ISHS Acta Horticulturae 644: International Symposium on Growing Media and Hydroponics
YIELD AND FRUIT QUALITY OF TOMATO GROWN IN A CLOSED HYDROPONIC GREENHOUSE SYSTEM AS AFFECTED BY YTHIUM ULTIMUM ATTACK AND BIOLOGICAL CONTROL AGENTS |
| Authors: | B.W. Alsanius, S. Lundqvist, E. Persson, K.-A. Gustafsson, M. Olsson, S. Khalil |
| Keywords: | acidity, ascorbic acid, bca, dehydroascorbic acid, dry matter, malondialdehyde, NFT, nutrient film technique, plant growth-promoting rhizobacteria, PGPR, Pseudomonas fluorescens, Pythium ultimum |
| DOI: | 10.17660/ActaHortic.2004.644.77 |
| Abstract:
Tomato plants (Lycopersicon esculentum cv. Gitana) grown in a closed system using nutrient film technique (NFT) were subjected to a two-factorial trial, i.e with or without artificial inoculation of Pythium ultimum (Pu) and with or without seed inoculation with the plant growth-promotive Pseudomonas fluorescens-strains 5.014 and 5-2/4, resulting in 4 treatments (i) non-inoculated control, (ii) control exposed to Pu, (iii) seed inoculation with 5.014 and exposed to Pu and (iv) seed inoculation with 5-2/4 and exposed to Pu. Fruits were analyzed three times every second week from week 13 through 17 after transfer to the NFT-system. The accumulated yield and fruit size were positively affected by seed inoculation with levels comparable to the non-inoculated control. The number of flowers in the first truss was higher in the seed inoculated treatments regarding both control treatments. Blossom-end rot was most abundant on fruit when plants were exposed to Pu only, but also occurred in the treatment with 5-2/4 and Pu. The harvest incident affected all the measured fruit quality parameters. Content of soluble sugars and ratio of soluble sugars : titrable acid increased in all treatments during the observation period and significant differences were established for the treatment using Pu only and 5-2/4 + Pu, respectively. The content of ascorbic acid (AA), dehydroascorbic acid (DHAA) and malondialdehyde (MDA) was lowest for fruit exposed to the combined treatments and a similar trend was found for DHAA and MDA. | |
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