolerant of cold than others. Therefore, it is important to select varieties that are suitable for the location you are farming. In the tables below, are yield data from the past five years for each location in the variety trial. Only the main medium grains varieties are shown (M-105, M-206, M-209, M-210 and M-211). This data will allow for a more informed decision when it comes to variety selection.

The warmer locations are north of Hwy 20,in Glenn, Butte and Colusa counties. At these locations, M-211 consistently outperforms the other medium grains by 4 cwt/ac, on average, over the five years and four locations. Among the other varieties shown, there were no consistent differences among them.

In the cooler locations, M-209 performed the worst in general. In the moderately cool locations (yellow dots on the map), M-105 and M-211 both did consistently well. In the coldest location (South Yolo), M 105 performed the best; while M-209 and M-211 performed poorly. Both M-209 and M-211 have similar days to maturity (about 5-7 days later than M-206). This data suggest that M-211 may have a broader adaptability range than M-209 becasue it appears to be slightly more cold tolerant. However, in the coolest location even M-211 did not perform well.

M-206 versus M-210: M-206 has beenthe most broadly adaptable variety available. While it may not always be the highest yielder, it generally does well across all locations. M-210 is a new variety which has blast resistance. It is basically M-206 with genes for blast resistance and has similar time to heading. Based on these data M-206 and M-210 have almost identical yields in both the warm and cooler regions.

Thoughts on M-211: As seen in the data provided, M-211 is a tremendously promising variety in terms of yield potential. Furthermore, its sensory qualities are similar to premium grain varieties such as M-401. However, one draw back is that for good milling quality, M-211 needs to be harvested at 20-22% moisture. Harvesting below this moisture can result in low milling quality. Given this, it may not be a variety that is suitable for large acreage planting and this should be tested by growers.

 

 

 

2021 Rice Growers Meeting 

When: February 11, 2021, 9:00am-12:00 PM

Where: Virtual via Zoom

Registration: $10

Register at:  https://ucanr.edu/survey/survey.cfm?surveynumber=32722 

 

Agenda: 

• 9:00 AM Introduction
• 9:10 Rice Research Board Nominations ‐ Dana Dickey, Rice Research Board
• 9:20 Ag Commissioner Update ‐ Scott Bowden, Deputy Agricultural Commissioner, Sutter
  County
• 9:40 Weed Management Update ‐ Kassim Al‐Khatib, UC Davis
• 9:55 Break
• 10:05 Disease Management Update ‐ Luis Espino, UCCE Butte
• 10:20 Arthropod Management Update ‐ Ian Grettenberger, UC Davis
• 10:35 Bird and Salmon Projects Update ‐ Paul Buttner, California Rice Commission
• 10:50 Break
• 11:00 Emerging Weeds Issues ‐ Whitney Brim‐Deforest, UCCE Sutter‐Yuba and Michelle
  Leinfelder‐Miles, UCCE San Joaquin
• 11:15 Fertility Update ‐ Bruce Linquist, UC Davis
• 11:30 Roxy Rice ‐ Kent McKenzie, California Rice Experiment Station
• 11:45 2020 Summary and Variety Update ‐ Bruce Linquist, UC Davis
• 12:00 PM Adjourn

Continuing education units applied for from CA Department of Pesticide Regulations (DPR) and Certified Crop Advisers (CCA).

Contact Luis Espino for more information.

 

In 2017, I started getting reports of a watergrass biotype/species (Echinochloa spp.) that was difficult to control using our suite of herbicides registered in rice. At the time, I knew we had multiple herbicide-resistance in late watergrass (Echinochloa phyllopogon), so I initially just thought the resistant biotype was spreading, and had maybe gained resistance to additional herbicide modes of action. However, once I started visiting fields, it quickly became apparent that this was not late watergrass (phenotypically-speaking). It also did not appear to be barnyardgrass (Echinochloa crus-galli), although the Echinochloa species are notoriously difficult to identify, and phenotypically quite variable in nature.

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).

Table 1. Preliminary distinguishing characteristics of watergrass species in California rice fields, based on seed characteristics. 

Preliminary Identification	Seed Description
Late watergrass	Large size, no awns
Early watergrass	Large size, awned (all seeds)
Barnyardgrass	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.