Safflower: Response to row configuration and population under different irrigation regimes in 2014

Abstract

Key findings •The current commercial safflower varieties, Sironaria and S317, have similar agronomic characteristics including plant structure, flowering time and yield potential. •Flowering duration was consistently 10 days, irrespective of irrigation regime or row spacing. Increasing plant population progressively shortened the flowering phase. •Safflower sown at 34 cm row spacing in a four-plant row configuration yielded 25% more than when sown at 60 cm row spacing in a three-plant row configuration. •Safflower has considerable compensatory ability to maintain yield at various plant populations. Yield was maximised at plant population thresholds of between 20 and 40 plants/m2. Yield declined at populations of 10 and 60 plants/m2. •Under a dryland regime (full soil water profile at sowing), yield progressively declined as populations increased above 20 plants/m2. •The dryland regime significantly out-yielded the two in-crop irrigation treatments at target populations of 10 and 20 plants/m2. •A single irrigation applied at early elongation consistently out-yielded the dryland and two in-crop irrigation treatments. •Compared with other treatments, two in-crop irrigations reduced yield. Two in-crop irrigations had no significant effect on yield at populations of 20 plants/m2 and greater. •Increasing populations from 10 plants/m2 to 40 and 60 plants/m2, decreased seed size by 9%. Seed size was not affected by irrigation regime or row configuration. •Plant height and the height above ground of the lowest flower increased as population increased. Effects on plant structure would not present harvest difficulties.