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| Field Crop Advisory Team Alert newsletter | |||||||
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| Vol. 23, No. 10, June 12, 2008 |
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| In this issue Now is the time to check wheat fields for armyworm Soybean Aphid Overwintering Survey Common lambsquarters escapes in sugar beets: What are my options? Optimizing fungicide timing for the control of Rhizoctonia crown and root rot of sugar beet and issues about mixing Quadris with Roundup. Volunteer potato control in corn Managing corn and soybean fields submerged by recent heavy rains Damage from late May frost now appearing in small grains Regional reports Weather |
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| Now is the time to check wheat fields for armyworm |
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Armyworm can attack corn and soybeans as well, and I had a few reports of both. Fields with cover crops and weeds are at risk for armyworm infestation although even clean fields can be infested. As with wheat, caterpillars hide out at the base of plants during the day, and also in the whorl of corn, feeding leaves behind tattered leaves (Photo 5). With warm temperatures insects can grow quickly, so damage can increase in just a matter of days. Recognizing an over-threshold infestation early and treating smaller larvae, which are more susceptible to insecticides and eat less, protects yield. In soybean, treat at 25 percent defoliation (this may be difficult to judge). For corn, treat when 25 percent of plants have two or more larvae per whorl, or when 75 percent of plants have one larvae. For both corn and soybean, you can choose from the same product list as for wheat. Check labels for rates and precautions; of course pre-harvest intervals are not an issue in either crop. Note that armyworms sometimes originate in one field and move into another. In that case, you may be able to limit your spraying to an edge or barrier treatment near the infested field.
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| Soybean Aphid Overwintering Survey A report from Dave Voegtlin from the University of Illinois. Dave conducts a soybean aphid over-wintering survey each spring. He visits buckthorn sites in Indiana, Ohio, Michigan and Illinois looking for aphid colonies or signs of infestation on leaves. Here are his findings. Note his Michigan observations relative to aphid numbers and soybean emergence relative to surrounding states. “Given the low fall flight numbers, I was not expecting to find many aphids and was also wondering how the cool, wet spring might have changed the dynamics. To my surprise, we managed to find some colonies at every major Rhamnus cathartica location that we visited from northeast Indiana to southeast Michigan/Toledo to Moline, Illinois. At most of the locations the colonies were small and uncommon. The highest numbers we observed were northwest of Battle Creek, Michigan near the Kellogg Forest where colonies were easily found and relatively large. Harmonia axyridis were seen only at the site near Kellogg Forest. At all locations there were alatoid (winged) nymphs present and at the Quad Cities, strongly deformed growing tips with remnant colonies suggests that most of the aphids were on their way to soybeans. However, finding soybeans will clearly be a problem in much of Illinois and Indiana. We saw very few fields of emerged beans and most of last year’s corn fields appeared uncultivated. The exception is Michigan, where it appears that most areas are planted.” |
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| Common lambsquarters escapes in sugar beets: What are my options? Rainfall and inclement weather conditions have lead to common lambsquarters escapes in many non-Roundup Ready or conventional sugar beet fields. This is particularly prevalent in many of the sugar beet fields being treated with micro-rate herbicide programs. When application timings are missed, common lambsquarters is often the number one weed escape. Over the last several years, common lambsquarters escapes have been extremely common in sugarbeet fields at harvest. These escapes can reduce yield by competing for moisture and light, cause problems with topping and harvest, and produce seeds that will lead to future problems. In fact, one common lambsquarters plant can produce as many as 72,000 seeds per plant and these seeds can remain viable in the soil for as many as seven decades. For example, if one common lambsquarters plant escapes control and produces 72,000 seeds, after 12 years as many as 36,000 of those seeds will still remain in the soil. Missed micro-rate application timings and erratic weed control due to unfavorable conditions can exacerbate these problems. So, in 2006 with the help of funding by Michigan Sugar Company, two studies were designed to determine the best options for common lambsquarters control if a micro-rate herbicide application timing was missed. Since common lambsquarters escapes can also occur with other weed control programs the second trial was conducted to examine rescue treatments for common lambsquarters control. Missed micro-rate application timings A standard micro-rate treatment of Betamix at 8 fl oz/A + Stinger at 1 fl oz/A + UpBeet at 0.125 oz/A + 1.5 percent v/v of methylated seed oil (MSO) was applied to all treatments when common lambsquarters was less than 1/8-inch in height after planting. To simulate a missed micro-rate application, the second micro-rate application was delayed until 400 growing degree days, base 34°F after the first micro-rate (0.25- to 0.75-inch lambsquarters) application for half of the treatments and 500 growing degree days (0.5 to 1.25-inch lambsquarters) for the other half of the treatments. The strategies examined to overcome a missed micro-rate application included: 1) increasing the Betamix rate in the next micro-rate application (12 fl oz/A and 16 fl oz/A), 2) adding Nortron to the next micro-rate treatment (2 fl oz/A and 4 fl oz/A), 3) increasing the Betamix rate and the Stinger rate to 2 fl oz/A in the next micro-rate treatment, 4) shorting the interval for the next micro-rate treatment to approximately 75-100 GDD34 (3 to 5 d), and 5) switching to a standard-split application of 2 pt/A of Betamix + 0.25 oz of UpBeet + 0.5 fl oz/A of Stinger + 0.25 percent v/v of non-ionic surfactant (NIS). Each of these strategies were implemented at the two missed micro-rate timings and compared with a standard micro-rate treatment. The third and fourth applications of the standard micro-rate were then applied 225 growing degree days after the second micro-rate application for all treatments. Seven days after the last micro-rate application, common lambsquarters control was 75 percent when the standard micro-rate treatment was delayed 400 growing degree days and 71 percent when it was delayed 500 growing degree days (Figure 1). Regardless of the missed micro-rate timing, shortening the interval between the missed micro-rate and the next micro-rate application or switching to a standard-split application provided the greatest common lambsquarters control, 90 percent or greater. Increasing the Betamix rate and Stinger rate to 2 fl oz/A or adding 4 fl oz/A of Nortron to the standard micro-rate also improved common lambsquarters control compared with the standard micro-rate treatment for smaller common lambsquarters. For the larger common lambsquarters, increasing the rate of Betamix to 16 fl oz/A in the micro-rate also improved common lambsquarters control compared with the standard micro-rate treatment.
Rescue treatments for common lambsquarters control In 2005 we conducted a study that examined several different options for control of escaped common lambsquarters. This study focused on increasing rates of micro-rate treatments and incorporating several different herbicides and/or adjuvants. At the time that the herbicides were applied in this trial, common lambsquarters heights ranged from two to 12-inches tall. There were no treatments other than glyphosate that showed any promise of lambsquarters control at this stage. This gives us an option in our Roundup Ready sugar beets, but what about our non-Roundup Ready sugar beets? The first step in keeping lambsquarters under control is to treat it at a much smaller stage. It is extremely important to recognize common lambsquarters escapes early. In our 2006 trial for control of larger common lambsquarters we treated common lambsquarters when plants were 1 to 5-inches tall and sugar beets were in the 4 to 6-leaf stage. Treatments that provided the greatest common lambsquarters control 14 and 21 days after treatment included: 3 to 4.5 pt/A of Betamix + 4 fl oz/A of Nortron + 4 fl oz/A of Stinger + 0.25 percent v/v of NIS or 6 pt/A of Betamix + 4 fl oz/A of Stinger + 0.25 v/v of NIS (Figure 2). Initially, the treatments with Nortron caused more sugar beet injury. All of these treatments are quite expensive, so it is important to get control of common lambsquarters before they get to this point.
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| Optimizing fungicide timing for the control of Rhizoctonia crown and root rot of sugar beet and issues about mixing Quadris with Roundup Recent weather conditions may have been suitable for the development of Rhizoctonia crown and root rot and possibly damping-off. Quadris can be applied early in the sugar beet growing season for control of Rhizoctonia damping-off and Rhizoctonia crown and root rot caused by Rhizoctonia solani anastomoses groups (AG) 4 and 2-2, respectively. Work at MSU/MSC has evaluated fungicide application timings based on crop growth stage and soil temperature thresholds in inoculated small-scale trials and in commercial fields with a history of Rhizoctonia crown and root rot. Soil temperature thresholds 50°F, 59°F and 68°F were selected for fungicide application timings and used to test whether soil temperature could be used to better time applications of azoxystrobin. In both small and large plot trials, timing applications after attainment of specific soil temperature thresholds did not improve efficacy of Quadris in controlling damping-off or Rhizoctonia crown and root rot, compared to application timings based on either planting date, seedling development, or leaf stage in a susceptible (E-17) and a resistant variety (RH-5). Application rate and split application timings of azoxystrobin had no significant effect on severity of crown and root rot. Other environmental factors such as soil moisture may interact with soil temperature to influence disease development. The variety RH-5 had higher sugar yield attributes than the susceptible variety (E-17) in seasons conducive and non-conducive to crown and root rot development. The rate of 0.4 or 0.6 fl.oz./1000 row feet were equally effective but the best timing over the three years of trials was at leaf stage 4 to 6 and 6 to 8. Quadris is only labeled for banded applications for Rhizoctonia crown and root rot control (up to leaf stage 6 to 8) and at a lower broadcast rate for foliar diseases such as leaf spot. The broadcast rate (max 15.5 fl.oz./A) is equivalent to about 20 percent of the in-furrow application rates and an equivalent rate for control of crown and root rot as a broadcast application would be about 40-60 fl.oz./A. There are no known data for crown and root control using 15.5 fl.oz./A of Quadris and it is likely that control of crown and root rot would be compromised as such a low rate. Mixing Quadris and Roundup is not an illegal tank mix, but there is no information available on the efficacy of such a mixture, given maximum permitted rates, for crown and root rot control. In addition, no phytotoxic studies have been completed using this combination, and the risk of crop damage to the beets has never been assessed. |
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| Volunteer potato control in corn Corn growers in potato growing regions will be looking to control volunteer potatoes where potatoes were grown in 2007. It is important to control volunteer potatoes to preserve corn yield, however, it is as important to control volunteer potatoes to manage pests that can be a problem if potato is in rotation for next year. There are a few different options that will provide suppression of volunteer potato and significantly reduce the number of daughter tubers per plant; however, there currently are no herbicides available that will completely control volunteer potato. Michigan State University researchers (Renner, Lee, Long, and Powell) have evaluated the effectiveness of several different postemergence options for control of volunteer potatoes in corn. Herbicide treatments were applied when volunteer potatoes were between four and six inches tall. From this research, Callisto (3 fl oz) + crop oil concentrate (1.0 percent v/v) + ammonium sulfate (17 lb/100 gal); Callisto (3 fl oz) + atrazine (0.5 lb ai) + crop oil concentrate (1.0 percent v/v) + ammonium sulfate (8.5 lb/100 gal); Distinct (6 oz) + non-ionic surfactant (0.125 percent v/v) + ammonium sulfate (17 lb/100gal); and Distinct (6 oz) + atrazine (0.5 lb ai) + non-ionic surfactant (0.125 percent v/v) + ammonium sulfate (17 lb/100 gal) were the best options available for controlling volunteer potatoes, 28 days after treatment. These treatments also stopped daughter tuber production, reducing the risk of transmitting disease to the next year’s potato crop. Good suppression of volunteer potatoes in the MSU trial was also obtained with Starane (1.33 pt) + atrazine (0.5 lb ai). However, in this trial Starane was applied at 1.33 pt/A, and is currently labeled at 0.67 pt/A for suppression of volunteer potatoes in corn with a maximum application rate of 1.33 pt/A per growing season. Starane has a similar mode of action as Distinct, Clarity, Stinger and 2,4-D and has been used in small grains for a number of years and has been registered for use in field corn. It is important to remember to be cautious when using this herbicide around sensitive broadleaf crops, such as, soybeans, sugar beets, grapes and dry beans. Starane is labeled for preplant and postemergence applications up to V5 (5 fully exposed leaf collars) corn at 0.67 pt/A for suppression of volunteer potatoes. Something to consider Corn inbreds are sensitive to many herbicides labeled in field corn. Consult the seed company agronomist before using any herbicides for weed control on inbreds. The only treatments that can be applied to seed corn that provided good suppression of volunteer potatoes were Callisto and Callisto + atrazine. Corn inbreds vary in their sensitivity to herbicides including Callisto, so it is important to consult the seed company on their inbred tolerances to Callisto.
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| Managing corn and soybean fields submerged by recent heavy rains Last week’s heavy rains have resulted in isolated areas of severe ponding in parts of the state. This problem has left growers struggling with the question of whether or not to replant water damaged stands. The replant decision is further complicated by the fact that we are now nearing the end of the viable planting season window for corn and soybean. Assessing plant viability The first step is to determine whether plants survived being underwater or in saturated soil. Seed that has germinated, but not emerged is also susceptible to excessive water damage. In corn, most of the plant mortality will be in localized low areas of the field that were subjected to standing water. The survivability of plants or seedlings underwater is dependant on temperature, growth stage, variety, soil type, nutrient status and other factors, but is generally in the 24 to 96 hour range. In cool temperatures, plants will survive longer as respiration slows. Conversely, when temperatures warm up, plants consume oxygen quicker, and submerged plants will not survive as long. In cool conditions, corn can survive four days submerged. With soil temperatures warmed up in the upper 70s, submerged corn may survive for only 24 hours. Unfortunately, the warm temperatures experienced throughout much of Michigan while plants were submerged have likely increased the chances for plant mortality in flooded areas. In soybeans, soil borne disease such as pythium and phytopthora can result in plant mortality beyond those areas that were under water. In assessing a soybean stand, for more fertile soils a minimum of 80,000 to 100,000 living plants per acre are needed to approach the full yield potential of the field. In poorer soils, 100,000 plants per acre are needed. In situations with less than the minimum number of plants remaining, the cost of replanting should be weighed against the expected increase in yield to determine if replanting will be economically feasible. Generally, the time it takes for submerged soil to dry out enough to get equipment on for replanting, is usually time enough to make a determination whether or not plants have survived. However, it can be difficult to determine survivability when plants are covered with soil and plant residue left behind by receding water. In these cases, split a plant lengthwise through the stem. The growing point should be relatively firm and white or cream colored. Darkening or softening of the growing point indicates a nonviable, dead plant. How late into the year can I plant/replant and still expect a reasonable chance of maturing grain? For corn, planting after June 15 is not recommended. Corn intended for grain harvest has a significant chance of not reaching physiological maturity when planted after June 15. Corn intended for silage can still reach a harvestable maturity, but feed quality will be diminished relative to corn planted in the optimum window of late April to early May. Soybeans can generally be planted up to the end of June although yields will likely be reduced commensurate with the later planting date. If replanting soybeans, do not drop more than one maturity group from what you usually plant. For example, if you generally plant group II soybeans, replant with group II or group I soybeans. Considerations for replanting into existing stands When replanting flooded out areas that still have some viable plants, it is usually best to tear up the existing stand and start over with an even-emerging stand. This may require you to manage the area differently than the non-flooded parts of the field with regard to activities based on plant growth stage such as weed control and time of harvest. Other considerations in flooded out areas include potential weed problems from weed seed brought in by encroaching waters, herbicide residue washed in from adjacent fields, loss of herbicide control from excessive leaching or erosion, loss of nitrogen through denitrification or leaching and increased incidence of phytophthora and other root disease. Nodule function in soybeans is also reduced in saturated soil. However, nodule activity resumes to normal levels once the soil dries out. Scout fields closely for these factors and use a PSNT soil test to determine nitrogen losses. Other considerations for late planting/replanting Following are other considerations with late planting that I have compiled over the years including some from Bob Nielsen at Purdue University and Jim Beuerlein at Ohio State. Bt corn hybrids. For most Michigan corn production systems, economic benefits from the use of transgenic Bt corn hybrids resistant to corn borers are more likely to occur with delayed plantings, especially when there is earlier planted corn in the vicinity. Consequently, growers may want to consider switching some of their late-planted intended non-Bt corn acreage to Bt hybrids as insurance against the higher risk of infestation by late brood corn borers. Previous herbicides applied. Before replanting review potential label restrictions associated with previously applied herbicides. Seeding rates. There is no need to consider changing seeding rates for corn simply because planting is delayed. Optimum seeding rates for most growers’ fields range from 28,000 to 33,000 seeds per acre. Lower rates (low to mid-20s) are suitable for fields with yield levels historically near or below 100 bushels per acre. Unlike corn, soybeans have a great propensity to compensate or “flex” when plant populations vary. Therefore, the optimal planting population range is wider for soybeans than it is for corn. Determining the minimal scale of that optimal soybean planting population range will optimize profitability and still maintain yield. As a starting point, begin with a planting population of 175,000 seeds per acre for drilled systems and 130,000 seeds per acre for 30 inch rows and then adjust down or up from there based upon field productivity, planting date, and planting conditions. When planting late, resulting soybean plants will be smaller than earlier planted soybeans. To compensate for the potential yield decrease of smaller plants due to late planting, increase your planting population by 20 percent. Seeding depth.The key factor that should be used for determining seeding depth for corn is the importance of adequate and uniform soil moisture in the seed furrow. Some might say this is a moot point given the current soggy soil conditions. Remember, though, how quickly Mother Nature can change and how quickly shallow-placed seed can find themselves in bone-dry soil. A seeding depth of 1.5 to 2.5 inches for corn and 1.0 to 2.0 for soybean is acceptable over a range of soil conditions. Shallower depths for corn are risky if rains stop altogether and surface soils begin to dry rapidly. Field tillage operations.Remaining pre-plant field operations should be scrutinized carefully to determine whether they are truly necessary. With today’s modern corn planters, there is little reason to overly-prepare a field to create a picture-perfect seedbed. In delayed planting situations, every day wasted overworking a field is a day lost to planting and represents lost yield potential. Furthermore, unnecessary tillage operations on soils that may be marginally wet increase the risk of creating tire and tillage compaction layers that can haunt root development and corn health later if excessively dry conditions suddenly become the norm. Planter sidewall compaction. Another concern to watch for is the potential for significant root restriction by severe sidewall compaction when a rapid shift from wet to dry conditions occurs. If at all possible, avoid planting fields when soil moisture conditions favor the smearing of furrow sidewalls by the coulters or double-disc openers of the planter. The potential yield loss from planting in fields that are too wet far outweighs the potential yield loss from delaying planting until field conditions are suitable. Planting in wet conditions often results in sidewall compaction of the seed furrow. This causes poor seed to soil contact which has several negative consequences including: reduced germination and poor stands; uneven emergence which reduces yield due to plant-to-plant competition; and, restricted root growth which compromises the plant’s ability to withstand moisture stress later in the growing season. In addition, the limited rooting can result in phosphorus deficiency even though soil test phosphorus levels are adequate. This occurs because the plant uses all of the phosphorus that is immediately available within the seed furrow. The roots of these plants will appear thickened and gnarled –a visual sign of compaction. After a period of time, the roots may break through the compacted sidewalls and explore more of the soil. As this occurs, the phosphorus deficiency may be overcome and the plant will begin growing normally again. However, the sidewall smearing and compaction is likely to have set the crop back by a week or more as it tries to overcome the inhospitable soil environment. Nitrogen fertilizer applications. It is not recommended to plant corn after June 15, in Michigan. However, if extenuating circumstances require that you plant corn, you may want to consider backing off on nitrogen fertilizer application rates due to the expected lower yield of the late-planted corn. The rule of thumb most commonly applied to lost yield potential for delayed planting is one bushel per acre per day after May 10, and up to 2 bushels per acre per day after June 1. Consider using a pre-sidedress soil nitrate test to further fine-tune your nitrogen application rates. Starter fertilizer. Where soil phosphorus and potassium soil test levels are adequate or better and tillage is other than pure no-till, consider eliminating starter fertilizer use for the remainder of this season’s corn planting. Soil temperatures at planting from here on should be more than adequate for rapid corn germination and early seedling growth, thus greatly diminishing the value of starter fertilizer. Eliminating starter fertilizer will not only reduce your costs, but will save some time during the planting operation. No-till corn, however, will likely continue to benefit from starter fertilizer applications, especially the nitrogen component, for planting throughout the remainder of the month. |
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Freeze injury should not be confused with damage from Fusarium head blight as shown in photo 2. With fusarium head blight the florets in the portion of the head that was infected are bleached in appearance, but are normal sized and do contain grain. Symptoms of fusarium head blight can appear within a few days when temperatures are in the 77°F-86°F range and moisture is continuous. Symptoms are usually evident by the soft dough stage. Grain from these heads may be shriveled, and have a chalky white or pinkish appearance.
Figure 1. Wheat resistance to freeze injury (From Spring Freeze Injury to Kansas Wheat
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Regional reports Weather has changed from warm to hot with several storms of locally heavy rain and high winds. Most of the four-county-area had 1.5 to 2.5 inches of rain over the past week. Crop report Alfalfa cutting continues as the weather permits, and the new growth looks good. Yields and quality of the first cutting are very good. Prices for small, square bales are in the $6 range. Barley is starting to turn. Corn is mostly at the V8 leaf stage and is quickly approaching knee high. Side dressing of nitrogen is finishing up and some post-emergence herbicide spraying is also being applied. European corn borer counts ranged from zero up to 20 moths found in traps in Monroe, Wayne, Lenawee and Washtenaw counties this week. Soybeans are still very small in the V3 leaf stage with several fields yet to receive any weed control. Wheat is mostly pollinated and generally continues to look very good with little disease pressure, though some fungicidal spraying has occurred. There is a concern about infection of fusarium head scab as we have had several periods of moisture and wet plant conditions within the past ten days. A pre-harvest field day at the MSU Wheat Variety Trial at the Dave and Jason Woods’ farm will be on Monday, June 23, from 5:00-8:00PM. The plot is located on Holloway Road, west of Bucholtz Highway north of Deerfield and east of Britton Highway, south of Britton. Miscellaneous The last trip to the MSU Soil and Plant Nutrient Lab to take soil nitrate samples will be on June 18. |
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2 -- Southwest What a difference one week can make in the crop environment. With an extraordinarily cold and dry spring, crop growth and development had been well behind the norm. That all changed late last week when temperatures reached the 90°F mark and a series of heavy thunderstorms dropped up to eight inches of rainfall overnight on Saturday, June 7. The hardest hit areas include portions of Allegan, Ottawa and Barry counties. Widespread flooding conditions also occurred in many other west Michigan counties. The general movement of individual cells was from south to north. Strong winds and localized hail were common in many of the most intense thunderstorm cells. Hail damage was generally light, mostly because the duration was short with moderate-sized hail stones in the fast moving storm cells. While lots of areas of fields were underwater for short periods of time, damage to these areas appear to have been light. There are more serious concerns in the areas where the rainfall was heavy enough to cause ponding for 24 hours or more and the plants were completely submerged. The high temperatures are likely to have contributed to plant mortality by reducing the amount of time corn and soybeans can withstand flooded conditions. Producers can slice plants up the stem to evaluate the growing points for healthy tissue following flooding. The growing points of healthy plants should have a creamy white appearance; plants that have suffered damage will have darker meristematic tissue. Crop report The earliest planted commercial corn fields are beginning to canopy over. Corn, which had grown little with cold temperatures, is growing so rapidly that it often has a spindly appearance. For those fields that are roundup ready or where total post herbicide programs are being planned, rapidly growing weeds will soon be causing potential yield losses. Research conducted by the MSU Weed Control Program has shown that to avoid yield losses, weeds should be controlled by the time they reach four inches in height in corn. Weeds have the potential to grow from four inches to six inches in two to four days under ideal conditions, so timing getting herbicides on soon will be critical for many producers. With more wet weather in the forecast and lots of nitrogen sidedressing operations also delayed by rains, it will be a challenge to get everything accomplished before corn height becomes an issue for some producers. We have also seen a lot of windy days associated with this weather pattern, which means there is likely to be more risk of drift if producers are trying to spray to keep ahead of the weather. We need to be careful, particularly around field edges where yards, gardens and sensitive crops are being produced. One example of this is Glyphosate drift, which can potentially cause minor plant growth delays in tomatoes, but can lead to very high harvest losses due to green tomatoes being dumped back on the field by color sorters on harvesters at the end of the season. Insect pests. We have seen a few fields that have very small European corn borer larvae feeding. These larvae have caused mostly window pane feeding on leaves, but have recently migrated to the whorl of the plants. Weed escapes. Grass escapes are still common in fields where pre-emergence herbicides may not have had sufficient rainfall to activate the herbicides. Most fields I have walked are fairly clear of broadleaf weeds. Wildlife damage. Sandhill cranes have been active in several areas in southwest Michigan. Look for plants being pulled out of the ground, with the seed removed from the bottom of the plant. The crop is beginning to outgrow the threat from the birds, but you may want to keep an eye out for later planted fields. Replanting drowned out areas. For those who are considering replanting in drowned out areas, be sure to consider the pesticides that have been applied to the field. If roundup ready corn was planted, and no soil insecticides were applied, it may be possible to plant soybeans in parts of fields damaged by floods if they dry out early enough that you plant and access the areas through the surviving crop. Second crop soybeans are often planted following very early wheat harvest in St. Joseph County, so if conditions allow, producers may be able to regain some value by planting late soybeans in these areas. Wet soil conditions have delayed the final planting of seed corn on a few fields. Most seed fields look pretty good, with good male row stands. Flaming has begun to help spread out pollen shed on some male rows. There was plenty of sand blowing June 6 with the strong southwest winds. Producers may want to examine fields for sandblast injury and to make sure that plants remain healthy, particularly in open fields with high exposure to south west winds. Armyworm has also been seen sporadically in St. Joseph County wheat fields, so their activity bears watching in seed corn fields. The soybean crop is growing rapidly, as are the weeds in many instances. We are beginning to work on the third trifoliate in early planted fields. Many of our presumably roundup ready soybean fields are quite weedy and are awaiting the first application of herbicide. Remember, MSU Weed Control Research suggests that weeds should be controlled before they reach four inches in height for drilled or narrow row soybeans, and six inches in height in 30-inch row soybeans. Weeds are growing very rapidly with the hot, moist conditions, so getting herbicides on in a timely manner is very important to achieve top yields. We have seen increasing bean leaf beetle feeding, with a very few pockets in fields approaching the threshold level of 50 percent defoliation. Chris DiFonzo reminds us that the main concern with bean leaf beetles is actually for damage by the summer generation later in the season, when they feed on pods and developing seeds. With higher numbers being seen in the southwest this season, it is a pest to keep on the radar screen. Stands continue to look good in most fields. Alfalfa hay harvest has been a big challenge for producers, especially those that were working on fields crops at planting. Lots of hay was cut prior to the last wet period, and at least some of it was ruined by the rainfall. Regrowth on fields that were cut earlier has been very good. We should be on track for a productive second cutting. Leafhopper activity has been low, but with the strong southwest flow from the recent storms, producers should be looking for the pest over the next week or so. Most of the wheat in St. Joseph had flowered before the heavy rains began to fall. However, humidity, light showers and fog in the period before last week’s thunderstorms kept the fields wet for prolonged periods. As you move farther north and perhaps west in the region, I would expect that this was not the case. We will have to see what happens to the crop at this point. The flag leaves still are looking fairly clean from leaf diseases at this point. I did walk a field of rye with a St. Joseph County producer. He was concerned about cold temperatures during flowering and heading affecting the kernel development in the heads. Upon closer inspection, there were several florets in each head that did not appear to be producing grain in this field. We have had several reports of armyworms in wheat spread throughout the area. For more information on armyworm control in wheat, see the article in this edition of the Field Crop CAT Alert. It would be a good idea to walk your fields and evaluate the fusarium head blight and armyworm pressure in your fields to protect the crop. |
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3 -- West Central Much needed rain fell over the entire region this week. Most areas received between two and three inches over a five-day period. Flooding has been minimal, the poorly drained soils have some ponding of water. Several fields have experienced some soil erosion due to the rapid rainfall. High temperatures have been in the mid-70s to mid-80s. Low air temperatures have been in the 60s. Low soil temperatures have been in the mid- to upper 60s. Crop report Alfalfa is starting to blossom. Grasses are maturing quickly. Harvest is under way with 20 percent of the crop cut or harvested and nearly all farms that have, or are currently harvesting, are harvesting haylage. Alfalfa weevil damage continues to increase with larvae present and many fields are at or above threshold. Growing Degree Day base 41 (GDD 41) are well past 750 at all locations, many locations are at 900 to 950 GDD41. In pastures with similar growth patterns, it is becoming over mature very quickly. Clipping or cutting surplus for hay will be needed. The majority of the corn crop is at the V3 to V5 growth stage with a few advanced fields at V7 and still a few others just emerging. Color and growth has improved again over last week with improved moisture and temperature. Some of the heavier soils have water standing in low spots. The majority of the soybean crop is planted. Early planted fields are at V2 to V3. Several fields have beans that are still emerging with the improved surface moisture. It is not entirely uncommon to find fields with beans that are just emerging and others at V2 within a few feet of each other. Wheat has completed flowering with a few late fields still in flower. Foliar disease pressure remains fairly low with powdery mildew present in several varieties low in the canopy. Many oat fields are in boot with little disease or insect pressure. Dry bean planting has begun, but is currently on hold, it will be in full swing when the weather forecast clears up. Sugar beets are doing well with good stands, one grower commented that his stand was too good and is considering thinning options. |
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4 -- Central The region received a good three inches of rain over the past week. In some areas there were high winds that took trees down as well as power lines leaving some farmers without power as of Wednesday, June 10. For the most part, fields took the water pretty well. Some areas will have some stand loss due to flooding, though as of Wednesday there is very little water standing. Most farmers are reporting fields just too wet to get in at this time. Crops have really progressed with the warm weather and rain. It is amazing how quickly corn and soybeans can make up for a slow start with the right growing conditions. Crop report The corn crop ranges from just emerging to about V-6. The warm weather and rains have really jump-started the crop as well as the weeds. Many fields are in need of herbicide applications as soon as field conditions allow. Weeds are quickly getting past the ideal size for control. Soybean stands are variable, but the crop is making up for lost ground with the early season cool and dry weather. There will be some additional stand loss due to flooding in some areas. Some seedling diseases are being reported. The weeds are also loving the good growing conditions and quickly getting past optimum size to control. Weed control should be made as soon as conditions allow. The wheat crop is just completing flowering. There is powdery mildew in most fields after the wet week, but remains low in the plant. Farmers are advised to scout fields for armyworms. They have been reported in the Thumb area of the state. The wheat withstood the high winds over the weekend very well. Yield potential is good at this point in the season. The oat and barley crop is approaching the boot stage. Stands look very good. Herbicide applications are going on as fields dry out. Alfalfa harvest has been halted with the rainy week and there was some quality loss. The crop is starting to flower. We have observed alfalfa weevil in nearly all fields. We expect the damage to increase rapidly with the warm weather. Cut fields as soon as possible to manage this pest. Scout the regrowth for alfalfa weevil. New seedings are doing very well. Sugar beet stands are very good, but are not filling the row at this time.Dry bean planting will continue as fields dry out. |
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| 5 -- Thumb Bob Battel Weather Warm temperatures and rains have sparked crop growth and slowed field work. The area has received between 1.5 and 2.5 inches of rain in the last week, and daytime high temperatures have ranged between 75°F and 90°F. Crop report Wheat has flowered or is flowering. Many are spraying wheat with a fungicide to limit head scab and vomitoxin development. Alfalfa has been cut, and some were able to finish harvest operations before the rains, but there is much alfalfa that was left in the field and soaked up a lot of moisture. Any uncut fields probably have alfalfa weevil feeding. Alfalfa that was cut and harvested has three to four inches of re-growth. Warm, wet, weather has really helped corn growth. Development generally ranges between the 4-leaf to 7-leaf stage with the majority at 5 to 6 leaves. Weed growth is extensive in many fields. Soybeans generally range at the one to two trifoliate stage with some soybeans at the unifoliate stage, and others at the third trifoliate. There are also many soybean fields that need to be sprayed for weeds as field moisture conditions allow. Some sugar beets are at the 6-leaf stage with more advanced fields at the eight to ten leaf stage. Conditions are right for rhizoctonia development. Dry bean planting had begun, but was delayed due to the rains. |
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| Weather news Jeff Andresen Agricultural Meteorology Geography Severe weather slams region Several rounds of severe thunderstorms brought heavy rains, strong winds, and hail to many sections of Michigan (and other sections of the Midwest) on a daily basis from the June 6-9 causing widespread property damage and loss of power for thousands. The thunderstorms brought widespread rainfall to the state, with totals since last Friday, June 6 generally ranging from less than 1 inch in far northern and southern sections of the state to more than 6 inches in some west central counties. While increasing the risk of foliar disease, the rain greatly eased or ended problems with dryness that had intensified during recent weeks. The severe weather outbreak across the Midwest was associated with meandering frontal boundary and an unusually hot humid air mass in place across the region, strong wind shear (increasing winds with height), and a series of upper air disturbances moving southwest to northeast across the region. On a statistical note, the severe weather outbreak kept the United States on pace to approach or set a new record for the greatest number of tornadoes in a calendar year. Looking ahead, the very active weather pattern across the Midwest is expected to continue into the early weekend. A cold front associated with a low pressure center over North Dakota Thursday morning is forecast to gradually move through Michigan during the next 24-48 hours, bringing the likelihood of showers and thunderstorms, beginning in far northwestern sections of the state Thursday and spreading southward into the Lower Peninsula by Friday afternoon or evening. Given that somewhat similar synoptic conditions to last weekend are expected to be in place by Friday, more severe thunderstorms will be possible with the primary threat of strong damaging winds and possibly some hail. Precipitation totals by Saturday morning are generally expected to reach the 0.50-1.00 inch range, with some locally higher amounts. A secondary cool front is expected to move through the state late Saturday through early Monday, bringing the possibility of additional showers and thunderstorms. In contrast to the next two days, any rainfall with the second system is expected to remain scattered in terms of areal coverage, with most totals remaining below one-half inch where rain occurs. High pressure will finally move back into the region by early next week, with fair and cooler weather expected for at least the first half of the upcoming workweek. Temperatures during the next couple of days will fall back to more normal levels, with highs Friday generally ranging from the mid- to upper 70s north to the low 80s south and lows from the low or mid- 50s north to the mid- or upper 60s south. Cooler temperatures are a good bet by Sunday into early next week, with highs ranging from the low to mid- 60s north to the low to mid- 70s south and lows falling to the mid- to upper 40s north to the mid- to upper 5’s south. Further ahead, the medium-range forecast guidance generally calls for significant changes in the upper air pattern across the United States, with the formation of upper air troughs across western and eastern sections and an upper air ridge expected across the Great Plains. This transition would bring at least a temporary end to the stormy weather pattern across the Midwest and leave Michigan and the Great Lakes region in northwesterly flow aloft, which typically translates to cooler and drier than normal weather conditions for us. The official National Weather Service 6-10 day and 8-14 day outlooks covering June 17 through 21 and June 19-25, both call for mean temperatures across Michigan to fall to below normal levels. Precipitation totals during the 6-10 day period are forecast to remain at near normal levels, while during the 8-14 day time frame they are expected to range from below normal levels across southern sections of the state to near normal levels across the north. There is a hint in the latest forecast guidance that the main axis of the upper air ridge could edge further eastward towards the eastern CornBelt in the 10-day time frame, which would likely mean a transition towards warmer than normal temperatures. Stay tuned. |
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