Personal Weather Station for Specialty Crop Management

Joe Hannan
ISU Extension and Outreach
Commercial Horticulture Specialist
jmhannan@iastate.edu

A personal weather station is simply integrated “tools” that measure weather variables such as temperature, humidity, rainfall, wind speed and direction, soil moisture, and leaf wetness. Some are affordable enough to install at your own farm which will give the most accurate representation for the weather in your farm.  Weather data found on television or popular internet sites providing local information is extrapolated or modeled from existing information and cannot take into account local variability due to hills, windbreaks, pavement, population, etc.  These extrapolations often do not provide accurate information on rainfall, wind, and temperature (especially during a spring freeze).  Personal weather stations allow you to know exactly what is going on at your farm.  Newer stations on the market generally connect to the internet and are capable of providing real time data directly to your smart phone. 

Ultimately, with the move towards constant connectivity we can use this data for making crop management decisions.  The information can be used to monitor conditions outside as well as conditions in a high tunnel.  You may use the information to determine which vents, doors, and sidewalls are open.  I think what is more useful though, is using the real time information to model insects and diseases to make better pest management decisions.  Pest emergence in the field is often directly related to growing degree days and in some instances other factors such as rainfall or leaf wetness.  This makes many insects and diseases predictable using data which allows us to apply pesticides when they can most efficiently be used.  Sometimes that means spraying less often and sometimes more often than normal but always at the most optimal time. 

There are many pests that can be predicted using fairly simple models across a broad range of crops.  Some common pest include Japanese beetle, fire blight, Melcast for certain cucurbit diseases, codling moth, grape berry moth, anthracnose on strawberry, etc.  It is critical to know what pests you want to predict and what variables must be measured by the weather station prior to making a purchase as not all stations come equipped with the sensors you may need.  For example, leaf wetness sensors are often used when modeling diseases but not commonly available on stations below the $1,000 price point.

Remember, pest modeling is not an excuse to avoid scouting.  Many of the models require a trigger point (biofix) that must occur and be observed in the field to start the model. 

There are a lot of personal weather stations on the market at a wide array of prices, accuracy, and features, and sensors.  Some factors to consider when purchasing a personal weather station include:

• How is data transmitted to you?
  • Data can be transmitted from the weather station to a receiver via Wi-Fi, a point to point radio receiver (usually then connected to the internet), hardwire connection to a computer, or in remote locations via a cellular modem.  Weather stations close to a house may be able to directly connect to a home Wi-Fi signal.  However, stations located close to a structure may record measurements that do not accurately represent field conditions.  Stations connected via radio receiver or Wi-Fi may require additional boosters between the station and the receiver for a stable connection.
• What are the monthly fees associated with accessing the data?
  • Accessing current conditions data, daily highs and lows, and rainfall is generally free.  However, to access or download daily/weekly/monthly data, a subscription is generally needed.  Subscription fees are generally not much more than $100 per year with the exception of services from Spectrum Technologies that offer pest modeling directly through their software.
• How will you access the data?
  • It is fairly common for manufacturers to provide their own proprietary app, website or software to access the data e.  Be sure to download the app and test its functionality prior to purchase.  On that same note, be sure to check if the weather station will connect to third party sources (such as Weather Underground) if you desire to access your data that way. 
• What is the initial cost of the hardware?
  • A good, basic, weather station will cost about $1000 but can cost upwards of $2,000 depending on what add-ons you select. 
• What sensors does it have and are they replaceable?
  • Low cost (sub $500 stations) may only measure wind speed, direction, temperature, and humidity.  While these stations may be suitable for predicting insects, leaf wetness sensors and/or rain buckets are necessary for disease modeling.  In addition, sensors wear out.  If they are integrated into the weather station, they likely cannot be serviced or replaced in the field and will require the entire unit be replaced or sent to the manufacture for repair.  The trend seems to be moving towards integrated systems that are easier to install but limit repairs in the field.
• Is there integrated pest modeling?
  • Most stations only record data.  You are required to download and import the data into a software program (excel, Maryblyt, Melcast, etc.) to model the data.  Spectrum Technologies is one of the few (if only) manufacturers that provides pest modeling directly through their subscription-based user interface. 

There are many options available when choosing a quality weather station for on-farm pest modeling. 

Spectrum Technologies 2000/3000 Series Stations

Available Sensors

Some units have additional expansion ports for extra sensors.  The newer 3000 Series stations are integrated, single piece units as opposed to the older 2000 series units where the modem, solar panel, and some sensors are separate units that the user connects to the base station.

Connectivity

Connect via a communications port (9 pin port that is not on most computers anymore) or via USB using a communications port adapter and driver.  You must take the computer to the weather station to get the data.  I don’t recommend this method of connection for pest modeling as trips to the field to connect to the station are time consuming.

Point to point radio or line of site radio up to about 1000 ft.  Radio receiver at computer requires similar hard connections as direct to pc.  PC must be on to connect and transmit data.  A booster may be needed if radio and receiver are not direct line of site.

Cellular modem via Verizon network.  Connects directly to Spectrum Technologies web interface for easy pest modeling.  Subscription cost is higher for this option as fee for cellular access is built into the subscription. 

What I Like

I have had a Spectrum Technologies weather station and SpecConnect user interface for 5+ years and there are a couple of things I like about the system.  First, the weather stations directly connect to a proprietary user interface that makes it easy to model a huge variety of pests across a wide array of crops.  The models can be tweaked and adjusted to account for local variances with no need to export data to excel or other software package.  Second, regardless of manufacturer, your station will go down and require repair.  Customer service over the years has been phenomenal and I have always been able to get the station repaired remotely (with staff walking me through the repairs) or been able to send it in for repair and returned to me quickly.  Finally, the system is very easy to deploy.

What I Dislike

The user interface and models do not allow you to forecast out and make predictions based on expected weather forecasts.  This makes it difficult to plan out pest management activities a day or two in the future based on forecast.  For instance, when modeling fire blight on apples in the spring, adding forecast data into the model helps to determine when to spray while avoiding adverse spray conditions.

Rainwise MKIII Weather Underground Package

Available Sensors

The base model has no expansion ports, no soil moisture meter, and no leaf wetness sensor.  An upgraded version is available with expansion ports for leaf wetness and soil moisture sensors for an additional $500 + sensors.  The Weather Underground package is a discounted system with limited sensors and connectivity, however, the price is greatly reduced and packaged for ease of setup.  The standard MKIII offers the ability to add sensors, connectivity, dataloggers, displays and a myriad of other features.

Connectivity

Point to point radio or line of site radio up to about 1000 ft.  The radio receiver hard wires into your home router and does not require a PC to transmit data to the internet.  A booster likely will be needed if radio and receiver are not direct line of site or more than a few hundred feet.

Upgraded models of the MKIII allow for hardwired or cellular connection.

What I Like

I have had a Rainwise MKII Weather Underground Package for one year now and there are several things I like about this particular weather station.  The package is a complete, off the shelf kit that has everything necessary for pest modeling but a leaf wetness sensor.  If you are primarily modeling insects or diseases that use rainfall (in lieu of leaf wetness), this is a very economical system.  It is fairly easy to deploy, has an excellent app for real time data, and connects to Weather Underground and other third party services seamlessly and for free.  For a fee, other data storage and access services are available.  If you opt for a higher end package, there are several add-ons for this station.

What I Dislike

The only thing I dislike about the Rainwise MKIII Weather Underground package is that the wireless connection from the station to the network interface box is poor.  Adding the Wi-Fi adapter ($50) to allow better placement of the network interface box should resolve the issue and still keep the package very competitively priced. 

Davis 6152 Vantage Pro

Available Sensors

The base model does not measure solar radiation, have a soil moisture meter, or have a leaf wetness sensor.  However, the Davis product line is the most expandable line on this list.  There is a huge array of sensors that can be added to the system allowing you to design a system that fits your needs.  In addition, auxiliary stations can be connected to the base station allowing for point specific data collection.  This could be especially beneficial when collecting data in the field but you also want to collect information inside a high tunnel or a nearby field.

Connectivity

The Davis 6152 Vantage Pro has a myriad of connection options like other offering on this list.  Data can be accessed via a website or phone application or through an add-on monitor. 

What I Like

I do not have a Davis 6152 Vantage Pro which limits what I can say in regards to positives and negatives about the system.  I like that the system is highly customizable and expandable with many nodes able to connect back to the primary station.  There is also a huge selection of replacement parts to service the station on your own.  The Davis Instruments systems are known to be very high quality and reliable. 

What I Dislike

The greatest advantage to the Davis 6152 Vantage Pro is also its greatest detractor.  It is very important to know exactly what you want and need from your station or your build out can get expensive quickly. 

Summary

Weather stations from Spectrum Technologies, Rainwise, and Davis Instruments are all excellent weather stations providing flexibility for weather data observation to help collect data to predict insect emergence and disease establshment in the field.  Ease of use, flexibility, and repairability vary greatly across the three stations.

Links to Resources

• Spectrum Technologies, Inc.
  • https://www.specmeters.com/
• RainWise
  • https://rainwise.com/
• Davis Instruments
  • https://www.davisinstruments.com