EFFECTS OF ENVIRONMENTAL FACTORS ON GRAIN YIELD AND QUALITY OF OATS (AVENA SATIVA L.) CULTIVATED IN FINLAND

Grain yield and yield quality characteristics were studied in the two oat varieties, Puhti and Veli, during 4 different years, 1987–90. The growing period of 1987 was extremely cold, while 1988 was warm and dry. Oat trials were established at eight locations throughout the oat cultivation area of Finland. Information on climatic and edaphic factors, as well as fertilization levels, was used to explain the variation in grain yield and quality characteristics by multiple step‐wise regression analysis. High temperatures during the growing period (x) significantly decreased grain yields (y) in the early variety Veli (y = 9241 — 335x). P fertilization was the main yield increasing factor in the later Puhti variety. The early variety, Veli, is better adapted to cultivation in a cool climate than the later variety, Puhti. Protein content was significantly decreased by heavy precipitation and oil content significantly increased by a low temperature during the growing period in both test varieties. High precipitat...