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Volume 9 Issue 3 June 19, 2018

Alert! Cucumber Downy Mildew By Kate Everts

Professor, Plant Pathology University of Maryland

keverts@umd.edu

Downy mildew on processing cucumber was found on Thursday, June 13 in Dorchester County, MD. This is one of the earliest occurrences of downy mildew in Maryland. Protect cucumber crops with products that are specific for downy mildew. Among the specific fungicides for this disease are Orondis Ultra or Ranman, which should be mixed with a protectant fungicide. Many additional fungicides are registered for downy mildew and are listed in the Commercial Vegetable Guide.

Remember to rotate products in different FRAC groups and to apply preventative fungicides, which are more effective than "rescue treatments". At this time, only cucumber (both processing and fresh-market) should be affected. The strains that infect other cucurbits have not been observed in our region.

Watch for Aphids in Melons By Jerry Brust

Extension IPM Vegetable Specialist University of Maryland

jbrust@umd.edu Several reports lately of very deformed watermelon plants, but also a few cucumber and cantaloupe fields. These distortions (fig. 1) most of the time are being caused by melon aphids Aphis gossypii Glover. Melon aphids are small and range in color from a light/dark green mottle (fig. 2), which is most common to whitish, yellow (seen during hot, dry weather), pale green, and dark green almost black forms. The legs are pale with just the tips of some parts black. The cornicles also are black. One trait of melon aphids that make them particularly difficult to manage is that unlike other aphids,

their populations do not fade with higher summer temperatures. Immatures look like adults, only smaller.

Fig. 1 Watermelon plant with heavy melon aphid population

Female melon aphids give live birth to clones of themselves during spring and summer and their populations can increase very rapidly especially when hidden on the underside of foliage. One of the things to look for to see if you have an actively growing aphid population is white cast skins of the aphids, aphids must shed their skins to grow so lots of skins show that the aphids are actively growing (fig. 2, orange arrows). The faster they grow the faster they become adults and can begin to reproduce. The reproductive period lasts about two weeks with a female producing 65-85 offspring in that time. The ideal temperature for reproduction is around 70o-80o F., which are the temperatures we are experiencing now. There is evidence that there are host races, i.e., melon aphids reared on cotton can be transferred successfully to okra but not to cucurbits. This inability to transfer from one host to another has been shown for other crop combinations.

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Fig. 2 Melon aphids on underside of leaf. Melon aphids feed on the underside of leaves and can be a major problem on young plants when they feed near the tips of vines, sucking sap and nutrients from the plant. Their feeding causes a great deal of distortion and leaf curling, hindering the photosynthetic capacity of the plant (fig. 1). The foliage may become chlorotic and die prematurely. They also secrete a great deal of honeydew which allows the growth of sooty mold and further reduces the photosynthetic ability of the infested plant. One of the other major problems with melon aphids (as with other aphid species) is that they are good at transmitting potyviruses such as cucumber mosaic virus, watermelon mosaic viruses, and zucchini yellow mosaic virus. These viruses are transmitted to plants despite insecticide applications, which include oil sprays. This is mostly because the aphids can transmit these nonpersistent viruses within 15 seconds of reaching the plant. Management: No thresholds have been established for melon aphid in cucurbits. Reflective mulches laid before planting can repel aphids from plants reducing or delaying virus transmission, until vine growth covers-up the plastic. In smaller fields row covers can be used. Biological control can have a significant impact on aphid populations and is our first line a defense. Therefore, weekly sprays of insecticides should not be used in watermelon unless really needed. Because cantaloupe and cucumber are very susceptible to bacterial wilt disease, which is vectored by striped cucumber beetles several insecticide sprays may be necessary. However, resistance by melon aphids to organophosphates and pyrethroid insecticides is common. Using neonicotinoids for beetle control will help control aphids, but the neonics should not be sprayed exclusively and pyrethroids or other insecticide classes should be used intermittently for beetle control. It should be noted that a plant damaged as severely as the one in figure 1 will not recover to produce a crop.

While many of the above suggestions are all good to prevent aphid problems what do you do once you have them? Organically there are not many good aphid control tactics to use once they show up. Applications of rosemary oil or insecticidal soaps or horticultural oils are options. These will have to be applied several times with thorough coverage of the foliage being critical for control of the pest. Rosemary oil will disrupt beneficial populations less so than soaps or oils. There are several synthetic controls that will work if thorough coverage is obtained. These chemical controls include: methomyl, dimethoate, acetamiprid, clothianidin, thiamethoxam, pymetrozine, flonicamid and combination products that include one of these. Be sure to read the label and the Commercial Vegetable Guide before applying any chemicals.

Seldom Seen Tomato Disease Found in High Tunnel

By Jerry Brust Extension IPM Vegetable Specialist

Karen Rane UMD Plant Diagnostic Lab

University of Maryland jbrust@umd.edu

A root disease that is most commonly associated with potato has turned up on tomato in a high tunnel last week. This disease goes by the delightful name of black dot root rot. The causal agent is Colletotrichum coccodes, which also causes anthracnose fruit rot on tomato (sunken, water-soaked, circular lesions). C. coccodes infection on tomato roots appears as lesions on the root surface that produce black microsclerotia (the ‘black dot’ in its name) (fig. 1). Infected plants will sometimes wilt (fig. 2), with the lower and middle leaves of the plant turning yellow.

Fig. 1 Black dots (microsclerotia of C. coccodes) on tomato root. C. coccodes has a very large host range, which includes members of Solanaceae, Cucurbitaceae and Leguminosae, both crops and weeds. Nightshade in particular (a solanaceous weed) can harbor the fungus, often without showing symptoms. The pathogen can survive in the soil for up to 8 years as microsclerotia.

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Assassin bug nymph (top) feeding on a spotted cucumber beetle. Adult wheel bug (bottom) feeding on a stink bug. Photos by E. Zobel

Gardening questions? Pest Problems? The Home and Garden Information

Center can help!

Visit the HGIC website at: http://extension.umd.edu/hgic

Fig. 2 High tunnel tomato plants with black dot root rot disease wilting.

This pathogen causes problems only under poor growing conditions or when other pathogens are present. The disease occurs in greenhouses or high tunnels where there has been a continuous cropping of tomato for several years, resulting in very high levels of inoculum. Other conditions that can be encountered in high tunnels, such as high soluble salt levels, low pH, low or excessive fertilization, high temperatures and water stress, can predispose plants to infection and root rot by C. coccodes. These infected plants can at times show few symptoms, but still be responsible for yield reductions.

Management. The disease can be prevented by growing in optimal conditions for tomato in the high tunnel. Deep plowing (12-15 inches, not easy to do in a high tunnel we know) degrades infected plant debris more rapidly and buries propagules both of which may help reduce fungal populations. Steam sterilization of the soil, or soil solarization for 8 weeks, can reduce disease incidence. Crop rotation is another tried and true management plan if growers can rotate out of any solanaceous, leguminous or cucurbit crops for 3-4 years; something most growers may not be able to accomplish.

What may be the best solution for high tunnel growers with heavy inoculum levels of this disease is to move the high tunnel to different ground. Grafting is another possibility, but the plants in this high tunnel were grafted tomato plants, a different root stock may be resistant or more tolerant of the disease, but this is something that would need to be checked before using. Small grain or corn can be used in rotation in the field to reduce fungal populations.

On-Line at: Commercial vegetable Guide

Know Your Beneficial Insects: Assassin Bugs

By Emily Zobel Extension Agent, Agriculture

Dorchester County ezobel@umd.edu

Assassin bugs (Reduviidae) are generalist predators that feed on a wide variety of insect pests including stinkbug (adults and nymphs), leaf beetles, leafhoppers, small-medium size caterpillars. They are in the order hemipteran, (true bugs) so they feed with a piercing-sucking beak. There are over 160 species of assassin bugs in North America, but the three most common ones found in fields and gardens are the spined assassin bug, the wheel bug, and the elongate assassin bug. Assassin bugs are generally larger (1/2-3/4”) with long legs, and round eyes on a narrow head.

Due to their red and gray color assassin bug nymphs often get confused with other true bugs nymphs such as squash bug nymphs. However, assassin bug nymphs have longer legs and thinner abdomens. They are also highly

mobile and are not found in groups compared to plant feeding nymphs. Assassin bugs are great biological control agents. To keep and conserve them in your field use IPM and avoid using broad-spectrum insecticides when possible.

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Has Rain Necessitated Vegetable Plant Petiole Sap Analysis for N and K?

By R. David Myers Principal Agent, Agriculture

University of Maryland Extension myersrd@umd.edu

Growers often need fast assessment of plant fertility coupled with soil and tissue testing to make economic and environmentally sound fertilizer applications. The Plant Petiole Sap rapid field test using the Horiba Cardy meter is almost essential when deluges of rain occur.

Recommendations for petiole sap sample consistency: 1) Sample fields between 10:00-2:00. For repeated field sampling try to be within one hour of previous sample time. 2) Sample is best taken on sunny days with adequate plant moisture, non-stressed plants. Avoid excessively wets soil conditions or during long periods of cloudy weather. 3) Take 15-25 leaflet samples at random for each test. The leaflets should represent the youngest fully sized leaflets on the plant. 4) Calibrate the meter. 5) Use only the petiole from the leaflets for the sample as described in figure 1. 6) Conduct the meter reading at the field. Plant sample most be placed on ice if it is not tested immediately. 7) Cut and crush the mixed petiole sample and immediately place the sap on the calibrated meter. 8) Avoid direct sunlight when placing the sap on the meters as the sap dries quickly and a false reading will occur. Meter reading should be taken within 10-seconds of sap placed on the meter. 9) Remember to convert the meter nitrate nitrogen reading to the table 1 nitrogen values by multiplying by .223. Table 1. Adequate nitrate-N and K concentrations in fresh petiole sap of most recently matured leaves for several vegetable crops at various periods in the season using the Hach or Quant-strip methods, or Cardy meter.

Figure 1: Petiole Delineation for Several Plant Species.

Table 2. Recommendations for correction of crop nutrient deficiencies.

Source: Plant Tissue Analysis and Interpretation for Vegetable Crops in Florida by G. Hochmuth, D. Maynard, C. Vavrina, E. Hanlon, and E. Simonne. Full Report available on-line at: http://edis.ifas.ufl.edu/ep081 Summarized plant tissue testing procedure is also published in the 2018 Mid Atlantic Commercial Vegetable Production Recommendation available on-line at: Commercial vegetable Guide

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Foliar Fertilization of Vegetable

Crops Revisited By Gordon Johnson

Extension Vegetable & Fruit Specialist University of Delaware

gcjohn@udel.edu

I recently looked a several vegetable plantings that showed severe damage from foliar fertilizers. The extended cloudy weather set up conditions where the plants were more susceptible to salt injury (thinner leaves with less developed waxy cuticles). With plant injury in mind, I thought it would be good to revisit the use of foliar fertilizers in vegetable crops.

Growers will apply most (>90%) of their plant nutrients for vegetable crops as soil applications (preplant, sidedressed, fertigated) based on soil tests and crop nitrogen needs.

To monitor vegetable nutrient status during the growing season, tissue testing is recommended just prior to critical growth stages. Growers can then add fertilizers to maintain adequate nutrient levels during the growing season or correct nutrient levels that are deficient or dropping. Foliar fertilization is one tool to maintain or enhance plant nutritional status during the growing season. Often quick effects are seen and deficiencies can be corrected before yield or quality losses occur. Foliar fertilization also allows for multiple application timings post planting. In addition, there is reduced concern for nutrient loss, tie up, or fixation when compared to soil applications.

However, foliar fertilization has limitations. There is the potential to injure plants with fertilizer salts, application amounts are limited (only small amounts can be taken up through leaves at one time), multiple applications are often necessary (increasing application costs) and foliar applications are not always effective, depending on the nutrient targeted and plant growth stage.

Where foliar fertilization does have a good fit is for deficiency prevention or correction, particularly when root system function is impaired. This commonly occurs when there is extended rainy weather and soils are waterlogged. Foliar fertilization is also necessary when soil conditions, such as low pH, causes the tie up of nutrients so that soil uptake is limited. Foliar fertilization can also be used to target growth stages for improved vegetable nutrition thus improving color, appearance, quality, and yield.

Foliar fertilizers are applied as liquid solutions of water and the dissolved fertilizers in ion or small molecule form. Foliar nutrient entrance is mostly through the waxy cuticle, the protective layer that covers the epidermal

cells of leaves. Research has shown that there is limited entrance through the stomata. While the waxy cuticle serves to control water loss from leaf surfaces, it does contain very small pores that allows some water and small solute molecules to enter the underlying leaf cells. These pores are lined with negative charges. Fertilizer nutrients in cation form or with neutral charges enter most readily through these channels: this includes ammonium, potassium, magnesium, and urea (NH4+, K+, Mg++, CH4N2O respectively). In contrast, negatively charged nutrients (phosphate-P, sulfate-S, molybdate-Mo) are much slower to move through the cuticle (they must be paired with a cation). Movement through the cuticle is also dependent on molecular size, nutrient concentration, time the nutrient is in solution on the leaf, whether the nutrient is in ionic or chelated form (complexed with an organic molecule), and the thickness of the leaf cuticle.

Another factor in foliar fertilizer effectiveness is what happens once the nutrient enters the leaf area. Some smaller molecules or those with less of a charge are readily transported in the vascular system to other areas of the plant (NH4+, K+, Mg++, Urea). Other larger molecules and more strongly positive charged nutrients stay near where they enter because they bind to the walls of cells in intercellular areas that contain negative charges. Tightly held nutrients include Calcium, Manganese, Iron, Zinc, and Copper (Ca++, Mn++, Fe++, Zn++, Cu++). Therefore, when applied as foliar fertilizers, calcium does not move much once it enters plant tissue, the negatively charged nutrients such as phosphorus and sulfur are very slow to enter the plant, and iron, manganese, copper, and zinc are slow entering and do not mobilize once in the plant.

The following is a list of the major plant nutrients that are effective as foliar applications, fertilizer forms best used for foliar applications, and recommended rates: Foliar applications of nitrogen (N) can benefit most

vegetables if the plant is low in N. Urea forms of N are the most effective; methylene ureas and triazones are effective with less injury potential; and ammonium sulfate is also effective. Recommended rates are 1-10 lbs per acre.

Foliar potassium (K) is used on fruiting vegetables such as tomatoes and melons. Best sources are potassium sulfate or potassium nitrate. Recommended rate is 4 lbs/a of K.

Foliar magnesium (Mg) is used on tomatoes, melons, and beans commonly. The best source is magnesium sulfate and recommended rates are 0.5-2 lbs/a of Mg.

Foliar calcium is often recommended, but because it moves very little, it must be applied at proper growth stages to be effective. For example, for reducing blossom end rot in tomato or pepper fruits, foliar calcium must be applied when fruits are very small. Best sources for foliar calcium are calcium nitrate (10-15 lbs/a), calcium chloride (5-8 lbs/a) and some chelated Ca products (manufacturers recommendations).

Iron (Fe), manganese (Mn), or zinc (Zn) are best applied foliarly as sulfate forms. Rates are: Fe, Mn, 1-2

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lbs/a, and Zn ¼ lb/a. While these metal micronutrients are not mobile, foliar applications are very effective at correcting local deficiencies in leaves.

The other micronutrient that can be effective as a foliar application is boron. Boron in the Solubor form is often recommended at 0.1 to 0.25 lbs/a for mustard family crops such as cabbage as a foliar application. Boron is very toxic to plants if applied in excess so applying at correct rates is critical.

For foliar fertilizers to be most effective they should remain on leaves or other targeted plant tissue in liquid form as long as possible. Urea and ammonium nitrogen forms, potassium, and magnesium are normally absorbed within 12 hours. All other nutrients may take several days of wetting and rewetting to be absorbed. Therefore, it is recommended that foliar fertilizers be applied at dusk or early evening when dew is on the leaves, in high volume water, and using smaller droplets to cover more of the leaf. Applications should also be made when temperatures are moderate and wind is low. While foliar fertilizers are sometimes applied with pesticides, for best effectiveness and reduced phytotoxicity potential it is recommended that they be applied alone. Use only soluble grade fertilizers for foliar applications (many are already provided in liquid form) and adjust water pH so it is slightly acidic.

Foliar fertilizers are most effective when applied to younger leaves and fruits. Research has shown that as leaves or fruits age, cuticles thicken, and these thicker cuticles absorb significantly lower amounts of nutrients such as potassium. However, younger plant tissue is also the most susceptible to potential fertilizer burn.

Because foliar fertilizers are in salt forms they can damage plant tissue if applied at rates that are too high. Generally, a 0.5-2% fertilizer solution is recommended. Certain vegetables are more sensitive to fertilizer salt injury than others. Vegetables with large leaves with thinner cuticles (such as muskmelons) have greater risk of salt injury when compared to crops, such as cabbage, that have thick cuticles. Apply foliar fertilizers at recommended rates and dilutions for each specific vegetable crop.

In addition, some fertilizer sources are much more likely to cause injury than others. In the past this was given as the salt index for a fertilizer, the lower the salt index the less osmotic stress the fertilizer would place on the plant tissue. A better index would be the osmolality values for the fertilizer material. For foliar nitrogen materials, osmolality values (mmol/kg) for common N sources are as follows: Urea = 1018, UAN-28 = 1439, Ammonium sulfate = 2314, Potassium nitrate = 3434. This shows that potassium nitrate has over 3x the osmotic stress potential compared to urea when applied as a foliar fertilizer. This means that potassium nitrate has much more potential to cause salt injury to plants than urea and must be used at lower rates.

On Farm Readiness Review is Being Offered to Farms that

Need to Comply with the FSMA-Produce Safety Rule

By David Martin Extension Agent Emeritus

University of Maryland

The Food Safety Modernization Act (FSMA) is a law that was passed by Congress in 2010 and gave the U.S. Food and Drug Administration (FDA) a legislative mandate to require prevention-based controls across the food supply. The Produce Safety Rule (PSR) is one of many rules within FSMA and has the greatest impact on producers of fresh vegetables and fruits.

Since the PSR was published on November 27, 2015, many fruit and vegetable farmers have attended meetings and trainings to learn about what is needed to comply with the new regulations. As the PSR is a mandated federal regulatory program, enforcement through inspections will begin in the future depending on compliance dates. As the FDA works with the state departments of agriculture to implement the PSR they have adopted a philosophy of “educate before you regulate” to help growers meet the requirements of the federal rule.

The Maryland Department of Agriculture (MDA) entered into a cooperative agreement with the FDA so that the MDA (and not the FDA) will be conducting inspections, beginning in 2019, to verify compliance with the PSR. In fact, January 26, 2018 was the date for farms with over $500,000 (3-year average) in produce sales to begin meeting the regulatory compliance requirements (with future dates for smaller farms). While many farms have taken steps to meet compliance deadlines, there are still questions about what needs to be done to be fully compliant and how the inspections will be structured.

The On Farm Readiness Review (OFRR) program was developed by the National Association of State Departments of Agriculture and in Maryland it is being coordinated by MDA with assistance from the University of Maryland and University of Maryland Extension. The OFRRs are not intended to be regulatory; the purpose is to provide education and technical assistance to farmers who are required to comply with the PSR. The OFRR will help address the many questions farmers have concerning compliance with the rule and assist farms with correcting non-compliant practices. The on-farm review is a discussion of PSR provisions and not an inspection nor an audit. Maryland farmers that have attended the one-day Produce Safety Alliance Grower Training have the option to request an OFRR of their farm. The on-farm review is voluntary and at no cost to the farmer. Farms that were required to be in compliance by January 2018

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will be inspected first, starting in 2019, and will be given preference in scheduling an OFRR.

How does the OFRR work? First, the farmer contacts MDA to indicate interest in scheduling a review of their food safety practices and how their practices line up with the regulations. Next, a food safety team representative will contact the farmer to discuss eligibility and scheduling prior to finalizing a farm visit. Once the farm visit schedule is finalized, a team of 3 or 4 will visit the farm operation to discuss and observe farm practices that may include growing, harvesting, and postharvest activities on the farm. At the completion of the OFRR, the team will discuss their observations with the farm operator and provide resources to help the farmer in those areas.

Who is on the OFRR food safety team? The team will usually have three people: one from the MDA Food Quality Assurance Section, one from the University of Maryland and one from the University of Maryland Extension office. The purpose is to help the farm operator better understand and meet the requirements of the federal Food Safety Modernization Act- Produce Safety Rule.

Maryland’s OFRR program will begin this summer. Farmers who have interest in having an OFRR of their food safety practices or questions about implementation of the PSR should email Produce.Safety@maryland.gov, call MDA at 410-841-5769 or complete the OFRR request form online at http://mda.maryland.gov/fsma. Farmers that need general help with on-farm food safety including the PSR should contact Justine Beaulieu (by email: jbeauli1@umd.edu or by phone: 301-405-7543)

Vegetable Disease Update By Kate Everts

Professor, Plant Pathology University of Maryland

keverts@umd.edu

June 15, 2018 Tomato Late Blight Tomato transplants were found at a garden center in northeast Pennsylvania last Friday (June 8) that were infected with late blight. We don’t know the origin of these transplants, and I understand that none were sold. However, the occurrence warrants extra vigilance of any tomato plantings to scout for late blight.

Cucurbit Powdery Mildew Please read labels carefully as some of the fungicides mentioned in this article are not labelled on all cucurbits. In planning your spray programs for powdery mildew on cucurbits, remember that many products that are labeled for this disease, are not effective because of the existence of fungicide resistance. The powdery mildew pathogen Podosphaera xanthii, is highly prone to the development of resistance and has lost sensitivity (become resistant) to some recently registered fungicides. To manage powdery mildew, begin with good

cultural practices – especially the use of resistant cultivars. In a spray program, alternate targeted fungicides in different FRAC groups, apply fungicides at manufacturer’s recommended rate (don’t cut the rate), tank-mix with a fungicide with different mode-of-action (or use combination product), and don’t apply at-risk fungicides if powdery mildew sporulation covers more than 20% of the leaf surfaces.

Currently the following targeted fungicides are NOT effective for managing powdery mildew (resistance in pathogen population is high): Topsin M (FRAC 1, Benzimidazole), and Cabrio, Quadris, and others (FRAC 11, QoI fungicides).

Resistance exists, but the following fungicides may be used judiciously, to a limited extent, in a rotational program: Rally, Procure, Folicur, (FRAC 3, DMI fungicides); Pristine (FRAC 7 + 11), Fontelis, Xemium, Aprovia (FRAC 7, SDHI fungicides). Luna is also a FRAC 7 fungicide, however it isn’t cross resistant with the other FRAC 7 group.

Fungicides that still have good efficacy in our area in the past two years are: Quintec (FRAC 13) and Vivando (FRAC U8). Luna Experience and Quintec alternated with Procure are alternations that I have tested and performed well. Unfortunately, resistance to Torino (FRAC U6) has now been documented in the eastern U.S. and it hasn’t performed well in my trials. Scab of Cucurbits Cool wet weather is associated with several vegetable diseases. One of these is scab on cucurbits, caused by the fungus Cladosporium cucumerinum, which is favored by temperatures at or below 70°F and wet weather. Watermelons are highly resistant to scab, and many cucumber cultivars also have resistance (see the Commercial Vegetable Recommendation Guide for a list of resistant cucumber varieties). However, summer and winter squash, pumpkin, gourds, muskmelon and honeydew are susceptible. Symptoms vary somewhat

depending on the cucurbit crop. However, leaf lesions appear as water-soaked, pale green to grey or white and angular. Dead leaf tissue cracks and looks “ragged” and is sometimes referred to

as shot-holed. Fruit may have sunken spots (summer squash or susceptible cucumber), or raised scabby lesions (butternut squash). Scab should be managed by using resistant cultivars when available, and rotating out of

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susceptible crops (cucurbits) for two years. Application of chlorothalonil is also effective. Hop Downy Mildew Hop downy mildew was found near Wye Mills, MD on the Eastern Shore on Friday. Our weather remains very conducive for this disease which likes cool temperatures and high humidity. Symptoms are angular lesions on the leaves that are brown and necrotic. Image shows the upper surface of leaves with angular lesions caused by downy mildew. Sporulation occurs on the lower surface of the leaf. Cucurbit Downy Mildew Please note that the pathogen that causes hop downy mildew is NOT the same as the one that causes cucurbit downy mildew. Cucurbit crops should be monitored for presence of downy mildew, however the closest reported outbreak of cucurbit downy mildew as of June 7, 2018 is in North Carolina.

Image show a screen shot of current outbreaks of downy mildew in the eastern U.S. from the ipmPIPE website. Red denotes counties where downy mildew was found in the last 7 days, and green counties represent

outbreaks reported more than 7 days ago. http://cdm.ipmpipe.org/scripts/map.php

Be Alert for Late Blight Showing Up on Tomatoes

By Jerry Brust IPM Vegetable Specialist University of Maryland

jbrust@umd.edu

Another disease we might be seeing now and in the next week or so is late blight. The weather conditions of the past week have been favorable for its development: cool (for summer temperatures) daytime and nighttime temperatures along with ample moisture. It is important to watch for this disease and treat for it as soon as it is observed or is found in your area. Symptoms of late blight on tomato leaves are irregularly shaped water-soaked lesions that appear on young leaves at the top of the plant. Under humid conditions, these lesions become brown (Fig.

1a) and white fuzzy sporulation can be seen (Fig. 1b). Eventually the leaves shrivel and die. Brown lesions with sporulation also can occur on stems and leaf pedicels (Fig. 1c). The pathogen infects tomato fruit and causes circular greasy lesions. The fruit remains firm but can become leathery and dark brown. Best management practices for late blight control are found in the 2018 Mid-Atlantic Commercial Vegetable Production Recommendations Guide found at: http://extension.udel.edu/ag/vegetable-fruit-resources/commercial-vegetable-production-recommendations/ What do we do? www.HiveLend.com connects farmers and beekeepers for crop pollination. Our website, allows farmers to be matched with beekeepers who have hives specific to their pollination needs. Sign up online and we will take care of the rest. Who do we work with? We work with farms of any size. Our network of beekeepers allows us to work with farms of any acreage and crop. If you have pollination set in place for this year, and are interested in opportunities for the next year, contact us below. The Team Nick and Dawn are residents of Baltimore, MD, and have more than 15-years of beekeeping experience and a passion for pollination. Contact Nick Zajciw at: nickzajciw@gmail.com (586)-703-0417 www.HiveLend.com

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Sulfur and Vegetable Crops By Gordon Johnson

Extension Vegetable & Fruit Specialist University of Delaware

gcjohn@udel.edu With the recent heavy, leaching rains, we are seeing signs of sulfur deficiency in some vegetable crops. Sulfur is considered one of the secondary macronutrients that vegetable crops require for growth. Sulfur is a component of four amino acids and is therefore critical for protein formation. It is also a component of certain glycosides that give pungency to mustard family crops (greens, cole crops) and Allium crops (onions, garlic). In the last 25 years, as industrial air pollution has been reduced (especially pollution from coal fired power plants) we have had less sulfur deposition from rainfall. Sulfur deficiencies are more common and sulfur additions in fertilizers or manures is being required for many crops to produce high yields. Most of the sulfur in the upper part of the soil is held in organic matter. Upon mineralization, sulfur is found in the soil as the sulfate ion (SO42-) which has two negative charges. The sulfate ion is subject to leaching, especially in sandy textured soils (loamy sands, sandy loams). It does accumulate in the subsoil but may not be available for shallow rooted vegetables. Sulfur can be added by using sulfate containing fertilizers such as ammonium sulfate, potassium sulfate, and K-mag (sulfate of potassium and magnesium). It is also a component of gypsum (calcium sulfate). In liquid solutions, ammonium thiosulfate is often used as the sulfur source. Sulfur is also found in manures and composts. For example, broiler litter has about 12-15 lbs of sulfur per ton. In vegetable crops, sulfur removal is generally in the 10-20 lb/A range. Mustard family crops (cole crops such as cabbage and broccoli, mustard and turnip greens, radishes) remove between 30 and 40 lbs/A of sulfur. Research in our region has shown response to added sulfur for sweet corn and for watermelons. In Florida research it was shown that adding 25 pounds of sulfur per acre boosted yields by 1.7 tons per acre in tomatoes. Similar results were found with strawberries. Our general recommendations are to apply 20-30 lbs of sulfur per acre on sandy soils for most vegetable crops. Remember to take credit for any sulfur being added with fertilizer sources such as ammonium sulfate (24% sulfur). One vegetable where we want to limit sulfur is with sweet onions. Because sulfur increases onion pungency, and sweet onions are sold based on their low pungency, we limit sulfur applications to this crop.

Welcome! To the Grapes and Fruit website. Statewide Extension and research programs (link is external) for viticulture (grape growing), tree & small fruits, and enology (winemaking), are being created and implemented at Western Maryland Research and Education Center by Dr. Joseph A. Fiola (link is external), Extension Specialist in Viticulture and Small Fruit. Dr. Fiola works with existing vineyard and winery owners to increase production and improve quality. He is working to expand the industry in Maryland by educating new vineyard owners. This site is designed for the commercial grower or someone who would like to start a vineyard.

Post-Bloom (June) • Downy Mildew Management (pdf) • Minimizing Herbaceous Character in the

Vineyard (pdf) • Pre-Bloom to Post-Bloom Disease Management

(pdf) • Red Leaves in the Vineyard—Diagnosis and

Management (html) (pdf) Mid-Season (June-July)

• Brown Marmorated Stink Bug (BMSB) - Part 1 (pdf)

• Brown Marmorated Stink Bug (BMSB) - Part 2 (pdf)

• Crop Estimation (html) (pdf) • Crop Management (html) (pdf) • Disease Management - Botrytis (html) (pdf) • Drought Stress, Vine Performance, and Grape

Quality (pdf) • Grape Berry Moth (html) (pdf) • Hail Damage (pdf) • Japanese Beetles (html) (pdf) • Mid-Season Disease Management (pdf) • Red Leaves in the Vineyard—Diagnosis and

Management (html) (pdf)

CDMS Pesticide Labels and MSDS On-Line at: http://www.cdms.net/

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Maryland Department of Agriculture

Announces 2018-2019 Cover Crop Sign-Up

The annual sign-up period for Maryland Department of Agriculture’s cover crop program will take place June 21 - July 17 at soil conservation district offices statewide. This popular grant program provides farmers with cost-share assistance to offset seed, labor, and equipment costs to plant cover crops on their fields this fall to control soil erosion, reduce nutrient runoff, build healthy soils, and protect water quality in streams, rivers and the Chesapeake Bay. Governor Larry Hogan has allocated approximately $22.5 million for Maryland’s 2018-2019 Cover Crop Program.

Maryland’s Cover Crop Program provides grants to farmers who plant small grains such as wheat, rye, barley, and oats, brassicas, and forage radish on their fields following the fall harvest. To help create diversity, eligible cover crop species may be mixed with radish and legumes including clover, Austrian winter peas and hairy vetch using a variety of two and three-species mixes.

Cover crops cost-shared through this program receive a base rate of $45/acre and up to $30/acre in add on incentives for planting early and using other highly valued planting practices. The aerial seeding deadline is October 7. Maryland’s nutrient management regulations require farmers to plant cover crops to help protect water quality when organic nutrient sources are applied to fields in the fall. Double-crop soybeans may be planted aerially at a reduced reimbursement rate and farmers may harvest their cover crops, but payment for this option is no longer offered. Program eligibility requires that the farm has a current nutrient management plan.

EPA Site Quick Finder

About EPA's Pesticides Program

Overview of EPA's program evaluating potential new pesticides and uses, providing for special local needs and emergency situations, reviewing safety of older pesticides, registering pesticide producing establishments, enforcing pesticide requirements, pesticide

issues in the works, overview of risk assessment in the pesticide program Types of Pesticides Pesticides are often grouped according to the type of pest they control or by chemical or source. type of pest, chemically-related Frequently Asked Questions Answers to questions from the public.

Fact Sheets Search general interest and technical fact sheets. Health and safety, regulatory actions, specific chemicals

Information Sources Additional information of general interest. General information, hotlines, information centers, databases

Pesticide Program Reports Reports produced by the Office of Pesticide Programs Annual Reports, Performance Management & Accountability, Pesticide Industry Sales and Usage, Progress Reports, Restricted Use Products Reports

Pesticide News Stories Pesticide related articles appearing in news media

EPA Announces Federal Register Notice Regarding the Availability of

Worker Protection Training Materials

EPA is notifying the public that the Agency intends to publish in the Federal Register a notice stating the pesticide safety training materials with the expanded content required by the 2015 FIFRA Worker Protection Standard (WPS) are available for use. The notice of availability will be published in docket EPA-HQ-OPP-2011-0184 on www.regulations.gov.

The training materials with expanded content have been available at the Pesticide Education Resources Collaborative (PERC) and were developed through an EPA cooperative agreement. EPA also approved training materials developed by other organizations, some of which are available on PERC’s website. Updated training materials must be used 180 days after the publication of the notice in the Federal Register.

EPA revised the WPS to implement more protections from pesticide exposure incidents for agricultural workers, handlers, and their families.

Note that EPA has initiated a process to revise certain requirements in the WPS. EPA plans to publish a Notice of Proposed Rulemaking later in 2018 to solicit comments on proposed revisions to the WPS requirements for minimum ages, designated representatives, and application exclusion zones. If the changes to the

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requirements are finalized, these safety training materials will be amended to reflect such changes. Until such time, all requirements are in effect.

For more information on the WPS and to see a prepublication copy of the notice, visit www.epa.gov/pesticide-worker-safety/agricultural-worker-protection-standard-wps.

The University of Maryland, College of Agriculture and Natural Resources will hold the 2018 Farmers' Field Day at LESREC on Wednesday, June 27, from 9-1:00 at the Lower Eastern Shore Research and Education Center in Salisbury, Maryland.

Lunch will be provided. Please register at your earliest convenience at: https://2018-farmers-field-day-at-lesrec.eventbrite.com

WHEN: TUESDAY, JULY 10, 2018 TIME: 8:30 a.m. - 4:00 p.m. Registration Deadline: Friday. June 29, 2017

For this year’s summer tour, we will be visiting two well-managed family farms (Hollabaugh Bros. Farm and Market & McCleaf’s Orchard), as well as attending the FREC Centennial Celebration and Field Day in Pennsylvania. This tour will showcase grower innovations in horticultural production, marketing, and attending the FREC Centennial Celebration luncheon, information sessions.

REGISTRATION CHECK IN AT: Hollabaugh Bros. Market 545 Carlisle Road, Biglerville, PA 17307 Directions: follow US-15 North. Take right exit PA-394 toward Hunterstown. Turn left onto PA-394. Turn right onto Table Rock Road (PA-394). Turn right onto PA-34, S Main Street (7-Eleven on corner). Hollabaugh Bros. Inc. is on the right.

COST: $25 (MSHS Member) $35 (Non-Member) (includes coffee & doughnuts, lunch and beverages)

AGENDA: click here...

REGISTRATION: To pay by *credit card go to: http://2018summertour.eventbrite.com *There is an additional processing fee from Eventbrite to pay by credit card.

To register by mail and pay by check: Complete the registration form click here... for offline registration form. Mail your check payable to Maryland State Horticultural Society (MSHS) with registration form to: Susan Barnes, c/o MSHS, 18330 Keedysville Road, Keedysville, Maryland 21756-1104 If you have any questions, please contact Susan Barnes at 301-432-2767x301 or by email sbarnes6@umd.edu SPONSORED BY: Maryland State Horticultural Society (MSHS); University of Maryland, College of Agriculture and Natural Resources; University of Maryland Extension; Farm Credit

Join fellow farmers, industry representatives and Extension Agents for a day of learning about no-till. Equipment demonstrations will occur throughout the day. See the attached flier for full details. For questions call Ben Beale at 301-475-4481 or email bbeale@umd.edu This will be an informal tour, with plenty of opportunity to discuss your no-till questions with other growers. Handouts and other brochures will be available.

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Crops Twilight Barbecue

& Ice Cream Social CMREC Upper

Marlboro Farm August 8, 2018

You are invited to a Fields Crops Research Twilight, Barbecue and Ice Cream Social at the Central Maryland Research & Education Center, 2005 Largo Road, Upper Marlboro, Maryland on Wednesday, August 8, 2018 from 4:00 to 9 PM. A barbecue dinner will be served at 4:00 pm followed by homemade ice cream prior to the evening tour. University of Maryland Extension Educators and Specialists will showcase their field crop, vegetable and fruit research plots.

Barbeque begins at 4:00 PM

Ice cream Served at 5:15 PM

Crops Twilight at 6:00 PM

Please arrive on time as the tour will start promptly at 6:00 PM. This event is free. However, a reserved meal ticket is required.

If you need special assistance to participate, please contact the Anne Arundel County Extension office at 410-222-3906 by August 6th.

Register on-line at the Anne Arundel County Extension website: http://extension.umd.edu/anne-arundel-county Click to Register or call 410 222-3906.

See the Attachments!

1. No-Till Field Day and Tour Flier

Vegetable & Fruit News A timely publication for the commercial vegetable and fruit industry available electronically in 2018 from April through October on the following dates: April 26, May 24, June 19, July 26, August 23, September 20 and October 25 (Special Research & Meeting Edition).

Published by the University of Maryland Extension Focus Teams 1) Agriculture and Food Systems; and 2) Environment and Natural Resources. Submit Articles to: Editor, R. David Myers, Extension Educator Agriculture and Natural Resources 97 Dairy Lane Gambrills, MD 21054 410 222-3906 myersrd@umd.edu Article submission deadlines for 2018 at 4:30 p.m. on: April 25, May 23, June 18, July 25, August 22, September 19 and October 24 (Special Research Edition). Note: Registered Trade Mark® Products, Manufacturers, or Companies mentioned within this newsletter are not to be considered as sole endorsements. The information has been provided for educational purposes only. The University of Maryland Extension programs are open to any person and will not discriminate against anyone because of race, age, sex, color, sexual orientation, physical or mental disability, religion, ancestry, national origin, marital status, genetic information, political affiliation, and gender identity or expression.

No-Till Field Day and Tour

Tuesday, July 3, 2018

8:30 am – 2:30 pm Registration Not Required

Lunch Provided

Private Applicator Pesticide Credits and Nutrient Voucher Credits Approved

Join fellow farmers, industry representatives and Extension Agents for a day of learning about no-till. Equipment demonstrations will occur throughout the day. See the full agenda on the back for all the details. For questions call Ben Beale at 301-475-4481 or email bbeale@umd.edu This will be an informal tour, with plenty of opportunity to discuss your no-till questions with other growers. Handouts and other brochures will be available. Directions: The farm is located off of Westham Lane in the Thompsons Corner/Mechanicsville area. Take Rt. 5 south toward Leonardtown. Turn left onto Rt 236 (Thompsons Corner Road). Proceed 2 miles. Turn left onto Woodburn Hill Rd. After 1/3 mile turn left onto Westham Lane. Proceed ½ mile to second farm on the left.

To be held at the farm of John Y. Stoltzfus 37510 Westham Lane

Mechanicsville, MD 20659

No-Till Field Day Agenda 8:30-9:00 am Introduction and morning refreshments 9:00-9:45 am Making No-Till Work for You

Gideon Stoltzfus, Pequea Planters An overview of no-till systems and how they can be used in your operation. No-till can provide many benefits including better soil health, soil moisture retention, and reduced equipment/tillage passes.

9:45-10:30 am Growing a Good Cover Crop

David Hunsberger, Kings Agriseed A review of the many cover cropping options for this area. There will be several summer crop plantings to look at including buckwheat, sorghum-sudan grass, pearl millet, sun hemp, clover and forage soybean.

10:30-11:15 am Planter Set-up and Maintenance

Gideon Stoltzfus, Pequea Planters In field demonstration of no-till planters, how to set them up and maintain them.

11:15-11:45 am No-till/Strip Till for Vegetables and Tobacco

Dave Myers/Ben Beale, University of Maryland No-till is not just for corn and soybeans. Look at different options for no-till vegetable production and tobacco production. See a demo of a strip-till machine and no-till vegetable planter. Learn about different pest complexes in reduced tillage.

11:45-12:00 pm No-Till Tobacco Planter Demo Joe’s Machinery, Willow Street, PA

See the new no-till tobacco planter in action. 12:00-12:30 pm Lunch-Enjoy pizza and homemade ice cream 12:30-1:00 pm Selecting the Best Weed Management Program for No-Till Systems

Ben Beale/Dave Myers, University of Maryland To be successful with no-tillage, good weed control must be achieved. Learn about different weed control options, herbicide programs and an updates on herbicide resistant weeds like palmer amaranth and common ragweed.

1:00-1:45 pm Hay Equipment Demonstration

Millwood Machinery In field demonstration of various hay equipment including Esh tedder, Hoover tedder, Scissor-Cut mower and no-till hay planter.

1:45-2:15 pm Sprayer Calibration, Pesticide Use and Safety

Ben Beale/Dave Myers, University of Maryland Demonstration of sprayer calibration techniques and how to choose the best nozzle for the job. Overview of pesticide use and safety topics, including MDA updates.

2:15-2:30 pm Wrap-Up, Questions, Pesticide and Nutrient Voucher Sheet Sign-Out** **Full day attendance at this meeting will provide full private pesticide recertification credits and nutrient voucher credits.

The University of Maryland is an Equal Opportunity Employer and Equal Access Programs