Sclerotinia risk model

Background Information


Sclerotinia is a fungal disease of oilseed rape. In the spring, sclerotinia sclerotia germinate in the soil and produce fruiting bodies which release airborne spores. Some of these spores are carried onto flower petals which fall off and stick to leaves or leaf axils, especially in damp conditions. Spores then germinate and infect the new leaves and the stem. Infection rate depends on three main factors: the presence of sclerotinia spores, warm and humid weather conditions and the flowering stage of the crop. 


The KisanHub Sclerotinia risk model uses these factors to give the user a High, Medium or Low risk warning at a farm or field level, along with guidance on fungicide choice and timing and the possible need for a second spray treatment. The optimum timing for a single spray is usually just before mid-flowering on the main raceme. In many seasons a single spray at this time will protect the crop as treatments can provide control for up to 3 weeks. Two sprays may be required to protect crops at high risk sites if the flowering period is prolonged. DO NOT USE sclerotinia products containing single active ingredients more than once on their own. 


Instructions


Firstly, you need to have your farm, fields and crops added in the MyFarm app. If you need Help with this, please CLICK HERE. Only fields that have the crop set as oilseed rape will show up in the OSR Sclerotinia Model landing page. Also, in order to receive daily alerts you need to be subscribed to the MyFarm app.


  • Then select the Decision Support tab on the left hand side (1)
  • The Pest and Disease tab will automatically be displayed
  • Select the OSR SCLEROTINIA tab (2)
  • Your farm and fields should show up in the Sclerotinia Risk table at the bottom. If not, make sure you have created a farm with OSR fields in it (3)




You can choose whether to run a farm level or field level report. Field level reports take into account spray records unlike the farm level as not all fields may be sprayed at the same time. In the Sclerotinia Risk table, click on the field or the farm that you want to use. This will bring up the following tab. 

  • Click on RECORD FLOWERING STATUS (1)
  • The RECORD FLOWERING STATUS card will pop up 
  • Enter flowering observation dates (2). There is no need to fill in all dates at once and you can do it at any point
  • Click RECORD FLOWERING STATUS AND RUN MODEL



The model is then run, and when completed, the following screen appears.


  • The high, medium or low risk tab (1) will automatically display relative to the risk. High and medium risk tabs contain action information, including recommended sprays and programmes to combat the disease. 
  • Two graphs will be displayed, SPRAY-ADJUSTED RISK LEVEL (2) and SCLEROTINIA- WEATHER IMPACT (3). The model shows the past 45 days and forecasts 5 days into the future. 
  • For graph (2), the green (low), yellow (medium) or red (high) risk line will highlight. In this case, the green is a bolder line. 
  • The current date (Today) is marked on both graphs, along with the flowering stage on graph (3).
  • On the weather impact graph, rainfall intensity is shown as blue columns. Average temperature is shown as a green line. Only when the average temperature exceeds the CRITICAL TEMPERATURE THRESHOLD (dashed red line) should there be a medium or high level risk. 


Please note that on the mobile app, only the spray adjusted risk level graph is shown due to the complexity of displaying the weather graph. 


Also displayed is the data for the closest AHDB monitor site to your farm (5). This displays the latest sclerotial germination, level of germination spores, petals testing positive to sclerotinia and petal infection data for comparison. 


Graphs can be downloaded or printed by clicking on the chart context menu () in the top right hand corner of each graph.

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