Basal and Inflorescence Branching in Response to Planting Density in Flax Cultivars (Linum usitatissimum L.)

Abstract

Numbers of basal branches (BB) and inflorescence branches (IB), which vary with planting density, are the important seed yield components of flax (Linum usitatissimum L.). The effects of planting densiy on the development of BB and IB of oilseed and fiber flax cultivars were studied. Seeds of “Lirina” and “NR2” (oilseed-type) and “Aoyagi” and “Pernau 1” (fiber-type) were drill-sown with row spacing of 30 cm in 2017 and 2018. After emergence, plants were thinned to 1 cm spacing (high planting density) and 5 cm spacing (low planting density) within a row. The oilseed cultivars were shorter, had a longer inflorescence compared with the total length, and produced more capsules and seeds than the fiber cultivars. All cultivars had capsule-bearing BB at a low planting density. “Lirina” had fewer capsule-bearing BB than other cultivars. Compared with the oilseed cultivars, “Aoyagi” had fewer IB on the main stem but “Pernau 1” did not. In all the cultivars, both the number of IB on the main stem and the number of capsules per IB were higher at a low planting density than at a high planting density. The increase in the number of capsules per IB, which was partly caused by the development of secondary inflorescence branches, was more conspicuous in the oilseed cultivars than in the fiber cultivars.