Recently, there has been some concern about odd symptoms of wilting and reduced stands in broccoli and cauliflower here in the Willamette Valley. See photos below.
Symptoms include: Weakened stems – necrosis of lower leaves – poor stand – girdling/calloused tissue at soil level – stem breakage – possible association with weed hosts – abnormal root growth
NOTE: AT THIS TIME, I HAVE ONLY EDUCATED GUESSES OF WHAT MIGHT BE CONTRIBUTING FACTORS TO THE FOLLOWING SYMPTOMS IN BRASSICA FIELDS. THIS ISSUE IS CURRENTLY UNDER INVESTIGATION IN CONJUNCTION WITH FIELD FACULTY AND DIAGNOSTIC LABS.
CRF prefers cool weather and activity tends to diminish during the summer heat.
HOWEVER: Summer activity is measured by pan traps, and
the authors of the model above agree that summer activity might have been underestimated because of ‘visible competition’ and attractiveness of blooming crops and weeds vs. yellow traps. The spring generation can be extended up to 3 weeks or more, depending on how long rainy, cool weather conditions persist. Also, we know that there are overlapping generations of CRF, and a study from California suggests that egg-laying behavior and subsequent damage during summer months is markedly different than fall:
ANOTHER FACTOR is that Delia radicum is actually part of a much larger ‘rootfly complex’, and different species have different ecological niches, behavior, and activity periods. This tableexplains some of those differences. Identifying rootflies is hard enough when they are adults, and nearly impossible as maggots and pupae. Thus, they are referred to as a pest complex that can affect growers year-round.
1According to a regional model (Dreves 2006), and current 2018 data (Agrimet station CVRO)
…the slimy worm-looking things covering the sidewalks around campus this week. They are the immature form of craneflies, commonly known as leatherjackets.
I’m hoping it’s not too late to save our campus lawns, but by the time this kind of damage is apparent, insecticides may not be effective. By mid-May, the leatherjackets will pupate then hatch into adults. Adults are harmless (other than a nuisance).
Maintaining grass health is the best defense against craneflies. Monitoring should be done from January to March, when larvae are feeding underground. More information is available at: http://whatcom.wsu.edu/cranefly/Index.htm
Participating in the OSU Extension Open House last night was fun and rewarding (thanks, staff!!). I enjoy outreach events and inevitably learn something from interacting with the public.
Yesterday’s conversations led to today’s topic: “Problems with my PEAS”
In the span of two hours, three different citizens came to me wondering why their early-planted peas are being “attacked by an unidentified marauder” (direct quote).
All 3 inquiries were similar and there were some important clues present: leaves are being damaged from the edge inward (chewing mouthparts); not cut off at soil level (cutworm); nothing obvious when scouting at night.
WEEK 0: Spring has sprung and we need field sites. Broccoli plantings will be starting soon, cooperating growers are encouraged to contact me to reserve their spot. Cutworms and armyworms are likely going to be a problem this year.
Many have been spotted already, even on campus sidewalks (see below)! This species is especially fond of ryegrass and orchardgrass, and outbreaks have occurred in western Oregon.
So..why did the caterpillar cross the road? Because it overwinters as a partially mature larvae and peristaltic searching mobility increases when ambient temperatures exceed 10°C, of course!
**NOTE: this blog site will be used for extended story content, photos, etc. To access weekly pest reports and data (APR-SEPT), please subscribe to the email newsletter using the box at left**
In anticipation of this month’s release of Oregon’s Agricultural Progress research magazine, I wanted to put a brief post up to help orient OAP readers.
As you saw in the article, VegNet uses an email marketing platform to inform program subscribers about insect pesttrends throughout the Willamette Valley. Our readership includes vegetable growers, crop consultants, and home gardeners from across the country.
The blog now has a ‘search by category‘ function located at left, if you are interested in a particular insect, or just want an easy way to browse through content. There is also an FAQ page. Or, you could go here to view all the reports from last year.
If this program interests you at all, please do join the mailing list to be included this season. Pest reports are delivered straight to your inbox, once a week, and only between April and October. The program is free, and you can unsubscribe at any time.
WEEK 24 – Cabbage maggots are one of the most challenging pests for brassica growers. They tunnel through root tissue and increase the risk of exposure to plant pathogens Read this cabbage maggot page, which includes more info on biology and how to sample for them. Another late season pest is diamondback moth. Many sites are listed as "n/a" this week, because fields have been harvested and traps are being removed.
Read the full report here: http://bit.ly/VNweek24 and subscribe on our homepage to receive weekly newsletters during field season.
WEEK 23 – Corn earworm flights have been consistently high, and scouting this week revealed late stage larvae, pupal exit holes, and newly-emerged adults that will lay eggs within 3-5 days. This diversity makes control difficult, and scouting is recommended. Spotted cucumber beetles do become active in the fall, but levels this year are about 500% higher than historical norms.
Read the full report here: http://bit.ly/VNweek23 and subscribe on our homepage to receive weekly newsletters during field season.