Special Edition   April 20, 2009

GUIDELINES FOR LATE-PLANTING SMALL GRAINS AND CORN

Small grains are cool season crops that require relatively cool temperatures in order to achieve high yield potential. Therefore, when planted late, small grains develop during warmer temperatures that are detrimental to yield. The optimum planting dates for small grains are listed in Table 1 for the various regions of ND. When planting is delayed beyond the last planting date, yield reductions accelerate and profitable crop production becomes risky. Full insurance coverage is available until June 5^th in northern tier counties and until May 31^st in all other counties. Of the small grains, oat is the most tolerant to late planting and barley the least tolerant.

When planting is delayed beyond the optimum date it may be beneficial to increase the seeding rate by 1% per day of delay, up to a maximum of about 1.6 million seeds. This increase will partially compensate for the decrease in grain yield associated with reduced tillering that occurs when plants develop in warmer than optimum temperatures. Though differences in the maturity of commonly grown small grain varieties are not great, earlier maturing varieties are recommended for planting dates in the latter part of the recommended period. For spring wheat, varieties from South Dakota (i.e. Briggs, Granger, and Traverse), Glenn, Kelby, Oklee and RB07 are among the earliest maturing. Data from South Dakota and southern locations in Minnesota also suggest that Steele-ND and Howard tolerate "heat" better than many of the other varieties released by NDSU and will therefore perform relatively well when planted late.

Table 1. Optimum and last planting date, and yield losses due to late planting of small grains.

Corn is a warm season crop and requires warmer temperatures than small grains before it will germinate and grow. The main concern with late-planted corn is that it will be at risk of being killed by frost before it reaches physiological maturity, and yield and grain quality will be reduced. Delayed planting also increases the probability that the harvested grain will be wet, difficult to handle, and expensive to dry. The recommended planting date for corn for all regions of ND is May 1, though the recommended maturity of the hybrid to be grown varies significantly by location (see Figure 1). Selecting earlier maturing hybrids when planting is delayed beyond May 20^th (except for the northern tier) is recommended (Table 2).

The final planting date for full insurance coverage for corn is May 25^th except for Cass, Ransom, Richland and Sargent counties, which have a final planting date of May 31^st. Recent research in southeastern ND indicates that yield losses and grain moisture increases at harvest are minimal if corn is planted by May 20^th (Table 3). Plantings delayed into the first week of June, however, resulted in yield losses between 1.1 and 3.0 bu/day. Yield losses were largest in 2004, a cooler than average season, illustrating the potential interaction between seasonal weather and planting date on yield reductions. The extra moisture at harvest with delayed planting can be a significant cost to production. Recent data indicate that planting on May 20 will typically add less than a point extra moisture to the harvested grain when compared to a May 1 planting date. Plantings delayed to June 8^th, however, resulted in up to 10% additional moisture in 2004 (Table 4).

Table 2. Recommended relative maturity corn hybrids for various regions and planting dates in ND.

Table 3. Yield (bu/acre) of corn as influenced by planting date and environment*.

*These data are an average of all hybrids included in the trials. Hybrids varied in relative maturity.

Table 4. Grain moisture (%) at harvest as influenced by planting date and environment*.

*These data are an average of all hybrids included in the trials. Hybrids varied in relative maturity.

Joel Ransom
Ext. Agronomist - Cereal Crops
joel.ransom@ndsu.edu

The ideal planting date for sugarbeet in favorable environmental conditions is around the last week of April. With good germination and uniform emergence, early planted sugarbeet get the opportunity to maximize photosynthesis during the full growing season resulting in high tonnage and good quality. One of the objectives of early planting for sugarbeet is to get the crop at full canopy or to close the rows at the beginning of summer (usually June 20 or 21^st), so that the crop will be able maximize production.

Research was done in 1977 and 1978 by Dr. Larry J. Smith at University of Minnesota who showed that earlier planting of sugarbeet at different populations, resulted in higher tonnage, higher sucrose concentration, and higher recoverable sucrose (Table 1-3).

(Effect of date of planting and population on sugarbeet development and yield - Larry J. Smith. www.sbreb.org/78/production/78p108.htm)

Table 1. Two year average of the effect of plant population and planting date on sugarbeet yield.

Table 2. Two year average of the effect of plant population and planting date on sugarbeet quality.

Table 3. Two year average of the effect of plant population and planting date on recoverable sucrose.

Research done by Mohamed Khan at North Dakota State University and University of Minnesota showed that earlier planting of Roundup Ready sugarbeet at different populations resulted in higher tonnage and recoverable sucrose at Prosper, ND in 2007 (Table 4), when there was adequate rainfall. The early planting date was May 2 and the later planting date was May 24.

Table 4. Effect of planting date at different populations on sugarbeet tonnage and recoverable sucrose.

The sugarbeet industry is unique in that growers produce sugarbeet to be processed in factories owned by the growers. Sugarbeet cooperatives are committed to produce their allocation of sugar that is determined annually by the Secretary of the US Department of Agriculture. As such, growers in North Dakota and Minnesota may plant sugarbeet from around April (April 11 in 2009) to around June 10 when field conditions are favorable. Please note that the final planting date for insurance purposes is May 31. However, since the Cooperatives need the beets for full utilization of the factories, growers have agreements that allow planting or replanting until around June 10. Early planting is desirable – historical records at American Crystal Sugar shows that planting in the last week of April (25) results in the best yield. It should be noted that planting too early, when the soil temperature is below 38 F at the 4 inch depth, is not recommended since germination will not take place. When fields are wet, it is better to wait for favorable field conditions than trying to plant into wet seedbeds. Please consult your agriculturist and insurance agent with regards to planting options after the final planting date.

Mohamed F. R. Khan
Extension Sugarbeet Specialist
701-231-8696
mohamed.khan@ndsu.edu

Flax yields drop dramatically when flax is planted later in the season. Eight years of data from Minot, ND, demonstrated the loss of yield with late planting dates. June plantings resulted in very low yields (Figure 1). Flax, like any other cool season crop, responds well to early planting, since this generally increases the period of bloom. When flax is seeded in June it takes approximately 90 to 100 days to reach physiological maturity or swathing stage. The stems of June planted flax will often remain green even at the end of the season, which makes swathing difficult. In the eight year planting date study at Minot, flax yields from early June plantings were 27% less than those of early May plantings. Once planting was delayed until mid-June, the yield decreased nearly 60% as compared to early May plantings. Average yields can be obtained when seeding flax in early June; however, if flax is planted after mid-June a realistic yield of 8 to 12 bushels per acre should be expected (Figure 1). Seeding rates somewhere around 40 pounds per acre will give stand counts between 50 and 80 plants per square foot, which would be considered ideal (Figure 2).

Figure 1. Flax planting date and yield expressed as percent, Minot ND 1977- 1984.

Figure 2. Flax established plants and yield potential expressed as percent.

Canola is a cool season crop and production risk increases with later seeding (see Figure 3). Canola becomes more risky to plant as you approach June 1. When comparing sunflowers and canola planted June 1 or later, sunflower will on average produce higher yields. When seeding canola, late in the season, early maturing varieties should be selected. A potential problem canola has when seeded in June is high green seed content at harvest. Often canola, which is swathed in late August or early September, will not have enough time to cure before a hard frost. This may lead to higher green seed content in the harvested seed. If canola planting is delayed into early June due to excess moisture, canola may not provide satisfactory yields due to above normal soil moisture. Canola is sensitive to heat during flowering and seed set, which usually results in lower yields.

Figure 3. Canola planting date and yield from 1992-1995 at Langdon, ND.

The earliest date soybeans should be planted in the northern and western regions of North Dakota is May 10. Soybeans have "hypocotyl" emergence; which is similar to sunflower. Once the cotyledons emerge, the growing point is above ground. The cotyledon "cracking stage" can handle temperatures of 29 F for a short time; however, if they are killed by frost the plant will die. Soybeans are more tolerant to an early frost than dry bean, but not as tolerant as sunflower. The optimum planting date for soybeans in the north, central, and western regions of North Dakota is May 12 to May 25.

An important consideration when planting soybeans is seedbed temperature. The minimum soil temperature for germination is 50 F. At that temperature soybeans will take 17 to 21 days to emerge. With soil temps of 56 to 60 F, emergence will only take approximately 10 days. It takes approximately 110 - 120 days for soybean to reach physiological maturity. In north and central North Dakota, assuming a normal fall frost date in September, a ‘00’ variety should make maturity if planted before June 10. A ‘0’ variety should reach maturity, with a normal frost date, if planted before June 5.

In Figure 4 and Table 1, yield decreased from May 10 to May 20 planting date in Carrington and from May 20 to June 6 at Minot in 2002. The yield advantage of narrower rows was less pronounced at later seeding dates compared with earlier seeding dates(Table 1 and Figure 5).

Figure 4. Planting date x variety interaction Carrington, 2002.

Table 1. Effect of planting date and row spacing on yield, Minot 2002.

Figure 5. Early and late planted soybean response with different row spacings.

Field pea is an early season crop. Most semi-leafless pea varieties have early maturity similar to barley. Susceptible peas seeded in June are at higher risk to get powdery mildew. In planting date studies at Carrington, Minot and Langdon, June plantings had yields close to 10 bushels per acre compared to 40 to 50 bushels per acre with early May planting dates (Figure 6). If peas are planted in June, select a variety that is resistant to powdery mildew. Many green pea varieties are susceptible to powdery mildew. Late planting will result in flowering during the hot part of the year, which will reduce pod and seed set.

Figure 6. Field Pea seeding date and yield information, Carrington, Minot and Langdon, ND.

Most lentil varieties have a similar number of days to maturity as spring wheat, reaching physiological maturity in 80 to 90 days. An exception is the variety ‘Laird,’ which is a very late maturing variety and is more risky to seed in June. The main concern with June planted lentils is the risk of cool, wet harvest weather in September. Growers seeding lentils in June should consider the option of desiccating and straight combining the lentils rather than swathing them, this helps to insure quality.

When planting an early maturing sunflower hybrid in June, it takes sunflower approximately 90 - 100 days to reach physiological maturity. Early maturing sunflower hybrids can be seeded as late as mid-June anticipating a normal frost date in September. However, the highest yield potential was achieved when planting sunflower mid to end May (Figure 7).

Figure 7. Sunflower planting dates and seed yield in lb/a.

Dry edible beans should not be planted until the soil has reached a minimum temperature of 50 F at planting depth. Soil temperatures of 55 F or higher are ideal for rapid germination and emergence. Plant the dry beans seed shallow if planting early. One to 2 inches deep is ideal under most conditions. Planting too early in cool, wet soil may result in reduced stands. In addition, frost may be a problem with early planted and emerged seedlings. The recommended planting time in North Dakota is from May 15 through June 1. Delayed plantings may result in reduced yield and delayed maturity. Dry edible bean is a warm season crop and is not usually affected by high temperatures if adequate soil moisture is present. Cool, humid or rainy weather is unfavorable to dry bean. Dry beans are adapted to a fairly wide range of temperature. The optimum average growing temperature for beans is 65 to 75°F. Dry bean production is more successful in areas where rainfall is light during the latter part of the growing season. It is essential that the crop be grown on a well-drained soil, since beans are extremely sensitive to standing water or waterlogged conditions. Dry beans are not tolerant to frost or to prolonged exposure to near-freezing temperatures at any stage of plant growth.

Reference: ProCrop ( www.ag.ndsu.edu/procrop/procrop.htm)

Hans Kandel
NDSU Extension Agronomist
hans.kandel@ndsu.edu

While much of the potato producing areas in North Dakota and Minnesota have experienced cool and wet conditions this spring, planting has already begun in many areas. Minnesota growers began planting irrigated Reds and Russets near the Hastings and Becker areas last week and will expand into the Rice and Little Falls regions next week. North Dakota growers are expected to begin planting irrigated potatoes in the southern, central, and north-western regions next week, while growers near Larimore are likely ten days away. Conditions remain wet in non-irrigated fields in the Red River Valley and planting likely won’t begin until the first week of May and will continue through the end of the month as conditions become favorable. Even though many areas of potato production have received record amounts of spring precipitation, planting is on schedule.

Nick David
Potato Agronomist
Nicholas.David@ndsu.edu