North Dakota State University Extension Service - Burke County |
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Burke County AgAlert |
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May 10, 2004 FLAX FERTILITY GUIDELINES: NITROGEN: Nitrogen inputs for flax are less than wheat. Excessive nitrogen rates may actually hold down yield potential through greater susceptibility to lodging. The formula for nitrogen application is still 3 lbs of N X Yield Goal; however, there is an upper limit of total 80 lb N/acre that should be considered. A common yield goal for flax is 25 bu/acre; which equates to a total of 75 lb N (soil residual N + applied N)/ acre needed. NEW NDSU PHOSPHATE RECOMMENDATIONS Flax is not very responsive to phosphate fertilizer. Mycorrhizae are soil fungi that live in a symbiotic relationship between most plants. The mycorrhizae receive carbohydrates from the plants, and in return the plant receives mineral nutrients from the mycorrhizae, particularly phosphate. Mycorrhizae hyphae explore the soil within a couple feet of the host plant and are very good at mobilizing phosphate from the soil and transferring it to the host. Research in Manitoba has shown that when flax is not fertilized with P, yield is maintained regardless of soil test and mycorrhizae infection is high. When flax receives fertilizer P, banded or broadcast, mycorrhizae infection is reduced and the net result is no yield increase. Since yield increase is seldom achieved through the application of phosphate, no phosphate fertilizer is recommended directly to flax. However, maintaining soil P levels for other crops is important. Phosphate can be applied to flax to serve as a carrier for zinc, but do not expect a yield increase due to the phosphate portion of the application. SEED PLACED FERTILIZER The maximum amount of nitrogen that can be placed with flax will vary on the distance of seed spread and soil type. A maximum/”safe” rate of 10 lb of actual N is recommended across all drill spacings and soil types. Do not apply urea as a seed placed fertilizer with flax. ZINC Zinc deficiency in flax is not common; however, it’s documented every year in North Dakota. If soil zinc levels (DTPA extract) are less than 1 ppm, application of zinc would be recommended. Zinc deficiency is expressed as a condition known as "chlorotic dieback". Zinc deficient plants are pale yellow at the growing point. In most cases the growing point dies and the plant regrows from lower nodes. Application of zinc sulfate at seeding is an option. Side_banded treatments of zinc EDTA or small amounts of ammoniated zinc liquid fertilizers may also be effective. Rescue foliar treatments can effective, but some yield loss may have already taken place. Preplant Weed Control in Pulse Crops What can we spray as a preplant burndown for the abundant winter annual populations and kochia this spring in pulse crops? Glyphosate: Glyphosate is labeled as a preplant burndown option for control of early emerging broadleaf weeds. Higher rates of Glyphosate should be considered for winter annual and kochia control. Do not add 2,4-D, Banvel, Express, or Harmony GT to the Glyphosate for 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 soils are cold that 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. FERTILIZER PLACEMENT WITH FIELD PEA AND LENTIL SEED Legume crops such as, field pea and lentil, are very sensitive to the amount of nitrogen and phosphorus (P) that can be placed with the seed. The limit of phosphorus fertilizer applied in the seed band is 20 lb of actual P per acre. The form of P fertilizer that should be used is MAP which is usually designated as 11-52-0 or 10-50-0. DAP or 18-46-0 is often to “hot” for germinating pea or lentil seed and/or young seedlings. MAP (11-52-0) at 40 lb total product per acre will result in approximately 20 lb actual P per acre. This recommendation is based on seed that is spread a distance of one inch. Using a hoe or sweep type opener will increase the safety of fertilizer that is placed with the seed. The effect of seed placed fertilizer on field pea stands and yield. Dickinson, Minot 1997.
IT’S CANOLA PLANTING TIME Late April - early May is “prime” time to seed canola. NDSU research has documented that canola is one the most responsive cool season oil-seed crops to early planting. Yield reductions of 40 to 60 percent is typical across all regions of the state when canola is planted June 1 verses May 1. Similar planting date studies with Flax indicate only a 20 to 30 percent yield reduction from a June 1 planting compared to May 1. It is very important to keep in mind that canola is more tolerant to frost at the seedling stages than flax, mustard, or safflower. There have been some late frosts in the area the last two growing seasons that has injured canola. Canola planted into heavy stubble has had more cases of severe frost injury than conventional tilled fields. Canola can withstand temperatures of 22 to 24°F in the early seedling stages. Mustard and flax can only withstand temperatures of 24 to 26°F. Seeding Depth: There has been many changes in canola production the last five years. A couple changes we see today is that varieties have better seedling vigor and have larger seed size. The optimum seeding depth for canola is 3/4 to 1 inch deep. A common question asked is, how deep can I possibly seed canola? The answer depends on the canola type, seed size, and soil type. Hybrid and synthetic hybrids have better seedling vigor than open pollinated varieties and can withstand deeper seeding depths of 1 inch. Canola varieties that are considered “large seeded” (approximately 110,000 seeds per pound or less) can be seeded deeper than 1 inch. Canola varieties that have small seed (150,000 seeds per pound +) should not be seeded deeper than 1 inch, if all possible. Soil type is a major factor in canola seeding depth. With loam soils, canola can be planted deeper than 1 inch as long as the other variety considerations have been met and soil crusting is not a concern. In light soils, canola can be seeded as deep as 1 ˝ inches. SECTION 18 EMERGENCY EXEMPTION FOR SPARTAN IN FLAX The EPA has approved the specific exemption for the use of Spartan in Flax in North Dakota in 2004. The exemption allows a single application of Spartan at a rate of 2 to 5.33 ounces per acre. Application must be made 30 days prior to, or 3 days after planting flax. The rate will be dependent on soil type, soil texture, and soil pH. Flax has good tolerance to Spartan and is more tolerant than field pea or sunflower. Common use rates will be 2 ounces per acre. Higher rates, if applicable, will be needed to suppress harder to control broadleaf weeds. A copy of the label needs to be in possession of the user. Consult label for use rates, soil classification charts, and crop rotation restrictions. Spartan should provide excellent control of kochia, russian thistle, common lambsquarters, and redroot pigweed. Do not expect foxtail or wild oat control with Spartan SEEDING RATES FOR 2-ROW AND 6-ROW BARLEY The recommended seeding rate for all barley types is 1.0 million pure live seed (PLS)/acre. For most 6-row types that equals 80 -90 lbs/acre or 1 ˝ bushels per acre. The biggest difference in the seeding rate is with the 2-row types. 2-row barley will often have less than 10,000 seeds per pound. This results in seeding rates of 120 - 130 lbs/acre or 2 to 2 1/4 bushels per acre to equal 1.0 M PLS/acre. SEEDING RATES FOR DURUM The recommended seeding rate fro durum is 1.5 M PLS/acre. Durum does not “stool-out” or tiller like spring wheat or barley. Even under low plant populations, durum will not compensate with extra tillers per plant like other small grains. For medium size durum varieties (12,000 - 13,000 seeds/lb) like Lebsock, Mountrail, and Pierce that usually equates to 120 lbs/acre or 2 bushels/acre. For large seeded durum varieties (10,500 - 11,000 seeds/lb) like Ben and Maier that usually equates to 2 1/4 to 2 ˝ bushels per acre. SPRING WHEAT SEEDING RATES: WHAT IS THE RATE? The common seeding rate for western North Dakota is 1.2 M PLS/A. For central and eastern North Dakota, the optimum seeding rate is 1.2 to 1.4 M PLS/acre. Some producers are looking at seeding rates as high as 1.8 to 2.0 PLS/acre. Increasing seeding rates from 1.2 - 1.4 M PLS/acre to 1.8 - 2.0 M PLS/acre has some advantages and some concerns: Advantages: 1. Decrease tillering; which results in larger seed size and higher test weight. 2. Increase main stem heads per acre; which will shorten the heading window resulting in a more consistent timing of a fungicide application for fusarium head blight control. Concerns: 1. Decreased stem strength resulting in the increased potential for lodging. A strong strawed variety should be considered if seeding 1.8 to 2.0 M PLS/acre. 2. Increase potential of leaf diseases such as, leaf rust and tan spot. No Effect: 1. Yield will be similar. 2. There will be no difference in protein percent.
Dan Folske |
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