The nutrition of container - grown lisianthus (Lisianthus russellianus)

Abstract

The response of lisianthus to N, P, K and lime was studied using a four factor central composite second order design with incomplete blocks. Added nutrients were 0-600 g m⁻³ N, 0-400 g m⁻³ P and 0-600 g m⁻³ K. Lime application was 0-12 kg m⁻³. High levels of N and P depressed plant growth and caused a reduction in plant height, stem thickness, shoot dry weight and number of flowers. Foliar chlorosis and the number of days from sowing to anthesis increased as the rates of these two nutrients were raised.

Increasing rates of fertiliser K up to 300 g m⁻³ caused an increase in stem diameter and reduced chlorosis and number of days to anthesis. Levels of K higher than this caused a reduction in growth of the plant. High levels of lime in the growing medium caused the strongest growth response. Plant height, stem diameter, shoot dry weight and number of flowers all increased as more lime was added. Foliar chlorosis and days to flowering decreased with increasing liming rate.

The best growth of this crop occurred at low levels of fertiliser N and P (below 150 g m⁻³), medium K (300 g m⁻³) and at high lime (12 kg m⁻³).