The seeds were germinated at 16 degsC and were transplanted on the appearance of two to three, five to six or eight to nine true leaves. The Linaria and Papaver plants were grown on in growth chambers at night/day temperatures of 5 degsC/11 degsC, 10 degsC/16 degsC or 15 degsC/21 degsC with a 12-hour day. The Lupinus seedlings were grown on in plastic greenhouses with night/day temperatures of 15 degsC/24 degsC, 18 degsC/25 degsC or 21 degsC/26 degsC in natural day lengths.
The optimum production temperature for Linaria was 10 degsC/16 degsC, especially if seedlings were transplanted at the two-to-three leaf stage. With Lupinus, the longest stems and the highest profitability were obtained at the 15 degsC/24 degsC temperature combination when seedlings were transplanted at the two-to-three leaf stage. Each plant of Papaver produced more than four stems and produced long stems most quickly at 15 degsC/21 degsC but they took more than 109 days to flower. Linaria appeared to be the most profitable crop as it produced a high number of marketable stems in a relatively short time. All three species suffered damage from thrips and powdery mildew.
Production Protocol Development for Greenhouse Cut Linaria, Lupinus, and Papaver Flowers by Dole and Greer (2009). Scientia Horticulturae 122 (2): 233- 237.The contents of issues of Scientia Horticulturae and abstracts of papers are provided at www.elsevier.com/locate/scihorti.