An evaluation of the maximum radius of the rosette as a growth index for subterranean clover

Summary The maximum radius of the rosette, defined as the distance from the centre shoot to the base of the leaf furthest from it, is highly correlated with yield of dry matter (r=0.98 to 0.93) over the earlier vegetative period, but becomes progressively less sensitive on approaching inflorescence.The maximum radius was tested for fidelity as a rapid index of dry-matter yield using data from other factorial eperiments. It proved satisfactory in nutrient experiments for the comparison of treatment means prior to harvesting, provided that correlation at harvest was greater thanr=0.85.The limitations of the index are discussed.