Yield, final population and emergence of seed treated lucerne (Medicago sativa L.) sown on five dates

Abstract

Dryland seedling lucerne establishment was examined at Lincoln University, Canterbury, New Zealand. Stands were sown on 4 October, 4 November, 2 December 201 O and 10 January and 7 February 2011 with four seed treatments; bare seed, ALOSCA ® granules, coated seed and peat inoculant. Accumulated crop dry matter (DM) yield decreased with each successive sowing from 15 t/ha to 2.5 t/ha for the latest sowing date. Lower DM yields were explained by less intercepted light and a change in DM partitioning from shoots to roots. The latest sowing grew 1.84±0.26 kg DM/ °Cd compared with 3.84±0.22 kg DM/ °Cd for the earliest sowing. Coated seed produced a higher (P<0.001) initial plant population of 331 plants/m2 which was 68% of the 490 seeds/m2 sown. It also had the highest population 12 months later although seedling numbers had declined by 27%. Thus, adequate plant populations were established from all sowing dates and seed treatments including the bare seed control