THE FIELD PEA CROP IN SW AUSTRALIA .2. EFFECTS OF CONTRASTING MORPHOLOGY AND ENVIRONMENT ON REPRODUCTIVE-PERFORMANCE

Reproductive performance of six field pea genotypes was assessed at th ree contrasting field sites in Western Australia and under optimal con ditions in a glasshouse using comparative data on phenology, branching pattern, green area indices, number distribution and fruiting success of reproductive nodes and final seed yields per plant or unit crop ar ea. Two genotypes (Dundale and Wirrega) were tall, indeterminate and c onventionally leaved, the other four semi-dwarf and more erect. Three of the latter were semi-leafless (Dinkum, L82 and L80) and the other t are-leaved (Progreta). Seed yields at the field sites increased genera lly in relation to rainfall during the growing season (May-October), v iz. Avondale (267 mm), Wongan Hills (350 mm), Mt Barker (421 mm). Supe rior performance at Mt Barker was related to greater biomass and green area index and higher number of reproductive nodes and pods per plant , but not to increased branches per plant, pods per node, seeds per po d or seed size. Improved harvest index, larger seeds and greater repro ductive yield from basal and aerial branches were responsible for the trellised well-watered and fertilized glasshouse plants mostly outyiel ding those at the field sites. Field-site specific superiority of cert ain genotypes over others was evident, e.g. the top ranking performanc e of the deeper-rooted, late maturing Wirrega at the drier sites of Av ondale or Wongan Hills and the much improved performance of the semi-l eafless types in the extended cool and moist season of Mt Barker. Poor seed yields of tall types relative to their vegetative biomass were p ronounced at Mt Barker due to poor fruit set and seed filling in the s everely lodged and self-shaded canopies. Data are discussed in relatio n to previous cultivar evaluations and ideotype prescriptions by other workers in Australia or overseas.