Biological determinants of plant and crop productivity of flax (Linum usitatissimum L.)

In Poland the cultivation of the fibrous form of flax (Linum usitatissimum L.) is dying out, but the acreage of its oilseed form, linseed, which provides seed (Semen lini) used in therapy and being a source of -linolenic acid, is expanding. Nowadays, linseed is grown in 64 countries of the world, but yield levels in these countries vary greatly. Under European conditions, seed yield of linseed shows high variation, which is evidence of little knowledge of the biology of this plant and the lack of precise cultivation solutions in agricultural technologies used. A major reason is the difficulty in obtaining optimal crop density. A sparse crop results in low above-ground biomass yield, which is translated into insufficient crop yields. The selection of highly productive domestic and foreign varieties can partially increase linseed yield; apart from some domestic varieties, the Canadian cultivar 'Flanders' and the Hungarian cultivar 'Barbara' are positive examples in this respect. There is a possibility of effective selection at early stages of linseed breeding, which bodes well for the prospect of obtaining highly productive varieties with normal or very low -linolenic acid content.