EFFECTS OF SOWING TIME ON GROWTH AND GRAIN-YIELD OF LUPIN AND HELD PEA IN SOUTH-EASTERN NEW-SOUTH-WALES

Cultivars of lupin and field pea were grown at different times over 4 years on a red earth at Wagga Wagga, New South Wales, to assess the influence of sowing time on growth and production from each crop. The cultivars of field pea (Pisum sativum) included Dinkum, Derrimut, Dunn, and Maitland; lupins used were Lupinus angustifolius cvv. Danja, Gungurru, and Geebung, and either the L. angustifolius line 75A/330 (1989-90) or L. albus cv. Ultra (1991-92). When autumn rain was sufficient to allow sowing, highest yield and dry matter production of lupin were gained by sowing from late April to 19 May. Yields declined with later sowing, though high spring-summer rainfall in 1992 reversed the decline. There was little difference between Danja, Gungurru, and Geebung, but these were usually higher yielding than the semi-dwarf 75A/330 when sown early. However, Ultra produced higher yields than the L. angustifolius cultivars in 1991 and 1992, particularly under high rainfall conditions. Early-sown crops (late April-mid May) of field peas were often severely infected with black spot blight and, in 1 year, with sclerotinia. In 1992 these diseases, devastated all cultivars when sown on 1 May. Sowing later markedly reduced disease infection but also reduced grain yields and dry matter when sown after late June. The semi-leafless, semi-dwarf cultivar Dinkum was usually the lowest yielding and displayed the highest incidence of black spot blight.