Alternative medicine for turf : Surprising materials such as silica and bacteria may offer new treatment options to solve difficult turfgrass problems.

For centuries, Chinese herbalists have been treating human ailments using ancient remedies extracted from plants and minerals. Over generations, these practitioners have developed naturalistic cures for diseases ranging from migraines and cancer to tennis elbow. Western medicine initially scoffed at acupuncture and tree branch extracts treating disease. But now modern science is taking a second look and finding some genuine benefits to these methods. Unfortunately for us, the Chinese never used their healing powers on lawns.

Recently, however, a cottage industry of alternative remedies has sprung up virtually overnight to treat many turf maladies.

I'm not talking about snake oil products of the past century -- I'm talking about actual alternative cures discovered and refined by some of today's leading turf experts.

Once upon a time, silica was an obscure fertilizer component. Now, due to its curative properties on agronomic pests, it's entered the mainstream. Today, a large proportion of U.S. rice and sugarcane crops are sprayed with silica for protection from pests. In the last few years, major agricultural conferences have focused on this mineral's healing power.

Surprising silica

Silica is a by-product of phosphate fertilizer mining. After phosphate is extracted, a water-soluble silica slurry remains. Initially, engineers had a tough time getting rid of it -- until agronomists learned that applying it to crops enabled them to fight certain pests, particularly fungal diseases.

Strangely enough, silica is everywhere. Soil and sand are chock-full of silica. But plants can't get it because it's in a fixed form unavailable to them.

"Our soils are high in silica, but it's not soluble silica," explains Dick Schmidt, turf professor emeritus at Virginia Tech. "The plants have no way of taking it up." Soluble silica -- applied to the foliage via spraying -- is the only way of getting silica into the plant.

Recent work at several northeastern universities has shown that silica can be used to treat a range of common turf diseases (see Table 1). Schmidt concentrated his work on dollar spot disease. Other scientists have found activity of silica against pythium blight, gray leaf spot, brown patch and powdery mildew.

Schmidt advises not to expect miracles from these natural remedies. "It doesn't mean we can throw away our fungicides. Silica will reduce …