In a few cases, however, cold stress and/or dry soils during germination have reportedly caused disappointing stands.  Fortunately, it is still early enough in the season to expect good yields if replanting is needed and it is carried out in the next few days.  Before you replant, however, you should carefully assess your current stand and its yield potential, the cost of replanting, possible alternative crops and the availability of seed.

The first step towards making an informed decision on the need for replanting is to determine your current plant population.  Count plants in several areas of the field that appear to be representative of the field as a whole.  Counting emerged plants in a row length of 17’ 5” if using a 30” row spacing will give you the plants in 1/1000 of an acre (for 22” and 20” row spacings use a row length of 23’ 10” and 26’ 1”, respectively).  Plant counts from this area can be converted to plants per acre by multiplying by 1,000.  Refer to Table 1 to determine the potential yield (as a percent of optimum) of your crop at its current population and the potential yield of a crop replanted at various dates.  These data apply to fields in the eastern part of North Dakota where moisture stress is typically not limiting. These data suggest that the deleterious effect of late planting (at least when planting is delayed to June) is generally greater than the deleterious effect of a reduced plant population within the range of plant populations listed.  For example, a plant population of 30% of the optimal stand would be as productive as a full population when planted on June 1.

These data may also provide a rough guideline for the value of replanting fields in drier regions of the state where optimum plant populations may be as low as 20,000 plants/acre by substituting the optimum population for an environment for 36,000 in table and adjusting populations downward in a proportional.

Joel Ransom

Extension Agronomist

One field was surveyed for approximately every 10,000 sunflower acres planted in each county. Agronomists, pathologists, entomologists, extension agents, and crop consultants conducted the survey. The teams were asked to assess the most limiting production factor for each field.  Other observations were also taken during the survey. The North Dakota State average yield estimate for the surveyed fields was 1,651 lb/a.

Yield-limiting Factors

In North Dakota plant spacing within the row and disease were the most prominent limiting factors to higher yields in both 2010 and 2011 (Table 1).  Producers should pay attention during planting to make sure the spacing between the plants and the plant population are accurate. The planter needs to be adjusted properly for the specific sunflower hybrid seed. Decreasing the planting speed will usually increase the accuracy of seeding. The sunflower seed needs to be planted at a depth of 1.5-2.5 inches with good seed to soil contact. With two seeds too close together there will usually be one dominant plant and one plant with a very small head, therefore, an even distribution of the seeds is very important.  In photo 1, solid seeding resulted in too many seeds too close together with some plants having very thin stalks. These plants did not contribute to yield. On the other hand there were gaps between plants in other areas of the filed.  Some diseases, like rust, can be managed and producers should scout their fields during the growing season.

Weed problems in North Dakota and NW Minnesota

The survey indicated that weeds were a limiting yield factor in 6.3% and 3.9% of the fields in 2010 and 2011, respectively. Over 29 common weeds were evaluated in the survey with the various infestation levels recorded.  The data in Figure 1 provides the percent of fields found with the major weed species being present in surveys from 2007-2011. It is important to plant sunflower in clean fields and manage weeds throughout the growing season. 

Reference

Kandel, H. 2012.  National Sunflower Association Survey 2011 PowerPoint pdf.

http://www.sunflowernsa.com/uploads/resources/616/2011-sunflower-survey---kandel.pdf

Hans Kandel

Extension Agronomist Broadleaf Crops

Seed pieces with this damage are randomly found in the fields, which indicates that is likely something carried over in the seed piece. These injury symptoms point towards glyphosate carryover, but this has not been confirmed. I have sent some samples to a lab to test for glyphosate.

If this is glyphosate carryover, it could be a result of glyphosate drifting onto a seed potato field or the spray tank not being properly cleaned before applying pesticides over-the-top of a seed potato field. Potatoes are sensitive to glyphosate throughout their life cycle, thus glyphosate drift at any time during the potato growing season is of concern. Precaution need to be made to not drift glyphosate when applications to nearby fields occur by using proper spraying techniques and making sure the wind direction is blowing away from sensitive areas.

It is important to scout the fields and be on the lookout for skips and plants with reduced growth and malformed leaves. In the skips, dig up potato seed pieces to see if symptomologies exist. Fields may have a small percent of plants affected, but it is unknown how this will affect yield. Please contact me if you suspect glyphosate carry-over in the seed. I would like to document how wide spread this problem may be to get a better understanding of how this is affecting potato production. 

Andy Robinson

Assistant Professor, Potato Agronomist

The dry topsoil is impacting germination and emergence of the more recently planted seeds. Emergence of earlier planted crops is reported to be excellent in most regions of the state; there are no drowned out areas that have been common in recent springs. I have noted that with the drier soils conditions, emergence has been impacted in areas of higher salt concentrations (lower spots, field margins). This results from the salt competing with the seed for moisture when moisture is limiting.

During the heat of the day, spring wheat that is in the 3 to 4 or younger leaf stages is starting to show some symptoms of drought stress. Seedlings do not use a great deal of water as they have limited leaf area and evapotranspiration rates are low.  Nevertheless, because the root systems of these seedlings are not well developed they cannot extract water that may be available deeper in the profile. If the plant shows a loss of turgor (wilting) during the early vegetative stages of development its ability to photosynthesize is reduced and yield potential can be significantly impacted. Stress during the pre-jointing stages reduces the number of tillers that are produced.  Furthermore, water stress and/or warm temperatures (above 65 degrees) can reduce the size of the spikes that do develop. Even established tillers may be lost if drought stress intensifies as the plant develops further. Dry soil around the crown reduces the plants ability to develop adventitious roots which are the primary roots for accessing water and nutrients as the plant develops beyond the seedling stage. This current dry spell adds an additional challenge for those wishing to top-dress their wheat crop with nitrogen. To have an impact on yield, N should be applied prior to the six leaf stage. Rainfall is needed to carry any surface applied N to the plant’s roots. Additives that reduce the loss of urea volatilization (including the urea in UAN) would likely be cost effective if the fertilizer sits on the soil’s surface for any period of time before the next rain event.

The emergence of most of the early planted corn looks exceptional. The corn being seeded this week may have more variable emergence if sown into drier soils. Variability in emergence is probably more damaging to corn yield potential than plant to plant spacing variability (skips and doubles). With regards to early season drought, corn is far less susceptible to yield loss from water stress during the early vegetative stage than wheat, primarily because the yield components of corn are fixed much later in the season. Just like with wheat, however, adventitious rooting may be impacted by dry soil conditions around the crown of the seedlings. Plants that fail to develop adventitious roots will have limited capacity to grow and extract water and nutrients. Such plants will eventually flop over as they do not have sufficient roots to anchor them. The terms floppy corn syndrome or rootless corn is used to describe such plants.

 Joel Ransom

Extension Agronomist for Cereal Crops

Joel.ransom@ndsu.edu

The survey was compiled by Research and Extension faculty at North Dakota State University and the directors of the growers association. The survey was mailed to all Northarvest bean growers in the region. Here are some of the results from North Dakota based on 99 and 63 returned surveys in 2010 and 2011, respectively. According to the survey in 2011, the most popular pinto varieties were Windbreaker, Lariat, and La Paz Dry bean varietal information from 2011 can be found at http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/a654.pdf. 

In Table 1, the production problems for 2010 and 2011 are provided in percent of those responding to the question and as a percent of the acres farmed by the responding producers. Both in 2010 and 2011 excess water was the issue most commonly reported as the yield limiting factor. In some fields, tile drainage has been used successfully to manage excess water risk.

This season, 2012, is starting off relatively dry in contrast to the previous two years. The second most commonly mentioned production issue in the surveys was disease. The first strategy to reduce the disease risk (anthracnose) would be to use good quality seed. The Crop and Pest Report will keep producers informed about upcoming disease issues and potential management strategies. Weeds were mentioned by approximately 10% of the respondents in both years as a production issue. Producers are advised to scout for weeds during the season and to select appropriate weed management strategies based on the weeds found in the fields. Although emergence and stand was only mentioned by about 2% of the respondents this is an important production issue. A good stand is achieved by using correct planter adjustments, depth, and proper speed of planting.

Source for the article: http://www.ag.ndsu.edu/pubs/plantsci/rowcrops/e1602.pdf

Hans Kandel

Extension Agronomist Broadleaf Crops

hans.kandel@ndsu.edu

Growing conditions during the season will affect yield, oil content and fatty acid composition. High temperatures during seed formation have been identified as the main environmental factor affecting the ratio of linoleic and oleic acid content. Therefore, the optimum planting date will be dependent upon the variety and location, as well as weather conditions during the growing season. Variety genetics also affect oleic content, so select adapted varieties for your area. High yields may be obtained from early planting dates but yields may be reduced by increased pest problems. For example, sunflower midge has reduced yield in the Carrington area the last several years, so local growers are advised to delay planting sunflower until late May to reduce injury potential from this insect. Planting too late can result in freeze injury to immature seed and an early snow storm in the fall can bring harvest to a sudden halt.  Sunflower planting date studies at Carrington Research Extension Center (http://www.ag.ndsu.edu/procrop/sun/sunpld05.htm) showed that planting date occurring during May 20-30 produced the highest seed yields while test weight and percent oil was greatest for sunflower seeded between May 10 and May 20.  Planting date studies conducted at the North Central Research Extension Center from 1989-1993 (http://www.ag.ndsu.edu/procrop/sun/plantn05.htm) and Langdon Research Extension Center indicate mid-May plantings produced higher yields, test weights and percent oil when compared to early June planting dates. On-farm studies on the Miles Hansen Farm near Bowman, ND, conducted by the Dickinson and Hettinger Research Extension Centers from 1999-2001 (http://www.ag.ndsu.edu/archive/dickinso/research/2001/agron01j.htm) indicate the optimum time for sunflower planting is May 20-25. Sunflower yield, test weight, percent oil and oleic acid oil content were highest for the planting date falling within the planting window of May 20-25. Miller, Rehder and Vick in a 2001 study done at the North Dakota Agricultural Experiment Station, Fargo, ND (https://www.sunflowernsa.com/uploads/research/53/53.pdf) found oleic acid content was highest for sunflower seeded on 29 May and lowest for 18 May for two sunflower varieties in this trail. Growing Degree Day accumulation from flowering to maturity may influence oleic concentration. What is the optimum date for seeding in your neighborhood? It gets down to weather and variety but what should be evident by now is sunflowers should be in the ground by June 1.

In the table below, combined data of the fatty acid profile comparison are presented for Mycogen 8242NS from five planting dates, Miles Hansen Farm, Bowman, ND, 1999-2001. (Ashley, Eriksmoen, Whitney, 2001.)  Planting dates include:  1^st planting date = 25-28 April, 2^nd planting date = 9-10 May, 3^rd planting date = 23-24 May, 4^th planting date = 4-7 June, and 5^th planting date = 14-20 June.

Roger Ashley

Area Extension Specialist/Cropping Systems

NDSU Dickinson REC

Roger.Ashley@ndsu.edu

Greg Endres

Area Extension Specialist/Cropping Systems

NDSU Carrington REC

gregory.endres@ndsu.edu

Data collected for Minot from 1998, 2010, and 2011 studies, and for Langdon from 1989-1994 averages, 1992-1995 averages, 2010, and 2011 was used to construct response curves for the different locations (Fig. 1-2). Yields were expressed as percent of the highest yield obtained from each separate experiment. The graphs indicate that the yield potential decreased as the canola planting date went later into the season. At the most northern location, Langdon, the yields stayed relatively stable from the earliest plant date though the third week of May. At Minot yields tend to decrease more rapidly after the optimum seeding date (first part of May).

Canola Growth Stages
Determining the growth stages of canola is relatively simple using a scale developed in Canada. This scale uses five principal stage designations and subdivides these into secondary stages. Many crop management recommendations are based on these specific growth stages of canola.

Hans Kandel

Extension Agronomist Broadleaf Crops

hans.kandel@ndsu.edu

Hi, my name is Andy Robinson and I am an assistant professor in the Plant Sciences Department at NDSU. Although my office is at NDSU, I have a joint appointment with the University of Minnesota. My passion for agriculture began at a young age as I grew up on my family’s farm in Parma, ID and from being an active member in the FFA. I completed my BS degree in Agronomy at Brigham Young University, my MS degree in Agronomy at Purdue University, and my PhD degree in Weed Science at Purdue University. My areas of responsibility will include extension and research for potato production in North Dakota and Minnesota. My research will focus on developing science-based solutions to address real-world problems in potato production, enabling producers to increase economic and environmental sustainability through improved crop management. I look forward to meeting you as I get to know North Dakota and Minnesota. Please let me know if I can be of assistance.

Andy Robinson

Assistant Professor, Potato Agronomist

Corn requires soil temperatures above 50 degrees before it will begin to grown and an accumulation of about 125 growing degree days before it emerges. With the warmer weather this week, soil temperatures are now warm enough for corn growth in most areas of the state. One factor that can impact early planted corn emergence is cold temperature injury. This injury can occur when the corn seed is exposed to cold temperature for an extended time. Furthermore, when the dry seed imbibes cold water (some refer to this as it first drink of water) imbibitional injury may result (this can also happen to soybeans). Temperatures below 50 degrees can be harmful, with colder soils (and therefore colder water that the seed imbibes) being more problematic than those approaching 50 degrees. Cell membranes in the seed can rupture at low temperatures, causing cell contents to leak, providing a good source of food for pathogens.  In addition to poor stands, cold injury may cause the mesocotyl to corkscrew or the coleoptile and true leaves to emerge from side of coleoptile.  Plants that developed from these seedlings may be stunted and have distorted leaves and may also develop more slowly than normal plants.  This can result in unevenness in the growth stages of plants within the field.  Anything that impacts plant stands and evenness of emergence and/or plant size has the potential to negatively impact yields. A cold rain heavy rain after planting seems to increase the chances of imbibitional injury probably because it overwhelms the ability of the soil to warm the water before it reaches the seed.

Joel Ransom

Extension Agronomist for Cereal Crops

Joel.ransom@ndsu.edu

Inoculants containing Rhizobia can be applied in liquid, peat-based powder, or granular form. Increasing the number of bacteria near the roots of the legume may improve the root nodulation and improve the N supply to the plant. Specific Rhizobia bacteria form associations with a specific legume (Table 1). It is therefore critical to use the correct inoculum species. The inoculum for field pea and lentil can be the same since identical species of bacteria form associations with both pea and lentil.  If a specific legume has never been grown in a field before, inoculation with the correct species of bacteria is essential. Fields which already have a specific rhizobium population may not always give a positive yield response to additional inoculation. Still in those cases positive yield responses may occur from one-third to one-half of the time. The responses to inoculation depend on the legume species and soil N levels prior to planting. The level of beneficial bacteria in the soil is related to the number of years between growing a specific legume and rotating back to the same legume. Last year many acres in North Dakota had excess moisture conditions, saturated, and flooded soils. Under those circumstances, it is likely that the Rhizobia bacteria population may have decreased due to the lack of necessary oxygen in the soil. Inoculation in these cases is strongly recommended. The bacteria in the inoculum are live organisms and extensive exposure to high temperatures (for instance seed pre-treated with an inoculum sitting out in the hot sun) may reduce the number of live bacteria.

Hans Kandel

Extension Agronomist Broadleaf Crops

hans.kandel@ndsu.edu