Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 40: 2652 - 2658. Published April 12, 2011.
Effects of seasons of bulb and seed production on the early bolting of onion (Allium cepa L.) cv ‘violet de Galmi’.
M. Tarpaga Windpouiré Vianney 1, Albert Rouamba1 , Tamini Zoumbiessé 2
1 Institut de l’Environnement et de Recherches Agricoles (INERA), Programme Cultures Maraîchères, Fruitières et Plantes à Tubercules, BP: 403 Bobo-Dioulasso Burkina Faso.
2 Université de Ouagadougou , 09 BP : 848 Ouagadougou 09 Burkina Faso.
ABSTRACT
Objectives: This study that was carried out from 2006 to 2009 in northern Burkina Faso, in Sudano-Sahelian climatic zone aimed to measure how the seasons of bulbs and seed production can affect early bolting of onion plants.
Methodology and results: The effects of three seasons of bulb production and two seasons of seed production are assessed with five types of onion seed produced by bulbs. Two variables ((seed sensitivity and their average time to bolt) were used. When producing seeds in normal season, we recorded 75.3 ± 6.4 % of bolting and 133.6 ± 2.9 days as time to bolt if the bulbs used were produced in normal season. If the bulbs were produced in the late season, 93.3 ± 2.9 % of bolting and 134.1 ± 1.8 days of time to bolt were recorded.
Conclusions and application of findings: This study shows that low temperatures lead to plant bolting by two ways. The first one is the result of a direct effect of low temperatures when growing plants in cool season. As the best yields are obtained both for bulbs and seeds in cool seasons, it is advice to produce at this time. The second way concerns the bulbs used for producing seeds. The cooler the season of bulbs production, the more resistant to bolt will be the seeds produced from these bulbs. So, we advise onion seed producers to sow in very cool season for obtaining bulbs. This approach will allow a better selection of bolting resistant bulbs before producing seeds. Thus, the results of this study permit to foresee the possibility of breeding bulbs by an artificial and very cold treatment for onion seed production.
Keywords: Onion, bolting, season, bulbs, seed, temperature
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