Number 345 April 13, 2012

Transcription

1 Number 345 April 13, Impcts of gypsum s soil mendment on clyey soils 1 2. Controlling volunteer corn, soybens, nd grin sorghum 5 3. Whet disese updte nd frequently sked questions bout fungicides 7 4. Disese prediction system for Fusrium hed scb on whet 9 5. The role of fungicides in controlling Fusrium hed scb in whet Comprtive Vegettion Condition Report: Mrch 27 April Impcts of gypsum s soil mendment on clyey soils Some producers hve wondered bout the potentil benefits of gypsum pplictions to hevytextured, clyey soils tht hve slow dringe. The potentil benefits of using gypsum (clcium sulfte dihydrte) s soil mendment on clyey soils include: Enhnced soil ggregtion o Improved infiltrtion o Reduced risk of runoff nd erosion Reduced luminum toxicity in cidic soils Source of soil clcium (C) nd sulfur (S) To test whether gypsum cn provide ny or ll of these potentil benefits, one-yer pilot study ws recently conducted in Knss. Similr experiments re underwy in other sttes on clyey soils, nd some unpublished dt for one 2011 site loction hs been supplied by Wisconsin resercher. Methods A test ws estblished on n Irwin silty cly lom soil in producer s field ner Mrion, Knss in December The 2010 crop ws conventionlly tilled soybens nd the 2011 crop ws no-till grin sorghum. The five tretments consisted of pplying 0, 0.50, 2.15, 4.30, nd 8.60 tons per cre of mined gypsum before plnting. Soil smples were collected prior to gypsum ppliction nd were nlyzed for bckground ction concentrtions (Tble 1). Grin yield nd grin nitrogen (N) nd sulfur (SO 4 -S) content were determined. After hrvest, soil smples were tken for wet-ggregte stbility nlysis nd for soil 1

2 fertility nlyses, including: ph, potssium (K), C, Mg, sodium (N) nd ction exchnge cpcity (CEC). Additionlly, soil hydrulic conductivity ws mesured. Dt ws lso obtined from similr study conducted in Dougls Co., Wisconsin, ner Lke Superior on cly lom soil with 39% cly using flue gs desulfuriztion (FGD) gypsum pplied t rtes of 0, 0.5, 1.0, nd 2.0 tons per cre in tilled corn field. In tht study, infiltrtion tests were conducted nd smples were collected for wet ggregte stbility nd bulk density mesurement pproximtely 12 weeks fter gypsum ppliction. Results Tble 1. Soil test results prior to gypsum ppliction (Knss). ph K C Mg N CEC C:Mg* (ppm) (ppm) (ppm) (ppm) meq 100 g ¹ *The C:Mg rtio my look incorrect t first glnce, but this rtio should be clculted fter converting C nd Mg concentrtions to units of meq per 100 grms. To convert C ppm to C meq per 100 grms, divide by 200. To convert Mg ppm to Mg meq per 100 grms, divide by 120. Sorghum yield nd nutrient content. In the Knss tests, no differences in sorghum yield nd grin N nd S content were observed mong gypsum ppliction rtes (Tble 2). Tble 2. Sorghum yield nd nutrient content s impcted by gypsum ppliction rte (Knss). Gypsum Appliction Sorghum Yield Grin Nitrogen Grin Sulfur (tons per cre ) (bu per cre ) (% N) (% SO 4 -S) Wet-ggregte stbility. Gypsum ddition of 8.60 tons per cre resulted in greter percentge of lrge ggregtes (>4.75 mm) reltive to no gypsum ppliction. Lesser percentges of smll ggregtes (<0.25 mm) were observed with gypsum ppliction rtes exceeding 0.50 tons per cre s compred to no gypsum ddition (Fig. 1A). Likewise, gypsum ppliction of 8.60 tons per cre incresed men weight dimeter (MWD) of wter-stble ggregtes by 0.23 mm compred to no gypsum ppliction (Fig. 1B). 2

3 Figure 1. Effect of gypsum ppliction on percentge of wter-stble ggregtes by size frction (A) nd MWD (B). In ll of the figures below, tretments with different letters re significntly different t p % Wter-stble Aggregtes A Gypsum Appliction (tons c ¹) b b b b b b b b b b > to to to to 0.5 <0.25 Size Frction (mm) bbc c c Men Weight Dimeter (mm) B b b b Gypsum (tons c ¹) Soil fertility. Unlike lime, gypsum does not impct soil ph. Any differences in soil ph observed in this study re most likely the result of within-field vrition (Fig. 2A). Soil C incresed by 883 ppm t the 4.30 tons per cre gypsum rte nd by 2530 ppm t the 8.60 tons per cre ppliction rte compred to no gypsum ppliction (Fig. 2B). This result should be expected s gypsum cn be composed of up to 23% C. On the other hnd, soil Mg decresed by 143 ppm t the 4.30 tons per cre gypsum rte nd by 389 ppm t the 8.60 tons per cre ppliction rte compred to no gypsum ddition (Fig. 2D). 3

4 Figure 2. Impct of gypsum ppliction rtes on soil chemicl properties t the Knss site. ph b b b C (ppm) c b b b A Gypsum (tons c ¹) B Gypsum (tons c ¹) Mg (ppm) b b c C:Mg rtio b C Gypsum (tons c ¹) D Gypsum (tons c ¹) Infiltrtion. Gypsum ppliction rte of 2.15 tons per cre resulted in lower hydrulic conductivity thn the control (Fig. 3), however, this difference is most likely the result of inherent, within-field soil vribility. Figure 3. Soil hydrulic conductivity s impcted by gypsum ppliction rte. Conductivity (cm s ¹) b b b b Gypsum (tons c ¹) Wisconsin Dt. Addition of gypsum t this site ppered to improve soil physicl properties by reducing bulk density nd incresing infiltrtion nd men weight dimeter of wter stble ggregtes; however, the effect ws not found to be significnt (dt not shown). Additionl tests 4

5 were completed t other sites in wtersheds drining to Lke Superior nd Lke Michign nd those sites lso exhibited no significnt tretment effect on soil physicl properties in the yer of gypsum ppliction. All sites hd fine-textured soils tht were reltively dense nd hd been in corn-whet or corn-soyben rottions under tillge. These soils would be similr to those in Knss but with shorter growing seson. Conclusion While the highest rte of gypsum ppliction in the Mrion County, Knss study (8.60 tons per cre) resulted in incresed soil wet-ggregte stbility, C concentrtion, nd CEC the first yer fter ppliction, no differences in sorghum grin yield or infiltrtion were observed. Additionlly, gypsum ppliction did not significntly lter soil physicl properties in Wisconsin. However, there is the potentil tht some of the benefits might tke longer thn one growing seson to be seen. To red more bout gypsum ppliction rtes nd gypsum s n mendment, you might be interested in 2011 publiction from Ohio Stte University by L. Chen nd W.A. Dick: Gypsum s n Agriculturl Amendment, vilble t: -- DeAnn Presley, Soil Mngement Specilist denn@ksu.edu -- In Kenney, Assistnt Scientist ikenney@ksu.edu (Contributions lso from Meghn Buckley, Soil nd Wste Resources Deprtment, University of Wisconsin-Stevens Point.) 2. Controlling volunteer corn, soybens, nd grin sorghum Lst yer s hot, dry wether resulted in widespred filure of drylnd corn, soyben, nd grin sorghum in much of Knss south of I-70. As result, there my be more volunteer corn, soybens, nd grin sorghum thn usul this yer in fields where the crop formed seed but ws either not hrvested or ws bled for hy due to low grin yield prospects. In most cses where crops re rotted, controlling volunteer plnts of these crops should not be too difficult. But control cn be chllenging in some cses, especilly where producers pln to plnt the sme crop gin this yer. Volunteer corn In stubble fields. If volunteer Roundup Redy corn is emerging in stubble field tht will be plnted lter to nother crop, it cn be esily controlled with grss herbicide such s Post or Post Plus, Select or Select Mx, or Assure II. Severl generics of these grss herbicides exist in the mrketplce nd could do n excellent job s well. Be sure to check the lbel for recrop restritions nd the pproprite use rte, which cn chnge depending your loction in the stte. The minimum witing intervl between ppliction nd plnting corn for these herbicides rnges from minimum of 6 dys for 6 oz of Select Mx to 120 dys for Assure II. The minimum witing intervl between ppliction nd plnting sorghum for these herbicides rnges from minimum of 30 dys for Post Plus to 120 dys for Assure II. There is no witing intervl required before plnting soybens. A non-selective herbicide such s Grmoxone could lso be used. However, the treted corn plnts my recover fter 5

6 tretment becuse this herbicide is not trnslocted. If the corn is not Roundup Redy, it cn lso be controlled with glyphoste. Volunteer corn left uncontrolled in fllow cn reduce subsequent whet crop yield s reported by John Holmn et.l. in K-Stte publiction SRL-141 Volunteer Corn in Fllow t: Within soyben crop. In most cses, volunteer corn will emerge before soybens re plnted, nd cn be controlled before plnting. If, however, Roundup Redy corn is growing in field of Roundup Redy soybens, it cn be controlled with Post or Post Plus, Select or Select Mx, or Assure II., or generics. If the corn is not Roundup Redy but the soybens re Roundup Redy, the volunteer corn cn be controlled with glyphoste. Within corn crop. It s importnt to know which herbicide resistnt trits exist in your volunteer corn. Liberty my control conventionl or Roundup Redy volunteer corn, but will not be effective if the corn is Liberty Link. Often it will require two pplictions with Liberty for optimum control. If the volunteer corn contins resistnce to both glyphoste nd Liberty nd emerges within newly plnted field of Roundup Redy corn, the volunteer cnnot be controlled. If volunteer densities re low, yields will not be ffected. Excessive plnts, however, could reduce corn yields nd my require row crop cultivtion. Volunteer soybens In stubble fields. If volunteer Roundup Redy soybens re emerging in stubble field tht will be plnted lter to nother crop, it cn be esily controlled with selective herbicide such s dicmb or 2,4-D, or non-selective herbicide such s Grmoxone. If the soybens re not Roundup Redy, it cn be controlled with glyphoste. Within corn or sorghum crop. If volunteer Roundup Redy soybens re emerging in field of Roundup Redy corn, the soybens will probbly get shded out by the corn cnopy nd not be problem. Postemergence tretments contining dicmb, Sttus, Clrity, or trzine should control emerged soyben plnts in corn if necessry. If volunteer Roundup Redy soybens come up in field of grin sorghum, the volunteer cn be controlled with, Atrzine+COC, dicmb+trzine, other combintions with trzine, or Ally+2,4-D. Within soyben crop. If volunteer Roundup Redy soybens hve emerged within newly plnted field of Roundup Redy soybens, the volunteer cnnot be controlled, unless the newly plnted soybens re Liberty Link. In tht cse, the volunteer cn be controlled with Liberty. If hevy volunteer densities re nticipted, rotting to grss crop would be recommended insted of plnting soybens gin. If soybens re plnted into clen seedbed, becuse of the nture of soyben growth nd development, it is unlikely tht soyben volunteer in-crop would ffect finl soyben yield. Volunteer grin sorghum In stubble fields. If volunteer grin sorghum is emerging in stubble field tht will be plnted lter to nother crop, it cn be esily controlled with glyphoste. Within corn or soyben crop. If volunteer sorghum is emerging in field of Roundup Redy corn, it cn be controlled with glyphoste or ny other herbicide tht would be used to control shttercne. If hevy densities re expected, herbicides such s Corvus or Blnce Flexx with trzine pplied 6

7 preemergence or before the 2-collr stge of corn cn hve ctivity on volunteer sorghum. Severl preplnt or preemergence herbicides used in soybens hve ctivity on volunteer sorghum nd should be used if hevy volunteer sorghum is expected. If volunteer sorghum emerges in Roundup Redy soybens, it cn be controlled with glyphoste or ny of the grss herbicides, Post, Select, Assure II, or generics. Within sorghum crop. Herbicides such s Degree Xtr, Lumx, Lexr, or other products contining chlorcetmide herbicide preemergence, my provide some level of control or weken the volunteer sorghum seedlings becuse they re not Concep treted s is the plnted sorghum seed. If seed of lst yer s crop is present in the soil, volunteer sorghum likely will emerge within newly plnted field of sorghum nd cn only be controlled between the rows with row crop cultivtion. However, s with soybens, it is unlikely tht emerging volunteer in the sorghum crop will hve much effect on finl sorghum yield unless popultions re very high. If high popultions of volunteer sorghum re expected, it would be our recommendtion to rotte to corn, soyben, or fllow nd plnt winter whet this fll depending on your loction nd soil moisture vilbility. -- Dlls Peterson, Weed Mngement Specilist dpeterso@ksu.edu -- Curtis Thompson, Weed Mngement Specilist cthompso@ksu.edu 3. Whet disese updte nd frequently sked questions bout fungicides The cooler wether the pst week to 10 dys hs slowed down development of the whet crop, especilly in centrl nd estern Knss. The crop is still hed of norml in development, but is not dvncing s rpidly s it hd been erlier. We continue to get reports of low levels of stripe rust, lef rust, Septori tritici blotch, nd tn spot from throughout centrl Knss. Most reports indicte tht low levels of rust diseses cn be found on the top three leves but is probbly most common on the second nd third lef down into the cnopy. Infection of the flg lef by stripe rust hs been reported in southest nd south centrl regions. Tn spot nd Septori tritici blotch re t moderte levels in mny fields, with infections commonly occurring on the lower leves nd mid cnopy. The excellent yield potentil of mny fields nd emerging risk of disese hs mny frmers thinking bout fungicides pplictions. Bsed on the informtion I hve to dte, it ppers tht most res of centrl Knss re t moderte risk for disese relted yield loss this yer. I suggest tht frmers scout their fields for disese nd crefully evlute the need for fungicides. The interest in fungicides hs stimulted lot of questions bout the different fungicide products. Below re some of the most common questions nd potentil misunderstndings from this week. Wht type of residul life cn I expect from the different fungicide products? The residul life of the fungicide is influence by mny fctors, including the rte t which the product is pplied, the trgeted disese, nd the level of disese pressure. Fungicides pplied t the full-lbeled rte will generlly hve longer residul life. Fungicides will generlly provide longer 7

8 residul life ginst rust diseses (often more thn 21 dys) thn lef spot diseses. Some of the products my provide some dditionl residul life but this extr residul does not lwys trnslte into more grin yield. The reserch tht I hve reviewed indictes tht fungicides listed in the publiction Folir Fungicide Efficcy Rtings for Whet Disese Mngement, 2012, EP130, will generlly provide 21 dys of solid protection ginst fungl diseses. This includes products with the ctive ingredient tebuconzole tht is listed in the tble s the product Folicur but is lso mrketed in number of generic formultions. This publiction cn be found t: The chrt below is just one exmple of the type of dt tht supports the 21-dy residul ctivity for the vrious fungicide products. Wht bout the different level of curtive nd preventive ctivity of the fungicides? Bsed on the questions I hve been getting this week, it ppers tht there is some confusion bout the preventtive nd curtive ctivity vrious fungicides. All the fungicides listed in the Folir Fungicide Efficcy Rtings for Whet Disese Mngement publiction mentioned bove re best pplied when the disese is t low levels. The trizole fungicides re generlly considered to provide some limited curtive ctivity. This mens tht they cn stop the development of fungi lredy inside the plnt. The trizole-only fungicides include products such s Prosro, Crmb, Tilt, nd Folicur. Trizole fungicides re lso included in mixed mode-of-ction products such s Quilt Xcel, Strtego 8

9 YLD, nd TwinLine. Both the trizole nd strobilurin fungicides provide excellent protection ginst new infections tht is often considered preventive ctivity. It would be n error to think tht trizole fungicide does not provide preventive ctivity simply becuse it lso hs curtive ctivity. The curtive ctivity is good thing, especilly with disese such s stripe rust where the fungus grows within the plnt to cuse dditionl expnsion of the stripes. The bottom line is tht producers hve lot of excellent fungicide options. In my experience, bsed on the ll the dt I hve seen in reserch trils in Knss nd other sttes, the importnce of correctly identifying situtions where fungicides re needed or not needed is fr greter thn the choice of fungicide product. -- Erick De Wolf, Extension Plnt Pthology dewolf1@ksu.edu -- Jim Shroyer, Extension Agronomy Stte Leder jshroyer@ksu.edu 4. Disese prediction system for Fusrium hed scb on whet A disese prediction system is currently vilble to help frmers evlute the risk of Fusrium hed scb in their re. The prediction system summrizes the wether conditions over the lst 7 dys nd provides dily estimte of disese risk. The risk of disese is presented in mp-bsed formt where colors represent the chnce of scb epidemic (green = low risk, yellow = moderte, nd red = high risk). I suggest tht growers ccess the site frequently during the next few weeks to monitor the risk of disese s they pproch flowering. The prediction tool cn be found t: Here s how to use this tool. * Click on the link clled Risk Mp Tool * When the next window ppers, first click on dte on the clendr on the left side of the pge. Then click on the big OK in the center box. * The next box to pper is Choose Model. Click on winter whet, then OK. * On the lrge mp of the U.S., click on the stte of Knss. * This bring ups lrge mp of Knss. The colors on the bckground of the mp (not the round or squre dots) indicte the reltive risk of severe outbrek of scb (green=low risk, yellow=moderte risk, red=high risk). * Buttons in the upper left corner mrked 24, 48 nd 72 sk the system to provide estimtes of disese risk bsed on forecsted wether informtion. * The dots on the mps indicte specific wether sttions. Click on wether sttion to request more detiled informtion for tht loction. * After clicking on one of the sttion dots, you ll see long the lower third of the pge, on the left side, the current risk ssessment for tht loction. In the lower right of the pge is link clled Commentry which will give you little more informtion on current conditions nd FHB. 9

10 If the fctors indicte moderte to high risk of hed scb when the whet is fully heded, fungicide my be needed to help suppress the disese. Selection of n pproprite fungicide is importnt for hed scb. The fungicides in the strobilurin clss re not recommended for control of hed scb. The trizole fungicides Folicur (nd generic tebuconzole), Prosro, Proline, nd Crmb re vilble for use in Knss nd cn help suppress disese development. The fungicides must be pplied to the heds to hve ny ctivity ginst scb, nd they should be pplied s close to flowering s possible. These products hve 30 pre-hrvest intervl. -- Erick De Wolf, Extension Plnt Pthology dewolf1@ksu.edu 5. The role of fungicides in controlling Fusrium hed scb in whet There re certin fungicides on the mrket now tht cn provide some degree of control of Fusrium hed scb in whet: Crmb, Folicur (nd generic tebuconzole), Proline, nd Prosro. In 2011, we tested these fungicides for control of Fusrium hed scb on severl whet vrieties with vrying degrees of resistnce. This ws field tril ner Mnhttn. The plots were inoculted by spreding corn grin colonized by Fusrium on the soil surfce in three seprte pplictions bout two weeks prt beginning four weeks prior to heding. During heding nd flowering, plots were sprinkler irrigted during the overnight hours. The fungicides were pplied t Feekes Growth Stge 10.5 (fully heded) in 20 gllons of wter per cre. Effect of Folir Fungicides on Fusrium Hed Blight: Mnhttn, 2011 Vriety (nd Fusrium hed scb rting: 1=Best, 10=Worst) Fungicide Rte (oz/cre) Avg. % disesed spikelets (My 30-June 9) 10 Grin yield (bu/cre) DON (ppm) Everest (4) None Prosro Art (6) None Prosro Krl 92 (6) None Prosro Fuller (7) None Crmb Folicur Proline Prosro TopGurd Snt Fe (7) None Prosro Overley (9) None Prosro LSD (P=0.05) The inocultion of this plot resulted in moderte Fusrium hed scb infection. The fungicides were ble to significntly reduce the % disesed spikelets in ll vrieties. The fungicides did not significntly increse grin yields in ny vrieties, in prt becuse lef diseses were not present.

11 In terms of reducing DON (deoxynivlenol) concentrtions in grin to cceptble levels, the fungicides were not quite s effective. Applying Prosro to Overley, for exmple, did not reduce the DON concentrtion. The cceptble level of DON is 2 ppm. These results demonstrte tht mngement of hed scb is difficult with fungicides. Most fungicide lbels only list suppression of this disese. Dt from other yers in Knss nd other sttes indicte tht the best vilble fungicides (Prosro, Proline, nd Crmb) generlly provide pproximtely 40-50% suppression of disese nd DON. Products contining tebuconzole (Folicur nd other generics) provide bout 30-40% suppression of the hed scb nd DON. Bsed on these nd other pst yers results, it tkes combintion of fungicides nd more resistnt vrieties to reduce DON concentrtions to cceptble levels. More resistnt vrieties seem to show higher benefits from fungicide ppliction for Fusrium hed scb thn susceptible vrieties, in terms of DON reductions. -- Bill Bockus, Plnt Pthologist bockus@ksu.edu -- Erick De Wolf, Extension Plnt Pthology dewolf1@ksu.edu 6. Comprtive Vegettion Condition Report: Mrch 27 April 9 K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory (EASAL) produces weekly Vegettion Condition Report mps. These mps cn be vluble tool for mking crop selection nd mrketing decisions. Two short videos of Dr. Kevin Price explining the development of these mps cn be viewed on YouTube t: The objective of these reports is to provide users with mens of ssessing the reltive condition of crops nd grsslnd. The mps cn be used to ssess current plnt growth rtes, s well s comprisons to the previous yer nd reltive to the 21-yer verge. The report is used by individul frmers nd rnchers, the commodities mrket, nd politicl leders for ssessing fctors such s production potentil nd drought impct cross their stte. The mps below show the current vegettion conditions in Knss, the Corn Belt, nd the continentl U.S, with comments from Mry Knpp, stte climtologist: 11

12 Mp 1. The Vegettion Condition Report for Knss for Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows incresed photosynthetic ctivity continues to spred northwrd, prticulrly in the centrl nd estern portions of the stte. Less photosynthetic ctivity is seen in the Flint Hills, nd the High Plins of western Knss. 12

13 Mp 2. Compred to the previous yer t this time for Knss, the current Vegettion Condition Report for Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows much higher NDVI vlues cross the stte. Wrmer tempertures nd more bundnt moisture hve resulted in much greter photosynthetic ctivity. This trend is prticulrly evident in west centrl Knss. 13

14 Mp 3. Compred to the 23-yer verge t this time for Knss, this yer s Vegettion Condition Report for Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows tht NDVI vlues re much higher thn verge. Lowest vlues re seen in the extreme northestern counties, s well s the extreme southwestern Knss. In the northestern counties, tempertures hve been slightly cooler thn the rest of the stte. In the southwest, moderte to severe drought is still present with the resulting dely in photosynthetic ctivity. 14

15 Mp 4. The Vegettion Condition Report for the Corn Belt for Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows tht biomss production hs continued to increse long the southern reches of the Corn Belt. Limited photosynthetic ctivity cn be seen in the northestern region of the Corn Belt, while very little ctivity hs yet to develop in the western portions of the region. Abnormlly dry conditions re present in North Dkot, while moderte to severe drought is present from Minnesot to northern Iow nd estwrd into Wisconsin. 15

16 Mp 5. The comprison to lst yer in the Corn Belt for the period Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows tht the sesonl difference in snow pck continues to result in incresed NDVI vlues in the northern portions of region, despite the dry conditions in these res. For the rest of the region, wrmer-thn-norml tempertures hve resulted in much greter photosynthetic ctivity thn lst yer t this time. 16

17 Mp 6. Compred to the 23-yer verge t this time for the Corn Belt, this yer s Vegettion Condition Report for Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows greter photosynthetic ctivity cross the region, to vrying degrees. Incresed ctivity ws limited in the western res of the region by cooler tempertures nd drier soil conditions. 17

18 Mp 7. The Vegettion Condition Report for the U.S. for Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows tht photosynthetic ctivity is highest in the southestern U.S. into the estern portions of the High Plins. Vegettive development is limited in west Texs, where extreme to severe drought conditions persist. 18

19 Mp 8. The U.S. comprison to lst yer t this time for the period Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows tht the lower-thn-verge snowpck hs resulted in higher NDVI vlues in the northern res nd into Mountin West. This does not indicte prticulrly high biomss productivity, just greter ctivity thn lst yer t this time. Centrl Texs nd Oklhom continue to stnd out for the much greter photosynthetic ctivity thn lst yer. 19

20 Mp 9. The U.S. comprison to the 23-yer verge for the period Mrch 27 April 9 from K-Stte s Ecology nd Agriculture Sptil Anlysis Lbortory shows continued wrmth in the estern hlf of the U.S. hs resulted in much greter photosynthetic ctivity. This erly development hs incresed concerns for potentil freeze dmge nd higher wter use. This is n incresing concern from res of Wisconsin, Northern Iow, nd Minnesot westwrd into North Dkot s well s New Englnd. In these res, low winter moisture hs contributed to incresing drought conditions. Note to reders: The mps bove represent subset of the mps vilble from the EASAL group. If you d like digitl copies of the entire mp series plese contct us t kpprice@ksu.edu nd we cn plce you on our emil list to receive the entire dtset ech week s they re produced. The mps re normlly first vilble on Wednesdy of ech week, unless there is dely in the posting of the dt by EROS Dt Center where we obtin the rw dt used to mke the mps. These mps re provided for free s service of the Deprtment of Agronomy nd K-Stte Reserch nd Extension. -- Mry Knpp, Stte Climtologist mknpp@ksu.edu -- Kevin Price, Agronomy nd Geogrphy, Remote Sensing, Nturl Resources, GIS kpprice@ksu.edu -- Nn An, Grdute Reserch Assistnt, Ecology & Agriculture Sptil Anlysis Lbortory (EASAL) nnn@ksu.edu 20 These e-updtes re regulr weekly item from K-Stte Extension Agronomy nd Steve Wtson, Agronomy e-updte Editor. All of the Reserch nd Extension fculty in Agronomy will be involved s sources from time to time. If you hve ny questions or suggestions for topics you'd like to hve us ddress in this weekly updte, contct Steve Wtson, swtson@ksu.edu, or Jim Shroyer, Reserch nd Extension Crop Production Specilist nd Stte Extension Agronomy Leder jshroyer@ksu.edu