Climate change and pest control

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I recently learned some more about online weather tools for farmers from Eric and Joanna Reuter in Growing for Market. The National Weather Center Climate Prediction Center (CPC) has a wealth of useful info. From the “WPC 7-day QPF” map above (Weather Prediction Center 7 day quantitative precipitation forecast) I see we could get up to an inch of rain over the coming week in central Virginia. Other maps on the site show we can expect above normal temperatures and rainfall for the first week of January. (I’m saying rain, because with above normal temperatures, the precipitation won’t be snow.)

There are maps with forecast conditions for the next month, the next three months and even the whole of 2018, although of course the more intervening time means more chance of things changing before we get there.There is a detailed discussion explaining “La Niña conditions are present, with a transition to ENSO-neutral favored during January-March 2017.” The report was written in November, predicting weak La Nina conditions continuing through March 2017.

Winter offers a good opportunity to explore these tools and get familiar with them (the abbreviations and technical language do take a bit of getting used to). If I were to open this site in mid-summer when already very busy, I think I would struggle to sit still long enough to absorb the information. By figuring it out at the slow time of year, I’ll be more ready to dip in and take advantage of timely info in the main growing season.

If the embedding has worked out right, here is a “Climograph” for Louisa County, Virginia:

<iframe frameborder=”0″ width=”470px” height=”430px” style=”overflow:hidden;” scrolling=”no” src=”http://www.usclimatedata.com/climate-graph.php?id=usva0445&system=american&title=1″></iframe>

And if it didn’t embed, here’s the link: http://www.usclimatedata.com/climate/louisa/virginia/united-states/usva0445/2015/2

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Outdoors in December – rowcover everywhere! Photo by Wren Vile
Hoophouse beds in December. This is why we have a hoophouse! Photo Wren Vile
Hoophouse beds in December. This is why we have a hoophouse!
Photo Wren Vile

This week I also read an interesting article by Rebekah L Fraser in Growing magazine on the Push-Pull Method of pest control, which was developed in Kenya. In Kenya this method is used to protect crops from both invasive weeds and insect pests. Some plants can suppress others by selective allelopathy. Tick-trefoil not only suppresses some weeds but also repels pests, while conserving the soil in the process, and providing stock feed or green manure when cut. Plus, as a legume, the tick-trefoil fixes atmospheric nitrogen (which feeds the next crop) and reduces greenhouse gases (which helps save us all). This is the “push” half of the combination. Tick-trefoil interplanted with corn repels weeds and pests.

Push-pull pest control
Push-pull pest control

The “pull” half involves Napier grass as an attractive trap crop for corn borers. This trap crop is planted as a border around the corn patch. The female stem-borers are repelled by the tick-trefoil out of the corn to the border where they lay eggs on the Napier grass. It’s sticky exudates and sharp silica hairs kill the stem borer larvae when they hatch. Read more on www.push-pull.net .

It’s so heartening to read about organic sustainable ways farmers in sub-Saharan Africa are working to end hunger and poverty. And these principles can surely be applied to other crops in other regions.

More strategies for dealing with a changing climate – article in Growing for Market

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The January issue of Growing for Market is out, and in it is my article More strategies for dealing with a changing climate. A photo of our fava beans is on the cover.  This is the third in a series of four. (You can see earlier blog posts about the first two, in the Articles category.) This article covers the use of soil temperature as a deciding factor on when to sow or plant, and includes a table of minimum (spring) and maximum (summer/fall) temperatures for about 50 crops. As the climate becomes harder to predict, using a calendar (“Plant potatoes on St Patrick’s Day!”) will need to be replaced by using information like soil temperatures, which reflect what the plants will actually experience this particular year.

The article also discusses scouting, which is the practice of making a regular tour of your crops to monitor growth and health. If you see a pest or a disease, you can determine if the level of infestation is enough to call for action, or if watchful waiting is in order. Keeping in touch with how your crops are doing will help you know when you need to take action to avert disaster or to make good use of an opportunity like an early-finishing crop opening up the possibility of using a longer-term cover crop.

droughtI also talk a bit about being prepared for more extreme temperatures – trialing varieties that are more cold- or heat-tolerant than your old favorites, and using shadecloth and organic mulches to reduce heat stress.  ATTRA’s Drought Resistant Soil addresses ways to increase the organic matter content of the soil, and keep the soil covered at all times, helping you farms’ resilience.

In addition I added in a few more resources I’ve found to help with predicting climate change. DailyClimate.org – a daily email newsletter; NOAA Climate Prediction Center, and Weatherspark.com, a fun weather site is where you can see, for instance, what your average winter low has been, and plan plantings accordingly.

Two additional resources on frost management are NCSU’s Frost/Freeze Protection for Horticultural Crops and the Food and Agriculture Organization 126-page book Frost Protection: Fundamentals, Practice and Economics.

Favas, spring sown, good germWhy the fava bean photo? Wait till the soil temperature reaches 36F (2C) before sowing.

As well as my article, there are many other gems – Identify your biggest money-making crops by Chris Blanchard; A Tool Review of The Quick Cut Greens Harvester by Jean-Martin Fortier; 8,000 miles and 18 farmers markets, a travelogue by Gwynn Hamilton and Bert Webster about their cross-country road trip visiting farmers markets all the way; Understanding one of the few insecticides for organic growers by Raymond A. Cloyd, about spinosad formulated as Entrust, and Growers create their own wholesale market for local flowers in Seattle by Debra Prinzing, co-author of The 50-Mile Bouquet  about the movement toward locally grown, sustainable flowers.