Serenade Soil has been touted as a “new approach for soil fungicides” by Denise Manker, vice president of global product development for Davis, Calif.-based AgraQuest Inc.
Introduced in January 2010, the product is the first soil fungicide based on its patented ingredient Bacillus subtilis (strain QST 713), the company says.
It is designed to protect potatoes, tomatoes, cucurbits and other plants from diseases, such as rhizoctonia, fusarium, pythium and Phytophthora.
But how well has Serenade Soil actually performed so far?
Growers and researchers report mixed results with the product, and most want to give the biological fungicide more time to prove itself.
Fighting common scab
Wysocki Produce Farms of Bancroft, Wis., used Serenade Soil to fight common scab on its potatoes for the past two seasons, says Gary Barten, agronomy operations manager.
“Scab costs us a lot of money,” Barten says.
The company grows fresh-market potatoes and, since scab is a visual blemish, tubers can become unmarketable if the condition gets serious.
Serenade Soil does not control scab, he says, but it suppresses it.
“If we get some suppression, it certainly pays for itself,” Barten says.
He estimates that applying Serenade Soil costs about $20 per acre, in line with the cost of similar conventional products.
Wysocki Farms also has used Blocker (PCNB) fungicide, and Barten says Serenade Soil typically is comparable.
AgraQuest says the product increases yields and plant size. Although Barten did not formally evaluate Serenade Soil on those criteria, he says he did not notice an increase in tuber yields or plant size.
Time will tell whether the company stays with Serenade Soil, but Barten says he’s leaning in that direction.
“I think Serenade will always be some part of Wysocki’s program,” he says.
Varied onion results
Bill Gasser, pest control adviser and consultant for Basin Fertilizer & Chemical Co. in Merrill, Ore., has been involved with tests of Serenade Soil on dehydrator onions for two seasons.
He noticed good results in 2010.
But preliminary indications as digging began in mid-October this season showed no difference on white rot or yields.
“The [return on investment] was favorable,” he says about last year’s trials. He saw a 15 percent increase in yields.
This year, he tried two different rates but did not see any difference in yields or incidence of white rot. But white rot pressure was low this season.