Rose culture in scoria. [Conference paper].
1980
Feigin A. | Dasberg S. | Singer Z.
A greenhouse experiment was carried out from November 1970 to July 1973. Roses (cv. Baccara) growing in 20-, 30- or 40-cm-deep beds of partially weathered scoria (lapilli tuff), were treated with six different nutrient solutions: three levels of N - 100, 200 and 300 pp, combined with two levels of K - 100-200 and 300 ppm K. The pH of the substrate was affected by the N treatments, being ca. 7-8, 6-7 and 5-6 in the low, medium and high N levels, respectively. A high yield was obtained in the 200 ppm N treatment. No further yield increase resulted from the application of 300 ppm N, but a singificantly lower yield was measured with 100 ppm N. A significant positive response to K was detected in the first season, when 300 ppm was compared with 200 ppm K. No significant effect of K on the yield was found later, probably due to the increased quantites of K adsorbed on the scoria surface (a phenomenon typical to a weathered or partially weathered scoria). No significant effect of scoria depth on flower yield or quality was detected. The results of this experiment were subsequently confirmed by observations in commercial greenhouses.
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