Number 401 May 3, 2013

Transcription

1 Number 401 May 3, Winter canola and recent freezes: Response and recovery 2. Effect of delayed planting on corn yield 3. Considerations for planting corn under wet conditions 4. Wheat disease update: Stripe rust detected in southeast Kansas 5. Update on sulfur deficiency in wheat 6. Reminder: Wheat and Canola Diagnostic School, May Winter Canola Field Day, Manhattan, May 9 8. Makeup day for Sedgwick County canola tour 9. The Oil Spill Prevention, Control, and Countermeasure (SPCC) Program 10. Comparative Vegetation Condition Report: April Winter canola and recent freezes: Response and recovery As we reported in the April 12, 2013 Agronomy eupdate (No.398), winter canola in central Kansas was covered with ¼ inch or more of ice at that time. Since then it has been exposed to freezing temperatures for a second and third time. Initially, we didn t have a good feel for the possible effects of the ice in combination with the freeze. We know now that the majority of the canola in central Kansas survived and it has resumed normal growth. However, where development was slow last fall and plants were smaller going into the spring, we have seen severe damage in some cases. Based on previous years experiences, we anticipate a delay in maturity of 5 to 7 days and shorter plants because of the frequent cold temperatures this spring. But as usual, we won t have a firm idea of yield potential until flowering is complete. Canola plots at the K-State Redd Foundation Field near Partridge suffered injury from hail, freeze, and ice from the weather system during the week of April 8. The canola was at the bolting stage when that system came through. The initial symptoms included leaf area loss; leaf burn; bud cluster tip burn; leaning plants; and pitted, cracked, and split racemes (stems). The hail caused the most damage to the plants in terms of leaf area loss and split racemes. Some weakened racemes were observed, but the majority of the damage was cosmetic. Because of the weight of the ice and the freeze, the plants had a distinctive lean. However, as warm temperatures returned, the plants quickly straightened up. No lodging was observed. 1

2 Pitted, split, and leaning canola plants at the Redd Foundation Field on April 12, Photo by Mike Stamm, K-State Research and Extension. If stem cracking occurs higher up on the main raceme, we don t anticipate major problems with the plant continuing normal growth. Any stem and bud loss around and above the crack will be compensated for by lower secondary branches on the plant. If the crack occurred lower on the raceme, lodging might occur as the plant adds weight from pods and seeds. If the split is more severe, the raceme is definitely weakened. As we saw in 2007, however, canola plants can continue normal growth even with a severe split. These splits are the biggest concern for stem rot and eventual lodging. 2

3 Severe splitting of canola raceme caused by the hard freeze on April 24, The plants may continue normal development but lodging could be a concern. Photo by Jay Smith, Crop Quest, Inc., Dodge City. A field day was held on April 24 near Conway Springs. Temperatures dropped into the upper 20s for about 5 hours in the early morning. The growth stage of most fields in the area was bolting to early flowering. Canola plants were covered with frost and those that were split open had ice formed inside. Taller plants were leaning, but shorter plants remained upright. Some flowering racemes were bent over and the flowers had a dull, droopy appearance. By mid-afternoon on the 24 th however, the plants and flowers had perked back up and had a normal color. Five days later, the canola showed no ill effects of the second freeze and was entering full flowering. 3

4 Canola plants north of Conway Springs the morning of April 24. Photo by Mike Stamm, K-State Research and Extension. A winter canola variety trial located west of Marquette suffered significant damage from the freeze. Dry soils may have also contributed to the severity of the damage. Growth in the variety trial had been slowed by an early fall freeze in October and by weed competition. These plants were much smaller than most canola last fall. The growth stage was bolting to early flower when the freeze events occurred on April 11 and April 24. The damage observed included severe leaf burn and loss of lower leaves, stunting, loss of the main raceme, and plant death. Unfortunately, variability across the trial did not allow for varietal differences to be observed. Nonetheless, the producer s canola field adjacent to the variety trial suffered minimal damage, primarily leaf burn and loss of lower leaves. The loss of leaf area is not a major concern because most of this would have senesced by the end of flowering. New leaf area higher up on the plant was observed and the crop was flowering normally. The producer s canola field had larger, more robust plants because weed control was much better. 4

5 Severe injury to canola from freeze. These plants are much smaller than most canola planted last fall. Cracks indicate dry soil conditions may have contributed to the injury. Photo by Mike Stamm, K-State Research and Extension. One long-term effect of late freezes that is almost always observed is a bend or crook in the main raceme. The crook will often be blank, but pods and flowers below it -- and pods, flowers, and buds above it -- will continue to develop normally. We anticipate this will be evident in nearly all canola fields that were at the flowering stage at the time of the freezes. As we have learned through experience, whenever any damage occurs to the main raceme of canola, the plant can compensate with secondary branching. The indeterminate growth habit of canola provides a survival mechanism as more favorable conditions return after a significant stress event. Yet we will have to wait until flowering is complete to get an estimate of the 2013 crop s full yield potential. -- Mike Stamm, Canola Breeder mjstamm@ksu.edu -- John Holman, Southwest Research-Extension Center Cropping Systems Agronomist jholman@ksu.edu -- Kraig Roozeboom, Cropping Systems Agronomist kraig@ksu.edu 5

6 2. Effect of delayed planting on corn yield With another storm system rolling through Kansas this week, more questions have been coming in about the effect of delayed planting on corn yield. A series of studies at K-State looking at delayed corn planting was conducted a few years ago. Three hybrid maturities were tested: 100-, 108-, and 112-day. Over the two years and three locations (Belleville, Manhattan, and Hutchinson), there were three distinct environments (as related to the environmental stress): * Low Stress where rainfall was favorable during the entire growing season * Early Stress where cool temperatures and wet conditions limited early corn growth * High Stress -- where conditions (rainfall and temperatures) were favorable early in the season, but the mid-summer was hot and dry In the Low Stress environments, yields were reduced by less than 20% when planting was as late as mid-june. Yields were not statistically different for any planting date before May 20 (starting from early April). Maximum yield in these non-irrigated environments was 176 bu/acre. The yield responses were similar for hybrids of all maturities. In the Early Stress environments, yields actually increased as planting was delayed until late June. This response was similar for all hybrid maturities. These environments had favorable temperatures and rainfall throughout July and early August. Maximum yield in these environments was 145 bu/acre. In the High Stress environments, yields dropped by about 1% per day of planting delay, depending on hybrid maturity. The shorter-season hybrids had the best yields if they were planted before late May (maximum yield = 150 bu/acre), but all hybrids had yield reductions of more than 50% when planting was delayed until early to mid-june. 6

7 The top chart (LS, or Low Stress) shows how little corn yields changed as planting dates got later when growing conditions were good through the remainder of the season. The middle chart (ES, or Early Stress) shows that corn yields actually increased with later planting dates when conditions were too cool and wet early, but then became more favorable. The lower chart (HS, or High Stress) shows how dramatically corn yields decreased when conditions were favorable early in the season, but the mid-summer was hot and dry. H1 refers to the 100- day hybrid. H2 refers to the 108-day hybrid. H3 refers to the 112-day hybrid. In many ways, the current growing season is shaping up like the Early Stress scenario above, with cool conditions early in the season. Will this cool spring be followed by favorable temperatures and rainfall or by hot and dry conditions during the rest of the growing season? While long-term weather predictions are highly unreliable, the National Weather Service Climate Prediction Center ( three-month outlook indicates a 40% likelihood of above-normal temperatures and an equal chance of above- or below-normal precipitation for most of the state. The extreme west has a 33% probably of below normal precipitation. 7

8 So, depending on what you believe will happen during the rest of the growing season, delayed planting may or may not have much of an effect on corn yields. Last week s eupdate (April 26, 2013, No. 400) article on historical yield and planting date relationships certainly confirmed that planting date is not necessarily a strong predictor of corn yield. -- Kraig Roozeboom, Cropping Systems Agronomist kraig@ksu.edu -- Ignacio Ciampitti, Cropping Systems Specialist ciampitti@ksu.edu 3. Considerations for planting corn under wet conditions What should producers expect if they plant corn into soils that are too wet in order to get it planted on time, and what can they do to minimize any problems? It is best, of course, to allow time for the soil to dry adequately before tillage or planting operations if at all possible. Wet conditions will make the soil more susceptible to compaction. Tilling some soils when they are too wet can produce large, persistent clods, complicate planting, reduce herbicide effectiveness, and destroy the seedbed. Also, compaction can occur in the seed furrow itself, restricting proper root development (also diminishing nutrient accessibility) and early plant growth. If soils remain or become unusually wet after the corn has emerged, corn may look sickly for a while. Saturated soils inhibit root growth, leaf area expansion, and photosynthesis because of the lack of oxygen and cooler soil temperatures. Yellow leaves indicate a slowing of photosynthesis and plant growth. Leaves and sheaths may turn purple from accumulation of sugars if photosynthesis continues but growth is slowed. Corn plants can recover with minimal impact on yield if the plants stay alive and conditions return to normal fairly quickly (early during the growth period). Although root growth can compensate to some extent later in the season, a saturated profile early in the season can confine the root system to the top several inches of soil, setting up problems later in the season if the root system is inadequate to extract needed water from lower in the profile. Saturated soils can also cause loss of nitrogen fertilizer by either denitrification (loss of nitrogen to the atmosphere) or leaching (movement of nitrogen beyond the rooting zone). For denitrification to occur, the soil doesn t need to be completely saturated. Denitrification can also occur at 85-90% of the pore space filled with water. Corn may respond to in-season nitrogen applications if a large portion of early-applied nitrogen is lost to these processes. Keep an eye out for nitrogen deficiency symptoms on fields that have been saturated for long periods. It may not be a bad idea to apply a strip or two of a high rate of nitrogen in those fields as soon as possible to serve as a fully-fertilized reference point. -- Kraig Roozeboom, Cropping Systems Agronomist kraig@ksu.edu -- Doug Shoup, Southeast Area Crops and Soils Specialist dshoup@ksu.edu 8

9 -- Dorivar Ruiz Diaz, Nutrient Management Specialist -- Ignacio Ciampitti, Cropping Systems Specialist 4. Wheat disease update: Stripe rust detected in southeast Kansas The wheat in southern Kansas ranged between the flag leaf emergence and boot stages of growth this week. Most fields in central Kansas are at or near flag leaf emergence. These growth stages signal the critical time for growers to be evaluating the need for fungicides for leaf disease management. At a regional level, both leaf rust and stripe rust were reported in Texas as early as February and March but so far Oklahoma is only reporting low or trace levels of these rust diseases. The disease levels have also been low locally in Kansas. I visited fields Sumner, Reno, McPherson, Marion, and Dickinson counties this past week and found only trace levels of powdery mildew, Septoria tritici blotch, and tan spot lower in the canopy. In southeast Kansas, Doug Shoup, Kelly Kuzel, and Josh Coltrain (K-State Research and Extension), reported trace levels of stripe rust in several fields in Labette and Neosho counties this week. The stripe rust was reported on the variety Everest, which is known to be susceptible to stripe rust after the changes in the stripe rust population last year. This report of stripe rust is important and growers in this area should carefully monitor their fields for signs of disease. There are some things to consider when considering fungicides this year: Be sure to evaluate the yield potential of your wheat. If you have experienced weather conditions (freezing temperature or drought) that make you question the yield potential of your crop, you may want to be more conservative when considering additional inputs. At this time, the risk of severe leaf rust or stripe rust is low or moderate. If disease is detected in the mid-canopy at the heading stages for growth, previous research indicates that there is about a 50 percent chance of a 10 percent yield response. If there are no reports of regional outbreaks of disease and the disease is not present at heading, the chances of 10% yield response are low (approximately 20% or less). There are a lot of excellent or very good products available for leaf disease management in wheat. The cost of fungicides varies significantly and the decision to apply is often influenced by product cost. Take a little time to investigate your product options and costs. The information about product costs will help you make the final decision when considered along with yield potential of the crop and yield benefit of the fungicide. More information about making fungicide decisions in wheat and fungicide efficacy can be found in the K-State Extension publications below. o Evaluating the need for foliar fungicides: 9

10 o Foliar fungicide efficacy ratings for wheat disease management: -- Erick De Wolf, Extension Plant Pathology 5. Sulfur deficiency in wheat: an update Two weeks ago (April 19, 2013, eupdate No. 398) I wrote concerning sulfur deficiency showing up in wheat, especially in northeast and north central Kansas. At the time some photos were included to show the visual symptoms of S deficiency, and some information on possible corrective measures that could be taken, primarily adding pounds S as a sulfate sulfur source. As a means of documenting the impact the observed deficiency might have on yield, and how some of the alternatives worked to correct the problem, a small experiment was initiated in a field near Randolph in northern Riley Co. There are five treatments in this test: No fertilizer applied control; 20 pounds N per acre as urea; 20 pounds N plus 20 pounds S as urea plus elemental sulfur; 20 pounds N plus 20 pounds S as ammonium sulfate; and 20 pounds N and 20 pounds S as an alternative ammonium sulfate product. The experiment was in a farmer s field of wheat, planted minimum-till following soybeans and planted in mid-october No history of sulfur deficiency had previously been noted, and no sulfur had been applied. The field had received 20 pounds of N and 40 pounds P 2 O 5 at planting, and an additional 60 pounds of N as urea on April 2, The experiment was placed in the field and S fertilizer treatments applied on April 21. Clear response to the sulfate S treatments was visible within 6-7 days. The photo below was taken on May days after treatments were applied. In the photo, several individual small plots can be seen. Individual plots defined by the white flags. The stake, visible in the lower center of the photo, gives the plot number as No. 105, and the treatment as ammonium sulfate, AS, The plot immediately behind No. 105 is plot No. 305, and is a lower analysis specialty ammonium sulfate product, which also appears to be giving an excellent response. To the left of plot No. 305 is 304, which received 20 pounds of N as urea, and to the right of plot 305 is another urea plot. Because the S deficiency is variable across the area, sensor readings were taken to measure growth and color of each plot in the experiment. That process was repeated on May 1.Looking at the whole experiment, the control, N only, and urea-n plus elemental sulfur plots have not changed. They are still yellow and have reduced growth. All of the ammonium sulfate treatments have greened up, similar to what is shown in the photo, and have increased growth or biomass. At this point it is clear that the wheat is responding to the application of a sulfate sulfur source. Perhaps with some warm weather there will be some oxidation of the elemental S to sulfate in the soil, and those treatments that haven t responded yet may still green up. But will that occur quickly enough to benefit this year s crop? Leaf samples will be taken from all the plots at Feekes 9, flag leaf emergence, to confirm the S deficiency and differences in S uptake between treatments. The plots will hopefully be harvested to 10

11 document any yield response, also. An additional update will be provided in a future issue of this newsletter after harvest. Response of sulfur-deficient wheat 10 days after application of different N and S sources. Photo by Ray Asebedo, Department of Agronomy graduate student. -- Dave Mengel, Soil Fertility Specialist dmengel@ksu.edu -- Ray Asebedo, Department of Agronomy graduate student ara4747@ksu.edu 6. Reminder: Wheat and Canola In-Depth Diagnostic School in Garden City, May 8-9 The Southwest Research and Extension Center (SWREC) will hold its 2013 Wheat and Canola In- Depth Diagnostic School on May 8 and 9 at the Center, 4500 E. Mary St. in Garden City. On May 8, the hours are from 8 a.m. until 5 p.m. On May 9, the school begins at 7:30 a.m. and ends at 1 p.m. Topics and presenters will include: Aerial Imagery and Crop Scouting o By Kevin Price Canola Production o By Mike Stamm Commercial Pesticide License Recertification Core-hour o By Kansas Department of Agriculture Crop Growth, Development, and Staging 11

12 o By Doug Shoup, Stu Duncan, and Jeanne Falk Enhanced Efficiency Fertilizers and Methods o By Dave Mengel and Dorivar Ruiz Diaz Entomology o By JP Michaud and Sarah Zukoff Fertilizer Rate and Placement o By Dorivar Ruiz-Diaz and Dave Mengel Seeding Management and Tillage o By Kraig Roozeboom, Jeanne Falk, and Stu Duncan Weed Control and Crop Herbicide Injury o By Curtis Thompson, Dallas Peterson, and Randall Currie Weed Identification o By Dallas Peterson, Curtis Thompson, and Randall Currie Wheat and Canola Diseases o By Erick DeWolf The school has approval for 11 hours of CCA Continuing Education credits, 5 hours of Commercial Pesticide Applicator credits, and 1 Commercial Pesticide Applicator core hour. This school is open to everyone interested in wheat and canola production. The cost is $100 for both days for those who RSVP by May 1. After that date, the cost is $125 for both days. To register for the school, contact Ashlee Wood at or awood22@ksu.edu. For more information, contact John Holman at or jholman@ksu.edu. -- John Holman, Southwest Research and Extension Center Cropping Systems Agronomist jholman@ksu.edu 7. Winter Canola Field Day, Manhattan, May 9 Producers can get a full update on winter canola production in Kansas at the Winter Canola Field Day, May 9. The field day will be held at the USDA Plant Materials Center, 3800 South 20 th St. in Manhattan, starting at 5:30 p.m. Topics and speakers (K-State unless otherwise noted) include: * Winter Canola Breeding Program and Variety Updates Mike Stamm, Canola Breeder * Winter Canola Cropping systems for Kansas Kraig Roozeboom, Cropping Systems Agronomist * Beneficial Insects in Winter Canola Brian McCornack and Ximena Cibils Steward, Entomologists * Marketing Winter Canola in Kansas Joni Wilson, Merchandiser, ADM/Northern Sun, Goodland A dinner will be provided after the program, sponsored by ADM/Northern Sun. There is no cost for the field day or dinner, but in order to get an accurate count for dinner, please RVSP to Nancy William ( ) or nkw@ksu.edu by May 3. 12

13 8. Makeup day for Sedgwick County canola tour, May 14 This spring s Sedgwick County canola tour has been rescheduled for May 14 at 10 a.m. The tour will begin 2½ miles south and 1½ miles west of Andale on W 37th St. N. The second stop will be 1½ miles west and 1 mile north of Colwich on N 199th St. W at approximately 11:00 a.m. View a commercial field of winter canola planted no till in 30-inch row spacing. See 24 commercial winter canola varieties and a harvest management study. Lunch is sponsored by American Ag Credit. 9. The Oil Spill Prevention, Control, and Countermeasure (SPCC) Program Compliance Deadline Update The compliance date of May 10, 2013 is next Wednesday. Farms that meet the SPCC requirements are expected to have prepared and implement their plans by this date. There is some relief, as part of the continuing resolution passed in March the environmental protection agency (EPA) will not begin enforcing the SPCC rules for agriculture until October 1, 2013 What is SPCC? The goal of the SPCC program is to prevent oil spills into waters of the United States and adjoining shorelines. Oil spills can cause injuries to people and damage to the environment. A key element of this program requires farmers and other facilities that exceed the oil SPCC storage requirements to have an oil spill prevention plan, called an SPCC Plan. These Plans can help farmers prevent oil spills which can damage water resources needed for farming operations. What is considered a farm under the SPCC program? Under SPCC, a farm is: a facility on a tract of land devoted to the production of crops or raising of animals, including fish, which produced and sold, or normally would have produced and sold, $1,000 or more of agricultural products during a year. Does my farm have to meet requirements of the SPCC program? The SPCC program applies to a farm which meets ALL 3 following criteria: 1. Stores, transfers, uses, or consumes oil or oil products, such as diesel fuel, gasoline, lube oil, hydraulic oil, adjuvant oil, crop oil, vegetable oil, or animal fat. 2. Stores more than 1,320 US gallons in aboveground containers or more than 42,000 US gallons in completely buried containers; Count only containers of oil that have a storage capacity of 55 US gallons and above. Adjacent or non-adjacent parcels, either leased or owned, may be considered separate facilities for SPCC purposes. Containers on separate parcels (that the farmer identifies as separate facilities based on how they are operated) do not need to be added together in determining whether the 1,320-gallon applicability threshold is met. 3. Could reasonably be expected to discharge oil to waters of the US or adjoining shorelines, such as interstate waters, intrastate lakes, rivers, and streams. The environment and flow properties of oil when combined with a rain event must be considered. Farms that meet all 3 criteria are required to develop an oil storage containment plan by May 10, Additional information on the SPCC program can be obtained from the following website: 13

14 Can I develop my own plan? An owner or operator of a qualifying Tier I facility can develop a self-certified SPCC Plan. Qualifications to be a Tier I facility: Total above ground capacity between 1,320 and 10,000 gal No aboveground single oil storage container with a capacity greater than 5,000 gal In the 3 years prior to the date the SPCC Plan is certified, had no single discharge of oil exceeding 1,000 gals or no two discharges each exceeding 42 gal within any 12-month period What information goes into my SPCC plan? A list of oil containers at the farm or parcel with a capacity of 55 gal or more. Description of the procedures to prevent a spill Description of measures installed to prevent oil from reaching water. Description of measures to contain and clean-up and oil spill to water. A list of emergency contacts and first responders Sample plans and plan templates are available at the following website: What do I do with my SPCC Plan? The plan should be maintained at your facility if you are usually present at least 4 hours per day or at your nearest office if the facility is not staffed. Your SPCC plan will need to be updated when any changes are made to your storage and/or containment. Additionally the plan must be reviewed every five years. -- Peter Tomlinson, Environmental Quality Specialist, Agronomy ptomlin@ksu.edu -- Aleksey Sheshukov, Watershed Assessment Specialist, Biological and Agricultural Engineering ashesh@ksu.edu -- James Pat Murphy, Livestock Systems Specialist, Biological and Agricultural Engineering jmurphy@ksu.edu -- Kerri Ebert, Extension Assistant, Ag Safety and Health Program, Biological and Agricultural Engineering kebert@ksu.edu 14

15 10. Comparative Vegetation Condition Report: April K-State s Ecology and Agriculture Spatial Analysis Laboratory (EASAL) produces weekly Vegetation Condition Report maps. These maps can be a valuable tool for making crop selection and marketing decisions. Two short videos of Dr. Kevin Price explaining the development of these maps can be viewed on YouTube at: The objective of these reports is to provide users with a means of assessing the relative condition of crops and grassland. The maps can be used to assess current plant growth rates, as well as comparisons to the previous year and relative to the 24-year average. The report is used by individual farmers and ranchers, the commodities market, and political leaders for assessing factors such as production potential and drought impact across their state. NOTE TO READERS: The maps below represent a subset of the maps available from the EASAL group. If you d like digital copies of the entire map series please contact Kevin Price at kpprice@ksu.edu and we can place you on our list to receive the entire dataset each week as they are produced. The maps are normally first available on Wednesday of each week, unless there is a delay in the posting of the data by EROS Data Center where we obtain the raw data used to make the maps. These maps are provided for free as a service of the Department of Agronomy and K-State Research and Extension. The maps in this issue of the newsletter show the current state of photosynthetic activity in Kansas, the Corn Belt, and the continental U.S., with comments from Mary Knapp, state climatologist: 15

16 Map 1. The Vegetation Condition Report for Kansas for April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that snow continues to be a feature across much of the state. This is the latest the snow mask has been maintained since the Vegetation Condition Report has been produced. The snow mask will likely continue next week to reflect the snow received in the last few days. 16

17 Map 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for September April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that statewide biomass production is much below last year. In the Flint Hills, this is particularly noticeable. Growth of the grasses has be greatly delayed. 17

18 Map 3. Compared to the 24-year average at this time for Kansas, this year s Vegetation Condition Report for April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that some areas have slightly above-average photosynthetic activity. This is most noticeable in the eastern-most areas of the state, where temperatures have not been quite as cold and where moisture has been more favorable. In western Kansas, much of the region shows below-average productivity. In southwest Kansas, the impacts of the mid-april freeze are being seen in reduced photosynthetic activity. 18

19 Map 4. The Vegetation Condition Report for the Corn Belt for April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that snow is most concentrated in the northwestern portions of the region. In North Dakota and northern Minnesota, snow water equivalents of the snowpack ranged from 6 to 10 inches, while snow depths were more than 20 inches. 19

20 Map 5. The comparison to last year in the Corn Belt for the period April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows photosynthetic activity has been much lower. Illinois and the Boot Heel of Missouri are the exceptions, and are just slightly ahead of last year s activity. 20

21 Map 6. Compared to the 24-year average at this time for the Corn Belt, this year s Vegetation Condition Report for April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that in the area from Iowa to Pennsylvania, photosynthetic activity is at or slightly above normal. The greatest departure from average activity is in the northern areas, where temperatures continue well-below normal, and snowpack persists. 21

22 Map 7. The Vegetation Condition Report for the U.S. for April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that the Northern Plains and Northern Rockies have the greatest snow cover. Areas east of the Continental Divide have had near- or above-normal snow water equivalents, while west of the Divide and in the Southern Rockies, many areas have snow water equivalents less than half of normal. 22

23 Map 8. The U.S. comparison to last year at this time for the period April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that the biggest departure can be seen in the Plains, where cold temperatures and dry conditions have provide much less favorable conditions. Cold temperatures have had the biggest impact in the northern reaches, while dry conditions have had a bigger impact in the southern regions. 23

24 Map 9. The U.S. comparison to the 24-year average for the period April from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that the Pacific Northwest and Upper New England continue to have greater-than-average productivity. This is despite drier-than-average conditions in the Pacific Northwest. In contrast, the Central Plains region continues to have below-average productivity. Cold temperatures have delayed photosynthetic activity in the Northern Plains, as has lingering drought impacts in the South Plains. -- Mary Knapp, State Climatologist mknapp@ksu.edu -- Kevin Price, Agronomy and Geography, Remote Sensing, Natural Resources, GIS kpprice@ksu.edu -- Nan An, Graduate Research Assistant, Ecology & Agriculture Spatial Analysis Laboratory (EASAL) nanan@ksu.edu These e-updates are a regular weekly item from K-State Extension Agronomy and Steve Watson, Agronomy e-update Editor. All of the Research and Extension faculty in Agronomy will be involved as sources from time to time. If you have any questions or suggestions for topics you'd like to have us address in this weekly update, contact Steve Watson, swatson@ksu.edu, Jim Shroyer, Crop Production Specialist jshroyer@ksu.edu, or Curtis Thompson, Extension Agronomy State Leader and Weed Management Specialist cthompso@ksu.edu. 24