Category Archives: Commodity

Registration is open for the Mid-Atlantic Crop Management School.

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CropSchool

November 15-17, 2016
Princess Royale Hotel in Ocean City, MD

Registration is open for the 22nd annual Mid-Atlantic Crop Management School. This year’s school will feature 2 ½ days of timely presentations in the areas of crop management, nutrient management, pest management, soil and water management, and climate. This year, the school will also feature the popular Crop School on Wheels field tour (limited to 50 participants). Nutrient management (VA, MD, DE, PA), pesticide, and certified crop adviser (CCA) credits will be available. Register early for the best selection of sessions.

The session schedule is online at: https://cdn.extension.udel.edu/wp-content/uploads/sites/12/2016/09/23151701/2016_CMS_Program_Final.pdf

Registration information is posted at: http://www.cvent.com/events/2016-crop-management-school/event-summary-bbd4a7d2717545af9770626ef761a930.aspx?tw=E3-C1-0B-14-32-A0-CB-AB-1C-D6-9A-06-46-74-20-5F.

Contact Amy Shober (ashober@udel.edu) or Jarrod Miller (jarrod@umd.edu) with questions about the school. We look forward to seeing you there.

The Mid-Atlantic Crop Management School is organized by Extension Specialists from Virginia, West Virginia, Delaware, and Maryland featuring speakers from across the nation.

BMSB and kudzu bug survey of soybean: Sep. 22, 2016 update

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Our soybean scouts detected brown marmorated stink bug (BMSB) in three new Virginia counties this week (Halifax, Greensville, and Brunswick).  They found soybean fields in the following counties at BMSB threshold (3-5 adults + medium to large nymphs per 2-minute visual count or per 15 sweeps):  Albemarle, Bedford, Fluvanna, Goochland, Greene, Orange, Rappahannock, and Shenandoah.  Please see the map for more details.

When monitoring, don’t forget about our native stink bug species–we have been seeing moderate to high numbers of green stink bugs in some fields.  The threshold for a normal mix of stink bug species (green, brown, and BMSB) is 5 in 15 sweeps.

BMSB_map_22_Sep_2016Kudzu bug numbers in soybean remain below threshold.

KB_map_22_Sep_2016

Peanut maturity progress in Suffolk, VA

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The peanut maturity progress from Sep 2nd and until now seems to be optimal. Images taken on Sep 2nd and Sep 12 for ‘Bailey’ (Bailey peanut maturity progress in Suffolk), and ‘Sullivan’ and ‘Wynne’ (Sullivan and Wynne peanut maturity progress in Suffolk) peanut cultivars are presented here. Bailey, regardless when was planted May 2nd or June 4th, seems to be ready to dig in 10 to 15 more days. In the past 10 days, Sullivan shows a substantial increase of black and brown pod content, however the pod color spread is highest for this cultivar. This suggests that Sullivan may have two main crops this year, which is not surprising given the drought stress experienced for most part of August. This situation always makes digging decisions difficult, but we will continue to watch the maturity progress for this cultivar and extend the search to other locations than Suffolk. None the less, location and individual field conditions have significant effects on maturity. Under the conditions of 2016, Wynne is behind Bailey and Sullivan maturity wise. The images of podblasted pods suggest that digging for Wynne is expected in 20 to 25 days from Sep 12.  Again,  determining maturity in each field individually is the best method for farmers to determine the optimum digging time. Podblasting clinics, such as the one on Sep 19 planned by the new Extension Agent in Southampton County VA, Ms. Livvy Preisser <livvy16@vt.edu>, should be attended rigorously by peanut growing farmers.

Update on Boxwood Blight in Virginia

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English boxwood defoliated by the boxwood blight pathogen following introduction of infected container plants on the patio. (Photo by A. Bordas)

English boxwood defoliated by the boxwood blight pathogen following introduction of infected container plants on the patio. (Photo by A. Bordas)

Recent outbreaks of boxwood blight, caused by the fungus Calonectria pseudonaviculata, are causing concern in Virginia. Boxwood blight can cause severe defoliation of susceptible boxwood, including English and American boxwood, and is of serious consequence to nursery growers, landscapers and homeowners. All diagnoses of boxwood blight in home landscapes made by the Virginia Tech Plant Disease Clinic since last fall are linked to new boxwood purchased from several Virginia locations of one national retailer, and new cases are likely to emerge. (See news article at: http://www.newsadvance.com/news/local/boxwood-blight-hits-lynchburg/article_a2860e97-438c-523a-9c63-202902eaf42b.html).

We strongly recommend that growers purchase boxwood from a nursery or retail outlet that has purchased boxwood exclusively from a boxwood producer in the Boxwood Blight Cleanliness Program (http://www.vdacs.virginia.gov/plant-industry-services-boxwood-blight.shtml). These producers follow stringent practices to avoid the introduction of this disease to their nurseries and are subject to followup inspections by the Virginia Department of Agriculture and Consumer Services.

Black streaking on green stems of boxwood plant with boxwood blight.

Black streaking on green stems of boxwood plant with boxwood blight. (Photo by A. Bordas)

Symptoms of boxwood blight include leaf spots, black streaking on stems and severe defoliation. Other diseases of boxwood, such as Volutella blight and root diseases, can be confused with boxwood blight; therefore, laboratory confirmation is necessary. Learn to recognize symptoms of boxwood blight by viewing the image gallery on the Virginia Boxwood Blight Task Force web site (http://www.ext.vt.edu/topics/agriculture/commercial-horticulture/boxwood-blight/). Information on best management practices, resistant boxwood cultivars, and sanitizers for cleaning tools is also available on the web site.

In all the cases of boxwood blight diagnosed by the VT Plant Disease Clinic in home landscapes, the disease was introduced on infected boxwood plants. The fungus has sticky spores and is not adapted for movement on air currents; however, spores may stick to and be transported by spray hoses, tools, clothing, shoes, and vehicles. The fungus can also be transported in soil and likely by animals moving through infected plants, e.g. deer, dogs. Infected boxwood may also be present in holiday greenery.

If you suspect boxwood blight, collect symptomatic branch samples with at least a few green leaves still attached. Double bag the samples in sealable bags and take them to your local Virginia Cooperative Extension office (http://www.ext.vt.edu/offices/index.html). Samples will be forwarded to the Virginia Tech Plant Clinic for diagnosis.

Brown marmorated stink bug and kudzu bug in soybean: Sep. 1, 2016 update

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This week, our soybean scouts Ed and Jamie reported two new counties with BMSB this season (Rockingham and Rapphannock).  Eight counties had threshold levels of BMSB (3-5 adults+medium & large nymphs per 15 sweeps or 2-minute visual inspection)–see the BMSB map for details.  Kudzu bugs were found in one new county–Chesterfield.  Over all counties sampled, kudzu bug numbers ranged from zero to 3 per 15 sweeps–still below threshold.

BMSB_map_1_Sep_2016KB_map_1_Sep_2016

Why is my late-planted 110 day RM maturing in 100 days (or less) this year?

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Recent observations from around the state have found corn maturing at a fast pace this year, especially corn that was planted late.  The most commonly used method for assigning corn hybrid maturity ratings is based on Days to Maturity.  This typically indicates the number of days it would take a corn hybrid to reach physiological maturity or “black layer”.  But temperature drives corn development, not calendar days.  So the “thermal time” to maturity calculated using growing degree days (GDD) is a more accurate measure.  Especially when the growing season has been particularly warmer or cooler than normal.

The chart below shows the difference in cumulative GDD between 2016 and the 30 year mean temperatures beginning on JUNE 1.

GDD_16

 

 

We are 6, 7, and 10% above the “normal” GDD accumulation for August 31 at Suffolk, Richmond, and Orange, respectively.

This might explain why a 110 day RM corn is maturing more quickly than expected based on the “day” count.  The plant has actually accumulated heat units at a faster rate this year.

If May 1 is the starting point, we are 3, 4, and 7% above the “normal” GDD accumulation for these sites.  So this effect is likely to seem greater in later planted corn.

BMSB and kudzu bug in soybean: update for Aug. 25, 2016

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This past week our scouts found four new Virginia counties with brown marmorated stink bug (BMSB) in soybean (Caroline, Shenandoah, Rockbridge, and Henry).  Thresholds for field edges where BMSB is the predominant stink bug species are 3-5 adults + medium and large nymphs per 2-minute visual count, or 3-5 in 15 sweeps.  The Shenandoah field (R5 growth stage) that was sampled was above threshold with 8 BMSB per 2-minute count; six counties were approaching threshold (please see the map for specifics).

BMSB_map_25_Aug_2016

Kudzu bugs were found in three new counties (Prince George [reported by ANR Agent Scott Reiter), James City, and Franklin).  No counties had threshold levels of kudzu bugs (threshold is one nymph per sweep, which equals 15 nymphs per 15 sweeps).

KB_map_25_Aug_2016

Corn earworm soybean update.

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In both 2014 and 2015 we experienced very light corn earworm (CEW) infestations in our soybean crop. This summer we are back to a more normal situation with spotty light to moderate level infestations. Some fields have hit thresholds for sure, but not all. And, as is the case in most years, worms are in some fields that are only in the flowering stage—which has been proven many times over the years NOT to be a problem, that is, does NOT result in any yield loss. CEW do their damage when they feed on developing seed during the R5-R6 growth stages. If needed, a single application (if the right insecticide is used) during this stage should be all that is needed for season-long CEW control.

As always, in a year with spotty infestations, it pays to scout fields carefully to find those at threshold so they can be protected. We have recently proven that pyrethoid insecticides have a devastating effect on the thousands of beneficial insects and spiders in a soybean field. If left alone, they have then potential to control CEW infestations by eating the eggs and small worms and therefore prevent the need for an insecticide spray. So, be careful with pyrethroid applications and use them only if thresholds are met. You will very likely save money in the long run.

What are the thresholds for CEW in soybean? There is not a one-size-fits-all answer. This fact sheet Soybean_insect_mgmt_2016 has a CEW Calculator that can provide a good answer based on some of the factors that must be considered—like the estimated application cost and bushel value. Use this as a starting point.

What to treat with? We have been monitoring CEW for pyrethroid insecticide resistance for several years by collecting and testing adults (moths). This year is no exception. Individual moths are exposed to a pyrethroid and we document the percent that survive (=resistant). This year we are seeing high levels of survivorship averaging about 40% over all sample dates and locations.  This means that to achieve good CEW control, non-pyrethoids insecticides should be considered. For CEW, I would focus on those that ‘specialize’ in worm control (like Prevathon, Besiege, or Spinosad).  Lannate is another option but has essentially zero residual activity, whereas the others should provide several days of protection, depending on rainfall amounts and frequency. If stink bugs are also present in the field, the worm products will not be effective. A pyrethroid will need to be tank mixed with the worm product (example, Prevathon plus bifenthren)—or a product like Besiege can be used that contains both a worm product and a pyrethroid. Below is a list of insecticides labeled for use in soybean.

Soybean_insecticides_2016

Cotton insect pest update—bollworms are here.

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At this point in the season, many cotton fields have been treated once for mid-season plant bug/stink bug. The next decision will be focused on bollworm control—whether it is needed, and if so, what insecticides to use. We are seeing a general increase in bollworm moth activity at TAREC and have gotten recent reports of some pretty large worm infestations in a couple of peanut fields in the cotton area, and outbreaks in a couple of soybean fields in the Suffolk area. Caution: if the earlier applied mid-season plant bug/stink bug spray included a pyrethroid (e.g., bifenthrin), the beneficial populations in those fields will have been depleted—which makes them more susceptible to bollworm.

We have plenty of data that shows that cotton varieties with bollworm protection traits can be damaged by worms. Some escape the toxin, survive, and feed on bolls. We have seen as much as 9% or more boll damage in some varieties which is 3 times our working threshold of 3% live worms/fresh boll damage.  But, that was in years when bollworm pressure was high.  In years like 2014 and 2015 when bollworm populations were very light, we saw essentially no boll damage in any of the varieties.  So what is the 2016 situation?  So far it looks like we may be looking at heavier pressure than last year, light to moderate depending on the field—but—we won’t know for sure for another few weeks—as the main flight out of field corn has not kicked in yet. The corn crop is generally a little behind and a little less mature than normal for this time of year because of later planting and good rainfall.

The best approach for managing bollworm in cotton is to scout fields for worms by inspecting small bolls, the terminals, and under flowers (boll tags) for live worms or damage. As mentioned, our current threshold is 3% of the fruit or positions inspected with either live worms or damage.

We have a history of bollworm resistance to pyrethroids in Virginia and this year is no exception. Of the 650 or so moths tested so far, we are seeing about 40+% survival. This is high. So for the best control results we suggest using a non-pyrethroid (e.g., Prevathon, Belt, Blackhawk, or Intrepid Edge). Note that Belt is not widely available this season due to the registration being canceled by EPA. Distributors and growers can use existing stocks according to label, but when that is gone, that will be it—at least as far as we know.

We also recommend adding a pyrethroid to the worm product to clean up any plant bugs/stink bugs that may be in the cotton. There are several pyrethroid options, and I would use the highest labelled rate for stink bugs—for better kill and longer residual. Besiege is the only product that contains both the non-pyrethroid (= Prevathon) with a pyrethroid (= Karate). With all the other non-pyrethroids, you will have to do the tank mixing on the farm. And, it is past time to include any of the insecticides in the neonicotinoid class as they do not provide good control of either bollworms or stink bugs.