Agronomic studies in flax (Linum usitatissimum L.) in south-eastern Australia

This paper reports on field agronomy studies into flax (Linum usitatissimum L.) conducted in Tasmania, Australia from 1994 to 1997. These studies investigated the performance of selected cultivars, and responses to sowing date, plant density and irrigation. The work formed part of a feasibility study assessing the potential of fibre hemp (Cannabis sativa L.) and flax as sources of fibre for the Australian newsprint industry. Two cultivar evaluation trials were conducted at the University of Tasmania Farm, Cambridge, in Tasmania's south-east. One of these included 7 European and Australian flax cultivars, and the other, 4 mucilage linseed cultivars. The European flax cultivars yielded significantly more stem and bark fibre than the Australian flax cultivars. Of the former group, Ariane (841 g/m2) and Marina (883 g/m2) performed the best in terms of stem yield production, while Viking had comparable bark yields to these 2 cultivars. With the exception of cv. Kreola (543 g/m2), which produced comparable stem yields to the Australian flax cultivars, the linseed cultivars were short and produced relatively low stem yields. Interestingly, seed yields (149-194 g/m2) were not superior to those for the flax cultivars (156-218 g/m2). While offering little dual-purpose seed/fibre potential, they may supply a future niche market for seed production. Three other trials were conducted to investigate the response of flax to seeding rate and sowing date, and the interactions between seeding rate, sowing date and irrigation availability. Autumn sowings of flax gave higher yields of both stem and seed compared with winter and spring sowings. Reasonable stem and seed yields were achieved from dryland cropping of flax. However, good results from such rainfed crops in Tasmania will depend on autumn sowing and good rainfall during winter and spring seasons. There were clear yield benefits from irrigation between early November and January, when the amount and distribution of rainfall was poor. The selection of an optimum seeding rate will depend on the sowing date and involve a compromise between maximising yield and minimising potential losses from lodging. The decreased occurrence of lodging with winter and spring sowings in this study, suggests that later sowings can accommodate higher seeding rates.