Linseed genotype growth and development response to varying sowing date – Narrabri 2015

Abstract

Key findings •Time to flowering progressively decreased in all genotypes when sown after mid April on all sowing dates (SD) with the exception of the early May SD. •The Glenelg variety genotype was quickest to start flowering and the quickest to mature on all sowing dates. Croxton was the slowest to start flowering. •The genotypes LM14 and LM17 showed no significant difference in the time to flowering. Differences between genotypes decreased as sowing was delayed beyond 28 May (SD3). •Glenelg was the quickest to finish flowering when sown in April and May. Flowering ceased in all genotypes in late September and early–mid October for April and May SDs. •Environmental conditions, principally high temperatures, halted flowering in all genotypes for SD4 (26 June) and SD5 (13 July). The flowering duration was greatest for SD4 and SD5, due to the short vegetative growth period. •The flowering period was shortest in all genotypes for SD3 (28 May). •LM14 and LM17 displayed no significant difference in growth and development traits and agronomic characteristics, including days to the start and end of flowering, plant height, height of lowest capsule, branching, number of seeds per capsule, and the number of infertile capsules per plant. •Overall plant height and the height above ground of the lowest capsule decreased as SD was delayed. The Glenelg plant structure was the most compact of the genotypes tested. •Sowing date had a significant effect on seed size. Linseed sown in July (SD5) was 22% smaller than that sown in April (SD1). Glenelg had the largest seed size at 5.34 g/1000 seeds. •The data suggests that the optimal sowing window for the four genotypes was late April to early May at Narrabri.