Cucurbit downy mildew was found this past week on Florida grown transplants (squash and zucchini) at a Home Depot in Charleston, SC. Once discovered, the transplants were destroyed, but, several may have been sold prior to discovery. The transplants originated from Pure Beauty Farms in Miami, FL (where cucurbit downy mildew is currently active). Growers and home owners should thoroughly inspect transplants prior to purchasing. We will continue to monitor the situation in SC to see if in-field development of downy mildew occurs. Let us know if you have any questions.
Tag Archives: Urgent News
Section 18 for Avipel use in Virginia – APPROVED by EPA
It’s official. EPA has approved the Section 18 for Avipel use on field and sweet corn planted in Virginia. Recall that birds need to feed on a few Avipel treated seeds before they will move on. Avipel does not kill birds. As always, if you have any questions please don’t hesitate to contact me. Rod Youngman: youngman@vt.edu; office 540-231-9118; cell 540-357-2558; FAX 540-231-9131.
Apology on email issue
Section 18 for Avipel use in Virginia – down but not out
Greetings,
In an email I received yesterday from Micah Raub at VDACS, he said the Section 18 for use of Avipel in Virginia was returned for lack of sufficient economic justification. One of the benchmarks for EPA approval is documentation of 20% loss, which we don’t have. However, in lieu of that, grower testimonials for 2010, as many as possible, will go a long way in swaying the argument. So, I need you to fax me (540-231-9131) ASAP your full name and address including County where bird-damaged field(s) was located; field size (ac); unit cost/bag; full name of seed used; row spacing; plant population density (i.e., # seeds planted/ac); and finally, and most important — out of a ?? acre field, the number of acres that were replanted? For example, 3 of 10 ac were replanted 2 times or 10 of 10 acres were replanted 1 time, etc.. NOTE: If you don’t have all the data I’m requesting, provide what you can, and estimate to the best of your ability the rest. Remember, some data is better than no data at all.
Also, if you sustained bird losses to corn in 2010, but did not replant, please send the number of acres/field, acres damaged/field, and estimates such as what it would have cost to replant and/or yield loss costs associated with the bird-damaged acres.
The sooner I receive this information, the sooner I can send it off to Micah Raubb, who will quickly review it, and then forward on to EPA. So I encourage you to do your part in this important matter.
Thank you,
Rod
Late season fall armyworm outbreak
I started getting calls and visits yesterday from homeowners and growers with complaints about ‘worm’ infestations. Fall armyworm is the culprit and apparently the problem is severe and widespread. Fall armyworms are spreading into newly planted fields of oats, rye and other fall grass forages, and into newly seeded home lawns. Calls are coming in mainly from Surry and Isle of Wight Counties, but that could be the result of the attention growers and crop advisors are paying to fields in those areas. One common denominator seems to be that most infested fields are adjacent to pasture or hay fields. Apparently, the worms have been developing in those fields and are now on-the-move into fields with tender newly emerge leaf shoots. Based on the number of reports, I suspect this problem is even more widespread. Emerging wheat and barley fields are certainly also at risk.
Fall armyworm has two ‘strains’ and I suspect this is the ‘grass strain’. I also suspect that this widespread infestation is the result of a huge migratory flight from the south—another in a long line of caterpillar invasions that started with early corn earworm problems back in July. This late season fall armyworm invasion is certainly an unusual problem. I have never seen anything like this in the 22 years I have been working in this area.
Rod Youngman on main campus (he works with insect pests of turf and forages) advised that any of the pyrethroids labeled for forages or small grains should provide good control if applied at the high rate, but should be applied NOW. He believes that seedlings are the most at risk and should be treated ASAP. Fall armyworms are surface plant feeders, so they are pretty vulnerable to pesticides. We also believe that fields grazed off by these worms should spring back once they have cycled out. Their life cycle should put them into to the pupal stage in another week or less. And of course, a good hard frost would take-em-out.
Spider mite infestations are rampant in many Virginia peanut fields
It’s September 24 and we hit 98 degrees yesterday and today here at the research station, and still no rain. A hot, dry wind is blowing across the fields and for all it’s worth, it feels like Arizona, not Virginia. Populations of spider mites which thrive in this kind of environment are exploding in peanut fields across the region. Populations are so large that they are forming pencil eraser sized balls of solid mites on the tips of the upper branches of the peanut plants. Their feeding has extracted the last bit of moisture, what little was left, from already struggling plants. The ONLY solution is to DIG THOSE PEANUTS. We are very close to the normal peanut digging window for Virginia and with the dry conditions, there is no advantage to waiting. In normal years with normal soil moisture, we encourage growers to wait as long as possible to begin digging. By waiting, you allow nuts to gain more ‘meat’ content which improves the grade and value. Not so this year. In the near total absence of soil moisture, peanuts have essentially stopped maturing. What you have is it and you might as well dig. Some are waiting to dig until they get some moisture which will improve digging conditions. Fields with heavier natured ‘tight’ soils will be almost impossible to dig efficiently unless it rains. But I still do not recommend treating for mites. Their feeding has not compromised vine strength, which is the biggest concern late in the season. Where late season plant diseases can cause vines to deteriorate which causes them to shed pods during the digging process, spider mite feeding is not having the same effect. Even in fields with the heaviest infestations, vine strength has not been compromised. My advice, just dig them as soon as you can. But be prepared, after the vines are inverted, mites will move to the exposed tap roots. It will look bad, but it is of no economic importance.
Brown marmorated stink bugs found in more soybean fields
We have now documented brown marmorated stink bugs in soybean fields in at least 15 counties in Virginia. My guess is that if we had more time to look, we would find them in most of the others. The numbers are still low, 1 to 4/15 sweeps, and fields are in senescence, so there is no economic threat. Prior to this year, we had not found them in soybean fields. The bigger question in my mind has to do with next season. Is this low number going to increase significantly next year? I think the probability is high given the incredibly huge populations that are aggregating on and in homes and structures, trees and shrubs over most of the northern, western, and central parts of the state. Will these huge overwintering populations move into gardens and crops next spring? Based what has been reported from other areas, it appears that the answer is ‘yes’. One area of the state that has escaped these large overwintering aggregations is the coastal plain. Although we have found a few in crops and in black light traps, I have not seen or gotten complaint calls about large aggregations from homeowners from this region of the state. If the numbers do build in this area, will cotton become the next victim? Other native stink bugs species are highly attracted to cotton bolls and are capable of doing extensive damage. Will brown marmorated stink bugs join this complex? Time will tell and we will be monitoring closely next season.
Spider mite infestations picking up in peanut fields
It is not surprising that we are getting reports of spider mite build-ups in peanut fields. There are areas that have been fighting this dry weather pest for several weeks. These newer outbreaks are particularly bothersome as they are coming so close to the end of the season. D. Rick Brandenburg (NCSU) and I have done a lot of work on how to achieve the best control of spider mites in peanuts. There are several limiting factors, not the least of which is the limited number of products registered for spider mite control in peanut. There are only three products currently labeled, Danitol, Brigade and Comite. For reasons that must have to do with marketing, Comite has not been readily available to Virginia growers for the last 3 or 4 years. That leaves Danitol and Brigade (= Capture) which are both pyrethroids. These products if applied with high spray volume (15 + gpa) will provide good knockdown of adult and immature mites. But, neither kills the eggs so if applications are made to fields where there are a lot of eggs, these hatch in 2 or 3 days and the infestation begins again. Our work showed that the only way to make these products work well was to make two sequential applications about 5 to 7 days apart. The first application knocks down the adults and immatures, and the second gets the new hatchlings, thus breaking the cycle. But, this late in the season when digging will begin soon, we are recommending that if mites are doing a lot of damage and need to be controlled, make a single application using the highest labeled rate, knock them back, and hope for the best.
Soybean loopers finally beginning to phase out
Although there are still soybean loopers in a lot of fields, the numbers are declining. The larger worms are going into pupation and, thankfully, no new eggs are being deposited. For example, I visited several fields where last week the numbers were in the 15 to 20/15 sweep range and found only 2 or 3 larger worms remaining. Also, most of these fields were much closer to being mature enough to be in the ‘safe’ zone. I am still getting a few calls and am referring them to last week’s advisory note. One nice feature of our advisory is that it archives notes. To see last week’s note that provides guidelines for determining the need for late season looper treatment, go to www.sripmc.org/virginia and scroll down to the Sept. 9 soybean looper note.
Brown marmorated stink bug found on the Eastern Shore of Virginia
The brown marmorated stink bug was found last week on the Eastern Shore of Virginia. Nymphs of this exotic pest were feeding on yellow squash in our research plots in Painter, VA. As far as I know, this is the first documented occurrence of this pest on the Eastern Shore of Virginia. Based on reports from New Jersey, West Virginia, Maryland, Delaware, Pennsylvania, and western counties of Virginia, this insect can be quite damaging to numerous crops, and population densities can build up to extreme levels. Crops that can be particularly hard hit include tree fruit, peppers, tomatoes, sweet corn, and from what I saw, cucurbits as well. In the fall, this stink bug will also aggregate on and in building structures similar to the Asian multicolored lady beetle. Click more to view an image of this pest. Additional information: brownmarmoratedstinkbug-01-jpg
