Physical Impedance Retards Top Growth of Tomato Transplants

Autor: Cyrus Samimy
Rok vydání: 1993
Předmět:
Zdroj: HortScience. 28:883-885
ISSN: 2327-9834
0018-5345
DOI: 10.21273/hortsci.28.9.883
Popis: Two-week-old 'Ohio 8245' tomato (Lycopersicon esculentum Mill.) seedlings were subjected to physical impedance by placing a sheet of Plexiglas on the shoots for 15 hours a night for 12 consecutive nights. This treatment reduced stem length by 21% and increased stem diameter by 20% compared to nontreated plants. Stems of treated seedlings were considered sturdier than those of nontreated seedlings since the treated seedlings remained erect for 28 to 33 days after impedance ended and the stems of control seedlings did not. Forty-four days after impedance ended, stems of treated plants were 18% shorter and 9% thicker than those of nontreated plants. The results showed that tomato seedlings subjected to impedance developed growth characteristics that are desirable in transplants. The use of greenhouse-grown, plug trans- plants to establish processing tomatoes in the field is replacing the use of field-grown trans- plants. The close spacing of plants in plug trays (200 to 400 cells/tray) can cause etiola- tion and excessively tall, low-quality trans- plants with thin stems. Thus, controlling seed- ling height in the greenhouse has become a major challenge to plug-transpla nt producers. Breaking tomato transplant stems during ship- ping or exposure to post-transpla nt winds would be less likely in short, sturdy seedlings. Applying the growth retardant butanedioic acid mono (2,2-dimethylhydrazide) (damino- zide, B-nine) no longer is permitted to control the growth of vegetable transplants. There- fore, research efforts have been directed to- ward studying the feasibility and effectiveness of nonchemical methods for restricting trans- plant stem elongation. Nonchemical height-control methods for seedlings that werereviewed by Latimer( 1991)
Databáze: OpenAIRE
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