Scouting soybean fields for disease
By
John Grimes-
The roller-coaster ride that has been our spring weather pattern continued last week. It seems like we have been hard-pressed lately to get a window of dry weather that will let farmers complete spring planting and make significant progress with hay harvest.
On the bright side, most of the early planted crops are developing rapidly with the recent increase in temperatures. I suppose it is too much to ask for the weather conditions to be “just right.”
Most of you know I will talk about current sporting events from time to time. Here’s something that I have been wondering about lately. Does anyone find it odd that we are still playing professional basketball and hockey in June? I thought those were winter sports!
Scout soybean fields
for water-borne diseases
Ohio soybean growers should be keeping an eye on their crop for water-borne diseases that may have cropped up during the recent heavy rains.
Anne Dorrance, an Ohio State University Extension plant pathologist, said that saturated soils and ponding conditions make it ideal for the development of diseases such as pythium seed rot, phytophthora root and stem rot, fusarium root rot and rhizoctonia stem rot.
“Right now, because of the cooler soils, the crop is most susceptible to pythium seed rot and damping-off,” said Dorrance, who also holds a research appointment with the Ohio Agricultural Research and Development Center. “We’ve been pulling some pythium from our plots already.”
Dorrance said that growers should scout their fields for classic signs of damage from water molds and other soil-resident pathogens.
“When scouting fields, what you’ll see are big blank spaces where seedlings have died and plants haven’t emerged, or plants will come up and will damp-off, meaning that they turn brown and die,” said Dorrance. “If a dead plant has a red canker at the base, it’s probably Rhizoctonia. If it’s brown and soft, it’s Pythium or Phytophthora. If it’s pink, then it’s probably Fusarium.”
Dorrance said that in situations where growers have to replant, wait until the soil is completely dry for a few days before planting new seed.
“Pathogens tend to go dormant under dry conditions and they have to be re-wetted to get started back up again,” said Dorrance. “You don’t want to re-plant quickly into these fields when the pathogens are active. You may end up having to re-plant two or three times.”
In addition, Dorrance highly recommends growers use seed treatments to protect the seedlings. Despite the risk from water-borne pathogens, Ohio’s soybean crop so far is in good shape, said Dorrance.
Forage fertility
Through the series of drought, escalating price, managing dynamic change, and every other type of ‘stress’ meeting we’ve hosted in Ohio during recent years, it’s apparent that the message regarding fertility is getting out. While not a new story, simply put, fertilizer is expensive yet we all know you can’t starve a profit into a cow, and likewise, you can’t starve production or profit into a forage field either.
This past year I’m seeing significantly more interest in soil testing, as well as receiving questions about interpreting soil tests and developing efficient fertilizer recommendations. It’s also apparent some of those who make fertilizer recommendations for a living may not have attended our meetings, or perhaps do not subscribe to the concepts contained in the Tri-State Fertilizer Recommendations, OSU Extension bulletin E-2567.
Hence, let’s review:
a) Soil Test, always soil test! Fertilizer is too expensive to apply if it’s not a yield limiting factor. If we don’t know what we presently have, we can’t possibly know what we might need!
b) Read the soil test or get help reading it. I’d discourage anyone from blindly accepting the fertilizer recommendations that sometimes come back with a soil test.
I’m not even certain I’d believe their little graphs that I sometimes find on the soil test results which indicate a sample might be high, medium or low in a certain nutrient.
What I was told by one of the labs when I asked how their recommendations are generated is that after they establish the nutrient levels in the soil through their laboratory procedures. The recommendations are often generated based on the opinions of the company who might have submitted the sample for the land owner. This means, unless you send in the sample yourself, you may get back a recommendation based on data other than what Ohio State’s (or other universities’) research might suggest as published in OSU Extension Bulletin E-2567. Ask your local agriculture educator for help in developing a recommendation if you have questions.
c) If one insists on fertilizing without the benefit of knowing the present fertility levels, or if you know your present fertility levels meet or slightly exceed critical minimum levels, then it’s prudent to base your fertilizer application rates on expected crop removal. If you are harvesting hay from the field, Bulletin E2567 tells us every ton removed (regardless of quality) takes with it 13 pounds of P2O5 and 50 pounds of K2O. No matter how you slice it, that’s a ratio of 1 to 4, phosphorus to potash. Without benefit of a soil test to tell us otherwise, fertility needs to be replaced in that ratio when harvesting hay. To put that into a little different perspective, consider that the average hay yield in Ohio is and has been for decades about 3 tons per acre per year. At 1 to 4, that’s 13 and 50 pounds respectively multiplied times 3, or 39 pounds of P2O5 and 150 pounds of K2O per acre. As an FYI, since corn grain only removes about 0.27 pounds of K2O per bushel, it would take a yield of over 555 bushels of corn to remove the same amount of potash that an average Ohio hay yield removes!
To recap . . . you can’t starve a profit into a crop or critter, immediately after first cutting is removed is an appropriate time to apply fertilizer to a hay field, and one ton of hay removes P and K in a ratio of 1 to 4, or 13 pounds P2O5 to 50 pounds of K2O. To maintain current fertility levels in your soils, it must be replaced with either fertilizer, manure nutrients, or some other form of fertility . . .1 to 4, 13 to 50, per ton of hay removed!
John Grimes is the Ohio State University Extension Educator for Agriculture and Natural Resources in Highland County.[[In-content Ad]]
On the bright side, most of the early planted crops are developing rapidly with the recent increase in temperatures. I suppose it is too much to ask for the weather conditions to be “just right.”
Most of you know I will talk about current sporting events from time to time. Here’s something that I have been wondering about lately. Does anyone find it odd that we are still playing professional basketball and hockey in June? I thought those were winter sports!
Scout soybean fields
for water-borne diseases
Ohio soybean growers should be keeping an eye on their crop for water-borne diseases that may have cropped up during the recent heavy rains.
Anne Dorrance, an Ohio State University Extension plant pathologist, said that saturated soils and ponding conditions make it ideal for the development of diseases such as pythium seed rot, phytophthora root and stem rot, fusarium root rot and rhizoctonia stem rot.
“Right now, because of the cooler soils, the crop is most susceptible to pythium seed rot and damping-off,” said Dorrance, who also holds a research appointment with the Ohio Agricultural Research and Development Center. “We’ve been pulling some pythium from our plots already.”
Dorrance said that growers should scout their fields for classic signs of damage from water molds and other soil-resident pathogens.
“When scouting fields, what you’ll see are big blank spaces where seedlings have died and plants haven’t emerged, or plants will come up and will damp-off, meaning that they turn brown and die,” said Dorrance. “If a dead plant has a red canker at the base, it’s probably Rhizoctonia. If it’s brown and soft, it’s Pythium or Phytophthora. If it’s pink, then it’s probably Fusarium.”
Dorrance said that in situations where growers have to replant, wait until the soil is completely dry for a few days before planting new seed.
“Pathogens tend to go dormant under dry conditions and they have to be re-wetted to get started back up again,” said Dorrance. “You don’t want to re-plant quickly into these fields when the pathogens are active. You may end up having to re-plant two or three times.”
In addition, Dorrance highly recommends growers use seed treatments to protect the seedlings. Despite the risk from water-borne pathogens, Ohio’s soybean crop so far is in good shape, said Dorrance.
Forage fertility
Through the series of drought, escalating price, managing dynamic change, and every other type of ‘stress’ meeting we’ve hosted in Ohio during recent years, it’s apparent that the message regarding fertility is getting out. While not a new story, simply put, fertilizer is expensive yet we all know you can’t starve a profit into a cow, and likewise, you can’t starve production or profit into a forage field either.
This past year I’m seeing significantly more interest in soil testing, as well as receiving questions about interpreting soil tests and developing efficient fertilizer recommendations. It’s also apparent some of those who make fertilizer recommendations for a living may not have attended our meetings, or perhaps do not subscribe to the concepts contained in the Tri-State Fertilizer Recommendations, OSU Extension bulletin E-2567.
Hence, let’s review:
a) Soil Test, always soil test! Fertilizer is too expensive to apply if it’s not a yield limiting factor. If we don’t know what we presently have, we can’t possibly know what we might need!
b) Read the soil test or get help reading it. I’d discourage anyone from blindly accepting the fertilizer recommendations that sometimes come back with a soil test.
I’m not even certain I’d believe their little graphs that I sometimes find on the soil test results which indicate a sample might be high, medium or low in a certain nutrient.
What I was told by one of the labs when I asked how their recommendations are generated is that after they establish the nutrient levels in the soil through their laboratory procedures. The recommendations are often generated based on the opinions of the company who might have submitted the sample for the land owner. This means, unless you send in the sample yourself, you may get back a recommendation based on data other than what Ohio State’s (or other universities’) research might suggest as published in OSU Extension Bulletin E-2567. Ask your local agriculture educator for help in developing a recommendation if you have questions.
c) If one insists on fertilizing without the benefit of knowing the present fertility levels, or if you know your present fertility levels meet or slightly exceed critical minimum levels, then it’s prudent to base your fertilizer application rates on expected crop removal. If you are harvesting hay from the field, Bulletin E2567 tells us every ton removed (regardless of quality) takes with it 13 pounds of P2O5 and 50 pounds of K2O. No matter how you slice it, that’s a ratio of 1 to 4, phosphorus to potash. Without benefit of a soil test to tell us otherwise, fertility needs to be replaced in that ratio when harvesting hay. To put that into a little different perspective, consider that the average hay yield in Ohio is and has been for decades about 3 tons per acre per year. At 1 to 4, that’s 13 and 50 pounds respectively multiplied times 3, or 39 pounds of P2O5 and 150 pounds of K2O per acre. As an FYI, since corn grain only removes about 0.27 pounds of K2O per bushel, it would take a yield of over 555 bushels of corn to remove the same amount of potash that an average Ohio hay yield removes!
To recap . . . you can’t starve a profit into a crop or critter, immediately after first cutting is removed is an appropriate time to apply fertilizer to a hay field, and one ton of hay removes P and K in a ratio of 1 to 4, or 13 pounds P2O5 to 50 pounds of K2O. To maintain current fertility levels in your soils, it must be replaced with either fertilizer, manure nutrients, or some other form of fertility . . .1 to 4, 13 to 50, per ton of hay removed!
John Grimes is the Ohio State University Extension Educator for Agriculture and Natural Resources in Highland County.[[In-content Ad]]