This week I thought you all might want to hear what we are doing differently this year. Last year was a terrible melon, cucumber, and pumpkin year, do in part to an incredibly wet season on the farm, and unusually high pest pressure. 2016 ushered in one of the strongest El Nino/La Nina cycles since the NOAA began keeping records in 1950, and it decided to stick around for not 1 year, but 2. It seems the weather patterns are starting to stabilize, and the unpredictable jet stream may be returning to its normal spot(hopefully). This is a pattern that should occur every 10 years or so, but due to climate change, is becoming more unpredictable. During el nino/la nino events, drought vs. heavy rainfall oscillations are stronger and more frequent, as well as temperature extremes and summer storms (high winds and thunderstorms).
On a farm that uses organic growing practices, this can wreak havoc. Organic fungicides and pesticides (at least the ones we feel comfortable using), are easily washed off during rainfall. They are no match for conventional pesticides that soak into the plant tissue, and stick around for the entire growing season (and also stick around in the vegetables and fruit...no thank you). We use an agricultural peroxide to control fungal issues, and to be effective, it must be applied every time there are wet conditions on the farm (rain, fog, high humidity). The pesticides that we use are actually just a soil based bacteria, and are easily washed away with the rain, and break down quickly in high heat/humidity. You may wonder, why not just use a stronger organic approved substance? Well, as time goes on, we are discovering that even some organic pesticides are dangerous...rotenone, pyrethrums, etc.. In fact, you may be surprised to learn that some conventional chemicals are safer than organic (I know...it's mind boggling). Just because a chemical is approved for organic agriculture use, does not mean that we will use it on our farm; the mechanism and mode of actions must match our growing philosophy. The health of our farm and our members is paramount to all other decisions.
Our main nemesis are cucumber beetles (both spotted and striped), and squash bugs. Since we remain steadfast in not using conventional or dangerous organic chemicals, we have spent the majority of winter researching advanced growing techniques to ensure our success with the crops that these pests target: watermelon, muskmelons, cucumbers, summer squash, winter squash, and pumpkins. We have read books, researched what farmers in other countries are doing, poured through the state extension website, and scoured the internet for any piece of knowledge to add to our arsenal of defenses. What we have learned is that it is going to take a multi-step approach to ensure our success, and here is how we are going to do it:
Step 1: Early start
Older plants can sustain feeding damage better than young plants, which pests seem to have a penchant for. Usually cucurbit crops are direct seeded, as it is easier, faster, and more economical than starting them in the nursery and then transplanting into the field. Cucurbit crops are notoriously finicky, and require a high level of management when started indoors. These fastidious requirements, coupled with our dwindling nursery space, has precluded us from considering this approach in the past. However, our csa members are very important to us, so we have decided to stop selling to local restaurants for the 2018 growing season, which will allow us to have more room (both in the nursery and the field) to dedicate to crops for our members. Side note: Dropping restaurants from our sales outlets will also allow us to resume growing crops that took large amounts of room, and provided little return (such as sweet corn, ornamental pumpkins, and decorative gourds). We have made lots of changes in many different areas of our operation to make sure that the csa program is the best you will find in the state...we love you guys!
Step 2: Mechanical Exclusion
Maybe one day soon we will be able to install a screened high tunnel for pest exclusion, but until then, we are going to rely on something that we already have plenty of: fabric row cover. We've used this for years to extend our growing season both earlier in the spring, and later into the winter. Even though this will create several new issues that we will need to manage, it will give the newly transplanted seedlings a safer environment to grow. New issues will be overheating the plants, damaging tender stemmed crops, and pollination. To address overheating, we have sourced the thinnest fabric we can find, which is thin enough to see through. We will use thin metal hoops to suspend the fabric up off of tender stemmed crops like melons and cucumbers. Pollination issues leads us to the next step...
Step 3: Complex Hybrid Varieties & Use of Multi-Species Pollinators
Pollination is the single most important aspect of growing the crops that we are trying to protect, as not only are we going to be excluding pests, but also the pollinators that are essential to fruit formation. Unlike peppers, tomatoes, lettuce, etc., the cucurbit (cucumber and muskmelon) and citrullus (watermelon) species require an insect to climb inside the male flower, and transfer the pollen to each female blossom. If this fails to happen within about 3 days of the female blossom opening, it will wither away and die, and no fruit will be produced. So, we are going to use a little science, and a little nature to work around this problem. Our first approach will be to use parthenocarpic varieties. These varieties are complex hybrids that have been bred for greenhouse production, where insect pollinators are usually absent; they do not require pollination to set fruit. However, these varieties are only available in a handful of crops, namely cucumbers. For watermelons, pumpkins, and squashes, we are going to have to take a different approach: the use of novel pollinators. We have found a source of solitary bees (those that don't build hives) as well as mason bees (which only need a piece of food for nesting). These beeds are notoriously docile, as they are not social, and thus do not have a colony to protect. We will place these pollinators inside the enclosed tunnels where they will hatch. We will provide them with water and a supplemental food source, and in exchange they will carry out pollination duties. Once the pollination has been completed, we will remove the covers, allowing them to flee the enclosed space, and carry out pollination duties on other crops that do not require protection. They are native to our area, so they will reproduce, overwinter, and provide their services for years to come. A win-win for everyone.
Step 4: Provide the pest with their favorite food source
Our last line of defense is going to be providing the pests their favorite varieties to snack on. Since they will be easily accessible (and far away from our protected crops), they should congregate en masse to breed and lay eggs. Once they hatch they are slow and can't fly very well. With careful attention to timing, we will then use our flame weeder for a chemical free extermination. We normally use the flame weeder for pre-emergent weed control, but at 400,000 btus (a normal bbq is around 50,000 btu), it is capable of many different tasks...plus, it is just plain fun (and safe) to use.
Hopefully, these new growing techniques will improve our success with this small handful of crops that are a challenge to produce successfully on our farm. We aren't ones to shy away from a challenge, and we think this year we have the best plan of attack, yet. See you guys net week!