Edited: June 28, 2005 NEW Pecan Scab Mdel Descriptin Mdel active frm March 1 t August 31 The Oklahma Mesnet, in cperatin with scientists and prfessinals frm Oklahma State University and the University f Oklahma, has develped and maintains peratin f the NEW Pecan Scab Mdel. This mdel, while simple in calculatin f pecan scab hurs, prvides pecan grwers and industry prfessinals a web-based tl with a variety f prducts. NEW Pecan Scab Mdel users have the ability t lk at current and histrical pecan scab hur data fr each Oklahma Mesnet twer lcatin. Data is displayed in interactive maps and graphs, as well as tables. NEW Pecan Scab Mdel The Oklahma Mesnet NEW Pecan Scab Mdel is a tl that has been develped t aid grwers in prper timing f fungicide applicatin fr pecan scab. Using data frm the Oklahma Mesnet, the state's autmated weather statin netwrk, the Mdel calculates daily "scab hurs" fr all Mesnet sites. The NEW Pecan Scab Mdel prvides new features and prducts, while using the same scab hur frmula as the current Oklahma Mesnet Pecan Scab Mdel. A scab hur is defined as ne hur with relative humidity f 90% r higher and an air temperature f 70 F r higher. Research at pecan rchard sites using Mesnet weather data has shwn that nly the ttal scab hurs during the 14 days preceding a scab rating were critical in crrelating disease develpment. The Mdel assumes that a crrectly applied fungicide, labeled fr pecan scab, prtects the crp fr tw weeks fllwing applicatin. When the user clicks n a Mesnet site, the Mdel calculates the number f scab hurs at that site that have ccurred in the unprtected part f the last 14 days. If n fungicide applicatin date was entered, the mdel uses March 1 as a default. Knwing the Pecan Scab Mdel hurs and the susceptibility f the pecan variety, the grwer can decide whether t spray r nt. The threshld fr highly susceptible pecan varieties is 10 scab hurs, fr mderately susceptible varieties is 20 scab hurs, and fr natives and less susceptible varieties is 30 scab hurs. The Oklahma Mesnet NEW Pecan Scab Mdel is updated hurly. The frecast f scab hurs is based n the Natinal Weather Service Eta Mdel. This NWS mdel is a gridded numerical mdel fr each 36 square mile area. The NEW Pecan Scab Mdel is peratinal frm March 1 thrugh August 31. Outside f these dates the Fungicide Timing Decisin Supprt and 18-Day Scab Hurs Graph text and graphs will nt prvide reliable display data. 1
NEW Pecan Scab Mdel Specificatins NEW Pecan Scab Mdel Frmula: Infectin hur = One hur with relative humidity at r abve 90% and air temperature at r abve 70 Fahrenheit. NEW Pecan Scab Mdel Rules: The mdel run time is frm March 1 t August 31. The interactive Fungicide Timing Decisin Supprt mdule calculates infectin hurs frm the end f a 14-day fungicide cntrl windw. Only pecan scab hurs during the last 14 days are cnsidered in making fungicide applicatin recmmendatins. A fungicide applicatin is recmmended based n scab susceptibility f the pecan variety. Fr highly susceptible varieties, a fungicide applicatin is recmmended when 10 scab hurs have ccurred ver the last 14 days. The scab hurs that trigger an applicatin recmmendatin are increased t 20 scab hurs fr mderately susceptible varieties. 30 scab hurs are necessary befre a fungicide applicatin is recmmended fr resistant imprved varieties and native pecans. NEW Pecan Scab Mdel Prducts SITE SPECIFIC PRODUCTS: Mesnet Site Selectin The Mesnet site lcatin can be selected by clicking n the Oklahma map r frm the list that appears when the small "blue arrw bx" t the right f the "SITE: windw" bx is selected. When a site is selected frm the Oklahma state map, the name f the selected Mesnet site will shw up in the "SITE: windw." Weather data used in the mdel will be frm the Mesnet twer selected. Fungicide Timing Decisin Supprt The Fungicide Timing Decisin Supprt prduct is an interactive graph and text that can be used t decide when t make a fungicide applicatin. The graph is updated every hur. Each hur weather data recrded by the Oklahma Mesnet replaces the frecast data. The frecast data is updated twice a day, in the mrning and evening. When the graph is flat, n pecan scab hurs are accumulating. When the graph rises, pecan scab hurs are accumulating. The graph times are shwn in Central Daylight Time (CDT). The Pecan Scab Decisin Supprt page includes user selectins fr highly susceptible, mderately susceptible, and resistant pecan varieties. The default fr Date f Last Fungicide Spray: is March 1 f the current year. Text fr the Pecan Decisin Supprt Page includes: 2
A recmmendatin statement indicating whether a fungicide applicatin is Recmmended r Nt Recmmended, based n the scab susceptibility selected and the number f pecan scab hurs ver the last 14 days. Tday's Date: When the Date f Last Fungicide Spray is left n the default date f March 1, a Seasn started n March 1 line is displayed. When a Date f Last Fungicide Spray is entered, the indented text shwn belw is displayed. This prvides a check f the date entered and the imprtant fungicide cntrl windw dates. Last Fungicide Applicatin date entered was: date Furteen day Fungicide Cntrl Windw was: - Start f Fungicide Cntrl Windw: date - End f Fungicide Cntrl Windw is: date Pecan Scab Hurs since end f Fungicide Cntrl Windw: _hurs_ The pecan scab hurs are shwn as numbers n the left vertical axis, y-axis. The dates are shwn n the bttm hrizntal axis, x-axis. Graph line key: Green slid line - the pecan scab hurs fr the last 14 days, based n Oklahma Mesnet data. Blue slid line - the frecast scab hurs, based n the Natinal Weather Service Eta Mdel. Black line and diamnds - the previus year's daily scab hurs frm Oklahma Mesnet data. Red line and diamnds - the 10-year average f daily scab hurs frm Oklahma Mesnet data. 18-Day Scab Hurs Graph The 18-Day Scab Hurs Graph shws the pecan scab hurs that have ccurred ver the last 14 days and a frecast f pecan scab hurs fr up t 84 hurs fr each Oklahma Mesnet lcatin. The graph is updated every hur. Each hur weather data recrded by the Oklahma Mesnet replaces the frecast data. The graph times are in Central Daylight Time (CDT). The pecan scab hurs are shwn as numbers n the left vertical axis, y-axis. The dates are shwn n the bttm hrizntal axis, x-axis. Graph line key: Green slid line - the pecan scab hurs fr the last 14 days, based n Oklahma Mesnet data. Blue slid line - the frecast scab hurs, based n the Natinal Weather Service Eta Mdel. Black line and diamnds - the previus year's daily scab hurs frm Oklahma Mesnet data. Red line and diamnds - the 10-year average f daily scab hurs frm Oklahma Mesnet data. 3
Frecast Scab Hurs Table Table Data fr a single Mesnet site: Time: In Central Daylight Time (CDT). Air Temperature: Frecast f air temperature in Fahrenheit ( F) fr each hur. Relative Humidity: Frecast f relative humidity (%) fr each hur. Wind Speed: Frecast f average wind speed in miles per hur fr each hur. Wind Directin: Frecast f the prminent wind directin fr each hur. Rainfall: Frecast amunt f rainfall in inches fr each hur. Scab Hurs: Frecast f pecan scab hurs fr each hur. Cumulative Scab Hurs: Frecast f the accumulating pecan scab hurs ver the time perid f the frecast. Seasnal Scab Hurs Table Table Data fr a single Mesnet site: Date: Calendar date frm March 1 t the current date. Daily Scab Hurs: Daily pecan scab hurs fr each calendar date frm March 1 t the current date. Cumulative Scab Hurs: Accumulatin f pecan scab hurs fr each day frm March 1 t the current date. Maximum Air Temperature: Highest air temperature in Fahrenheit ( F) fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Minimum Air Temperature: Lwest air temperature in Fahrenheit ( F) fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Maximum Relative Humidity: Highest relative humidity in percent fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Minimum Relative Humidity: Lwest relative humidity in percent fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Rainfall: Recrded rainfall in inches fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Histrical Daily Scab Hurs Table Table Data fr a single Mesnet site: Day: Sequence f days frm March 1 t the current date. Date: Calendar date frm March 1 t the current date. Average Temperature: The 24-hur average air temperature in Fahrenheit ( F) fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Average Humidity: The 24-hur average relative humidity in percent fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Rainfall: The rainfall in inches fr each 24-hur perid ending at 1:00 am CDT frm March 1 t the current date. Cumulative Scab Hurs: The accumulatin f pecan scab hurs fr each day frm March 1 t the current date. Daily Scab Hurs: The daily pecan scab hurs fr each calendar date frm March 1 t the current date. Cumulative Scab Hurs Last Year's Seasn: Last year's accumulatin f pecan scab hurs fr each day frm March 1 t the current date. Daily Scab Hurs Last Year's Seasn: Last year's daily pecan scab hurs fr each calendar date frm March 1 t the current date. Cumulative Scab Hurs Seasn 2 Years Ag: The accumulatin f pecan scab hurs fr each day frm March 1 t the current date fr the seasn 2 years ag. 4
Daily Scab Hurs Seasn 2 Years Ag: The daily pecan scab hurs fr each calendar date fr the seasn 2 years ag frm March 1 t the current date. Cumulative Scab Hurs 10 Year Average: The 10-year average f the accumulatin f Pecan Scab infectin hurs fr each day frm March 1 t the current date. Daily Scab Hurs 10 Year Average: The 10-year average f the daily pecan scab hurs fr each calendar date frm March 1 t the current date. Histrical Daily Scab Hurs Graph This is a graph f the daily pecan scab hurs fr each calendar date fr the current and each f the last 10 years frm March 1 thrugh August 31 fr a single Mesnet lcatin. The legend prvides a key t the clr line and dts fr each f the years listed. The display f each year's line can be turned ff r n by the user. Histrical Cumulative Scab Hurs Graph This is a graph f the cumulative pecan scab hurs fr each calendar day fr the current and each f the last 10 years frm March 1 thrugh August 31 fr a single Mesnet lcatin. The legend prvides a key fr the clr line and dts fr each f the years listed. The display f each year's line can be turned ff r n by the user. STATEWIDE DATA PRODUCTS: Statewide Cumulative Scab Hurs Map This is an interactive, zmable, clr-cntured statewide map f pecan scab hurs accumulated frm March 1 t the current date and time fr all Oklahma Mesnet sites. The values displayed are the accumulated pecan scab hurs since March 1 fr the Mesnet sites shwn. 14-Day Statewide Cumulative Scab Hurs Map This is an interactive, zmzble, clr-cntured statewide map f pecan scab hurs accumulated ver the previus 14 days fr all Oklahma Mesnet sites. The values displayed are the accumulated pecan scab hurs fr the last 14 days fr the Mesnet sites shwn. DAILY REFERENCE DATA: Daily Table f All Mesnet Sites Table Data fr the Date selected: STID: Mesnet site identifier DINF: Pecan scab hurs fr each 24-hur perid ending at 1:00 am CDT. TINF: Ttal Pecan scab hurs accumulated frm March 1 f the seasn selected. TMAX: Maximum air temperature in Fahrenheit ( F) fr each 24-hur perid ending at 1:00 am CDT. TMIN: Minimum air temperature in Fahrenheit ( F) fr each 24-hur perid ending at 1:00 am CDT. HMAX: Maximum relative humidity in percent (%) fr each 24-hur perid ending at 1:00 am CDT. HMIN: Minimum relative humidity in percent (%) fr each 24-hur perid ending at 1:00 am CDT. RAIN: Recrded rainfall fr each 24-hur perid ending at 1:00 am CDT. 5
View Reference Data This links t the reference data used by the Pecan Scab mdel fr the current and last ten years. Only the data fr the date selected will be shwn. Date and Time Stamp: This is a table f all Mesnet lcatins fr the date and time selected. Table Data: STID: Mesnet site identifier STNM: Cunt f days since March 1. TAIR: Maximum air temperature in Fahrenheit ( F) fr each time perid. RELH: Relative humidity in percent (%) fr each time perid. INFH: Pecan scab hurs fr each time perid. TINF: Ttal pecan scab hurs accumulated frm March 1 f the year selected. Map: This is a clr-cntur map f the seasnal pecan scab hurs accumulated frm March 1 t the date and time selected. Graph: This is a graph f the air temperature, relative humidity and pecan scab hurs fr each hur ver the time perid selected. References: Pecan Diseases: Preventin and Cntrl, Fact Sheet F-7642, Oklahma State University, Sharn vn Brembsen, April 2005. Authrs: Albert Sutherland, Sharn vn Brembsen, Mike Smith, and J.D. Carlsn Oklahma State University, June 28, 2005 6