- Author: Luis Espino
Number of moths trapped per day is increasing. Numbers are higher in areas where crop diversity is higher. I haven't seen any worms yet, but they are expected by the end of the month. At this point, moths may be mating and laying eggs on weeds and other plants in the area, including rice. This week I received a picture from a PCA of what seemed to be armyworm eggs laid in a rice seedling. No worms are expected on rice until late June or early July. In 2016, worms were observed in fields only after catches were around 20 monts/trap/day.
- Author: Luis Espino
Grow Rice? Help Birds! Rice provides livelihoods and food for people and places to rest and feed for many birds, too. Small changes to field management can increase the value of rice fields for the birds that use it. The NRCS Regional Conservation Partnership Program (RCPP) provides assistance to farmers to voluntarily modify their field management in small ways to benefit birds that are also compatible with farming.
We strongly encourage new growers/landowners who have not enrolled in WHEP or RCPP in the past to apply. New applicants will be preferentially ranked for acceptance into the program. However, we anticipate that quality proposals from past WHEP/RCPP participants will also be considered for funding. Practices available through the program include:
- Two weeks of continuous shallow flooding July-October
- Variable drawdown of winter-flooded fields in February/March
- Planting and maintaining cover crops through July
- Nesting islands for safe breeding habitat
- Bird-friendly straw management
Long-term commitments are not required in this program. EQIP-eligible producers in Butte, Colusa, Glenn, Placer, Sacramento, Sutter, Yuba, and Yolo counties can apply. For more information, join us on June 6th at the Colusa Casino Community Room from 10:30-1:30, visit your local NRCS office or contact Paul Buttner (pbuttner@calrice.org).
- Author: Luis Espino
I have set up seven armyworm pheromone traps in the Sacramento Valley, and Michele Leinfelder-Miles is monitoring one trap in the Delta. Last year the traps showed a distinctive peak mid August, when worms started causing problems during heading. This year, we will start monitoring earlier and so we will try to identify the peak that corresponds to when worms start feeding on foliage in late June - early July.
I will publish the results of the monitoring weekly or biweekly on the UC Rice On-line website and I will sound the alarm when monitoring efforts need to be increased to make sure infestations don't go unnoticed.
- Author: Luis Espino
A FIFRA Section 2(ee) Recommendation has been issued for control of tadpole shrimp (TPS) using Dimilin 2L. The recommendation states to use Dimilin two to 10 days after the field is flooded; it also states that Dimilin does not appear to control adult TPS.
Dimilin is an insect growth regulator. In many insects, it interferes with the molting process of immatures. In rice water weevil, it sterilizes adult females and also kills eggs. TPS are not insects, but crustaceans; however, they also molt. TPS molt 10 to 15 times before becoming adults; after that, they continue to molt as they grow larger.
I evaluated a field application today in a field with a known TPS problem. Four days after the application, there doesn't seem to be any surviving TPS and injury to the seedlings is minimal. The application went out soon after the field was flooded.
Last year, I conducted a trial to test several products for TPS control. Dimilin was one of them. As you can see below, the kill of TPS with Dimilin was slow, and survival was still 10% three days after the treatment.
The TPS used in this trial had a shell length size that ranged from 1/3 to 1/2 inch. It is difficult to determine when a TPS is an adult, since the immatures and adults look the same. I have noticed that eggs appear when the TPS shell reaches about 1/4 inch in length, so the TPS used in the trial were most likely adults. This might explain why the results of the trial were not very striking.
I will continue evaluating Dimilin this season in commercial fields and I will repeat the trial conducted last year. The 2016 trial is described in the attached document.
Chemical Control of Tadpole Shrimp 2016
- Author: Whitney Brim-DeForest
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