Posts Tagged ‘19:7’

Black Light and Pheromone Trapping Program

Friday, May 6th, 2011

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Our black light and CEW pheromone traps are now up and running for the season. The traps are generally checked on Monday and Thursday and counts are posted by early Tuesday and Friday morning. True Armyworm moth catches will be posted only through the month of May. This year we have also added a page for Stink Bugs (green, brown and brown marmorated). Please use the following link to access all trap information (http://ag.udel.edu/extension/IPM/traps/trapindex.html). I will also begin the Crop Pest Hotline on May 10 (instate – 800- 345-7544; out of state- 302- 831-8851)

 

Grain Marketing Highlights – May 6, 2011

Friday, May 6th, 2011

Carl German, Extension Crops Marketing Specialist; clgerman@udel.edu

Weather Delays U.S. Corn Planting
Exceedingly wet soils in the key growing areas of the Corn Belt are making it increasingly difficult to remain optimistic about the prospects for U.S. corn production this year. U.S. corn plantings were reported to be 13% complete as of May 1, well behind the five-year average of 40% and last year’s pace of 66%. There have been five years since 1986 that U.S. corn plantings were below 18% by April 30 : including 1993 at 8%; 1995 at 10%; 1999 at 18%; 2008 at 17%; and this year at 13%. Past history would suggest both an acreage cut and a yield reduction are in the making for 2011 U.S. corn production. The average acreage reduction for these late planted years is 1.278 million acres, while final yields averaged 7.3% below trend. Trend line yield was being estimated at 162 bushels per acre before the late plating scenario developed.

USDA Export Sales Report
U.S. soybean, corn, and wheat export sales were all reported to be bearish for the week ending on April 28. Several factors could be at play in the sluggish export sales report, among them the possibility that we may be experiencing some demand destruction due to commodity price levels. Further, competition from the Southern Hemisphere crop is now in play.

Pre-report estimates for weekly export sales of soybeans ranged from 5.5 to 9.2 million bushels. Total export sales were reported at 0.8 million bushels, below the 3.7 million bushels needed this week to stay on pace with USDA’s demand projection of 1.58 billion bushels. Total shipments of 7.4 million bushels were below the 13.3 million bushels needed this week. This report is bearish.

Pre-report estimates for weekly corn export sales ranged from 13.8 to 21.7 million bushels. Total export sales for the week were reported at 11.2 million bushels, below the 18.3 million bushels needed this week to stay on pace with USDA’s demand projection of 1.95 billion bushels. Total shipments of 31.4 million bushels were below the 43.8 million bushels needed this week. This report should be considered bearish.

Pre-report estimates for wheat ranged from 9.2 to 16.5 million bushels. The weekly report showed total export sales (old-crop and new-crop) of 20.2 million bushels, with old-crop sales of 10.1 million bushels above the 0.1 million bushels needed this week to stay on pace with USDA’s demand projection of 1.275 billion bushels. Shipments of 31.9 million bushels were below the 44.7 million bushels needed this week. The report is considered bearish. Total shipments fell further behind pace with only four weeks left in the 2010-2011 marketing year.

Market Strategy
Corn, soybean, and SRW wheat futures for both old and new crop contracts lost ground this past week attributed to non-commercial long liquidation. Soybean, corn, and wheat futures are expected to continue to lose ground through the remainder of the week. Corn futures improved the last couple of trading days supported by late planting reports and trader concern about the five to ten day forecast. However, with outside market forces currently impacting commodity prices negatively, namely the Dow (12,647) and crude oil prices (nearby at $109.24, about $5.00 per barrel off the recent high of $114.00 per barrel), corn futures are likely to follow the near term decline. Technical analysis suggests that there aren’t any sell signals in these markets at the present time. Currently, Dec ‘11 corn futures are trading at $6.11; Nov ‘11 soybean futures at $13.38; with July ‘11 SRW wheat futures at $7.72 per bushel. USDA will release the May supply and demand report on May 11th.

For technical assistance on making grain marketing decisions contact Carl L. German, Extension Crops Marketing Specialist.

 

Spring Hay Harvest Timing

Friday, May 6th, 2011

Richard Taylor, Extension Agronomist; rtaylor@udel.edu

When deciding on the time for the first hay harvest of the new growing season, a number of factors come into play. First and probably foremost among these is the question of whether to delay harvest until the grass or legume hay crop is in full flower to obtain the maximum amount of yield possible or to harvest early reducing yields but gaining in quality. That is a question each hay grower will need to answer for him or herself. If the hay is for your own operation, which do you need? – high quality or more quantity? If the hay is to sell, have your buyers demanded real quality in the past? or just pseudo-quality (a green color to the hay, fresh smell, and hay free of dust and mold)?

If quality rather than strictly quantity is your goal, then you need to be aware that at least historically the first half of May offers the best chance of good hay making weather we’ll have before mid- to late-June. I’ve come to the conclusion that rather than relying on the weather forecasters you have an equally good chance and maybe even a better chance of predicting the possibility of rainfall or poor hay making weather in your location if you examine the national weather maps and look for patterns indicating a chance for good weather. We’ve become so dependent on what the weather forecaster has to say that we tend to ignore our own brain’s ability to interpret the weather maps and create our own forecast.

So what happens if you have hay making weather and you decide to harvest your hay early? Remember that as the grass or legume crop goes from vegetative growth into the reproductive stages, yield, fiber components, and lignin increase and crude protein, digestibility, and palatability (intake) go down. The closer the crop gets to flowering the more rapid the decline in quality and the more difficult it can be to make quality hay. In part, this is because as tonnage per acre increases, the time it takes to dry the hay increases. Hay left in the field for longer periods also increases the risk that it will be rained on and cause even further declines in hay quality.

Perhaps the easiest crop to make the timing decision on is alfalfa since it is often near the ideal stage for harvest in early to mid-May in most years. We already make use of early harvesting on alfalfa if we find that alfalfa weevil is becoming a problem since the early harvest often solves the problem. In addition, alfalfa tonnage can rapidly increase with a delay in harvest and cause all kinds of drying problems.

A more difficult decision surrounds many of the grass hays that we use. Orchardgrass although it may have some seed heads visible is not approaching its maximum yield potential yet. Early harvest with this crop will result in excellent quality hay (if not rained on) but yields will be low. The second harvest will be heavier than normal and many of the side, younger tillers of the plants will produce seed heads, boosting yield and making the second harvest appearance more like the first harvest. Depending on the time of harvest for the second cutting, the quality may be a little below that of the traditional second cutting orchardgrass but should still be very good. The total tonnage of the two harvests when the first one is taken very early will not be as high as that for the typical almost mature late first cutting and leafy second cutting system.

Kentucky bluegrass in many areas is approaching full head emergence so the first half of May harvest for this crop will work fine. Similarly, the ryegrasses should respond well to this early cutting system when weather permits growers to harvest in May. Timothy harvest in Delaware seems to vary greatly so scout the crop carefully to assess its stage of maturity. When the heads are mostly emerged but still relatively small and not yet flowering, you’ll be at the point that is the best compromise between quality and quantity.

 

Soil-Applied Herbicides to Emerged Field Corn

Friday, May 6th, 2011

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

There are times (like this year) that corn has been planted and is emerged without residual herbicides being applied. Or to reduce the risk of crop injury, the residual herbicides are applied as the corn begins to emerge. Most of the soil-applied herbicides can be applied to emerged field corn. Only those products containing atrazine will provide control of weeds that have already emerged; so if there are emerged weeds, you may need an additional product to help control them. The following is a table for applying residual herbicides to emerged corn with maximum height of corn at time of application.

Herbicide Maximum Corn Height
Atrazine 12 inches
Callisto 30 inches or 8 leaf
Dual II Magnum/Cinch 12 inches
30 inches with RR corn
Outlook 12 inches
Princep do not apply to emerged corn
Prowl/Prowl H2Oa 30” or 8 collar, whichever is more restrictive
Sharpen do not apply to emerged corn
Topnotch/Harness/Degree/Breakfree 11 inches

Premixes

Basis no later than 2 collars
Bicep II Magnum/Cinch ATZ 12 inches
Bullet 5 inches
Expert 12 inches with RR corn
Fultime/Keystone/Breakfree ATZ 11 inches
Guardsman Max 12 inches
Harness Xtra/Degree Xtra 11 inches
Hornet WDG 20 inches
Lexar 12 inches
Lumax 12 inches
Sequence (RR corn only) 30 inches
SureStart/TripleFlex 11 inches
Verdict do not apply to emerged corn

 

Small Grain Disease Update – May 6, 2011

Friday, May 6th, 2011

Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu

Wheat
Be sure to keep scouting for the presence of diseases, especially powdery mildew, at this time. With the return of cooler temperatures and risk of showers and cloudy weather as well, powdery mildew could become a problem, especially in very thick stands of susceptible wheat. It is important to keep the uppermost two leaves as free of diseases as possible to protect yields. At the most, you can wait until you see 5-10% of the upper two leaves infected before applying a fungicide. Tilt, Stratego, Twinline, and Quilt can be applied as late as heads emerged but not yet flowering. If scab should be a concern this year it may be best to use only a triazole fungicide at heading through flowering to avoid mycotoxin issues if scab infection occurs. There is evidence that if fungicides containing strobilurins (Quilt, Twinline, Stratego) or strobilurins alone are applied during heading up to flowering, they can increase mycotoxin production if scab occurs during flowering. If a fungicide is needed as late as flowering for powdery mildew, Septoria leaf blotch, tan spot, or other disease and conditions are favorable for scab development consider applying Prosaro, Caramba, or Folicur for scab suppression and control of the other diseases just mentioned. For a table that rates the efficacy of fungicides for use on wheat diseases see the following link to the Kansas State fact sheet with the NCERA-184 ratings. This is a group of wheat pathologists from across the country that collaborates on wheat disease control. http://www.ksre.ksu.edu/library/plant2/ep130.pdf

Head Scab Risk Assessment Tool
Scab is still the one wheat disease that can cause major economic losses if weather conditions are favorable prior to and during flowering. The tools that we have to manage scab are limited but the use of rotation, resistant varieties and fungicides can help reduce the losses from scab should it appear. One of the tools that we have to help predict its occurrence and aid in making fungicide application decisions is the Head Scab Risk Assessment Tool that is found on the wheat scab website http://www.wheatscab.psu.edu/. The site provides information on how to use the tool and its limits.

 

Agronomic Crop Insects – May 6, 2011

Friday, May 6th, 2011

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Alfalfa
Economic levels continue to be found in fields throughout the state. If economic levels of alfalfa weevil are present before harvest and you cut instead of spray, be sure to check fields within one week of cutting for damage to the regrowth. If temperatures remain cool after cutting, there is often not enough “stubble heat” to control populations with early cutting. In some cases, damage to re-growth can be significant. A stubble treatment will be needed if you find 2 or more weevils per stem and the population levels remain steady.

Field Corn
In areas were corn is emerged, be sure to sample all fields for cutworms and slugs. For cutworms, fields should be sampled through the 5-leaf stage for damage, even if an at-planting control strategy was used. We are finding leaf feeding by cutworms as well as slug damage in some fields so be sure you do not confuse the damage. If slugs are damaging plants, you will be able to see “slime trails” on the leaves. As a general guideline for cutworms, a treatment should be considered in 1-2 leaf stage corn if you find 3% cut plants or 10% leaf feeding. With the continued wet weather, slug damage is starting to increase on newly emerging corn, especially in no-till situations. As indicated in a past newsletter, DuPont issued a 2ee recommendation for Lannate LV for slug management last season; however, we have limited experience with its use (http://www.cdms.net/LDat/ld183004.pdf). Most of our experience has been with the use of Deadline M-Ps which has provided control in past years. Be sure to read the following fact sheet from Ohio for more information on slug management (http://ohioline.osu.edu/ent-fact/pdf/0020.pdf).

Small Grains
Continue to watch for the movement of aphids into grain heads. In many cases, beneficial activity will not be high enough to take care of fields were populations are moving from the lower canopy of the plants into the grain heads. Continue to watch for cereal leaf beetles since larvae can be found in unsprayed fields throughout the state. We can find larger larvae up on the flags leaves and smaller larvae still in the lower plant canopy. Depending on the temperature, newly hatched larvae will feed for up to 3 weeks. Research from Virginia and North Carolina indicates that the greatest damage can occur between flowering and the soft dough stage, so continue to sample carefully for this insect. The treatment threshold is 25 eggs and/or small larvae per 100 tillers. Treatment is suggested when the egg threshold is reached and more than 50% of the sample consists of larvae, i.e. 50% egg hatch.

Wheat and barley should also be sampled for sawfly and armyworm larvae. Both can now be found in fields throughout the state; however, population levels and presence vary from field to field so scouting will be important. Armyworm larvae are nocturnal so larvae are generally found at the base of the plants during the day. However, during cool, cloudy weather, you may also see them feeding on the stems during the day. As a general guideline, a treatment should be considered if you find one armyworm per foot of row for barley and 1-2 per foot of row for wheat. Since sawflies feed on the plants during the day, small sawfly larvae can often be detected early using a sweep net. However, there is no threshold for sweep net samples. Once sawfly larvae are detected, sample for larvae in 5 foot of row innerspace in 5-10 locations in a field to make a treatment decision. You will need to shake the plants to dislodge sawfly larvae that feed on the plants during the day. As a guideline, a treatment should be applied when you find 2 larvae per 5 foot of row innerspace or 0.4 larvae per foot of row. If armyworms and sawflies are present in the same field, the threshold for each should be reduced by one-half.

 

Fungicide Recommendations for Strawberry Disease Control

Friday, May 6th, 2011

Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu

Anthracnose Fruit Rot
Strawberry anthracnose can be extremely destructive during warm, wet weather causing significant fruit rot. Symptoms of anthracnose include blackish-brown circular spots on maturing green fruit and soft, sunken (flat) circular lesions on ripe fruit. On ripe fruit, lesions can expand rapidly and are often covered with a pinkish-orange spore mass. Spores are spread from infected to healthy fruit with splashing water. Control of anthracnose always begins with a 7 to 10-day preventative spray program no later than 10% bloom and/or prior to disease development. For control apply the following combinations:

Application #1:
captan (M3) at 4.0 lb 50WP/A plus Pristine (pyraclostrobin + boscalid, 11 + 7) at 18.5 to 23.0 oz 38WG/A

Application #2:
captan (M3) at 4.0 lb 50WP/A plus Abound (azoxystrobin, 11) at 6.0 to 15.5 fl. oz 2.08SC/A
or
Cabrio (pyraclostrobin, 11) at 12.0 to 14.0 oz 20EG/A

Application#3:
Captevate (captan + fenhexamid, M3 + 17) at 3.5 to 5.25 lb 68WDG/A

For subsequent applications, alternate:
captan (M3) at 4.0 lb 50WP/A plus Abound (azoxystrobin, 11) at 6.0 to 15.5 fl oz 2.08SC/A
or
Cabrio (pyraclostrobin, 11) at 12.0 to 14.0 oz 20EG/A plus captan (M3) at 4.0 lb 50WP/A
or
Captevate (captan + fenhexamid, M3 + 17) at 3.5 to 5.25 lb 68WDG/A

To help manage fungicide resistance development, do not make more than 2 consecutive applications of either:

Pristine (pyraclostrobin + boscalid, 11 + 7), Cabrio (pyraclostrobin, 11) or Abound (azoxystrobin, 11) before switching to another fungicide chemistry.

Botrytis
Botrytis (gray mold) and blossom blight can cause serious losses in strawberry plantings in high tunnels and the field if not controlled properly. Development is favored by moderate temperatures (59 to 77°F) with prolonged periods of high relative humidity and surface wetness. Control of gray mold begins with preventative fungicide applications. Apply at 5 to 10% bloom and every 10 days until harvest. During periods of excessive moisture, spray intervals of 5 to 7 days may be necessary. Rotate fungicide chemistries to aid fungicide resistance management.

Application #1:
captan (M3) at 4.0 lb 50WP/A plus Topsin M (thiophanate-methyl, 1) at 1.0 lb 70WP/A
or
Switch (cyprodinil, 9) at 11.0 to 14.0 oz. 62.5WG/A

Application #2:
Elevate (fenhexamid, 17 – See restrictions) at 1.1 to 1.5 lb 50WDG/A
or
Pristine (pyraclostrobin + boscalid, 11 + 7) at 18.5 to 23.0 oz. 38WG/A

Application #3:
captan (M3) at 4.0 lb 50WP/A plus Topsin M (thiophanate-methyl, 1) at 1.0 lb 70WP
or
Switch (cyprodinil, 9) at 11.0 to 14.0 oz. 62.5WG/A

For subsequent applications, alternate:
captan (M3) at 4.0 lb 50WP/A
or
Captevate (captan + fenhexamid, M3 + 17) at 3.5 to 5.25 lb 68WDG/A
or
Switch (cyprodinil, 9) at 11.0 to 14.0 oz. 62.5WG/A.

From Rutgers Plant and Pest Advisory, Veg Crops Edition, by Andy Wyenandt, Ph.D., Specialist in Vegetable Pathology and Wesley Kline, Ph.D., Cumberland County Agricultural Agent

 

Strawberry Deformities

Friday, May 6th, 2011

Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu

Strawberry harvest is underway in the region and a common observation, especially with the earliest berries, is that there is a significant amount of deformed or misshapen berries. The most common cause of these deformities or odd shapes is weather issues during pollination. This year, low temperature damage was likely to flowers, even under row covers. Cold affected berries will have blunted tips or may appear folded. Conversely, high temperatures and drying winds can dry out some of the stigmas in strawberry flowers, especially in the center of the flower causing doughnut shaped berries. Boron deficiencies can also cause deformed berries, so can damage from spray materials – anything that affects pollination and seed development. Tarnished plant bugs can also feed on strawberry seeds and therefore cause odd shapes to develop. Growers new to the plasticulture system may also note that berries have odd shapes, especially in the large primary berries. This is most often just a characteristic of the variety. Some of these varieties produce fasciated berries that look like cockscombs.

 

Pepper Phytophthora Blight Control Recommendations

Friday, May 6th, 2011

Bob Mulrooney, Extension Plant Pathologist; bobmul@udel.edu

For control of the crown rot phase of phytophthora blight in pepper:
Apply 1.0 pt Ridomil Gold 4SL/A or 1.0 qt Ultra Flourish 2E/A (mefenoxam, 4), or MetaStar (metalaxyl, 4) at 4.0 to 8.0 pt 2E/A. Apply broadcast prior to planting or in a 12- to 16-inch band over the row before or after transplanting. Make two additional post planting directed applications with 1 pint Ridomil Gold SL or 1 qt Ultra Flourish 2E per acre to 6 to 10 inches of soil on either side of the plants at 30-day intervals. Use formula titled “Calibration for Changing from Broadcast to Band Application” from Calibrating Granular Application Equipment in Section E of the Delaware Commercial Vegetable Production Recommendations to determine the amount of Ridomil Gold needed per acre when band applications are made. When using polyethylene mulch, apply Ridomil Gold 4SL at the above rates and timing by injection through the trickle irrigation system. Dilute Ridomil Gold 4SL prior to injecting to prevent damage to injector pump. Do not use mefenaoxam or metalaxyl if insensitive strains of Phytophthora capsici are present.

 

Tomato Spotted Wilt Problems in High Tunnel/Greenhouse Tomatoes

Friday, May 6th, 2011

Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu

I recently visited a grower that grows both tomatoes and bedding plants. The plants are grown in a high tunnel-like setting, i.e., with heat. The grower was having problems in his tomato plants, but not in his bedding plants. The tomato plants looked like they had tomato spotted wilt virus (TSWV). The symptoms were found on most of his tomato plants, which would be unusual, as most of the time only an occassional plant here and there would be infected with the virus. The grower thought that is what he had as did an alert County Educator—and they were right. The grower unfortunaetly had a perfect storm in his operations that produced high percentages of TSWV infection in his tomato crop, but not his bedding plants.

Tomato spotted wilt virus is an obligate parasite; it must have a living host and must be moved from one plant to another by thrips or through cuttings or possibly seed. TSWV is transmitted most efficiently by Western flower thrips (WFT) (Frankliniella occidentalis), and less so by Onion thrips (Thrips tabaci), Tobacco thrips (Frankliniella fusca) and a few other thrips species. It is not transmitted by Eastern flower thrips (Frankliniella tritici).

WFT completes its life cycle in about 10-18 days. Eggs are laid in the leaf or tomato fruit. When WFT oviposit into tomato fruit they often cause a deeper dimple (black arrows Fig. 1) than other thrips species and very often the dimple is surrounded by a halo of white tomato tissue (white arrow Fig 1). This is how I could tell the grower had WFT present at one time (when I visited I could find no live thrips) at fairly high levels by the ovipositioning marks on his tomatoes. Larvae hatch in about three days and immediately begin to feed and in so doing pick up the virus. After four days, they pupate in the soil, and in a little over three days, the pupae become adults. Only immature thrips can acquire the virus, which they can acquire within 15 minutes of feeding, but adults are just about the only stage able to transmit the virus. Adults can transmit the virus for weeks.

TSWV infected leaves may show small, dark-brown spots (Fig. 2) or streaks on stems and leaf petioles (we found one prickly lettuce weed with such a symptom). Growing tips are usually affected with systemic necrosis and potentially stunted growth. Tomato fruit will have mottled, light green or yellow rings usually with raised centers (Fig 3).

Weed hosts function as important virus reservoirs for TSWV and can survive in and around greenhouses or even high tunnels through the winter. Some of these weeds include prickly lettuce, chickweed, (Fig. 4) spiny amaranth, lambquarters, black nightshade, shepherd’s purse, galinsoga and burdock. This grower unfortunately had a good crop of prickly lettuce at one end of his high tunnel.

The grower had been able to control his thrips populations with spinosad, but western flower thrips are notorious for developing resistance and sure enough have developed resistance to this insecticide in many greenhouses. So populations of WFT increased and with the weeds that were around and in the high tunnel some of which tested positive for TSWV, but negative for INSV, it was a perfect scenario for an outbreak of TSWV. I should note here that we tested for both INSV and TSWV on the tomatoes, weeds and impatiens. Only TSWV was found in the tomato and the weeds. No INSV was found in any sample. Although both viruses are transmitted by the same thrips species these viruses tend to infect either bedding plants (INSV) or tomato/pepper plants (TSWV). The grower threw out all his infected tomato plants and is in the process of killing his weeds in and around his high tunnel. He was able to get control of his thrips in his bedding plants using combinations of pylon and pyrethroids. One variety of tomato the grower was growing that did not show any symptoms of TSWV, even though it was right next to the other infected varieties was Mountain Glory.

Fig 1 Tomato fruit with WFT ovipostion marks

Fig. 2 Tomato leaves with TSWV symptoms and positive immunostrip (two black arrows; Agdia, Inc)

Fig. 3 Tomato fruit with TSWV symptoms

 

Fig. 4 Two common weed hosts of TSWV; prickly lettuce and chickweed