North Dakota State University Extension Service

April 28, 2005

SEEDING PULSE CROPS

When seeding pulse crops, remember that firm seed to soil contact is critical. This is especially true with field peas as they typically take over three times more water for germination than small grains. Seeding peas 2 to 3 inches deep is recommended, with a rule of thumb that they should be seeded at least an inch into moisture and never seeded just into the interface where soil moisture meets the dry soil.

The optimum seeding rates for field peas is 300,000 plants per acre or 7 to 8 per square foot. Reducing the seeding rate will increase the potential for lodging, which could make straight combining difficult. A minimum stand would be around 4 plants per square foot.

Lentils should be seeded 1 2 to 2 inches deep and can be seeded as deep as 3 inches. While not as critical as peas, seeding into dry soil should be avoided as with peas. Optimum seeding rate for lentils is 500,000 plants per square foot or 12 plants per square foot. The actual seeding rate by weight will depend upon seed size and germination. A minimum stand for lentils would be around 6 plants per square foot.

Seeding equipment should be calibrated using inoculated seed as the inoculant may reduce the flow rate through the metering system.

When seeding pulse crops with an air seeder, caution is advised as seed damage may occur if the seed is too dry (below 14% for lentils and 16% for peas) and/or if the air velocity in the distribution system is too great. Cracking and chipping seed as it goes through the air seeder will reduce the germination percentage of the seed.

To minimize damage, the lowest possible air speed that avoids plugging should be used. To obtain low enough airflow rates to reduce seed damage in some machines, it may be necessary to reduce the travel speed. Since a lower speed requires lower seed flow rates, a lower air velocity will carry the lesser quantity of seed without plugging. Refer to your manufacturer=s recommendations for optimum fan speeds and air seeder configuration.

PREPLANT/PRE-EMERGENCE WEED CONTROL IN PULSE CROPS

What can be sprayed this spring as either a preplant or pre-emergence burndown for weed control in pulse crops?

Glyphosate - Glyphosate is labeled as a preplant burndown option for control of early emerging broadleaf weeds. Aim can now be added to the glyphosate to improve kochia control. Aim should provide excellent control of small, Afuzzy stage@ kochia; especially under Adroughty@ or dusty conditions. Do not expect Aim to give satisfactory control of winter annual weeds. Higher rates of glyphosate should be considered for winter annual control. Do not add 2,4-D, Banvel, Express, or Harmony GT to the glyphosate as severe seedling injury can occur. Glyphosate can be tank mixed with most preplant herbicides such as Prowl, Sencor, or Spartan. Consult herbicide label for mixing and compatibility restrictions with glyphosate. Avoid early morning applications when temperatures are close to freezing. Glyphosate should be applied when air temperatures are above 50° F.

Pursuit - Pursuit is labeled as a premergence application in field pea and lentil. Field pea has good tolerance to pursuit; while lentil tolerance is marginal to good. Pursuit at 2 fl oz/acre or Pursuit DG at 0.72 oz WDG can be added to a Glyphosate burndown for improved mustard and winter annual control in field pea. It is recommended that the half rate of Pursuit (1fl oz/A) or Pusuit DG (0.36 oz WDG) be used in lentil. Keep in mind that user assumes all risk of crop injury. Crop injury potential increases when cold soils delays crop emergence. Hill-tops, low organic matter soils, or sandy/light soils have more potential for increased crop injury with lentil. Refer to label for tank-mix options, application recommendation, rate structure, and crop rotation restrictions.

Urea is best managed by covering with soil soon after application. This can be accomplished by either direct placement or incorporation. Incorporation should be completed within two days on fields with surface residue and within four days on fields that are mostly free of residue when weather is hot and windy or if soils are moist. When temperatures are cool (50's - 60's), the soil is dry and the wind is calm, urea may be stable as long as a week. Rainfall shortly after application can negate the need to incorporate urea. One-quarter to 2 inch of precipitation with 48 to 72 hours is sufficient to incorporate urea, with 1/4 inch needed under low residue and 2" under high soil residue soil surface conditions.

While urea is best managed by covering with soil soon after application to minimize nitrogen loss due to volatilization, there are situations such as direct seeding or no-till where producers have to rely on surface applications. The best scenario for surface applied urea to prevent volatilization loss would be to have rainfall of at least 2" within 24 hours of application. The worst scenario for surface applied urea would be application to heavy residue when the residue is wet, followed by continued damp conditions (high humidity, drizzle or light rain, dews) but not really any significant rainfall, and winds. Nitrogen losses under these conditions could be as high as 50 percent. To minimize nitrogen loss, try to apply urea when the air temperatures are cool and when the residue is dry, and then hope that things remain dry until a significant rainfall occurs.

Surface applied urea can be treated with Agrotain to lengthen the time that the fertilizer remains stable on the surface. Agrotain inhibits the urease enzyme that is responsible for the volatilization of urea. Agrotain will add to the cost of the fertility program but will provide protection against volatilization and significant nitrogen losses for about 10 days. If adequate rainfall is not received during this time period to incorporate the urea, then it would be subject to volatilization losses the same as an un-treated urea application.

Producers are reminded that weather data from the North Dakota Agricultural Weather Network (NDAWN) station in Burke County is available through the website, http://ndawn.ndsu.nodak.edu/ , or by telephone modem at 377-4455. When calling the weather station by phone to get the instantaneous weather report, please remember to press the star key (*) on your telephone before hanging up. Pressing the star key before you hang up resets or disconnects the computer from the phone line. Hanging up without pressing the star key leaves the computer connected to the phone line and drains the battery in the weather station. The star key can be pressed at anytime during the weather report, at which time you will hear a Agood bye@ message, the computer will then disconnect and you can hang up.

The AgAlert newsletter is also available by email. If you would like to receive the AgAlert by email, just let us know your email address by calling the Burke County Extension Service at 377-2927 or send an email to burke@ndsuext.nodak.edu and ask to be added to the AgAlert email distribution list.

The minimum soil temperatures for germination of various crops or groups of crops is 40 degrees for spring wheat, durum, barley, canola, mustard, safflower, field peas and lentils; 45 degrees for oats, chickpeas, and sunflowers; 48 degrees for flax, and 50 degrees for corn, soybeans and dry beans. Optimal soil temperatures for germination and emergence are about 10 degrees warmer.

Soil temperatures from the Divide County NDAWN for the last 7 days (April 18 to April 24) have averaged 44 to 46 degrees at 8 am, depending on whether you use the bare ground or turf temperatures, with daily averages of 52 to 54 degrees.

A consideration when planting crops on fields that were seeded to flax or canola the previous year is the control of volunteers.

The best option to control volunteer flax in small grains if not adequately controlled by the burn-down is Starane. Another option would be to use higher rates of Express. In terms of canola, Express XP, Harmony GT XP, and Harmony Extra XP are now labeled for pre-plant or pre-emergence applications in wheat, durum, and barley to aid in the control of RUR canola and can be tank-mixed with glyphosate for increased broadleaf control. When it comes to controlling volunteer canola in the crop, research at the North Central Research Extension Center at Minot found excellent volunteer canola control from a number of products including Starane + 2,4-D, Express + 2,4-D, and Bronate, but they found that it is very important to spray the volunteer canola before it reaches the 5^th-leaf stage. Once the volunteer canola started to bolt, it became much harder, if not impossible, to achieve acceptable control.

A frequent question the past couple of years has been how to control volunteer canola or flax in field peas, especially if the canola was RUR? A study conducted by the North Central Research Extension Center at Minot showed good to excellent control of volunteer canola from pre-emergence applications of Sencor and Pursuit and post-emergence applications of Sencor at higher labeled rates, Raptor plus Basagran (2 oz. + 1 pt.), and Basagran at a 2 pint rate. Pursuit and Raptor wouldn=t be expected to provide volunteer canola control if the canola was a Clearfield variety. Volunteer flax was more difficult to control in field peas with only pre-emergence applications of Sencor at higher labeled rates and Pursuit showing acceptable control. Spartan, which has been another commonly used pre-emergence herbicide in field peas, did not provide adequate control of either volunteer canola or flax.

Many producers have asked about tank-mixing either Harmony Extra or Express with glyphosate to aid in controlling RUR canola and to increase broadleaf weed control when making pre-plant or pre-emergence burn-down applications on pulse crops. Adding Harmony Extra or Express to the burn-down is not an option as neither is currently labeled for use pre-plant or pre-emergence in pulse crops. Plus, significant injury may occur, especially in lentils. Research conducted last year by the North Central Research Extension Center to evaluate lentil tolerance to pre-emergence herbicides resulted in lentil injury that ranged from 12 to 31 percent from Express and 17 to 78 percent from Harmony Extra, depending on the location and rate used. No injury was observed in the one trial with field peas, but more years of data will be needed to make sure there are no problems and then, the company will still need to label these herbicides for this specific use before it becomes an option.

Dan Folske
Extension Agent/Burke County
Soil Conservation Technology Specialist
PO Box 280
Bowbells, North Dakota 58721
dfolske@ndsuext.nodak.edu
701-377-2927


North Dakota State University Extension Service - Burke County
	Burke County AgAlert
	April 28, 2005 SEEDING PULSE CROPS When seeding pulse crops, remember that firm seed to soil contact is critical. This is especially true with field peas as they typically take over three times more water for germination than small grains. Seeding peas 2 to 3 inches deep is recommended, with a rule of thumb that they should be seeded at least an inch into moisture and never seeded just into the interface where soil moisture meets the dry soil. The optimum seeding rates for field peas is 300,000 plants per acre or 7 to 8 per square foot. Reducing the seeding rate will increase the potential for lodging, which could make straight combining difficult. A minimum stand would be around 4 plants per square foot. Lentils should be seeded 1 2 to 2 inches deep and can be seeded as deep as 3 inches. While not as critical as peas, seeding into dry soil should be avoided as with peas. Optimum seeding rate for lentils is 500,000 plants per square foot or 12 plants per square foot. The actual seeding rate by weight will depend upon seed size and germination. A minimum stand for lentils would be around 6 plants per square foot. Seeding equipment should be calibrated using inoculated seed as the inoculant may reduce the flow rate through the metering system. When seeding pulse crops with an air seeder, caution is advised as seed damage may occur if the seed is too dry (below 14% for lentils and 16% for peas) and/or if the air velocity in the distribution system is too great. Cracking and chipping seed as it goes through the air seeder will reduce the germination percentage of the seed. To minimize damage, the lowest possible air speed that avoids plugging should be used. To obtain low enough airflow rates to reduce seed damage in some machines, it may be necessary to reduce the travel speed. Since a lower speed requires lower seed flow rates, a lower air velocity will carry the lesser quantity of seed without plugging. Refer to your manufacturer=s recommendations for optimum fan speeds and air seeder configuration. PREPLANT/PRE-EMERGENCE WEED CONTROL IN PULSE CROPS What can be sprayed this spring as either a preplant or pre-emergence burndown for weed control in pulse crops? Glyphosate - Glyphosate is labeled as a preplant burndown option for control of early emerging broadleaf weeds. Aim can now be added to the glyphosate to improve kochia control. Aim should provide excellent control of small, Afuzzy stage@ kochia; especially under Adroughty@ or dusty conditions. Do not expect Aim to give satisfactory control of winter annual weeds. Higher rates of glyphosate should be considered for winter annual control. Do not add 2,4-D, Banvel, Express, or Harmony GT to the glyphosate as severe seedling injury can occur. Glyphosate can be tank mixed with most preplant herbicides such as Prowl, Sencor, or Spartan. Consult herbicide label for mixing and compatibility restrictions with glyphosate. Avoid early morning applications when temperatures are close to freezing. Glyphosate should be applied when air temperatures are above 50° F. Pursuit - Pursuit is labeled as a premergence application in field pea and lentil. Field pea has good tolerance to pursuit; while lentil tolerance is marginal to good. Pursuit at 2 fl oz/acre or Pursuit DG at 0.72 oz WDG can be added to a Glyphosate burndown for improved mustard and winter annual control in field pea. It is recommended that the half rate of Pursuit (1fl oz/A) or Pusuit DG (0.36 oz WDG) be used in lentil. Keep in mind that user assumes all risk of crop injury. Crop injury potential increases when cold soils delays crop emergence. Hill-tops, low organic matter soils, or sandy/light soils have more potential for increased crop injury with lentil. Refer to label for tank-mix options, application recommendation, rate structure, and crop rotation restrictions. UREA APPLICATIONS Urea is best managed by covering with soil soon after application. This can be accomplished by either direct placement or incorporation. Incorporation should be completed within two days on fields with surface residue and within four days on fields that are mostly free of residue when weather is hot and windy or if soils are moist. When temperatures are cool (50's - 60's), the soil is dry and the wind is calm, urea may be stable as long as a week. Rainfall shortly after application can negate the need to incorporate urea. One-quarter to 2 inch of precipitation with 48 to 72 hours is sufficient to incorporate urea, with 1/4 inch needed under low residue and 2" under high soil residue soil surface conditions. While urea is best managed by covering with soil soon after application to minimize nitrogen loss due to volatilization, there are situations such as direct seeding or no-till where producers have to rely on surface applications. The best scenario for surface applied urea to prevent volatilization loss would be to have rainfall of at least 2" within 24 hours of application. The worst scenario for surface applied urea would be application to heavy residue when the residue is wet, followed by continued damp conditions (high humidity, drizzle or light rain, dews) but not really any significant rainfall, and winds. Nitrogen losses under these conditions could be as high as 50 percent. To minimize nitrogen loss, try to apply urea when the air temperatures are cool and when the residue is dry, and then hope that things remain dry until a significant rainfall occurs. Surface applied urea can be treated with Agrotain to lengthen the time that the fertilizer remains stable on the surface. Agrotain inhibits the urease enzyme that is responsible for the volatilization of urea. Agrotain will add to the cost of the fertility program but will provide protection against volatilization and significant nitrogen losses for about 10 days. If adequate rainfall is not received during this time period to incorporate the urea, then it would be subject to volatilization losses the same as an un-treated urea application. NDAWN WEATHER STATION Producers are reminded that weather data from the North Dakota Agricultural Weather Network (NDAWN) station in Burke County is available through the website, http://ndawn.ndsu.nodak.edu/ , or by telephone modem at 377-4455. When calling the weather station by phone to get the instantaneous weather report, please remember to press the star key () on your telephone before hanging up. Pressing the star key before you hang up resets or disconnects the computer from the phone line. Hanging up without pressing the star key leaves the computer connected to the phone line and drains the battery in the weather station. The star key can be pressed at anytime during the weather report, at which time you will hear a Agood bye@ message, the computer will then disconnect and you can hang up. AGALERTS AVAILABLE BY EMAIL* The AgAlert newsletter is also available by email. If you would like to receive the AgAlert by email, just let us know your email address by calling the Burke County Extension Service at 377-2927 or send an email to burke@ndsuext.nodak.edu and ask to be added to the AgAlert email distribution list. MINIMUM SOIL TEMPERATURES FOR GERMINATION OF VARIOUS CROPS The minimum soil temperatures for germination of various crops or groups of crops is 40 degrees for spring wheat, durum, barley, canola, mustard, safflower, field peas and lentils; 45 degrees for oats, chickpeas, and sunflowers; 48 degrees for flax, and 50 degrees for corn, soybeans and dry beans. Optimal soil temperatures for germination and emergence are about 10 degrees warmer. Soil temperatures from the Divide County NDAWN for the last 7 days (April 18 to April 24) have averaged 44 to 46 degrees at 8 am, depending on whether you use the bare ground or turf temperatures, with daily averages of 52 to 54 degrees. CONTROLLING VOLUNTEER CANOLA AND FLAX A consideration when planting crops on fields that were seeded to flax or canola the previous year is the control of volunteers. The best option to control volunteer flax in small grains if not adequately controlled by the burn-down is Starane. Another option would be to use higher rates of Express. In terms of canola, Express XP, Harmony GT XP, and Harmony Extra XP are now labeled for pre-plant or pre-emergence applications in wheat, durum, and barley to aid in the control of RUR canola and can be tank-mixed with glyphosate for increased broadleaf control. When it comes to controlling volunteer canola in the crop, research at the North Central Research Extension Center at Minot found excellent volunteer canola control from a number of products including Starane + 2,4-D, Express + 2,4-D, and Bronate, but they found that it is very important to spray the volunteer canola before it reaches the 5^th-leaf stage. Once the volunteer canola started to bolt, it became much harder, if not impossible, to achieve acceptable control. A frequent question the past couple of years has been how to control volunteer canola or flax in field peas, especially if the canola was RUR? A study conducted by the North Central Research Extension Center at Minot showed good to excellent control of volunteer canola from pre-emergence applications of Sencor and Pursuit and post-emergence applications of Sencor at higher labeled rates, Raptor plus Basagran (2 oz. + 1 pt.), and Basagran at a 2 pint rate. Pursuit and Raptor wouldn=t be expected to provide volunteer canola control if the canola was a Clearfield variety. Volunteer flax was more difficult to control in field peas with only pre-emergence applications of Sencor at higher labeled rates and Pursuit showing acceptable control. Spartan, which has been another commonly used pre-emergence herbicide in field peas, did not provide adequate control of either volunteer canola or flax. Many producers have asked about tank-mixing either Harmony Extra or Express with glyphosate to aid in controlling RUR canola and to increase broadleaf weed control when making pre-plant or pre-emergence burn-down applications on pulse crops. Adding Harmony Extra or Express to the burn-down is not an option as neither is currently labeled for use pre-plant or pre-emergence in pulse crops. Plus, significant injury may occur, especially in lentils. Research conducted last year by the North Central Research Extension Center to evaluate lentil tolerance to pre-emergence herbicides resulted in lentil injury that ranged from 12 to 31 percent from Express and 17 to 78 percent from Harmony Extra, depending on the location and rate used. No injury was observed in the one trial with field peas, but more years of data will be needed to make sure there are no problems and then, the company will still need to label these herbicides for this specific use before it becomes an option. Dan Folske Extension Agent/Burke County Soil Conservation Technology Specialist PO Box 280 Bowbells, North Dakota 58721 dfolske@ndsuext.nodak.edu 701-377-2927
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