eupdate Extension Agronomy 06/07/2013 Issue 407

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1 Issue 407 Extension Agronomy eupdate 06/07/2013 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.

2 eupdate Table of Contents 06/07/2013 Issue Drought stress, late effects of freeze damage, and premature leaf death in wheat Corn seedlings: Purple color effects Cover crop opportunities after wheat in central and eastern Kansas Using plant analysis as a nutrient management tool May weather summary for Kansas: Big changes Comparative Vegetation Condition Report: May 21 June

3 1. Drought stress, late effects of freeze damage, and premature leaf death in wheat Although the wheat crop has benefited from a week of relatively mild temperatures, we are getting reports of wheat declining more quickly than expected in some areas of the state. Visits to wheat fields indicate the leaves are rapidly drying up and some fields have scattered white heads. In general, this rapid decline of the wheat can be explained by drought stress and freeze injury. In some cases, however, it appears that leaf diseases such as tan spot or Stagonospora leaf blotch also are increasing rapidly on the flag leaves, further accelerating the loss of leaf tissue. These leaf diseases appear to be a factor in the southeast and south central regions of the state where rain was more plentiful this spring. We have seen fields in Ellsworth, McPherson, and Rice counties showing symptoms of drought stress despite recent rains. As we talk with growers in these areas it appears that parts of these counties experienced dry soil conditions and windy days that caused wheat to roll leaves and "turn blue" about 2-3 weeks ago. The wheat would have been at heading and flowering stage of growth at this time. Wheat at these growth stages is very sensitive to environmental stress, and dry conditions and/or hot temperatures will often damage developing wheat heads. This period of moisture stress would show up now as leaf-tip necrosis and scattered white heads. These white heads might be from tiller abortion or heads that were sterilized by the stress, depending on the growth stage when the stress occurred. Some irrigated fields in western Kansas were also showing similar symptoms. Of course we would not expect moisture stress to be a problem in well-managed irrigated fields, and in this case, freeze injury to the stems appears to be an important factor. Many irrigated fields in western Kansas were jointing during multiple freeze events back in April. Evaluation of these fields indicates leaf tip-die back (Figures 1 and 2). This is a result of moisture deficiency, even under well-irrigated conditions. The freeze damaged the vascular tissue of the wheat plant, so that the plant has been unable to transport enough water to keep up with demand, especially now that grain fill has initiated. Another symptom of the freeze injury is weak stem strength, which could make the plants very susceptible to lodging (Figure 3). In this situation, as temperatures increase and kernels try to fill, the plant will be under more moisture stress and it may be difficult to meet the evaporative demand of the plant even with irrigation. Kernel size and test weight may also be reduced. Another concern will be that the plant will easily lodge as it matures. The lodged plants may make grain harvest a challenge. 3

4 Figure 1. Wheat field in Finney County showing signs of drought stress caused by spring freeze damage to vascular system. In this case, the later-maturing variety has less injury than the early-maturing variety. Photos by John Holman, K-State Research and Extension. 4

5 Figure 2. Necrosis on the flag leaf showing symptoms of drought stress under well-irrigated field conditions. 5

6 Figure 3. Irrigated wheat with lodging due to very weak stem strength caused by spring freeze damage to vascular tissue. -- Erick DeWolf, Extension Plant Pathologist -- John Holman, Cropping Systems Agronomist, Southwest Research-Extension Center -- Doo-Hong Min, Southwest Area Crops and Soils Specialist 6

7 2. Corn seedlings: Purple color effects The recent rains combined with unusual low temperatures (day/night) this spring are causing slow plant growth for all summer crops, including corn. Related to the slow growing conditions, today I received a question on the presence of purple coloration in corn seedlings. The first thought that comes to the mind of agronomists and producers is that this could be an indication of phosphorus deficiency. Phosphorus deficiency is also generally associated with stunted plants and thin stalks. Other potential causes of purple color can be hybridrelated, a buildup of sugars (sunny days/cold nights), and restricted root growth. Thus, the question is: What is the main factor affecting the plant color if the crop otherwise looks very healthy, uniform, and vigorous? In recent years, purple coloring on corn seedlings has been documented in different environments under diverse management practices and hybrids. The color is just the expression of a pigment called anthocyanin. The expression of this color is governed by multiple genes, and some of those are more sensitive to low temperatures (40-50 degrees F). Therefore, low night temperatures such as those we have experienced at times over the past couple weeks will promote the purpling color in corn seedlings. Producers do not need to worry about this. As soon as the temperature warms up, the purple color should disappear. If not, then consider taking a soil sample for potential phosphorous deficiency. At this point, the purple color is simply reflecting a small degree of cold temperature stress -- nothing severe. The plant is growing very slowly, but good growth and development should resume after the temperatures go back to the normal for this time of year. Will the yield be affected by this stress? Previous information collected by several researchers concluded that yield is not likely to be affected by this phenomenon. Still, it is always good to continue scouting your acres for early identification of any potential problem affecting your crops. 7

8 Figure 1. Purple color on corn, due to buildup of anthocyanin caused by cold temperatures. Photo by Ignacio Ciampitti, K-State Research and Extension. -- Ignacio Ciampitti, Crop Production and Cropping Systems Specialist 8

9 3. Cover crop opportunities after wheat in central and eastern Kansas In a wheat/row crop rotation in central and eastern Kansas, the 10 to 11 months between winter wheat harvest and planting of the next grain crop the following spring provides an excellent opportunity to insert a cover or forage crop. Planting a cover crop immediately after wheat harvest can take advantage of the 8 to 12 inches of precipitation usually received in central and eastern Kansas from July through September. Cover crops can provide a number of benefits: Erosion control: The cover crop canopy protects the soil from wind and water erosion while it is growing. The residue remaining after termination can continue to protect the soil until the next crop gets established and provides adequate cover. Weed suppression: This same canopy and residue cover can suppress weed emergence and growth. Research at K-State has documented a 50% to 80% reduction in Palmer amaranth biomass with an adequate stand of a late-maturing soybean cover crop. Nitrogen fixation: Legume cover crops can fix atmospheric nitrogen that could be available to following crops. Research at Hesston a few years ago showed that late-maturing soybean and sunn hemp provided the equivalent of 60 lb N/acre to the following sorghum crop. More recent research at Manhattan has been less favorable, with only about 20 to 30 lb N/acre from late-maturing soybean, doublecrop soybean harvested for grain, and winter pea. Nutrient trapping: Both legume and non-legume cover crops can capture soil profile nitrogen in their plant tissues for release in subsequent seasons. Crops that tend to turn over nitrogen more quickly (making a greater fraction available to the next crop) include legumes, brassicas (canola, turnip, radish), and any other crop with a lower carbon to nitrogen ratio (C:N) of 20:1 or less. In the Manhattan study mentioned above that showed a nitrogen response in sorghum of 20 to 30 lb N/acre from legumes, a similar response was observed following canola. No fixation had occurred, but the canola cycled the nitrogen in such a way that more was available to the sorghum planted the next year compared to the sorghum-sudangrass cover crop that had a high C:N ratio. Building soil organic matter: Any time additional crops are introduced into the system, more carbon is fixed via photosynthesis, and the opportunity exists to transfer some of that carbon into long-lasting organic matter. Don't expect dramatic changes in soil organic matter after one planting of a cover crop. Changes in organic matter take time and are often limited to the upper few inches of the soil profile. Cautions -- cover crops can present some challenges that should not be ignored: Excessive residue: Crop residue is generally a good thing for all the reasons mentioned above. However, some cover crops can produce so much residue that planting the following crop can be made more difficult, especially in regions with heavy soils and/or substantial spring rains. Depending on the crop and planting date, early growth of the next crop can be slowed due to cooler temperatures or tie-up of soil nitrogen. In those cases, cover crops or mixtures of cover crops should be selected that will either not leave so much residue or will break down quickly in the spring. Utilizing forage from high-biomass cover crops will minimize these potential negative effects. 9

10 Water use: Cover crop choice and timing of termination becomes more critical in areas with less annual precipitation. Research has shown that cover crops must be terminated before June 1 in western Kansas to minimize the impact on stored soil moisture for a wheat crop to be planted that fall. Water drives biomass production, therefore cover crops that produce more biomass generally extract more water from the soil profile. Additional expense: Seed of some cover crops can be expensive. Planters or drills must make additional passes over the field. Termination may require more aggressive herbicide mixtures or relatively expensive mowing operations. Think through your seed sources and termination options to minimize these expenses. Utilizing the cover crop as forage generates an immediate economic benefit that can offset some of these additional costs. Regrowth after grazing or haying can provide many of the canopy and residue benefits discussed above. Herbicide carryover: Many commonly used wheat herbicides may have residual effects after wheat harvest. STS soybeans or sorghum are relatively tolerant of most of these herbicides, but exercise caution if a herbicide with a long rotation restriction has been applied to the wheat. Volunteer wheat: Even with aggressive biomass production, volunteer winter wheat can establish and survive under the canopy of most cover crops. This could bridge the host gap for wheat curl mites, the vector of wheat streak mosaic virus. A number of cover crops and mixtures have been evaluated in experiments in central and eastern Kansas in recent years. The following table summarizes their performance in a cropping system where the summer cover crops were planted soon after wheat harvest and terminated in mid-september, and the winter cover crops were planted in late August and terminated in late April. Earlier planting of the winter cover crops may increase fall growth. Sorghum was planted in late May or early June with no additional fertilizer N (not recommended). Other studies have shown that if enough fertilizer N is applied to the sorghum, sorghum yields can be roughly equivalent regardless of preceding cover crop. 10

11 Cover Crops Evaluated in South Central and Northeast Kansas in 2007 to 2009 Cover Crop Biomass Production Nitrogen Content in Plant Tissues Comments Sorghum Yield After Cover Crop** Summer non-legumes Sorghum sudan grass H* L Long-lasting residue L Pearl millet MH M Good grazer M Buckwheat L M Rapid growth ML Summer legumes Lab lab bean ML M Viney growth MH Cowpea M H Heat tolerant MH Sunn hemp M, MH MH Heat tolerant, residue can be difficult with MH Late-maturing or forage soybean M, ML H later termination Rapid residue breakdown Summer mixtures Cowpea/Pearl millet M M Shorter residue life MH Sorghum sudan/pearl Mixture is dominated by H ML millet/sunn hemp/cowpea sorghum-sudan MH Winter non-legumes Canola ML H Provides good no-till seedbed MH Barley M L Possible disease host ML Annual Rye L ML Little fall growth ML Oats M L Killed by frost M Winter Triticale MH L Long-lasting residue L Annual Fescue L H Little fall growth M Winter legumes Winterpea L H Hard to kill with herbicides MH Yellow Sweetclover L H Little fall growth MH Winter mixtures Winterpea/Winter triticale M M Mixture is dominated by triticale L Yellow sweet clover/ Winter Mixture is dominated by M M triticale triticale L * H = high, M = medium, L = low; relative to other cover crops evaluated in these experiments. ** No fertilizer N was applied to the sorghum in these tests. Other studies have shown that if sufficient fertilizer N had been applied, the cover crops would have little effect on sorghum yields in most cases. -- Kraig Roozeboom, Crop Production and Cropping Systems Agronomist kraig@ksu.edu MH 11

12 4. Using plant analysis as a nutrient management tool Plant analysis is an excellent quality control tool for growers interested in high yield crop production. It can be especially valuable for managing secondary and micronutrients which don t have high quality, reliable soil tests available, and providing insight into how efficiently you are using applied nutrients. There are two basic ways plant analysis can be used by Kansas farmers: 1) monitoring nutrient levels at a common growth stage, and 2) for diagnostic purposes. Monitoring is generally done at a common growth stage, the beginning of reproductive growth, while diagnostics can be done any time. Plant analysis for nutrient monitoring For general monitoring or quality control purposes, plant leaves should be collected as the plant enters reproductive growth. Sampling under stress conditions for monitoring purposes can give misleading results, and is not recommended. In the case of corn, ear leaves, or first leaf below and opposite the ear, should be collected at random from the field at silk emergence, before pollination, and before the silks turn brown. In sorghum, the first or second leaf below the flag leaf at heading should be collected. Again individual leaves should be collected from the field at random. In soybeans, the top, fully developed trifoliate leaflets should be collected when the first pods are ¾ to one inch long. The top fully developed trifoliate leaflets are normally the third set of leaves below the terminal bud on the main stem of the plant. They should be dark green, and will likely be positioned at the top of the canopy. Developing/growing leaves will be a lighter green color and generally be below the fully developed leaves in the canopy. Collect sets of leaflets at random, removing the petiole, or stem connecting the leaflets to the stem. In wheat, the flag leaf is normally collected at heading. Since the flag leaves are small, individual leaves will be needed to have enough dry plant material to have adequate plant material for analysis. Again, collect the leaves at random from the field or area which is being monitored. Diagnostic sampling Plant analysis is also an excellent diagnostic tool to help understand some of the variation seen in the field. When using plant analysis to diagnose field problems, try to take comparison samples from both good/normal areas of the field, and problem spots. Also collect soil samples from the same good and bad areas since physical problems such as soil compaction often limits the uptake of nutrients otherwise present in adequate amounts. Don't wait for tasseling or silking to sample. When sampling for diagnostic purposes, collecting specific plant parts is less important than obtaining comparison samples from good and bad areas of the field. As a general rule, if plants are less than 12 12

13 inches tall, collect the whole plant, cut off at ground level. If more than 12 inches tall, and until reproductive growth begins, collect the top fully developed leaves. Once reproductive growth starts, collect the same plant parts indicated for monitoring purposes. When doing diagnostics, it is also helpful to collect a soil sample from both good and bad areas. Define your areas, and collect both soil and plant tissue from areas which represent good and bad areas of plant growth. Shipping and handling plant samples How do you handle samples, and where should you send the samples? The collected leaves should be allowed to wilt over night to remove excess moisture, placed in a paper bag or mailing envelope, and shipped to a lab for analysis. Do not place the leaves in a plastic bag or other tightly sealed container, as they will begin to rot and decompose during transport, and the sample won t be usable. Most of the soil testing labs working in the region provide plant analysis services, including the K-State laboratory. Make sure to label things clearly for the lab. What nutrients should you analyze for? In Kansas nitrogen (N), phosphorus (P), potassium (K), sulfur (S), zinc (Zn), chloride (Cl), and iron (Fe) are the nutrients most likely to be deficient. Recently questions have been raised by consultants and others concerning copper (Cu), manganese (Mn), and molybdenum (Mo). Most labs can analyze for most of these. Normally the best values are the bundles or packages of tests offered through many of the labs. They can be as simple as N, P and K, or can be all of the 14 mineral elements considered essential to plants. K-State offers a package which includes N, P, K, Ca, Mg, S, Fe, Cu, Zn, and Mn for $20. What will I get back from the lab? The data returned from the lab will be reported as the concentration of nutrient elements, or potentially toxic elements, in the plants. Units reported will normally be in percent for the primary and secondary nutrients (N, P, K, Ca, Mg, S, and Cl) and ppm, or parts per million, for the micronutrients (Zn, Cu, Fe, Mn, B, Mo, and Al). Most labs/agronomists compare plant nutrient concentrations to published sufficiency ranges. A sufficiency range is simply the range of concentrations normally found in healthy, productive plants during surveys. It can be thought of as the range of values optimum for plant growth. The medical profession uses a similar range of normal values to evaluate blood work. The sufficiency ranges change with plant age (generally being higher in young plants), vary between plant parts, and can differ between hybrids. So a value slightly below the sufficiency range does not always mean the plant is deficient in that nutrient, but it is just an indication that the nutrient is relatively low. Values on the low end of the range are common in extremely high-yielding crops. However, if that nutrient is significantly below the sufficiency range, then you should ask some serious questions about the availability and supply of that nutrient. Keep in mind also that any plant stress (drought, heat, soil compaction, etc.) can have a serious impact on nutrient uptake and plant tissue nutrient concentrations. So a low value in the plant doesn t always 13

14 mean the nutrient is low in the soil and the plant will respond to fertilizer. Rather, it could be that the nutrient is not available to the plant. Levels above sufficiency can also indicate problems. High values might indicate over fertilization and luxury consumption of nutrients. Plants will also sometimes try to compensate for a shortage of one nutrient by loading up on another. This occurs at times with nutrients such as iron, zinc and manganese. Plants will load up on iron at times, in an attempt to compensate for low zinc. In some situations very high levels of a required nutrient can lead to toxicity. Manganese is an example of an essential nutrient which can be toxic when present in excess. This can occur at very low soil ph, generally well below 5. The following table gives the range of nutrient content considered to be normal or sufficient for corn at silking, soybeans at pod set, and wheat at heading. Keep in mind that these are the ranges normally found in healthy, productive crops. Sufficiency nutrient contents for various crops Crop Nutrient Units Corn: Ear leaf at green silk Soybeans: Top leaves at pod set Wheat: Flag leaf at boot to heading Nitrogen % Phosphorus % Potassium % Calcium % Magnesium % Sulfur % Chloride % Copper ppm Iron ppm Manganese ppm Zinc ppm Boron ppm Molybdenum ppm Aluminum ppm <200 <200 <200 In summary, plant analysis is a good tool to monitor the effectiveness of your fertilizer and lime program, and a very effective diagnostic tool. Consider adding this to your toolbox. -- Dave Mengel, Soil Fertility Specialist dmengel@ksu.edu 14

15 5. May weather summary for Kansas: Big changes The month of May brought big changes both in precipitation and temperatures, although it was uneven across the state. Overall, the mean temperature across the state was slightly cooler than average. The western third of the state was the warmest. In contrast, the eastern divisions were all below average. Statewide, the average precipitation was 3.74 inches, which 82% of normal. As percent of normal, the Northeast Division ranked the highest at 124 percent. Statewide temperatures averaged 63.2 of, which is 0.3 degrees below normal. Changes in the Drought Monitor have been mixed. In the Eastern divisions, with normal to above normal precipitation and cooler than average temperatures, there has been improvement. A small portion of east central and northeast Kansas is actually near normal. Extreme and Exceptional drought expanded in southwestern Kansas, where moisture was very limited. The latest Drought Outlook indicated some drought conditions are expected to improve. The strongest signal for continued improvement is in the eastern third of the state. In the western division, there may be some improvement, but impacts of the drought are expected to continue. The El Niño/Southern Oscillation (ENSO) is expected to remain neutral, which reduces the skill in the forecast. The jet stream is expected to shift northward. For June chances are equally likely for precipitation to be above or below in the eastern two-thirds of the state, with below normal precipitation more likely in the western third of the state. In contrast to the May, June temperature outlook issued is for warmer-than-normal temperatures statewide. This does not indicate how much warmer conditions might be, and does not exclude the possibility of cooler weather in the period.. Severe weather also was a factor in May. A total of 49 tornadoes were reported in the state. Fortunately there were no deaths reported from the storms. There were also 183 hail reports and 146 wind damage reports. The end of the month also brought flooding in the eastern parts of the state. Despite the rains, water levels remain a concern, particularly at the Cheney Reservoir and at Clinton Lake. 15

16 Table 1 May-13 Kansas Climate Division Summary Precipitation (inches) Temperature ( o F) May January through May Monthly Extremes Division Total Dep. Normal Total Dep. Normal Ave Dep. 1 Max Min 1 % 1 % Northwest West Central Southwest North Central Central South Central Northeast East Central Southeast STATE Departure from normal value 2. State Highest temperature:103 of at ASHLAND (Clark County), Healy (Lane County) and Hays (Ellis County) on the 28th 3. State Lowest temperature: 22 of at Tribune 1W (Greeley County) and Richfield (Stanton County) on the 2nd and 3rd. 4. Greatest 24hr rainfall: 4.92 inches at Sterling, Rice County on the 30th (NWS); 6.08 inches at Pretty Prairie 6.7 NE,Crawford County, on the 30th (CoCoRaHS). Source: KSU Weather Data Library -- Mary Knapp, State Climatologist mknapp@ksu.edu 16

17 6. Comparative Vegetation Condition Report: May 21 June 3 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: 17

18 Figure 1. The Vegetation Condition Report for Kansas for May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that the western third of the state continues to have low vegetative activity, due to the continuing drought. In east central Kansas the low photosynthetic activity is due to excess moisture. Notably in Linn County, there has been significant delay in corn planting. 18

19 Figure 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for September May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that the middle third of the state has had the biggest increase in photosynthetic activity. This is due to a combination of the favorable conditions this spring and the advanced conditions of the wheat crop last year. In Pratt County, for example, wheat harvest started in May last year. This year, wheat is just beginning to head. In east central Kansas the lower activity can be attributed to planting delays. On the other hand, the drought continues to be a major problem in west central and southwest Kansas, where last year favorable wheat conditions had prevailed. 19

20 Figure 3. Compared to the 24-year average at this time for Kansas, this year s Vegetation Condition Report for May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows the sharp gradient of conditions across the state. In eastern Kansas, vegetative development has been delayed somewhat by cool temperatures and wet soils. The central divisions have had the most favorable combination of temperatures and moisture. Meanwhile, warm temperatures and dry conditions dominate the western divisions, particularly in west central and southwest Kansas. The Southwestern Division averaged 2.3 degrees above normal for temperature and only 27% of normal precipitation for the two week period ending June 3 rd. 20

21 Figure 4. The Vegetation Condition Report for the Corn Belt for May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that photosynthetic activity is mixed across the region. The greatest level of activity can be seen along the Upper Peninsula of Michigan and northern Wisconsin, with slightly lesser amounts in the eastern and southern edges of the region. In the Northern Plains, cold temperatures are a major factor, while in the central Corn Belt, from Iowa through Illinois, saturated soils have delayed planting. In Indiana, as of last week only 58 percent of the corn had emerged. 21

22 Figure 5. The comparison to last year in the Corn Belt for the period May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows a major improvement in vegetative condition in central Kansas. Much of this is due to the favorable combination of temperatures and moisture not too cool, not too wet. In the northern Corn Belt, much colder temperatures than last year have delayed activity, while along the Ohio River Valley saturated soils have delayed planting and emergence. In Indiana, only 58 percent of the corn had emerged as of last week compared to 99 percent at the same time last year. 22

23 Figure 6. Compared to the 24-year average at this time for the Corn Belt, this year s Vegetation Condition Report for May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that the lowest photosynthetic activity is along the Northern Plains, where cool, wet soils have dominated. In North Dakota, only 42 percent of spring wheat had emerged as of last week compared to the average of 73 percent. The obvious image splice lines that can be seen in northeast Missouri and southeast Iowa, and the eastern parts of North and South Dakota, are due to the use of different dates of imagery within this reporting period. This is normally due to cloud cover affecting one area more than another, requiring different dates to be used to create the near cloud-free composite. These lines, however also show the sensitivity of the mapping method to subtle variation in vegetation conditions even within the same reporting period. 23

24 Figure 7. The Vegetation Condition Report for the U.S. for May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that cool wet conditions continue to delay vegetative activity along much of the northern U.S. In the Central Plains through Texas, there is a very sharp gradient of activity from the mostly dry west to the wetter east. Saturated soils have delayed planting in the Ohio River Valley through the Central Mississippi Region. Flooding is a problem in northeastern Arkansas, southeastern Missouri, and western Tennessee. 24

25 Figure 8. The U.S. comparison to last year at this time for the period May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that there is a strong contrast in the northern U.S. Much cooler temperatures this year have delayed vegetation along the Canadian border. This delay is also evident in the Ohio River Valley. In this region, saturated soils is the main culprit. In the Central Plains, a combination of favorable temperatures and moisture has resulted in higher photosynthetic activity. In south central Kansas, vegetation is closer to normal activity, unlike last year when vegetation was 4 to 6 weeks advanced. 25

26 Figure 9. The U.S. comparison to the 24-year average for the period May 21 June 3 from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows that there is a distinct decrease in vegetative activity along the northern portions of the country and along the Ohio and Mississippi River Valleys. In these areas cool, wet conditions have delayed development. The lower level of photosynthetic activity in the western Plains from southeast Colorado through central Texas is due to the continuing drought conditions in these areas. There is a very sharp gradient from southern Oklahoma to north Texas along the Red River Valley, with parts of Oklahoma having over 12 inches of rain in May. Less than 40 miles west, the rainfall totals were less than 3 inches for May. -- 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 26