The influence of moisture regime on greenhouse rose production in various growth media

Abstract

The effect of irrigation regimes and growth media on the production and quality of ‘Baccara’ roses was examined in a greenhouse during the 1969/70 and 1970/71 seasons. The media tested were (a) sandy loam, (b) sandy loam mixed with peat moss, (c) vulcanic scoria (tuff), (d) sandy loam placed on top of the local soil; all except (d) were in raised benches. Two levels of fertilizers were examined in the tuff media. The irrigation treatments in the soil media were established according to pre-irrigation water suction in the range 5 to 50 centibars (cb). In the tuff media the irrigation treatments were scheduled at different frequencies ranging from eight irrigations per day to one irrigation every 2–3 days. Maximum flower production was obtained in sandy loam which was placed on top of the local soil and irrigated so that the soil water suction did not rise above 5 cb. Flower length was unaffected by the irrigation regime in this growth medium. Flower production in the raised benches dropped when the water suction was kept below 20 cb or when it was allowed to rise to 50 cb. On the other hand, the highest percentage of long-stem flowers was obtained when the water suction was maintained below 5 cb. No significant difference in flower production was found between 5–8 and 2 irrigations per day in the tuff media. Maximum yield from these treatments was significantly lower than that in the non-raised soil benches. An increase in fertilizer level had no effect on flower production or quality. The flowering buds were relatively small at the beginning of winter and became larger toward spring. Only minor effects of growth media and moisture regimes on bud weight were found.