Received for publication August 27, 1976. Paper No. 5062 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, North Carolina 27650. The use of tradenames in this publication does not imply endorsement by the North Carolina Agricultural Experiment Station of the products named, nor criticism of similar ones not mentioned.
The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper must therefore be hereby marked advertisement solely to indicate this fact.
Appreciation is expressed to Mikkelsens, Inc., Ashtabula, Ohio for provision of plants used in this study.