Effect of seed source and seed phosphorus content on the growth and yield of wheat in north-eastern Victoria

Abstract

Summary. Wheat (Triticum aestivum L.) seed was grown at 2 locations differing in phosphorus (P) status (low and high) in north-eastern Victoria (36°S, 146°E), with applied superphosphate (kg P/ha: 0, 12, 24, 100 and 200), to produce seed of different P content. This seed was used in field and glasshouse experiments in 1993 and 1994 to investigate the effects of seed source and P content on the growth and yield of wheat. Wheat seed grown at the low P status site was smaller than seed grown at the high P status site, irrespective of the amount of applied P. Seed from the low P status site produced less early dry matter in both field and glasshouse experiments in 1993, but there was no effect of seed source on grain yield in either experiment. High seed P content either had no effect or reduced seedling emergence in the field experiments. In the glasshouse, low P content in seed from the low P status site resulted in reduced emergence. Increases in dry matter production and grain yield with higher seed P content were only observed in the drought season of 1994. Application of P resulted in increased emergence, dry matter production and grain yield at most seed P content levels but there were no significant interactions between seed P content and applied P. Application of N did not affect dry matter production in either year, but increased grain protein in both years and grain yield in 1993. Seed from low P status environments can affect early seedling growth but in average growing seasons, or in glasshouse conditions, wheat growth compensates so that differences in grain yield are not observed. However, in order to avoid risk of poor early seedling growth and possible yield penalties when the crop is stressed, wheat seed should be collected from adequate soil P status sites.