Recognizing the needs of California coastal and desert Southwest spinach growers, Royal Sluis is committed to developing downy mildew resistant spinach varieties that are suitable for the baby
leaf, fresh market, cello pack and processing markets. In June, more than 60 spinach growers and seed dealers met at the Seminis research station in San Juan Bautista to attend a presentation on downy mildew and to view trials of new downy mildew resistant spinach varieties from Royal Sluis.

Jon Hubbard, a Seminis plant pathologist, told the group, "Downy mildew thrives in the cool, moist climate of coastal California and spores can be dispersed by the frequent winds that are typical of the area. The big problem with downy mildew is that we have had no varieties combining resistance to all of the different races we know are attacking fields in the area."

According to Brand Coordinator Rene Beussen, Royal Sluis is breeding its spinach lines to address that very problem. "Every spinach line we have in development for North America will have resistance to seven races of downy mildew," he says. "This will allow growers throughout the West to plant Royal Sluis spinach with confidence knowing that these new varieties will be resistant to whatever race is in their area. And, because Race Seven hasn't yet made it to North America, the growers know they'll have some insurance against it when it does."

Because it is of such importance to growers, Seminis evaluates for downy mildew resistance meticulously. "We make our evaluations on young plants in a controlled environment," says Hubbard. "We assess reactions on both true leaves and cotyledon tissues and inoculations are made twice to minimize escapes." 

"We expect to have seed available for commercial trialing on six new varieties in October," said Beussen. "I've seen them in Europe and I think they'll perform just as well here." 

Currently, Unipack 277 is proving to be an outstanding variety for Royal Sluis. It is excellent for baby leaf and cello pack with its slightly savoy, glossy, round leaves. A vigorous upright plant habit and an attractive dark green color have made Unipack 277 a popular choice for growers. Two other varieties are also working well for growers. Unipack 12 is very uniform and has an extremely wide harvest window and the exceptionally vigorous Unipack 271 is holding well against downy mildew Race 6.

Royal Sluis products are available through authorized Petoseed dealers. Royal Sluis is a member of the Seminis family of companies and its North American sales administration is located in Oxnard, CA.

Company news release
N2883