We have incorporated National Weather Service forecasts into the apple scab tool and also into the grape diseases tools on NEWA!  Some confusion arose early this week because of the way a combined wetting event was being displayed in the apple scab Infection Events Summary, but we have fixed that and added some explanations to the page to help you look into the 5-day future forecast for disease risk. As always, we welcome feedback at newa@cornell.edu. Now these IPM tools show the two past days, the current day, and 5 days in the forecast.

Apple Scab
The apple scab tool calculates the maturity of ascospores overwintering in leaf litter. The Ascospore Maturity degree day model begins at 50% green tip on McIntosh flower buds and provides an estimate of the potential for ascospore discharge in the next rain. To recalculate ascospore maturity for your specific orchard situation, you can enter your green tip date. Keep it always handy for the next time you use the apple scab tool, because NEWA doesn’t remember this for you. The ascospore maturity graph, accessed from the Ascospore Maturity Graph button, gives a snapshot of the primary scab season for your location; compare our most southerly location in Hendersonville, NC, to York Springs, PA, to Geneva, NY in the graphs below.

Ascospore maturity in Hendersonville, NC, York Springs, PA, and Geneva, NY. Mouse over to get details on the date, as shown for Geneva.

Apple scab infection events, shown in red in the Infection Events Summary, are calculated beginning with 0.01 inch of rain. The word “Combined” in the above table means the wetting event on this day is being combined with another wetting event. To calculate the length of a wetting period, we use the following rule: two successive wetting periods, the first started by rain, should be considered a single, uninterrupted wet period if the intervening dry period is less than 24 hours. When an infection event is in the 5-day forecast, the actual weather data logged may or may not translate into an actual infection event. Therefore, the table output may change once actual weather data is logged.

Apple scab Infection Events Summary for York Springs, PA, April 2015

Always check the download date and time, because the Current date in the Infection Events Summary has data that is made up of actual data and forecast data, so the infection event on this date may change, depending on the accuracy of the forecast.

The battery powering your weather station is good for 3 to 7 years, is easily monitored, and replaced. The Battery Installation instructions for checking the voltage and replacing the battery can be found on the NEWA website, under About Weather Stations. If your AgroMET (Rainwise) weather station isn’t transmitting data, the problem could be the battery. Instructions included in the Troubleshooting Guide cover battery check and replacement in the section Station not Transmitting. Updates were made to the Troubleshooting Guide to include safety procedures when handling sensitive parts of the weather station. There’s a YouTube video on how to change the battery, too!

Check the battery voltage on your RainwiseNet dashboard

Download the station data from the RainwiseNet webpage. (You must be logged into your account.) Click on Download.

Enter a date range and make sure the date range includes the time the system last communicated. Click Export.

Click on the Rainwise Weather csv file button to open the downloaded, exported file. The file will open in an Excel spreadsheet.

The “Station Voltage” column is the last column on the right. Look for the last recorded battery voltage which will be at the bottom of the Excel sheet. Because the battery is solar powered, the voltage should rise during the day and fall during the night. Voltage will be lowest when the solar panel receives little sunlight, on cloudy days, during winter, and at night.

Battery voltage that drops below 5.9 volts is insufficient and indicates the battery needs to be replaced.

The replacement 6 volt battery is a Werker WKA6-5F. These batteries can lose charge if they are left sitting on the shelf; install it soon after purchase. It is also best to charge them before installation, or to install them on a sunny day to ensure maximum performance.

Install the new battery

Turn off the weather station power switch.

Remove the solar panel from the sensor assembly. This is done by loosening the four screws located in the corners of the solar panel. Once the solar panel and cover are free from the housing, disconnect the solar panel connection and TAKE NOTE of the way the connectors clip together so you can reconnect them.

Remove the battery from the compartment and disconnect the two leads from the battery.

Install the new battery by connecting the leads on the battery and placing it back into the compartment.

Reassemble the weather station. Switch the power on.

NEWA is a partnership of land grant universities in Connecticut, Massachusetts, New Jersey, New York, Pennsylvania, and Vermont. A yearly subscription fee of $1750 from each member state supports the partnership. Individual farmers can connect to NEWA in non-member states with a yearly fee of $290. Let your friends and colleagues know about NEWA so they, too, can benefit from the IPM and crop production tools available. Want to know more about NEWA in your state? Contact us! Use our contact information in the table below. Learn more about NEWA from You’re NEWA or from NEWA’s website. Juliet Carroll, Cornell University, is the Leader of NEWA.