Articles
EFFECTS OF PLANT DENSITY, HARVEST METHODS AND BENDING OF BRANCHES ON THE PRODUCTION AND QUALITY OF ROSES
Article number
547_37
Pages
311 – 317
Language
Abstract
Modern rose growers in The Netherlands are increasingly using ‘heightened systems’. In these systems the plants grow in artificial root substrate which is mounted well above soil level, thus improving labour circumstances and creating space for bent branches. Using this system a crop is formed without the familiar plant form that the grower was used to.
When bottom- breaks are harvested near the base of the plant (on the first scale) or even very near to the base (arching-method or knuckle-cut), the shape of the rose bush remains rather small.
In the cropping systems used here, branches are regularly bent.
The bending increases the light-interception.
Two experiments were carried out to investigate the influence of harvest methods and plant density (experiment A) and bending of branches (experiment B) on the production and quality of roses.
Experiment A (February 1996 – January 1998) investigated the combinations of harvest method (first-scale and knuckle-cut), variety (‘Bianca’,’First Red’,’Frisco’ and ‘Mercedes’) and plant density (10, 7.5 and 5 plants per m2). Production and quality of the harvested roses were measured.
Experiment B (April 1997 – September 1998) investigated four different methods of bending on two varieties (‘First Red’ and ‘Frisco’). Production, quality of the harvested product, Leaf Area Index (LAI) of the bent branches and the photosynthesis of the leaves on the bent stems were measured.
A higher plant density gave a higher production, but production levels differed per variety.
Average stem weight was higher with a lower plant density.
An interaction between plant density and harvest method was observed. A very small difference in harvested weight was found between the plant density when the roses were cut on the first scale.
The production was higher when roses were constantly harvested on the first scale.
The knuckle-cut method gave a higher stem weight but results differed per variety.
More and regular bending of branches gave a lower production of stems but a higher average stem weight, although there were differences per variety.
The production in kg/m2 differed per variety but the influence of bending was only visible for Frisco.
The LAI could vary per plant and per season and was not always influenced by bending.
Leaves on branches which were bent showed a higher photosynthetic efficiency of photosystem II. Leaves on stems which were bent had a leaf temperature of about one degree C lower than the temperature of leaves on harvestable upright stems.
When bottom- breaks are harvested near the base of the plant (on the first scale) or even very near to the base (arching-method or knuckle-cut), the shape of the rose bush remains rather small.
In the cropping systems used here, branches are regularly bent.
The bending increases the light-interception.
Two experiments were carried out to investigate the influence of harvest methods and plant density (experiment A) and bending of branches (experiment B) on the production and quality of roses.
Experiment A (February 1996 – January 1998) investigated the combinations of harvest method (first-scale and knuckle-cut), variety (‘Bianca’,’First Red’,’Frisco’ and ‘Mercedes’) and plant density (10, 7.5 and 5 plants per m2). Production and quality of the harvested roses were measured.
Experiment B (April 1997 – September 1998) investigated four different methods of bending on two varieties (‘First Red’ and ‘Frisco’). Production, quality of the harvested product, Leaf Area Index (LAI) of the bent branches and the photosynthesis of the leaves on the bent stems were measured.
A higher plant density gave a higher production, but production levels differed per variety.
Average stem weight was higher with a lower plant density.
An interaction between plant density and harvest method was observed. A very small difference in harvested weight was found between the plant density when the roses were cut on the first scale.
The production was higher when roses were constantly harvested on the first scale.
The knuckle-cut method gave a higher stem weight but results differed per variety.
More and regular bending of branches gave a lower production of stems but a higher average stem weight, although there were differences per variety.
The production in kg/m2 differed per variety but the influence of bending was only visible for Frisco.
The LAI could vary per plant and per season and was not always influenced by bending.
Leaves on branches which were bent showed a higher photosynthetic efficiency of photosystem II. Leaves on stems which were bent had a leaf temperature of about one degree C lower than the temperature of leaves on harvestable upright stems.
Authors
J. de Hoog, M. Warmenhoven, B. Eveleens-Clark, N. van Mourik, N. MARISSEN
Keywords
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