1Received for publication March 20, 1982. Scientific Paper No. 6174, Washington State University, College of Agriculture, Pullman. Project No. 1957 and 0038. Partially supported by grants from Columbia River Orchards Foundation and Oregon Strawberry Commission.
The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.
2Current address: Dept. of Plant & Soil Science, University of Idaho, Moscow, ID 83843.