Environmental effects on linseed (Linum usitatissimum L.) yield and growth of flax at different stand densities

摘要

In field trials in 1995-98 on different soils in Viterbo, Italy, linseed cv. Mikael was sown at rates of 200, 400, 600 or 800 seeds/m2 in the first 2 years, and 400 or 800 seeds/m2 in the other years. Growth analysis using the functional approach and modelling using the SUCROS model for potential production parameterized for linseed were used to carry out a more detailed analysis of environmental effects. Linseed yields varied greatly in response to weather and soil type but showed very little effect of plant density. The crop was able to compensate for reduced stand densities mainly by increasing the number of capsules per plant. All yield components were significantly influenced by weather as represented by the year of sowing. Growth analysis showed that the unit leaf rate had higher values at lower stand densities, suggesting that self-shading at higher densities decreased the efficiency of the foliage. The environmental factors most likely to affect yields were high temperature, due to its effect on development rate and the consequent shortening of the growing cycle, and possibly water shortage. The foliage duration was more important than the maximum leaf area index.