Articles
Effect of nitrogen supply, plant spacing, and cultivar on hollow stem development in broccoli
Article number
1327_19
Pages
149 – 154
Language
English
Abstract
Hollow stem is a frequent physiological disorder of broccoli starting with small elliptical cracks in the inner stem tissue.
As plants approach maturity these fissures enlarge and result in an undesirable cavity, which may adopt a brown discoloration prior to or after harvest.
In this case, the produce is usually rejected by the food retail trade.
Previous studies indicate that factors favoring rapid and strong plant growth promote the formation of hollow stem incidences in broccoli.
Therefore, this study aimed to investigate the impact of the nitrogen supply (100, 200, and 300 kg N ha-1) and planting distance (60×40 cm and 30×20 cm) in this respect.
The field experiments were conducted with two broccoli cultivars, ‘Parthenon’ and ‘Naxos’. The frequency and intensity of hollow stems was significantly influenced by plant spacing, nitrogen supply, and broccoli cultivar.
Almost no hollow stem was found with close planting.
At common plant density, the proportion of hollow stem increased with increasing nitrogen supply.
The cultivar ‘Parthenon’ proved to be particularly susceptible with a proportion of hollow stems between 30% (low N supply) and 70% (high N supply). ‘Naxos’ showed a distinctly lower cavity formation ranging from 1% (low N supply) to 28% (high N supply). Overall, the occurrence of the physiological disorder was closely correlated with the stem diameter (r2=0.93) and the head weight (r2=0.74). Scarcely any cavities were observed in broccoli with a stem diameter of less than 3.4 cm or a head weight of less than 450 g.
In the high-density plantation the head weight was usually too low for marketing of the produce even when two inflorescences were bundled.
Thus, further investigations are needed to determine the optimal plant spacing of broccoli considering both hollow stem incidences and marketable head weight.
As plants approach maturity these fissures enlarge and result in an undesirable cavity, which may adopt a brown discoloration prior to or after harvest.
In this case, the produce is usually rejected by the food retail trade.
Previous studies indicate that factors favoring rapid and strong plant growth promote the formation of hollow stem incidences in broccoli.
Therefore, this study aimed to investigate the impact of the nitrogen supply (100, 200, and 300 kg N ha-1) and planting distance (60×40 cm and 30×20 cm) in this respect.
The field experiments were conducted with two broccoli cultivars, ‘Parthenon’ and ‘Naxos’. The frequency and intensity of hollow stems was significantly influenced by plant spacing, nitrogen supply, and broccoli cultivar.
Almost no hollow stem was found with close planting.
At common plant density, the proportion of hollow stem increased with increasing nitrogen supply.
The cultivar ‘Parthenon’ proved to be particularly susceptible with a proportion of hollow stems between 30% (low N supply) and 70% (high N supply). ‘Naxos’ showed a distinctly lower cavity formation ranging from 1% (low N supply) to 28% (high N supply). Overall, the occurrence of the physiological disorder was closely correlated with the stem diameter (r2=0.93) and the head weight (r2=0.74). Scarcely any cavities were observed in broccoli with a stem diameter of less than 3.4 cm or a head weight of less than 450 g.
In the high-density plantation the head weight was usually too low for marketing of the produce even when two inflorescences were bundled.
Thus, further investigations are needed to determine the optimal plant spacing of broccoli considering both hollow stem incidences and marketable head weight.
Authors
A. Frieman, C. Vorsatz, D. Daum
Keywords
broccoli (Brassica oleracea L. var. italica), hollow stem, plant density, nitrogen fertilization
Groups involved
- Division Plant Genetic Resources, Breeding and Biotechnology
- Division Tropical and Subtropical Fruit and Nuts
- Division Temperate Tree Fruits
- Division Vine and Berry Fruits
- Division Ornamental Plants
- Division Vegetables, Roots and Tubers
- Division Plant-Environment Interactions in Field Systems
- Division Greenhouse and Indoor Production Horticulture
- Division Postharvest and Quality Assurance
- Division Precision Horticulture and Engineering
- Division Horticulture for Human Health
- Division Temperate Tree Nuts
- Division Landscape and Urban Horticulture
- Division Sustaining Horticulture in a Changing World
- Working Group Humulus and Other Cannabaceae
Online Articles (111)