Saturday, November 14, 2009

Farm Bulletin: Spraying with Abandon

Anthony and his incisively erudite and always stunning wife, Carol, are beginning their seventh season at the Hillsdale Farmers' Market this weekend. As Anthony notes, "the market opens at 10 am, regardless of rain, snow or even overly bright sunshine. So long as the market can be operated safely, it will open. Heavy winds are the biggest safety concern." For a complete list of their offerings this week, refer to the market website.

Some farms have signs stating that they are "No Spray" or "Spray Free." Occasionally people will ask if we are "no spray." We dodge the question by pointing out that we are "Oregon Tilth Certified Organic," which satisfies the subtext of the inquiry. Oregon Tilth (logo, below) is a local organization that certifies farms as complying with the National Organic Program standards. Our farm received Oregon Tilth certification in 1998.

Because we grow organically, we spray with wild abandon, and at any spare moment. We own a 200-gallon air-blast sprayer, a 100-gallon boom sprayer that sprays six rows of vegetables at a time, and 25 gallon sprayer that fits on the ATV, all told, a serious investment in spraying machines. Foliar feeding, or spraying dilute nutrient solutions on the crop, is standard practice among high quality organic growers. Typically we apply a solution of kelp extracts, sea salt and enzymatically digested fish. We also apply nettle and compost tea at various times.

We start spraying early in the morning, just before sunrise, when the dew is heavy upon the plants. We want to apply the nutrients when the leaves are cool and the stomata, the tiny organs through which the leaves regulate gas exchange, are fully open. At 5 am, the tank mix releases a daunting fragrance. The crop is drenched and dripping with the feeding mix yet, by the next morning, not a trace of odor can be detected in the field. The mixture has been absorbed by the plant and the colonies of micro-organisms it hosts. Like humans, plants have a wide array of bacteria and fungi that live upon and within the plant tissues. On a healthy plant they are beneficial and serve a protective function.

Foliar feeding is expensive and time-consuming, and many growers doubt the worth of such applications. In fact, this sort of feeding does not increase yields in any substantial way, and does not replace good soil management. So why do we invest so much time and money in spraying? The plant responds with better flavor and vigor. We have found that foliar feeding leads to fruits and vegetables that are brighter and denser, and they resist insect and disease pressure better. It is worth noting that even growers who rely on synthetic fertilizers and other agricultural chemicals use foliar applications to quickly correct trace mineral deficiencies in their crops.

Sea salt, especially, is an under-appreciated agricultural amendment. Deeply ingrained in our minds is the salting of Carthage's cropland following the Third Punic War (illustration, top). In reality, salt has long been used in crop production. Many vegetables are domesticated maritime plants. These include asparagus, beets, turnips, cabbage, chard and chicories. Old texts make note of this fact, and recommend sea salt applications for both forage and crop plants. Research in the US, Italy and Israel has demonstrated that foliar salt applications improve the quality and nutrition of tomatoes. Here in Oregon the soils are very low in sodium, an essential plant nutrient, and sea salt provides a rich collection of trace minerals in addition to the sodium. Although care must be taken in applying salt, either to the ground or as a foliar feed, crops respond well to its use.

At the southern end of the Venice Lagoon is the port of Chioggia. The vegetables grown in the area are renowned for their flavor and quality. In fact, many vegetable varieties bear the name Chioggia as a horticultural benediction of sorts. As we crawl along with our spraying rig, we like to think that we are duplicating, however feebly, the salty sea breezes that spray off the Adriatic and imbue those vegetables with their fine flavor. We cannot imagine why anyone would want to claim to be "no spray."

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