- Author: Whitney Brim-DeForest
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 has 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 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 2019.
- Author: Whitney Brim-DeForest
I have been to several farm calls in the past few weeks with this weed (pictured below). I have seen 7 fields between last year and this year that appear to have bad infestations of this new watergrass species (Echinochloa spp.). We are unsure of the exact identification yet, but we know it is in the watergrass family.
The weed is maturing around mid- to late-July. It is small-seeded, and the awns are long and purple. All of the plants I have seen so far have seed heads that are completely awned, which makes it different than barnyardgrass (which has seed heads that are variably-awned).
How to ID:
o Every seed head has awns (unlike barnyardgrass)
o Should already be headed (by mid- to late-July)
o Awns are purplish in color (see photos)
o Seeds are small (smaller than late watergrass)
Please call Whitney Brim-Deforest (541-292-1553) or Luis Espino (530-635-6234), if you suspect that you have this weed in your field. We would like to collect seed samples to see what can be done to control it.
Photo 1. Seed head of unknown watergrass species (Echinochloa spp.) Notice visible purple awns.
Photo 2. Seed heads of unknown watergrass species (Echinochloa spp.) Notice visible purple awns, which can be seed before seeds are fully mature.
Photo 3. Full plant sample of unknown watergrass species (Echinochloa spp.). This plant headed in late July.
- Author: Luis Espino
I visited a field with leafhopper damage. What was interesting about this field, is that the leafhopper causing the problem was not the aster leafhopper, which is the common one we have in rice. It was a different, green leafhopper that I have seen around in the past, but I have never paid much attention to. I don't even know what its name is (yet). It is green, larger than the aster leafhopper, and moves quite fast. We could not get a picture of it on a rice leaf, so here it is on a weed.
The damage was similar to what I have seen when aster leafhopper feeds on rice. The tip of the leaves get yellow and eventually burned. In this case, the damage was limited to a cold water check, so no treatment is needed.
Another interesting thing is that we found the eggs laid on watergrass plants around the field. Rice did not have any of the oviposition marks. They don't seem to like rice to lay their eggs. That is good because the lesions created due to the egg laying were quite large.
- Author: Bruce Linquist
Sign up for the 2018 UCCE Rice Yield Contest! You could win a John Deere side-by-side.
2018 marks the fourth year of the UCCE Rice Yield Contest. We have learned a lot from these contests and have seen yields close to 128 sacks/acre! To enter the Rice Yield Contest, you need to send us an Entry form. Entry forms are required by August 29, 2018 at the Annual Rice Field Day. Entry forms and contest details are available at http://rice.ucanr.edu/Rice_Yield_Contest/.
2018 changes: The main change in 2018 will be that we will have three regions competing instead of four (the two southern regions south of Hwy 20 will be combined into a single region). We also have a much higher value prize (see below).
The Prize: This year a number of companies have helped to sponsor the Grand Prize for the contest - a John Deere side-by-side (XUV 560E). The winner from each region will have an equal chance (1 in 3 chance) of winning the Grand Prize. Contest winners will draw for the prize at the 21019 winter grower meetings. Each winner will still receive the coveted hat.
Sponsors: The following companies each supported the contest with gifts of up to $1500 each: BASF, Bayer, Corteva, FMC, Gowan, Nichino, Oro-Agri, Syngenta, Valent, and Valley Truck and Tractor.
If you have any questions, go to our website listed above or call Bruce Linquist at (530) 902-2943.
- Author: Luis Espino
I got a report from a PCA early in the week of blast infections detected near Maxwell. Blast can occur at any time during the development of the crop. When it infects leaves, it is called leaf blast. If it infects the base node of the panicle, it is called neck blast, if it is on the nodes of tillers, node blast, etc. In all cases, it is the same pathogen. Usually, the first visual indication of blast infection happens in nitrogen overlap areas in the form of dead circular spots.
If you inspect these areas closely, the plants in the center are burned to the water, and the typical diamond shaped lesions can be found in the leaves of surrounding plants.
We do not recommend treating leaf blast. But presence of leaf blast is a good indication that a fungicide treatment will be needed once the crop starts heading.
Blast is a multi-cycle disease, meaning that infections produce spores that then can cause more infections later. After an infection occurs, lesions form after 14 days, and 3 days later new spores are formed. These spores can then repeat the cycle. This is why it is important to protect the panicles if leaf blast is present in a field or surrounding fields. Time your fungicide application anywhere from mid boot to panicle emergence.
All our varieties are susceptible to blast, with the exception of the new M-210. M-206 is considered less susceptible than M-104 and M-205. We have not seen the response of M-105 and M-209 in the field yet, but I suspect they are very susceptible based on their background.
