Number 300 June 3, 2011

Transcription

1 Number 300 June 3, Wheat Genetic and Genomic Resources Center 1 2. Common bunt in wheat 3 3. Loose smut on wheat: Causes and treatments 5 4. Delayed soybean planting: Variety selection, seeding rate, and row spacing 6 5. The 7 th Annual Ray Lamond Scholarship Golf Outing, July Comparative Vegetation Condition Report: May Wheat Genetic and Genomic Resources Center At the 2011 K-State Wheat Field Day, the role of K-State s Wheat Genetic and Genomic Resources Center (WGGRC) in wheat improvement was discussed by Bikram Gill, Distinguished Professor of Plant Pathology and director of the WGGRC. Bikram Gill discusses the accomplishments of the WGGRC at K-State's 2011 Wheat Field Day in Manhattan. Photo by Dan Donnert, K-State Research and Extension. 1

2 Gill explains the crucial role of Aegilops species has played in providing unique germplasm for wheat improvement. Photo by Patricia Blocksome, graduate student, K-State Research and Extension. Gill explained that the WGGRC has five main missions to assure future advances in wheat breeding: * Genetic Resources. The WGGRC maintains a gene bank, along with evaluation and passport data, including 13,250 wheat species accessions, cytogenetic stocks, and mapping populations. * Germplasm. The WGGRC has developed and registered 54 improved wheat germplasms containing genes protecting the wheat plant from leaf and stem rust; tan spot; Fusarium head blight; soilborne, wheat streak, and Triticum mosaic viruses; septoria leaf blotch; powdery mildew; Hessian fly; greenbug; and Russian wheat aphid. * Genetic Analysis. For any plant trait, genetic analysis is mandatory before it can be exploited in breeding. The WGGRC is developing trait-specific eternal mapping and mutant populations for initial genetic analysis and for adding value to the trait through biotechnology. 2

3 * Genomics. The WGGRC co-leads an international effort to map and sequence the wheat genome. * Graduate training. The WGGRC provides research and training opportunities to undergraduate and graduate students, postdoctoral fellows, and visiting scientists. WGGRC alumni occupy prominent positions in academia, the government, and industry in the U.S. and the world. Since 1984, the WGGRC has led a global effort in conserving and researching more than two dozen wild wheat and goatgrass species, including more than 12,000 strains. More than 30,000 samples from the collection of wild wheat relatives, genetic stocks, and improved genetic resources have been distributed to scientists in 45 countries and 39 states in the U.S. These lines are free of costs and intellectual property claims. The innovations developed and provided by the WGGRC have contributed hundreds of millions of dollars to the U.S. economy and protected the environment from pesticides that otherwise would be needed to protect genetically susceptible crops. -- Steve Watson, Agronomy e-update Editor swatson@ksu.edu 2. Common bunt in wheat Common bunt (stinking smut) occurs somewhere in Kansas almost every year, but may not be detected until a load of wheat is actually rejected at the elevator. This fungal disease causes moderate deformation of wheat kernels, and infected kernels often have a gray color. The infected kernels will also be filled with black powdery spores as opposed to the normal white starches of healthy kernels. The fungus produces volatile chemicals that have a strong fishy odor. This odor is readily detected in loads of grain and may persist through the milling and baking process. Clearly, this is not the smell most people would like to have filling their home when baking bread. Normal wheat on left; wheat infected with common bunt on right. Photo by Bill Bockus, K-State Research and Extension. 3

4 It is possible to confuse grain damaged by common bunt with another common problem known as black point. Symptoms of black point include a partial dark brown or black discoloration of the kernels. There is no fishy odor associated with black point and the interior of the kernels has the normal white starchy appearance. Black point is often associated with hot and wet conditions that delay harvest. These conditions can predispose the plants to colonization by decay fungi, which can discolor the kernels. These decay fungi are not aggressive pathogens and they normally are restricted to the outer layers of the kernel. Black point can also be caused by a physiological response of plants to weather during the later stages of grain fill. Physiological black point in wheat. Photo by Erick DeWolf, K-State Research and Extension. Both problems can result in price discounts when marketing grain and may lead to rejection of loads of grain. The rejection of grain is more frequent with common bunt. Common bunt is a seed-borne disease. The disease persists between seasons on seed contaminated with the black spores of the bunt fungus during harvest or subsequent grain handling. The spores will survive on the outside of the kernels until fall, when they germinate and infect the developing seedlings shortly after planting. This infection process is favored by cool and wet fall conditions. Unfortunately, many farmers do not recognize the problem until they have loads of grain rejected by a grain elevator. There do not appear to be many options for using the rejected grain. Saving this grain for seed will increase the chances of having problems with bunt in following years. In some situations, I have heard of growers working with local feed lots to move rejected grain. The availability of this option will likely vary regionally in the state. Management options for common bunt: * Common bunt is most likely to be a problem when wheat has been saved for seed for 2 or more years. Renewing the seed supply every few years will greatly reduce the risk of future common bunt problems. Do not use heavily infected wheat as seed if at all possible. If infected wheat is used as seed, be sure to have it treated with a fungicide. Even if the fungicide provides 97% control, however, that may not be enough to prevent price discounts or rejections in the subsequent crop. 4

5 * Fungicide seed treatments. I generally recommend that growers set priorities when using the fungicide seed treatments. The top priority for fungicide seed treatments should be on wheat that is intended for future seed production. Products such as Dividend Extreme, Raxil MD, and Charter are all highly effective at controlling seed-borne diseases like common bunt and loose smut. The use of these products on wheat intended for seed production should greatly reduce the risk of severe bunt or smut problems. -- Erick DeWolf, Extension Plant Pathology dewolf1@ksu.edu 3. Loose smut on wheat: Causes and treatments There have been several reports in recent years of loose smut in wheat. It is not uncommon to find low levels of loose smut in wheat fields, and the symptoms will be obvious by this time of year. It is easy to pick out plants with loose smut in a field. The spikelets of infected heads are completely black and sooty instead of the normal, healthy color. There is no grain. Instead, infected heads consist entirely of a mass of fungal spores. Loose smut in wheat. Photo by Erick DeWolf, K-State Research and Extension. Loose smut is a seedborne disease that is caused by the fungus Ustilago tritici. The fungus that causes loose smut survives as dormant mycelia within the embryo of an infected wheat seed. 5

6 When the seed germinates, the fungus becomes active again. The fungus develops within the growing point and moves into the developing grain tissue as the wheat plants grow. When the head emerges, there are masses of black spores on the spikelets instead of flowering parts. By harvest only an erect bare rachis remains. The spores are released into the air and can be blown onto healthy wheat heads were infection takes place at flowering or the early stages of kernel development. If the infection is successful, the fungus begins to grow within the developing wheat seed embryo. Newly infected grain appears healthy in every way, but when it germinates the following season, the plant that grows from the infected seed will produce nothing but a dark mass of spores instead of healthy grain. The yield loss on infected heads is total. On a field-wide basis, the amount of yield loss is proportional to the percentage of infected heads. Cool (60-70 degrees), humid weather accompanied by light showers or heavy dews is most favorable for infection. Under favorable weather conditions, the wheat produced from a field with only one percent of the heads infected, can have seed with 10 percent or more infection of loose smut. Once loose smut becomes evident in the field, it is far too late to control the disease. The best option at that point is seed treatment. If producers have a field that is infected with loose smut and plan to keep some of the grain back for seed, they should be sure to have the seed commercially treated with a systemic fungicide seed treatment such as Charter (triticonazole), a Dividend (difenoconazole) product, a Raxil (tebuconazole) product, or RTU-Vitavax (carboxin)- Thiram. These fungicides provide excellent control of loose smut, but good coverage of the seed is very important to ensure that the maximum benefit of the treatment is realized. Another option is to sell all the wheat from the infected field as grain and buy certified seed to plant in the fall. Certified seed in Kansas is allowed to have as much as 10 heads in 1,000 (or 1 percent) that are infected with loose smut. There is no requirement that this seed be treated in order to qualify as certified seed by the Kansas Crop Improvement Association, but it would be a good idea to buy treated seed. The cost of having seed treated with a standard low-rate fungicide seed treatment for loose smut is relatively low. Costs are higher if the seed treatment also includes an insecticide, such as Cruiser or Gaucho. There are no varieties are highly resistant to all races of loose smut. -- Erick DeWolf, Extension Plant Pathologist dewolf1@ksu.edu 4. Delayed soybean planting: Variety selection, seeding rate, and row spacing Where soils have been too wet to plant, soybean planting may be delayed until later than planned. Also, where young soybean stands have been devastated by hailstorms, drowning, or some other factor, producers may be thinking about replanting. In either case, with later-thanoptimal planting dates, should producers make any changes in management strategies? For example, should a shorter-season variety be substituted or should seeding rates be adjusted as we move into late-june planting dates? 6

7 The following is adapted from the variety selection section of the Soybean Production Handbook, C-449: As planting is delayed, the situation begins to resemble double-crop soybean production. The soybean crop following wheat is usually planted 2 to 6 weeks later than the optimum date for highest yields. Since planting is delayed, often until the end of June or early July, one is tempted to switch to a shorter-season variety to ensure the crop will mature before frost. While planting a variety that is too late in maturity may increase the likelihood of frost damage, switching to a substantially earlier maturing variety should be resisted. This is for two reasons. * First, early-maturing varieties planted late in the season will usually have limited vegetative development, short stature, and low yield potential. * Second, any given variety will have fewer days to flowering, pod development, and maturity when planted late compared to earlier planting dates. As planting dates get later into June, day length has begun or will soon begin to shorten and nights will start getting longer. This causes plant development to speed up. Consequently, there is not a one-for-one relationship between the number of days difference in planting dates and the number of days delay in maturity. As a general rule, for every three days delay in planting, maturity is delayed by only one day. Since soybean development is hastened with later planting, the highest yields in a late-planted or double-cropped system are often achieved by using the same variety or one very similar in maturity as what typically is used in full-season production. Sometimes a slightly later maturity variety will do better with later planting because it produces a larger plant before initiating flowering. Other management practices can be affected by late planting, however. Because late planting shortens the period for vegetative growth and reduces canopy development, increasing the seeding rate alone or in combination with narrow row spacing can help the crop compensate by providing the opportunity to produce more pods in the canopy. Seeding rates can be increased by 30 to 50 percent in high-rainfall environments if planting is delayed until late June or July. Although past research has demonstrated no consistent benefit for narrow row spacing (less than 30 inches) in Kansas, narrow rows may have an advantage in late plantings in the eastern half of the state. Another reason for increasing the seeding rate if shifting to narrow rows relates to height of the bottom pods. Within-row plant spacing is greater in narrow rows at a given seeding rate, often causing the lowest pods to be set lower than in wide rows. Increasing the seeding rate in narrow rows decreases the within-row plant spacing and should raise the height of the lowest pods making harvest a bit easier. -- Kraig Roozeboom, Crop Production and Cropping Systems Specialist kraig@ksu.edu 7

8 5. The 7 th Annual Ray Lamond Scholarship Golf Outing, July 7 The 7 th Annual Dr. Ray E. Lamond Scholarship Golf Outing will be held on Thursday July 7, 2011 at Stagg Hill Golf Course in Manhattan. This event generates money for the Ray E. Lamond Scholarship Fund to benefit graduate students in K-State s Department of Agronomy. Tee times will begin at 7:30 am with a better-ball arrangement. Please organize a foursome and enter a team by ing the information below. Everyone is encouraged to participate. Individual entrants will be assigned to a team based on need. If you are putting a team together, please indicate all players names on the entry form and provide an address so we can contact all participants. An entry fee of $50.00 per person will be collected to cover each participants green fee, one-half cart fee, and some prizes. As in the past, any leftover collections will be added to the scholarship fund. For those interested in donating to the scholarship fund, checks should be made payable to Ray E. Lamond Scholarship Fund. Donations can be made at the tournament or submitted prior to the tournament. The mailing address is: Ray E. Lamond Scholarship Fund, Department of Agronomy, Kansas State University, 2004 Throckmorton Hall, Manhattan, KS We need to know your intentions by Thursday, June 30 in order to decide if we need to release or get more tee times. Please complete this form and return to Gerard Kluitenberg via (gjk@ksu.edu) by June 30, For questions, contact Gerard Kluitenberg, at gjk@ksu.edu or (785) Other contacts for the outing are Dale Leikam, dale.leikam@sbcglobal.net, and Dana Minihan, prplpwr@ksu.edu. Ray E. Lamond Scholarship Fund Golf Outing - ENTRY FORM YES, I PLAN TO ATTEND Fee $50.00 Yes, I will need to reserve a cart How many? YES, I PLAN TO PUT A TEAM TOGETHER (see names below) NO, I WILL NOT BE ABLE TO ATTEND or RSVP Via (gjk@ksu.edu) TEAM Participants (we will help individuals find a team) Team Member Names 1. PHONE NUMBER/

9 Will you have any Tee Time preferences? If so, please note below. We will try to accommodate if possible. Starting at 7:30 a.m., and following at 8 minute increments. early middle late -- Gerard Kluitenberg, Soil Physics gjk@ksu.edu 6. Comparative Vegetation Condition Report: May 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 21-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. The maps below show the current vegetation conditions in Kansas, the Corn Belt, and the continental U.S, with comments from Mary Knapp, state climatologist: 9

10 Map 1. The Vegetation Condition Report for Kansas for May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows how the North Central and Central divisions have benefited from the recent rains. Moderate levels of photosynthetic activity can be seen in the region. In contrast, the South Central division, which experienced only 35 percent of its normal May precipitation, is showing much less photosynthetic activity. 10

11 Map 2. Compared to the previous year at this time for Kansas, the current Vegetation Condition Report for May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows the splice line is still visible. Western Kansas is much behind last year s photosynthetic activity, and that can also be seen in the Drought Monitor reports. Last year, no part of Kansas was in drought at this time. This year, more than 50 percent of the state is in moderate to extreme drought. 11

12 Map 3. Compared to the 22-year average at this time for Kansas, this year s Vegetation Condition Report for May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows the Eastern divisions have slightly higher levels of photosynthetic activity than the long-term average. Much of this can be attributed to cooler-than-average temperatures which moderated the impact of drier-than-normal conditions. Lower levels of photosynthetic activity in the western third of the state were the result of drier-than-normal conditions, aggravated by warmer-than-average temperatures. The warmest reading in May was 106 degrees F, at Ashland in Clark County on May

13 Map 4. The Vegetation Condition Report for the Corn Belt for May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows low levels photosynthetic activity in the Northern Plains and the Ohio River Valley as those regions continue to lag in crop progress. In Indiana, both corn and soybeans are lagging about 17 days behind the average planting date. 13

14 Map 5. The comparison to last year in the Corn Belt for the period May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows a small area of more photosynthetic activity this year. This area is concentrated along the Kansas/Missouri border, where favorable temperatures and timely rains have been beneficial to plant development. 14

15 Map 6. Compared to the 22-year average at this time for the Corn Belt, this year s Vegetation Condition Report for May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows the greatest favorable departure is in the Eastern Kansas/Western Missouri areas. To the east and north of that region, saturated grounds and cool temperatures have hampered progress. In western Kansas, warm temperatures have compounded the already stressed vegetation. South central Kansas experienced only 35 percent of the normal May rainfall, while southwest Kansas experienced less than a quarter of its normal rainfall. 15

16 Map 7. The Vegetation Condition Report for the U.S. for May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows a high level of photosynthetic activity in most of the eastern half of the country along with the Pacific Northwest. The exception in the region from Iowa to western Ohio is due mainly to saturated and flooded soils. That impact can also be seen along the Mississippi River from Illinois all the way to the Gulf of Mexico. 16

17 Map 8. The U.S. comparison to last year at this time for the period May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows the Corn Belt and the Northern Plains are behind in photosynthetic activity. This is due to saturated soils and cool temperatures. In contrast, the region of western Kansas and eastern Colorado south to Texas are showing lower photosynthetic activity due to drought stress. 17

18 Map 9. The U.S. comparison to the 22-year average for the period May from K-State s Ecology and Agriculture Spatial Analysis Laboratory shows the continued impact of saturated soils on photosynthetic activity in the Ohio River Valley and the Northern Plains. In the Central and Southern Plains, exceptional drought conditions are inhibiting photosynthetic activity. Parts of Texas experienced temperatures averaging 8 degrees above normal, and less than a tenth of an inch of rain. Note to readers: The maps above represent a subset of the maps available from the EASAL group. If you d like digital copies of the entire map series please contact us 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. -- 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 18

19 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, or Jim Shroyer, Research and Extension Crop Production Specialist and State Extension Agronomy Leader jshroyer@ksu.edu 19