Ever wonder what it takes to grow strawberries or blueberries? Or what kinds of challenges growers might face when they grow spinach? Fruit, vegetables, nuts, herbs and even landscape plants are in a unique group of their own, called “specialty crops.” Specialty crop growers face issues not experienced by growers of large-acre crops like cotton, soybeans or corn.
Weed control is one example. Cotton growers have a multitude of herbicides available to them to control weeds. The arsenal of herbicides for specialty crop growers, on the other hand, is much smaller.
Although most consumers don’t hear about entire crops being wiped out by a terrible weed, in the same way that they hear news reports of a voracious insect pest or virulent disease striking entire fields or devastating crops, weeds cause distinct problems in the field. First, a weed species that is particularly prolific can shade or crowd out developing vegetable seedlings. Weeds can steal nutrients from berry plants in the early fruiting stages. At harvest time, weeds can also comingle in with herbs like thyme or basil, decreasing the value of those crops at market time. Most specialty crop growers therefore try to minimize the number of weeds in their fields.
However, according to a 2008 article in Weed Technology, specialty crop growers face numerous challenges in weed control. First, specialty crop growers have few herbicides available to them. Why? On any pesticide, fungicide or herbicide label is a list of the crops or settings for which you can use that chemical. Homeowners, for instance, can use Roundup on their weeds because Roundup is labeled for use on home landscapes.
There are a few reasons why herbicide choices are limited for specialty crops. First, because many of the specialty crops are edible, consumers balk at the thought of having chemicals on their fruits and vegetables, so some of the “restricted use” chemicals are not labeled for specialty crops. Second, at least 26 herbicides and fumigants have been dropped from use for specialty crops since 1980. One of those is methyl bromide, an effective herbicide and fungicide, but labeled by the EPA as an ozone depleter. Methyl bromide is slowly being phased out, so growers who have depended on it in the past are now seeking alternatives that are not yet available.
Without an array of herbicides, what options do specialty crop growers have? For the most part, growers use labor to hand pull weeds. However, according to Steven Fennimore and Douglas Doohan, authors of the Weed Technology article, hand-pulling is both inefficient and expensive.
“In minor crops, crop values are often high, and herbicides (if available) represent a minor portion of the weed control costs compared with labor and machine costs for hand weeding and cultivation,” Fennimore writes in the article.
Specialty crops are typically high-value crops. In fact, they are worth nearly half of the total value of all U.S. agriculture (Fennimore & Doohan, p. 370). The Specialty Crop Research Initiative would be an excellent funding source for research for alternatives to more labor-intensive weed control measures.