EFFECT OF POTASSIUM FERTILIZATION OF PYRETHRUM (TANACETUM-CINERARIIFOLIUM) ON YIELD, PYRETHRINS CONCENTRATION IN DRY ACHENES AND POTASSIUM CONCENTRATION IN SOIL AND PLANT-TISSUES
Aa. Salardini et al., EFFECT OF POTASSIUM FERTILIZATION OF PYRETHRUM (TANACETUM-CINERARIIFOLIUM) ON YIELD, PYRETHRINS CONCENTRATION IN DRY ACHENES AND POTASSIUM CONCENTRATION IN SOIL AND PLANT-TISSUES, Australian Journal of Agricultural Research, 45(3), 1994, pp. 647-656
Pyrethrum (Tanacetum cinerariifolium), a small perennial plant, has be
en commercially grown for production of pyrethrins (Py) in Tasmania si
nce 1983. Two field experiments were conducted on clay loam and sandy
clay loam krasnozem soils at Harford and North Motton in the northern
region and a two-year experiment on an alluvial sandy loam at Ouse in
the southern region of Tasmania to study its potassium (K) requirement
s. Potassium, at rates up to 200 kg K ha-1, was band-placed at plantin
g (basal K) of pyrethrum splits. At Ouse in the spring of the followin
g year up to 100 kg K ha-1 was side-dressed in the subplots. No achene
yield response was observed at Harford with the soil Colwell K (K(c))
of 80 mg K kg-1 and North Motton (K(c) = 132), but at Ouse (K(c) = 50
) in the first year a maximum increase of 86% in the achene yield was
attained at 50 kg K ha-1. In the second year at Ouse, the achene yield
response occurred with residual basal K up to the 200 kg ha-1 rate, w
here the achene yield was 3 - 9-fold greater than the control. In addi
tion to the increase gained from the residual K in the second year, 50
kg side-dressed K ha-1 increased the achene yield by a maximum of 50%
. Basal K did not have any effect on the Py concentration of the first
year crops, but it increased the Py concentration in the second year
crop at Ouse. Side-dressed K also increased the Py concentration. The
Py yield at the highest rate of 200 kg basal and 25 kg side-dressed K
ha-1 was more than 6.5-fold that in the control treatment. The K(c) an
d the concentration of K in apical tissues were correlated to the rate
s of applied K, achene yield and Py yield, and their potential as tech
niques to predict pyrethrum response to K application is discussed.