The growth of safflower (Cathamus tinctorius L.) in a low latitude environment

Abstract

At the Kimberley Research Station, W.A., growth studies on safflower were made on a uniform crop in one year, and in the following year on a density experiment and a time of nitrogen application experiment. Density treatments extended from 25 to 1120 plants m^-2, to exploit as fully as possible the light environment in the crop canopy. In the nitrogen treatments, 90 kg ha^-1 of nitrogen was applied at seeding, elongation, and budding in an attempt to increase grain yield by increasing the size of the terminal inflorescences.

Although at higher densities the light microenvironment was exploited early there was no increase in total dry matter, and grain yield was highest with densities of about 100 plants m^-2. In the nitrogen experiments the early indications of higher yields due to treatment did not materialize as the crop matured, because rising temperatures at flowering and during seed development retarded further growth.

On the average, grain yield or economic yield constituted 20% of the total dry matter of tops. There was a greater difference in total dry matter and grain yield between years than between treatments within one year, and this was interpreted as a time of planting effect.

The effects of rising temperatures during seed formation are discussed. Avenues for further work are suggested.