SPRING WHEAT VARIETY TRIALS IN THE PRAIRIE PROVINCES

Abstract

A regression technique was used to analyze the behavior and adaptability of widely grown commercial strains of Canadian hard spring wheat. Yield advances achieved by plant breeding in the past 60 years were estimated. The analysis showed that the advantage derived from rust-resistant varieties has been to increase yields under high-productivity conditions. Manitou and Thatcher were shown to be the more widely adapted of the commercial strains considered. Park is adapted to high-productivity and Cypress to low-productivity conditions.The same method was used to analyze results from trials including strains from Mexico. Pitic 62 is a high-yielding variety shown to have low phenotypic stability. Of the strains tested, Carazinho is phenotypically the most stable but also has the lowest yield. This yield difference was particularly marked at the higher productivity levels.