Row spacing × population effects on yield and seed size in linseed – 2015 and 2016

Abstract

Key findings •In most situations, the 17 cm row spacing resulted in optimum grain production. •Crop establishment decreased as row spacing increased. Crop establishment was reduced by up to 49% when the row spacing increased to 66 cm. •Crop establishment rates declined as seeding rates increased. •Row spacings had mixed effects on yield. When sown before June with no pest pressure, yields were up to 62% higher at 17 cm row spacing than 33 cm and 66 cm spacings. Row spacing had no effect on yield where experiments were sown in July or where there was high pest pressure at seed fill. •Plant population had no significant effect on yield at populations except where crop establishment was low, at populations less than 21 plants/m2. •Neither row spacing nor population affected seed size in 2015. Severe Rutherglen bug (Nysius vinitor) pressure during seed fill in 2016 could have affected results where row spacing and population individually and together significantly affected yield, harvest index and seed size.