Tag: sorghum

Frost Can Cause Hazards in Forage

Amanda Grev, Forage and Pasture Management Specialist | agrev@umd.edu
University of Maryland Extension

With the first freeze of the fall just around the corner, remember that a frost can result in potential hazards for certain forages. When a plant freezes, changes occur in its metabolism and composition that can cause toxicity issues for livestock. A few issues to be on the lookout for are discussed below.

Prussic Acid Poisoning

Sorghum species like sorghum, sudangrass, sorghum-sudangrass hybrids, and johnsongrass contain a cyanogenic compound called dhurrin within the plant.  Under normal circumstances, the dhurrin is bound within plant tissues and remains non-toxic. However, if the plant tissue is injured by some sort of stressor such as a frost, the plant cell membranes can become damaged. This damage releases enzymes that can break down the dhurrin, resulting in the formation of a highly toxic hydrogen cyanide compound commonly referred to as prussic acid.

Prussic acid hinders the animal’s ability to transfer oxygen in the blood stream, resulting in asphyxiation. Ruminant animals are most susceptible, with a prussic acid concentration as small as 0.1% of dry tissue considered dangerous. Symptoms of prussic acid poisoning can appear within minutes following ingestion, with common symptoms including excessive salivation, difficulty breathing, staggering, convulsions, and collapsing. The greatest levels of prussic acid can be found in the leafier parts of the plant, particularly in new growth, and young, growing plants contain more prussic acid than older plants. To prevent prussic acid poisoning, follow these recommendations for grazing or harvesting frosted forages.

Grazing: Do not graze sorghum species on nights when a frost is likely, as high levels of the toxic compounds are produced within hours following a frost. After a killing frost, wait at least 7 to 10 days before grazing or green chopping forage, as prussic acid levels are highest in plant leaves and do not begin to decline until after the leaves have dried. After a non-killing frost, do not allow livestock to graze until the regrowth has reached a minimum of 2 feet in height or 2 weeks have passed, as the regrowth will likely contain high levels of prussic acid. When returning to grazing, don’t turn animals in hungry and use a heavier stocking rate and rotational grazing to reduce the risk of animals selectively grazing leaves or young growth that may still have higher concentrations of prussic acid present.

Harvesting: Proper field curing or ensiling can help reduce the potential for toxicity in harvested forages because prussic acid is volatile and some of the toxic components will dissipate as a gas during the drying or fermentation process. Forages should be ensiled for a minimum of 8 weeks if there was a risk of high prussic acid levels at the time of chopping. The prussic acid content in hay can be reduced by as much as 75% during the curing process, so hay is typically not hazardous when fed to livestock. Forages can also be analyzed prior to feeding to ensure the toxic compounds have been reduced to a safe level for consumption.

Nitrate Toxicity

Sorghum species, along with several other species including millet, brassicas, oats, and other small grains, are susceptible to nitrate accumulation. Under normal growing conditions, nitrate from the soil is absorbed by the roots of forage plants and is supplied to the upper portions of the plant, where it is converted into plant protein. However, under adverse environmental conditions such as drought, frost, or sudden weather changes, plant growth ceases and metabolism slows but the plants continue to take up nitrogen from the soil, resulting in a buildup of nitrates within the plant. Nitrate levels will remain high until there is new leaf growth, which increases photosynthesis and provides energy to utilize the excess nitrate.

When livestock consume forages with normal nitrate levels, the nitrate is broken down by rumen microbes to nitrite and then further to ammonia, which is converted to protein. With high-nitrate forages, nitrites accumulate faster than they can be converted to ammonia, and the accumulated nitrite is absorbed into the bloodstream. Nitrite combines with hemoglobin to produce methemoglobin, which is incapable of transporting oxygen, ultimately leading to asphyxiation. Symptoms of nitrate toxicity are related to a lack of oxygen in the blood and include weakness, difficulty breathing, rapid heartbeat, staggering, muscle tremors, and inability to stand. Affected animals typically show signs of poisoning within a few hours after consumption, and ruminant animals are most susceptible due to the rapid conversion of nitrate to nitrate by rumen microorganisms.

Nitrate levels are typically measured as nitrate nitrogen (NO3-N) on a parts per million (ppm) basis. Levels under 550 ppm NO3-N are typically considered safe to feed for all classes of livestock. Levels between 550 and 1100 ppm NO3-N may cause problems in pregnant and young animals, and levels between 1100 and 2200 ppm NO3-N are typically considered toxic and should be fed with caution. Levels above 2200 ppm NO3-N are likely unsafe to feed. Unlike prussic acid, which accumulates in the leafiest portion of the plant, nitrates tend to accumulate in the lower portion of the stem and stalks. To prevent nitrate poisoning, follow these recommendations for grazing or harvesting frosted forages.

Grazing: Avoid grazing susceptible forages when growth ceases due to drought, frost damage, or other adverse conditions. When grazing forages with suspected nitrate accumulation, introduce and acclimate livestock gradually. Feeding a low-nitrate forage or hay prior to turning livestock out onto high-nitrate forages will reduce the amount of nitrate consumed; avoid turning hungry livestock out onto a high-nitrate field. Graze high-nitrate forages in the afternoon when nitrate levels tend to be the lowest, and stock lightly so animals can selectively graze the leaves which are lower in nitrate concentration.

Harvesting: Delaying harvest until stress conditions have passed will help to lower nitrate levels within the forage and prevent toxicity. Because nitrates accumulate in the base of the plant, risk can also be reduced by cutting higher and leaving more stubble. The ensiling process can reduce nitrate concentrations by 30 to 60% following complete fermentation due to microbial degradation. However, nitrate concentrations are stable in cured hay so use caution if the forage must be baled and leave at least 12 inches of stubble to avoid baling the most toxic part of the plant.

Like with prussic acid, forages can be analyzed for nitrate concentrations prior to feeding. If forages are known to have higher than ideal nitrate levels, diluting the forage by incorporating a low-nitrate forage into the diet will reduce the overall nitrate consumption by the animal. Introducing the toxic forage slowly will help animals adapt, as well as feeding small amounts frequently rather than one large feeding. Increasing the energy content in the ration by offering a grain or high-carbohydrate feed can also help by enhancing metabolism in the rumen and aiding in the conversion of nitrates to protein, helping livestock to better tolerate higher nitrate levels in their diet.

Bloat Potential

Frothy bloat is the most common type of pasture bloat and results from the formation of a stable foam in the rumen that minimizes the animal’s ability to expel rumen gases. Consumption of forages containing high levels of soluble protein, such as alfalfa and clover, can contribute to stable foam production. Livestock suffering from bloat may indicate discomfort by stomping their feet or kicking at their belly. They will appear distended on the left side, and may die within hours.

Following a frost, plant cells rupture, producing small plant cell wall fragments and increasing the amount of K, Ca, and Mg present, all of which can increase the risk of bloat. Be aware that forage with bloat potential can be more likely to cause bloat for a few days following a frost event. If grazing pastures with high concentrations of bloat-inducing species like alfalfa or clover, waiting a few days to a week following a hard frost is a good management practice to reduce the risk of bloat.

Scout Sorghum for Key Insect Pests

David Owens, Extension Entomology Specialist, University of Delaware | owensd@udel.edu
and Kelly Hamby, Extension Entomology Specialist, University of Maryland | kahamby@umd.edu

Although sorghum faces relatively few pests compared to our other grain crops, it is not a “plant and forget” crop. Sorghum is often grown on marginal ground, in areas with greater deer pressure, dryland fields, and as a rotational component for managing weed and disease pressure. Sorghum is generally a minor component of a farming operation, and as such is easy to overlook during the season, especially now as other pests are requiring more attention and corn is nearing harvest. However, there are two significant insect pests that need to be scouted for to avoid potential losses and both are active right now on Delmarva.

The first pest that has the greatest impact on sorghum is corn earworm (Figure 1), also known as sorghum headworm (among many other crop related common names). Heads that began pollinating within the last two weeks coincided with a significant increase in earworm activity, and last week, earworm spray thresholds were exceeded in some locations in Delaware. The best way to scout for earworm is to use a ‘beat bucket’ – traditionally a 2-5 gallon bucket, although a sweep net can serve in a pinch. Gently bend the head to fit inside the bucket and shake it against the sides of the bucket several times to dislodge worms. Do this for 10 heads in a location, and 5 locations per field. Keep notes on how many larvae are small (1/4 inch or less), mid-sized (1/4 – ½ inch) and large (>1/2 inch). Texas A&M has a useful sorghum threshold calculator that takes into account control costs, grain value, and heads per acre and calculates a threshold based on the number of medium and large larvae. If your field is over threshold, we have several good options for earworm. In a 2019 spray trial, the greatest worm reductions came from Carbaryl (1.5 qts), Lannate (1.1 pints), Besiege (8 fl oz), Prevathon (now Vantacor), and Baythroid XL (2.8 fl oz). Before treating sorghum for corn earworm or the next pest of interest, remember to read labels carefully; the label is the law.

Figure 1. Corn earworm adult.

The second pest of concern is the white sugarcane aphid (Figure 2). This is a relatively new pest, and should not be confused with yellow sugarcane aphid or corn leaf aphid, both of which are common but not damaging. Yellow sugarcane aphids are bright lemon yellow, larger, and have hairs. Corn leaf aphid is a darker green color and often present in the whorl before head emergence, but quickly disappears afterward. I think of it as a beneficial insect in sorghum because lady beetles and other natural enemies get established on corn leaf aphids early. White sugarcane aphid are small, pale white-yellow, and buildup large colonies under leaves. When it is present in a field, it is obvious. Aphids produce copious honeydew which attracts flies, bees, and butterflies. It can cause yield loss as late as soft dough, particularly in drought stressed fields. So far this year in Delaware, its populations have been spotty, slow to build, and our soils for the most part have adequate moisture. There are two thresholds: 40-150 aphids per leaf or 30% of plants with aphids and scattered areas of honeydew slicks present on the upper surface of a leaf just below the aphid colony. In 2019, we found our first sugarcane aphid on August 8. By September 11, the field averaged between 227 and 644 aphids per leaf! If you recall, September 2019 was oppressively hot and dry. In 2020, sugarcane aphids were detected at the end of July and several fields were treated. I am optimistic that they will not pose as much of a threat this year, but you need to be scouting. Pay attention to any fields that are pollinating or still have heads emerging (pretty much any field you would scout for corn earworm). If you deem a field needs treating, the only good options are Sivanto, Transform, and Sefina. Sivanto has a 2ee recommendation to use at 4 fl oz, although even lower rates will work very well. Lorsban and dimethoate annoy aphids for about a week before their population increases. Pyrethroids are completely ineffective. If sorghum is going to continue serving in your rotation, reach out to your agronomist – several varieties have some level of resistance or tolerance to aphids, and this far north, that may be all we need for late sorghum.

Figure 2. White sugarcane aphids.

August IPM Insect Scouting Tips

Emily Zobel, Senior Agriculture Agent Associate | ezobel@umd.edu
University of Maryland Extension, Dorchester County

Soybean: Continue to scout for stink bugs, dectes stem borer, and defoliators (bean leaf beetle, Japanese beetle, grasshoppers, and caterpillars). Control may be needed if there is 15% defoliation from bloom through pod fill. Chemical control is not recommended for dectes stem borer since it would require multiple applications to reduce larval infestations, which is not economical. If a high number of adults are found, harvesting that field as soon as it matures will reduce losses associated with lodged plants.

With the upcoming hot weather there is an increased chance of spider mite outbreak in vegetable and soybean fields (Fig 1). Scout by using a hand lens to examine mid to upper canopy leaflets on two plants in twenty locations along the edges of the field. Consider treating if 10 % of plants have heavy stippling feeding damage on ⅓ of their mid and lower leaves.

The next flight of corn earworm (CEW) will be taking place soon. Bean fields with open canopies (wide rows), are drought-stressed, or have recently had an insecticide applied are at higher risk for CEW. CEW larvae can feed on flowers without impacting yields. NC State has a good economic threshold calculator to assist with management decisions: https://www.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html.

Field Corn: Check for stink bugs around the edges. The threshold is 1 stink bug per 2 plants from pollen shed to blister stage. Treatment is not recommended past the blister stage.

Sorghum: Sugarcane aphids typically show up in fields late July and August. Check underside of leaves for insects. Honeydew will turn leaves shiny and is an easy to see indicator that aphids are present. Sugarcane aphids are light yellow with black cornicles, antennae, and feet. Thresholds depend on plant growth stage; at boot to milk, thresholds are 50 aphids per leaf on 25 – 30% of plants. There is documented resistance to resistance to pyrethroids.

Double Crop Beans, Not So Fast

Jeff Semler, Principal Agriculture Agent | jsemler@umd.edu
University of Maryland Extension, Washington County

With barley harvest behind us and wheat harvest in full swing, our thoughts move to planting double-crop soybeans. This might be a prudent decision in many cases, but if you need forage, it may be a short-sighted choice. I suggest you look into your toolbox and consider forage sorghum, millet, or even grain sorghum.

Members of the sorghum family can be a profitable alternative crop, provided that it is managed well and used in the right situations. For instance, forage sorghum is cheaper to produce, has comparable yields, but has slightly lower forage quality when compared to corn for silage. This crop has a lot of potential in forage/livestock systems used on many farms.

These crops are best adapted to warm regions and are known for their drought tolerance compared to corn. They have higher temperature requirements than corn. For example, the minimum temperature for sorghum growth is about 60°F, and the highest yields occur when the mean temperatures during the growing season are between 75°F and 80°F. Forage sorghums have even been grown successfully in short-season areas of the mid-Atlantic, where 95-day corn is considered full season. Forage sorghum growth can range from 5 to 15 feet tall, depending on the hybrid. Hybrids can be fertile and produce grain yields comparable to grain sorghum, or they can be sterile and produce no grain.

Forage sorghum usually does not regrow following harvest; unlike sorghum-sudangrass, sudangrass or pearl millet, forage sorghum is best adapted to a single-cut harvest for silage. Forage sorghum silage is usually slightly lower in energy than corn silage and is similar in protein. Yields of forage sorghums are comparable to corn and range from 15 to 30 tons per acre depending on the soil, weather, and the hybrid. Both grain sorghum and forage sorghum have more resistance to deer damage than does corn. Consequently, they are also adapted to fields where deer damage makes corn production unprofitable.

When planted in early July, sorghum-sudangrasses can produce several tons by mid-September, where millet will likely produce slightly less per acre. However, there are improved varieties of pearl millet that can produce similar forage yields. Sorghum-sudangrass because its large stems is best used for silage or balage. Pearl millet has slightly smaller stems which makes it the better choice for dry hay. Additionally, using a higher seeding rate may help to reduce stem size when the goal is making dry hay. The forage quality will depend on the stage of maturity at harvest. A good balance between yield and quality is to cut sorghum-sudangrass or pearl millet hay during the boot stage. Forage quality can range from 55 to 65% total digestible nutrients (TDN) and 6 to 10% crude protein when the plant is between the dough and boot stage.

Sudangrass may be best suited for grazing. Sudangrass usually has less yield potential than sorghum-sudangrass. It has smaller stems and will regrow after the initial grazing, resulting in equal or better yields in a grazing situation. Sudangrass also has less risk of prussic acid poisoning than sorghum-sudan. Pearl millet can also be used for grazing, and unlike sudangrass and sorghum-sudangrass, it does not produce prussic acid, which means that it can be grazed during the initial frost period. To avoid prussic acid poisoning when grazing sudangrass or sorghum-sudan, cattle should be removed before the first frost and can start grazing again seven days after the killing frost. Grazing can begin when sudangrass and pearl millet reach 15 to 20 inches in height, but cattle should be moved when stubble height reaches 6 to 8 inches to allow for regrowth. Do not start grazing sudangrass before it reaches 15 inches as there is a risk of prussic acid poisoning. If the growth is greater than 36 inches tall, harvesting as hay or silage may be best since grazing cattle will trample the forage and result in both waste and slow regrowth. Thus, if the goal is for late summer grazing, it may be advantageous to delay planting until mid to late July to ensure that the plants are at the desired stage for grazing.

Weed control could be minimal after small grain if your cereal crop were relatively clean. No-till or vertical tillage can be used to establish the crop.

If you need forage, one of these members of the sorghum family may be a better choice. Feed is one of the highest costs in livestock production, and these crops are a cost-effective alternative for dairy heifers and beef cattle.

 

Early Fall Insect Scouting Guide and Tips

Emily Zobel, Agriculture Agent Associate
University of Maryland Extension, Dorchester County

Soybean: Keep scouting for stink bug, corn earworm, and leaf defoliators. Defoliation thresholds for R-stage soybean is 15-20% with defoliators present; however once the field has reached the R6 stage, defoliation thresholds can be relaxed. Bean leaf beetles may be found in fields but economic damage is rare in our area. Stink bugs will often aggregate in along fields edges, so make sure to check the middle of the field as well to see if the whole field needs to be treat or if you can just spot treat the edges. NC State Extension Stink Bug Economic Threshold Calculator can be used to help decide if it worth treating based on row with and bean type (https://soybeans.ces.ncsu.edu/stink-bug-economic-threshold-calculator/). As the month progress and fields get closer to harvest, sample stems in any field that have a history of Dectes stem borer issues. If your field has a large stem infestation, prioritize that field for as timely a harvest as possible to reduce loss due to lodging.

Sorghum: As fields reached the hard dough stages they are less likely to have sugarcane aphids. However, it worth keeping an eye out for honeydew, which can impended harvest, and aphids in any fields that were treated with an insecticide earlier this year and late fields that are younger than soft dough.

 

Corn Earworm Pressure Varying Regionally—Make Sure to Scout

Kelly Hamby1, Maria Cramer1, Galen Dively1, Sarah Hirsh2, Andrew Kness2   Alan Leslie2, Kelly Nichols2, Emily Zobel2, and David Owens3
1University of Maryland, Department of Entomology | 2University of Maryland Extension
3University of Delaware Extension

 

A few hot spots where corn earworm (also known as tomato fruitworm, soybean podworm, and sorghum headworm) activity is starting to rise have been identified in central Maryland and Delaware. The warm 2019-2020 winter allowed for overwintering in our area, and some parts of the state experienced a higher than normal first flight in early June. The warm weather through June and July made for speedy development and earlier activity for the second summer generation. Because corn earworm has developed resistance to most Bt hybrids, significantly more adult moths are emerging compared to levels a decade ago. Some areas continue to capture few moths and are experiencing low pressure, while others have been experiencing moderate pressure that may continue to increase towards heavy pressure (>65 moths captured per 5 days). Captures for select sites in Maryland and Delaware are pictured below, and values within the gray box indicate low pressure (<7 for weekly captures, and <5 for four to five day captures).

corn earworm on corn ear
Corn earworm larva feeding damage to corn

Although corn earworm prefer fresh corn silks for egg laying, they will lay eggs on wilted and brown silks if the plants remain green and unstressed. As corn matures further over the next several weeks, corn earworm activity will shift to other host plants including soybeans and vegetables. See last summer’s articles for scouting and management recommendations in vegetables as well as sorghum and soybeans.

Podworm outbreaks have historically occurred in growing seasons where the corn crop was drought and heat stressed, with corn senescing earlier than normal. However, narrow row spacing in soybeans makes the plants less attractive to female moths and increases the likelihood that fungal pathogens will infect the larvae. Therefore, it is important to scout bean fields, especially paying attention to those fields with a more open canopy in areas where the nearby maturing corn is no longer attractive to earworm moths. North Carolina State University has produced a helpful economic threshold calculator for podworm in soybean: https://www.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html

graph of maryland cew trap countsgraph of Delaware cew trap counts

Acknowledgements: Corn earworm trapping efforts in were supported by the Crop Protection and Pest Management Program [grant numbers 2017-70006-27171 and 2017-70006-27286] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

 

July Insect Scouting Tips 

Emily Zobel, Agriculture Agent Associate
University of Maryland Extension, Dorchester County

Soybean: The usual defoliators are starting to arrive, including bean leaf beetle, Japanese beetle, grasshoppers, and caterpillars. Control may be needed if there is 30% defoliation during the seedling and vegetative stages and 15% defoliation once plants start to bloom through pod fill.

Adult Dectes Stem borer will be emerging over the next several weeks. Chemical control is not recommended since it would require multiple applications to reduce larval infestations, which is not economical. If a high number of adults are found, harvesting that field as soon as it matures will reduce losses associated with lodged plants.

Fields that have an open canopy, drought-stressed, or have recently had an insecticide applied are at higher risk for corn earworm (CEW). CEW larva can feed on flowers without impacting yields because soybeans overproduce flowers. However, feeding during pod development can affect yield. An economic threshold calculator is available to assist with management decisions: https://soybeans.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html.

Field Corn:  As corn ears begin to form, check for stink bugs. Stink bugs will gather around the edges of fields, so scouting should be done at least 15 rows in. Thresholds are 1 stink bug per 4 plants when the ear is forming, and 1 stink bug per 2 plants from pollen shed to blister stage. Treatment is not recommended past the blister stage. Japanese beetles are minor defoliators and will clip corn silks, but control is not needed unless silks are cut back to less than ½ inch, and less than half the field has been pollinated.

Alfalfa: Once plants have hopper burn, there is no way to undo it, so continue scouting for leafhopper.  Since infestations are highly variable, individual fields should be scouted. If you are planning on selling your hay for horse feed, check for blister beetle as well since they produce cantharidin, which causes skin blisters on humans and can make horses sick.

Sorghum: Sugarcane aphids were found on the Eastern Shore last year and typically show up in fields late July and August. Check underside of leaves for insects.  Honeydew will turn leaves shiny and is an easy to see indicator that aphids are present.  Sugarcane aphids are light yellow with black cornicles, antennae, and feet. Thresholds depend on plant growth stage; at boot to milk, thresholds are 50 aphids per leaf on 25 – 30% of plants. There is documented resistance to resistance to pyrethroids.

 

Sulfoxaflor Registered for New Uses

The U.S. Environmental Protection Agency (EPA) has just issued a long-term approval for the insecticide sulfoxaflor, which the Agency has characterized as “an effective tool to control challenging pests with fewer environmental impacts.” The following information is from today’s EPA OPP Update.

“After conducting an extensive risk analysis, including the review of one of the agency’s largest datasets on the effects of a pesticide on bees, EPA is approving the use of sulfoxaflor on alfalfa, corn, cacao, grains (millet, oats), pineapple, sorghum, teff, teosinte, tree plantations, citrus, cotton, cucurbits (squash, cucumbers, watermelons, some gourds), soybeans, and strawberries.

EPA is providing long-term certainty for U.S. growers to use an important tool to protect crops and avoid potentially significant economic losses, while maintaining strong protection for pollinators,” said Alexandra Dapolito Dunn, assistant administrator for EPA’s Office of Chemical Safety and Pollution Prevention. “Today’s decision shows the agency’s commitment to making decisions that are based on sound science.”

Sulfoxaflor is an important and highly effective tool for growers that targets difficult pests such as sugarcane aphids and tarnished plant bugs, also known as lygus. These pests can damage crops and cause significant economic loss. Additionally, there are few viable alternatives for sulfoxaflor for these pests. In many cases, alternative insecticides may be effective only if applied repeatedly or in a tank mix, whereas sulfoxaflor often requires fewer applications, resulting in less risk to aquatic and terrestrial wildlife.

EPA’s registration also includes updated requirements for product labels, which will include crop-specific restrictions and pollinator protection language.

*Background*

In 2016, following a 2015 decision of the Ninth Circuit Court of Appeals vacating the registration of sulfoxaflor citing inadequate data on the effects on bees, EPA reevaluated the data and approved registrations that did not include crops that attract bees. The 2016 registration allowed fewer uses than the initial registration and included additional interim restrictions on application while new data on bees were being obtained. Today’s action, adding new uses, restoring previous uses, and removing certain application restrictions is backed by substantial data supporting the use of sulfoxaflor.

For additional information, please visit the EPA website.

Sorghum Growers Encouraged to Keep an Eye Out for Sugarcane Aphid this Season

Kelly Hamby, kahamby@umd.edu Assistant Professor/Extension Specialist, Department of Entomology

Ben Beale, bbeale@umd.edu Extension Educator, UME-St. Mary’s County

Sugarcane Aphid was found late last fall in Charles County, Maryland in a sorghum field that was being harvested for grain. Aphid populations were very high, with feeding present in the grain head and leaves. This is the first time that sugarcane aphid has been found in Maryland. While this aphid has caused substantial losses to sorghum in states to our South, it is unknown if the aphid will be present early enough and at high enough populations to cause significant injury in Maryland. Growers are encouraged to monitor sorghum fields through the summer for the presence of sugarcane aphid. We suspect sugarcane aphids are most likely to arrive later in the season in Maryland. Continue reading Sorghum Growers Encouraged to Keep an Eye Out for Sugarcane Aphid this Season