Articles
ALCOHOL DEHYDROGENASE INDICATING OXYGEN DEFICIENCY IN CHRYSANTHEMUM GROWN IN MINERAL MEDIA
Article number
401_33
Pages
273 – 282
Language
Abstract
In order to evaluate growth differences of chrysanthemum cv. ‘Improved Reagan’ in mineral growing media, root porosity, activity of the enzyme alcohol dehydrogenase (ADH) in the roots and leaf mineral concentrations were determined in a number of experiments.
In the first three experiments the growth of chrysanthemum on sand (volumetric air content 7–18 %) and two perlite fractions (volumetric air content 16–31% and 60–63%, respectively) was compared at two fertigation frequencies.
In the first two experiments (carried out in September through January) using drip fertigation no effects of oxygen deficiency on shoot growth were found.
Shoot fresh weight, ADH activity and root porosity were lower and percentage dry weight was higher in the coarse perlite treatments, suggesting water/nutrient stress.
ADH activity decreased during growth.
In the third experiment (February-March) the same media and pumice (vol. air content 39%) in combination with two fertigation frequencies were used with ebb and flow fertigation.
Shoot fresh weight was both lower in sand (oxygen stress) and in coarse perlite and pumice treatments (water/nutrient stress). Besides a higher ADH activity in the sand treatments no clear differences (root porosity, leaf mineral concentrations, percentage dry weight) were found between the sand and the fine perlite treatments.
It is suggested that oxygen stress in the roots of chrysanthemum may occur at volumetric air contents below ca. 35%. However, oxygen stress resulting in a yield decrease probably depends on climatic conditions.
In the first three experiments the growth of chrysanthemum on sand (volumetric air content 7–18 %) and two perlite fractions (volumetric air content 16–31% and 60–63%, respectively) was compared at two fertigation frequencies.
In the first two experiments (carried out in September through January) using drip fertigation no effects of oxygen deficiency on shoot growth were found.
Shoot fresh weight, ADH activity and root porosity were lower and percentage dry weight was higher in the coarse perlite treatments, suggesting water/nutrient stress.
ADH activity decreased during growth.
In the third experiment (February-March) the same media and pumice (vol. air content 39%) in combination with two fertigation frequencies were used with ebb and flow fertigation.
Shoot fresh weight was both lower in sand (oxygen stress) and in coarse perlite and pumice treatments (water/nutrient stress). Besides a higher ADH activity in the sand treatments no clear differences (root porosity, leaf mineral concentrations, percentage dry weight) were found between the sand and the fine perlite treatments.
It is suggested that oxygen stress in the roots of chrysanthemum may occur at volumetric air contents below ca. 35%. However, oxygen stress resulting in a yield decrease probably depends on climatic conditions.
Authors
R. Baas, M.G. Warmenhoven
Keywords
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