In a previous investigation, the wide amplitude of plant resistance of different soybean varieties to soybean borer has been discovered. Our further experiments are directed at the discovery of the main mechanisms of this resistance. It is known that the phenomenon of plant resistance to in-sects may be classified into three components: nonpreference, antibiosis, and tolerance (Painter, 1951). We use the term nonpreference when the plant is an unfavorable object for feeding and oviposition.

Introduction: In the summer of 1978, four chlorophyll-chimeric plants were observed within a population of 'Clark'. The four plants had a similar phenotype, and were surmised to originate from a common parent. These four plants were single-plant threshed.

In 1976, a plant was selected from the M3 generation of some 'Essex' soybeans that had been irradiated with neutrons and grown at the Eastern Virginia Research Station, Warsaw. The plant had a green stem and reduced seed set. The progeny row grown the following year had all normal appearing plants.