Category Archives: Forages

Bermudagrass Stem Maggot

BremudagrassStemMaggot

We are seeing damage from bermudagrass stem maggot (BSM) at this time and will have to start treating fields. I looked at this hay field in Boston last week. Colquitt County Agent Jeremy Kichler is reporting BSM in Alicia plots at the Expo.

The hay field will have a frosted appearance after the larvae (maggot) of the fly feed inside the shoot affecting only the top shoots (usually top 2). The lower shoots are not affected. The shoots stop elongating after feeding occurs. In the U.S., only bermudagrass is a host of BSM. Below are points I try to summarize from Biology & Management of Bermudagrass Stem Maggot. Click that link to read more detail.

Bermudagrass Stem Maggot - Adult

Bermudagrass Stem Maggot – Adult

Identification

The fly is small and yellow colored with dark eyes. The fly lays its eggs on the bermudagrass stem near a node. The maggot is yellowish in color and grows to be about 1/8 inch long. It may be hard to find the maggots, because they have usually left the stem by the time the plant shows symptoms of damage. There are multiple generations each summer. The fly has a life cycle that usually lasts about 3 weeks, but can be as short as 12 days.

Management

One cultural option we have is to go ahead and cut the hay. UGA Extension Specialists Dr. Will Hudson and Dr. Dennis Hancock say if damage is found within 1 week of the normal harvest stage, go ahead and harvest the crop as soon as weather conditions allow. Once the damage becomes apparent, the crop is unlikely to add a significant amount of yield. If damage is observed within 1 to 3 weeks after the previous harvest, it is also likely that the crop will not add a significant amount of yield. The damaged crop should be cut and (if the yields are substantial enough to warrant) baled and removed from the field as soon as weather conditions allow. Leaving the damaged crop in the field will only compete with any attempts by the plant to regrow and decrease the opportunity that the next cutting will have to accumulate mass.

Control

The most important insecticide spray is the first one which should occur 7 – 10 days after cutting. We then follow up with another application 7 days following this. Below is from Dr. Hancock:

We still do not have an insecticide that can successfully eradicate the invasive bermudagrass stem maggot (BSM). However, we have been able to suppress the fly population and the associated damage by the maggot when affected bermudagrass fields received two applications: 1) applying a pyrethroid (any labeled pyrethroid seems to work) as soon as the harvested bermudagrass begins to regrow (7 – 10 days after cutting) and 2) a second application 5-7 days later. Because of the expense of these treatments, these applications should only be made if a history of BSM damage would suggest that greater than 25% yield loss from the BSM is to be expected.

BermudagrassStemMaggot (2)

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Hay Storage

HayBales

Hay is a big expense for cattle operations. Keeping the expense down requires hay to be stored efficiently and cost effectively. A lot of hay harvested in Georgia is stored outside in large round bales. When hay is stored outside, it is exposed to rain and it deteriorates before it is fed in winter months. Some producers store forage in hay barns which significantly cuts down on waste and increases profits. Before the rush of hay making season is upon us, here are some tips on storing hay both outside and also under the barn from Colquitt County Ag Agent Jeremy Kichler:

Outside Storage Considerations

Hay that is stored outside will go through times when it will get wet and then dry out. It will subsequently develop a fibrous, weathered layer. When forages go through the wetting and drying process, nutrients are leached out. This causes the fiber component of the forage to represent a larger proportion of the dry weight. Table 1 (below) shows the changes in digestibility and crude protein of a grass and a grass-legume mixed forage when it is weathered and not weathered. This experiment shows that weathering causes TDN to decrease while the crude protein increases in both the grass and grass legume mix. Carbohydrates often leach out, but protein does not. So, weathering decreases digestibility and, by difference, the protein is a greater proportion (i.e., the percentage increases).

DigestabilityofCrudeProteinofWeatheredandUnweatheredGrasses

Table 2 shows the typical ranges of storage losses for various hay storage methods that include pole barns, hoop structures, and outside storage. This experiment also evaluates how baling the hay with twine or net wrap affects storage. When the hay is stored under a pole barn or hoop structure, dry matter losses range from 2 to 5%. Dry matter losses from outside storage ranged from 20 to 60%.

RangesinStorageLossforHayStorageMethods

Table 3 shows the value of hay lost based off the percent of forage lost and how much dry matter per ton the hay is valued. For example, if hay is valued at $100 per ton on a dry matter basis, and we experience 30 percent loss, then there is a $30 per ton loss forage. That is a lot considering the investment in fertilizer, lime, pesticides, etc. that is required in hay production.

ValueofHayLost

If hay must be stored outside, it should be stored in a sunny location. Hay should never be stored under trees where air circulation is questionable. Bale rows should run north and south instead of east to west. Hay growers should place the flat ends of round bales together and the rounded sides should not touch. Hay rows should be at least 3 feet apart to help with air circulation.

Having well-formed, tight bales can help hay growers reduce storage loses. A minimum of 10 pounds of hay per cubic foot is recommended for outside hay storage. A denser bale will resist water infiltration which will cut down on weathering. In order to make a denser bale, hay growers need to be aware of baling at safe moisture levels. This is because a more dense bale can reduce the amount of moisture and heat that escapes.

Soil contact of hay bales is an issue with outside storage. Research data shows that around 50% or more outside storage losses occur due to hay having contact with soil. Hay growers reduce storage losses by placing their crop on a rock pad, concrete or wooden pallets. If this is not possible, then look for well drained areas. Growers can place bales on a slope that allows water to drain away from the hay. Bales should be placed up and down the slope to minimize water flowing around the hay.

Inside Storage Considerations

If a hay producer has an open sided barn, then it should be oriented with the long axis east and west to minimize the exposure to sun light. If one side of the hay barn is open, then face it away from the prevailing wind which would generally be on the south side. This would minimize rain exposure of the hay being stored. Buildings for hay storage need to be open at the peak of the roof to allow moisture to escape as the hay dries. If the gables are closed, condensation and rust will occur inside the roof. More hay can be stored in a barn if you stack the bales on the flat end rather on the round side. Also consider the addition of side walls so the facility can be used for both equipment storage and hay.  

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Small Grain Issues

Triticale 026

We spent lots of time this past week looking at grazing and small grain crops. This photo of triticale above is real common in many fields. Stripes indicate nitrogen deficiency between former layby rows. This time last year, we were also seeing affects of barley yellow dwarf virus (BYDV) which is vectored by aphids. Last season, aphids were very bad early (November and December). The earlier planting of small grain/forage crops is more likely to contract BYDV based on early aphid presence. The issue is that we must plant our grazing earlier so they are established.

The presence of aphids were low early this season – opposite of last year. Following Christmas, however, I noticed evidence of aphid feeding was showing up in all small grains. We are now seeing symptoms of BYDV in some fields. The difference in cold injury, BYDV, phosphorus, and nitrogen and potash deficiency can be difficult to tell. Additionally, all elements depend on all other elements – if one is deficient, the whole thing collapses. UGA Extension Forage Agronomist Dr. Dennis Hancock sums up some of the issues we are seeing in the field:

Discoloration can mean different things in different situations. Yellow tips and leaf margins usually mean K deficiency, if N is sufficient. Yellow to tan tips but not leaf margins usually mean cold injury. Purpling tips usually means cold injury, but if temps have been mostly mild and we are dealing with susceptible species (oats, wheat, etc.), then it could also mean BYDV – especially if yellowing extends all the way to the base. Purpling at the base of the plant can also be cold temperature related or it could mean P deficiency. Usually in those situations, it is actually P deficient because of the cold (which slows down mycorrhizal fungi that assist the plant in absorbing P and Zn).

Lower leaves of triticale showing tip burn

Lower leaves of triticale showing tip burn

Symptoms of BYDV on oats

Classic symptoms of BYDV on oats

Fields have been wet the past 2 weeks, and anaerobic conditions could also be causing problems. Growers have been sidedressing when fields have been dry enough. Looking over the past month, some fields are looking better.

 

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Forage Update & Winter Fertilization Considerations

Triticale 026

We’ve been looking at more and more forage issues the past few weeks. Rust is evident in some fields. We’re also seeing evidence of N efficiency as lower leaves show chlorosis. Here is an update on our forage crops from UGA Extension Forage Scientist Dr. Dennis Hancock:

Yet again, the weather is making farming a high stakes game of chance. We had a very wet end to the summer growing season (in most areas) and this resulted in the leaching out of almost all of the residual N in the soil. Then, we’ve had lots of warm weather lately, and this has encouraged disease issues to severely limit the growth potential of winter forages. The warm weather has also allowed for some additional N mineralization to occur, but this N hasn’t stuck around long enough to provide N to our winter forages. That is because we’ve had quite a bit of rainfall in the past several weeks (pretty much the whole state) and what little available N was released has quickly been leached away. Many (if not most) of our winter forage crops are starving for N at the moment. Even fields with good stands of clover are suffering because these legumes aren’t yet fixing much N (because the soils have been so water-logged that they can’t fix N).

To make matters worse, the weather projections are not particularly positive. The models suggest a lot more of the same on the near-term: mild to cool temperatures and above normal rainfall through March-April. They also project a short end of spring: above normal temps fairly normal rainfall in late April – June.  This means that the remaining bit of the production season is likely to be compressed from what is normally a February – May growing season in a good year to what may be just March – April in some areas.

Ryegrass

Standard soil test recommendations are that one should put out 50 lbs of N/acre on ryegrass and small grains in late winter (late January – February) and another 50 lbs of N/acre on ryegrass in early spring (mid-March – mid-April). Applications of N at these rates are likely to result in more than 15-20 lbs of DM per lb of added N for the late winter application and more than 20-25 lbs of DM per lb of added N.  As a general rule of thumb, N response rates greater than 15-20 lbs of DM per lb of added N will result in an economical response.

This year, timely action with the winter applications will be absolutely crucial. Even if adequate N was applied at planting, it is likely that little or none of that is still available at the time of this writing.

The response to N (lbs of DM gained per lb of added N) has to be considered in context. To illustrate this, let us consider three scenarios:

Scenario 1) Ryegrass or small grains that have been slow to grow, either because of bad weather or N deficiency (and, sometimes, a late planting). These winter annual forage crops will often respond very aggressively to a winter application (20-30 lbs of DM per lb of added N assuming N rates are 40 – 60+ lbs of N/acre).  It is analogous to compensatory gains in growing livestock. It is the same basic principle: an organism that has had growth limitations will often grow at extraordinary rates whenever those factors are no longer limiting.

Scenario 2) Ryegrass or small grain plantings that have been growing strong. Winter annual forage crops in this scenario are unlikely to respond as aggressively to N at this time. For example, they may barely provide 15 lbs of DM per lb of added N during the few weeks following N application. However, this N is still crucial, as it keeps the plant growing at least at a healthy rate. Therefore, it is important to fertilize them at the same or nearly the same rates because they will need the fertility during the remainder of the season.

Scenario 3) Winter annual forages that have been moderate to severely damaged by disease (Helminthsporium leaf spot, grey leaf spot/blast, leaf rust, or barley yellow dwarf virus, etc.). These forage crops are unlikely to respond to N application. For example, tillers that are exhibiting physical symptoms of barley yellow dwarf (BYD) infection will die quickly, especially following a hard freeze. Therefore, if more than 30% of the tillers in a stand of oats have been damaged by barley yellow dwarf, those plants are unlikely to respond well to N. Each producer will have to determine if they are willing to take the risk, but if it were my oats, I doubt I would put any more N into those areas/fields.

Oats

Another consideration is the growth cycle of the crop. Here again, oats provide us a good example. Oats generally grow very well in the fall and in the spring, but not very well in the winter. The N recommendations for small grains as winter grazing states “…these crops can utilize about 100 (lbs of N) per acre during the growing season. Split the (N) application, applying 50 (lbs of N) per acre at planting and 50 (lbs of N) per acre in late winter before spring growth begins.” The instruction to apply 50 lbs of N/acre in late winter for small grains applies to oats, as well as to rye, wheat, and triticale. However, the operative part of this recommendation is the final phrase “in late winter before spring growth begins.” The spring growth of rye, wheat, and triticale have already begun or will do so imminently.  The spring growth of oats really won’t begin until early March.  Therefore, one would be wise to delay the late winter application of N to oats until the end of February.

Which Form of N?

Last, but certainly not least, one should consider the form of N being applied. If a producer applies ammonium nitrate, the fertilizer quickly dissolves into the soil moisture. Consequently, this source of N is almost immediately available to the plant. However, most of our producers no longer have access to ammonium nitrate.

Many of the N products that are most readily available are based on urea.  Urea and urea-based N formulations are, chemically speaking, organic forms of N. Urea must be broken down via a biological process to form nitrate, which is the form of N that plants predominantly absorb. Because this process is dependent upon the activity of microorganisms in the soil, weather can effect how rapidly this N becomes available to the plant. Cool and wet weather slows down the conversion of urea to a form of N that is available to the plant. Many producers will put on a significant amount of urea only to find that their crop fails to green up. This is NOT because they received “bad fertilizer.” It may be the result of the cool, wet weather.

Poultry litter is a great source of N… in the summer months. But, in the winter months, it is marginal at best. The reason for the difference is that most of the N is in an organic form. Just like the urea, the N in poultry litter has to be broken down by biological activity (bacteria) in order for it to be made available to the plant.  Further, putting poultry litter out now (February) is likely to pose an environmental risk such as the contamination of runoff water and therefore contaminating the water in your ponds, streams, and other freshwater resources. Of course, that assumes that poultry litter is even available to put out now or that one could get one of those trucks in the field at present, given how wet the soil is at present. Many producers apply poultry litter in the fall whenever they plant their winter grazing. This gives it a little bit of N to get off to a good start. But, it doesn’t provide much during the winter.

There are three reasonably good alternatives to these aforementioned N sources. The first one to be considered is liquid N (UAN), which is approximately half urea and half ammonium nitrate. Because of the ammonium nitrate portion, it is more readily available to the plant than many other N sources.

One should also consider using either Agrotain Plus-treated urea or SuperU. Both of these products are urea-based, but are sold under different trade names. Both are treated with a urease inhibitor (N-butyl-thiophosphoric triamide), which prevents loss as ammonia, and a nitrification inhibitor (dicyandiamide), which prevents N loss to leaching.  These still have the challenge of urea’s slow release, but they are less likely to be lost to the environment as ammonia gas or nitrate leaching into the groundwater.

Last, but not least, one should consider using the 18%N 19E product, which is a liquid N product. This product is essentially liquid calcium ammonium nitrate with sulfur and a few other micronutrients.  The N from this product, like ammonium nitrate, is almost immediately available to the plant. Further, it is often quite economical compared to other N sources because it is locally produced.

N deficiency in triticale

N deficiency in triticale. Lower (older) leaves turn yellow since N is mobile in the plant.

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Cold Weather Welcome

Frost-Smutgrass 003

We had a few frosts this week. With record warm temperatures in December, this cold is going to help some of our winter crops claim some chill hours. We’ve also been having plenty of rain as El Nino was predicted. Here are some screen shots of rain, temperatures and chill hours from the Dixie weather station from www.georgiaweather.net. You can see how much lower chill hours are as were last winter this far. The ’12 to ’13 winter was also warm.

ChillHours-GAWeather

Chill Hours

DecemberTemp-GAWeather

Temperature

Rainfall-GAWeather

Rainfall

Small Grain/Forage

Our forage crops look okay and hearing some good reports. We need to watch some of our forage now as cool temperatures are going to come back this weekend and next week. Oats, of course, are more susceptible to the cold damage.  Some cattlemen are fertilizing forage after heavy grazing to encourage new growth. Ryegrass is one of our small grains that has 3-way split, with one fertilization through the winter. Everything else we fertilize once at planting and then before spring to encourage more tiller growth. We may want to be careful with management inputs during these upcoming cold hits. Below is the forage recommendation fact sheet from the UGA Soil Test Handbook:

WinterGrazingFertilizer-FactSheet

Here are some oats I looked at today. Overall, they look good. Fields are wet and we need to watch for compaction. And we need to watch our grazing. To determine when to pull cows off, we look at the node or joint inside the stem of the plant. This is the growing point, and it feels like a bump or bee bee inside the stem. We don’t want them to graze lower than the growing point. In the picture below the joint is between my thumb and the roots.

Joint in oats

Joint in oats

I also see a little crown rust showing up. These orange/red pustules on the leaf resemble that of aphid feeding. The rust pustules will rub off on your finger. They are also raised above the leaf.

Oats 012

Pustules of crown rust in oats

Oats-Dissecting

Crown Rust

Aphid Feeding

Aphid Feeding

Crown rust will cut back on yield even in grazing, so we have to graze heavily when rust is seen so we remove the leaf tissue where spores land.

Citrus

Frost-Smutgrass 004

Some crops are not going to appreciate the cold. Thomas County has 2,500 citrus trees in commercial production now – mostly Satsumas. The biggest challenge for citrus north of Florida is cold protection. Certain plants handle cold more than others. Satsumas have the greatest degree of cold hardiness. Bearing satsumas can withstand temperatures as low as 19º to 20ºF without considerable wood damage. (Citrons, lemons and limes, on the contrary, are most easily killed by freezing temperatures – as low as upper 20s.)

I took a picture of these satsumas Tuesday morning. The temperature that morning was 29 degrees. Once temperatures get down to 24 and 25, they will cut on the irrigation as a form of cold protection. Previous cool weather allowed the plants for some cold acclimation. Cold acclimation is very important for citrus. The sudden, hard freezes in November 2014 hurt us so much more, because plants were essentially not ready for the cold. A few nights in the upper 20s is good for our citrus.

Cold damage always takes some time to show up. Lowndes County Agent, Jake Price, gave a good talk on cold damage at the Satsuma meeting this week. There are a few types of cold damage we may see. Sometimes damage occurs on the leaves only. If damage is on the stem, it is worse. If the plant incurs cold damage on the leaves, it may drop those leaves. This is a good sign since the plant has to be alive to drop the leaves. If cold damage occurs and leaves do not drop, this is not good news. Here are some pictures of cold damage. The darker green is cold damage:

Satsuma-ColdDamage-J.Price

Cold damage on Satsuma – Photo by Jake Price

 

Satsuma-ColdDamage-4-J.Price

Cold damage on Satsuma – Photo by Jake Price

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Filed under Citrus, Forages, Weather

Herbicide Timing In Small Grain

Oats-Tillering 002

Oats-Tillering 006

Wild Radish

Though little to no wheat is planted this season, we are still looking at other small grains and forages for winter weeds. Yesterday, we were looking at wild radish in oats that need to be treated. Sometimes we have injury reported after using broadleaf herbicides in small grain, particularly oats. There are  many things that influence herbicide injury, but the timing of our broadleaf products, such as 2,4-D and MCPA is critical in small grains.

UGA Extension Weed Scientist Dr. Stanley Culpepper says we do not need to use 2,4-D and MCPA until we have full tiller and before jointing.

Growth Stage

What is full tiller? Following emergence and the spike stage, small grain crops begin to tiller. These are essentially stems that will produce a grain head in the future. When we have 4, 5, or 6 tillers on a plant, it is considered full tiller. Depending on growing degree days, it will generally take between 20 and 35 days to reach full tiller.

Oats-Tillering 004A

We looked at two oat fields yesterday – one planted in October and one in November. The later planted field had just 3 tillers per plant (above) where the older field had 5 tillers. The difference here and in other small grain is that these oats are planted for grazing only. Therefore, we have less concern over injury. It will be fine to go ahead and treat both fields.

With the same herbicides, we don’t want to treat once crop enters the jointing stage. Just before jointing, the stems will elongate. At the base of the stem, you will feel a swelling of the stem (almost like a bee bee inside the stem) which is the first node or joint. The joint is the growing point. The plants have now moved into the reproductive growth stages. Here is a shot of growth development from the 2015-2016 UGA Wheat Production Guide.

HerbicideTimingInWheat

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Filed under Forages, Grain, Weed Science

Crown Rust In Oats?

Oats (4)

I was asked about rust in some oats east in the county. These oats are coming along, getting closer to graze. It has been a little dry here, and many aphids are present. Tip burn is showing up where temperatures dropped. Once we started looking through the field, it was apparent spots on the leaves were the result of aphid feeding. We still need to scout for aphids since they vector barley yellow dwarf virus (BYD). Many times, aphids feeding will leave a small, circular red spot. This appears different than rust since the rust postule is raised from the leaf.

Oats-AphidFeeding

Aphid feeding

Oats-Aphids

Aphids

Crown Rust

Crown rust is something we see more in our area south. Like rust we see in wheat and corn, the spores are carried by wind and move long distances easily. The spores overwinter in warmer southern climes and come back to our region in the summer. Rust is identified on the leaf by the small pustules which contain orange-yellow spores. Though grazing and grain are managed differently, UGA Extension Forage Scientist Dr. Dennis Hancock says rust can reduce yields in grazing. If rust is present, it is recommended to grave heavily to reduce the amount of fungal inoculant on the oat crop. We would also have to monitor this close grazing.

The key to differentiating rust from leaf spot or aphid feeding is the orange powder spores on your finger after rubbing the leaf. Here is a photo of rust from Seminole County Agent Rome Ethredge:

Crown Rust - Photo by Rome Ethredge

Crown Rust – Photo by Rome Ethredge

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Winter Forage Fertilization

FaithPittman-Weed 030

Our forage crops look much better now than they did this time last season. October was dry just like last season, but some soil had enough moisture to get a stand though mid October. Last year, frosts and rain hurt us. We checked some oats for aphids and found none this week. Aphids were also a big issue this time last year.

We are talking about fertility programs in our forage crops compared to our grain crops this week. When we plant wheat for grain, we go out with our recommended N based on previous crop at planting. We then check the stand in January to see how tillering is doing. If we have enough tillers, we hold off and put out the rest of our nitrogen at one time. If tillers are low, we split nitrogen to encourage tillering.

The difference in our forage crop UGA Extension Forage Scientist Dr. Dennis Hancock says that we only intend to increase our vegetative growth. With grain, we want to count tillers and fine tune our nitrogen. “With forage we want apply 40 – 50 lbs of N per acre at planting or soon after the plants emerge to increase growth, tillering (thickening of the stand), and provide earlier grazing. A second application of 40 – 50 lbs of N per acre should be applied in mid-winter to increase winter and spring forage production. Because ryegrass is longer-lived, a third application of 40 – 50 lbs of N per acre may be needed in early spring when ryegrass is used for late spring grazing, hay, or silage crop. Rates of N in excess of these amounts may result in substantial N losses to leaching and excessive growth during the winter. Fresh, tender growth that occurs when nitrogen is in excess could be damaged by extremely cold weather.” More information on fertilization can be found on the Georgia Forages website.

As weather turns colder, there are some issues we will have in our grazing crops. Most fields this year are oats, rye, ryegrass or a blend. Oats are more susceptible to cold injury than other small grains. With cold injury, we will see purpling of the foliage. The purpling is the result from accumulation of anthocyanins after temperature drops. We do not expect permanent damage, as the growing point is below ground during the tillering stage until jointing.

Purpling due to cold injury in oats

Purpling due to cold injury in oats

This reddish/purple color can also indicate barley yellow dwarf virus. These symptoms start from the tip of the leaf blade. The virus is vectored by aphids which are observed on the foliage. Most fields will have some level of BYDV each season. We are not seeing aphids now, so this is less of a concern.

Another cause of purpling is due to phosphorus deficiency. P is not soil mobile and is taken up by root ‘interception meaning’ the roots must grow to it. Cold can decrease root growth and this becomes evident. Nitrogen and potassium on the other hand are soil mobile. They can leach down into soil profile with rain. This time last season, rain was leaching N out of the soil. N is also mobile inside the plant, so older or lower leaves will show deficiency first.

Nitrogen deficiency in wheat

Nitrogen deficiency in wheat

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Minimize Risks From Moldy Hay

UGA Extension Forage Scientist Dr. Dennis Hancock has new information on moldy hay issues:

Because of the wet fall, many producers have faced extremely difficult field curing conditions for their hay. Additionally, hay that was bone dry in the field has, in many cases, developed mold problems in the barn. This later issue has been problematic for us in 2015, resulting in a large number of square and round bales covered with black sooty mold. It is arguably more problematic because this is often a barn design issue (e.g., open sides, poor air drainage, lack of ventilation, inability to close off ventilation, etc.). Under the high levels of humidity that we’ve had (because of periods of nearly continuous rain and cool weather) the last 2 months, dry hay will draw moisture from the moist air. For example, hay that is 12-15% moisture (the appropriate moisture for hay storage) may have a 6-12” layer along any exposed surface that may equilibrate at about 30%+ moisture if the surrounding environment is cool (< 70 F) and moist (relative humidity stays > 60%). Any moisture level greater than 20% on the surface could result in significant mold growth/discoloration, and levels greater than 30% moisture can result in the entire stack’s exposed surface being covered in black sooty mold.

HayBales

As a result, our County Extension Agents and I have had an extraordinary number of emails and calls about feeding moldy hay, especially to horses. First, let me clearly state: moldy or dusty hay should NOT be fed to horses. Moldy and dusty hay can lead to respiratory issues in the horse, and can also pose health risks to the men and women who feed the hay to the livestock (e.g., farmer’s lung, etc.). Here’s a link to an excellent Extension article on the subject. Soaking the hay in a water trough before feeding will reduce the “dust” (which is usually mostly mold), but it will also leach out soluble sugars and lower forage quality. This may not reduce the risk of mycotoxins (and yes, hay can have mycotoxins in it just like moldy grain, peanuts, or oilseeds can have in them). For a discussion of mycotoxins, see this article I wrote on the subject. Several companies now sell hay “steamers,” which is a chamber or box wherein hay bales are placed and steam is pumped into the chamber. In addition to the expense, the downside of these steamers is that they will lower the forage nutritive value of the hay and they are unlikely to change the mycotoxin levels appreciably.

Ruminant animals aren’t as sensitive to mold problems as horses, but they still can be negatively impacted if care is not taken to prevent health challenges. Feeding slightly to moderately moldy hay (mold spore counts up to 1 million cfu/gram) is relatively safe if feeding cattle or small ruminants, as long as the animals are fed outside or in a very well-ventilated feeding area. Keep in mind that palatability is likely to be a challenge. Hay that emits a substantial cloud of “dust” or continues to emit dust after the disturbance ceases should be assumed to be > 1 million cfu/gram. A test can confirm mold levels. Hay that is obviously moldy (moldy or “mousey” smell or sending off visible “dust” or mold spores when disturbed) should be tested for mycotoxins before being fed. UGA’s Feed and Environmental Water Laboratory is not equipped to conduct the mold spore count test or the mycotoxin screen. (I contacted Waters Agricultural Labs in Camilla, GA and they are set up for this test.) You can, however, work through the UGA lab to arrange for these tests to occur. Alternatively, you can submit samples directly to labs that do conduct these tests (e.g, Cumberland Valley Analytical ServicesDairy One).

Bales that are covered with black sooty mold on the exterior can be removed and discarded, and usually the interior bales are not affected. Bale stack design can help minimize the surface area exposed and, thereby, minimize the damage. Barn design issues can also be corrected to prevent this problem in the future. Barns that can be open to allow moisture to escape during the initial 2-4 weeks of storage and then shut during prolonged periods of high humidity and cool temperatures will offer flexibility in this regard.

For more information on forage management issues, visit our website at www.georgiaforages.com.

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Winter Grazing Coming Along

Oats&Rye 005

Our winter forage crops are looking good so far on the east side of the county. This pasture is a blend of oats and rye. It was planted the first week of October. This is before it became very dry. It was after this that growers had to wait until next rainfall. So, there was a downtime of establishment. It’s tillering now and growing tall. The cows are soon to be brought over to graze. This field is ready to graze. UGA Extension Forage Agronomist Dr. Dennis Hancock talks about the “art” of grazing in not grazing too early:

In general, the earlier one starts grazing, the more damage will be done to the pasture’s growth potential. It is a function of the growth curve. In that early stage (lag phase), when growth is slow or just beginning to get going good, grazing can essentially stop growth or slow it to a crawl. It is like a bank account with some principal in it. The more principal one has, the more growth in the account one will get. The growth rate is like compounding interest. Grass grows grass. Take away principal (grass), and the amount of growth will decrease.

So, that’s enough professor talk… Practically speaking, one really shouldn’t start grazing until there is at least 1800-2500 lbs of DM/acre, though I would wait a little later on oats as they’ll slow growing in December (particularly if it becomes very cold). For rye, that would be about 5-6 inches. For ryegrass, I’d wait until it is at least 6 inches. For oats, I’d wait until it is about 6-8 inches. The ideal would be to only graze it a little… removing just what it’s average growth rate is and maintaining at least 1500-1800 lbs DM/acre. This is why I am a BIG fan of timed (limit) grazing.

Remember… don’t be too quick to graze. Grazing too early can cost one more in the long run.

Oats&Rye 012

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