Potential of Onion Seed Production in a Tropical Environment

Kariuki, J.L.W; Peters, R. D.; Kimani, P. M.; Rabinowitch, Haim D.

doi:10.17660/actahortic.1994.358.56

Cited by 3 publications

(2 citation statements)

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“…As a result inflorescence primordia in larger bulbs are in a more advanced stage than those of small bulbs at the time of planting, resulting in earlier inflorescence emergence (early bolting) and floret opening. Studies were made to explore the possibility of producing onion seed using artificial vernalization and vernalization under natural conditions at high altitude in Kenya [20]. Bulbs were stored for 8 weeks in a cold room (5˚C or 10˚C), in a well-ventilated storage room at high altitude (2530 m.a.s.l, average temperature 13.4˚C) or at room temperature at a lower altitude (1820 m.a.s.l, average temperature 21.9˚C).…”

Section: Vernalizationmentioning

confidence: 99%

Flowering and Seed Development in Onion—A Review

Khokhar¹

2014

OALib

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Proper vernalization temperature of mother onion bulbs stimulates early flowering and produces a heavier yield of seed. Moreover, onion cultivars seem to differ in their optimal temperature requirements depending on the locality to which they are adapted. Most studies on the effects of storage temperature on inflorescence initiation in onion have shown that the optimum temperature for flowering is in a range between 5˚C to 13˚C for 90 to 120 days and bolting resistant varieties require a longer cold stimulus (154 -185 days) in comparison to normal spring sown cultivars. Flowering is greatly reduced or suppressed at temperatures in the range of 15.5˚C -30˚C and low temperatures of −3˚C to 0˚C. Studies on both bulbs and seedlings have shown that, depending on genotype, flower initiation starts only after a juvenile phase, when the plant has a minimum number of 4 -14 leaves, including leaf initials. The initiation of inflorescence is favoured by a large set or bulb size. The post planting environmental conditions greatly affect bolting percentage of bulbs stored at an inductive temperature. Maximum seed yield in onion has been reported from large mother bulbs and early planting time. The emergence of inflorescence is faster at high temperatures (20˚C -30˚C) and long days (14 -16 hours).

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Section: Vernalizationmentioning

confidence: 99%

Flowering and Seed Development in Onion—A Review

Khokhar¹

2014

OALib

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“…Vernalization in onion is an important research interest because of the need to induce flowering for seed production for breeding purposes in the shortest period of time (Brewster, 1987). Lack of cold temperatures to induce flowering is the prime constrain to onion seed production in tropical countries (Kimani et al, 1994). The reaction of plants to vernalization is occurred by the combination of 2 factors, the duration of the vernalization period and the temperature during the vernalization period (Hodges and Ritchie, 1991;.…”

Section: Introductionmentioning

confidence: 99%

Vernalization and Gibberellic Acid Response in Summer Onion’s (Allium Cepa L.) Reproductive Phases

Khatun¹,

Karim²,

Talukder³

et al. 2020

Trop.cal.Agr

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The present study was aimed at determining the effect of vernalization and Gibberellic Acid (GA3) on seed yield and quality of summer onion. There were three vernalization treatments viz., no vernalization (control), vernalization at 5°C for 14 days and vernalization at 10°C for 14 days and four GA3 treatment viz., 0, 50, 100 and 150 ppm. The two-factor experiment was laid out in the Randomized Complete Block Design with three replications. The results of the experiment showed that the vernalization and GA3 had significant influence on all the parameters studied. Solitary Effect of vernalization and GA3 was significant on the parameters such as plant height, number of leaves plant-1 , the highest number of flowering stalk, number of umbels plant-1 , number of bud umbel-1 , percent flowering at 45 and 60 DAP, number of seeds umbel-1 , weight of seeds umbel-1 , weight of seeds plant-1 , weight of seeds plot-1 , 1000 seed weight, seed yield, number of fruits umbel-1 , percent of fruit set umbel-1 and percent germination. The highest seed yield (248.16 kg ha-1) was obtained from vernalization at 5°C for 14 days. The lowest values of all the parameters were recorded at control treatment. The highest seed yield (191.77 kgha-1) was obtained from 100 ppm GA3. The lowest values of all the parameters were recorded in the 0 ppm GA3 treatment. Use of suitable vernalization of mother bulb and proper concentration of gibberellic acid can be a possible way to expand onion production at the time of summer.

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Vernalização em bulbos e efeito no rendimento e potencial fisiológico de sementes de cebola

Reghin¹,

Otto²,

Olinik³

et al. 2005

Hortic. Bras.

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O estado do Paraná contribui significativamente para o abastecimento de cebola no Brasil. No entanto, a atividade de produção de sementes está muito aquém do desejado, o que torna urgente a necessidade de pesquisa nessa área. Este experimento foi conduzido em Ponta Grossa (PR) e teve como objetivo avaliar o efeito de períodos de vernalização em bulbos de tamanhos diferentes, no rendimento e potencial fisiológico de sementes de cebola da cultivar Crioula. O delineamento experimental utilizado foi de blocos casualizados, com quatro repetições; os tratamentos foram dispostos segundo esquema fatorial 4x2, sendo quatro períodos de vernalização a 5(0)C (controle, 25; 35 e 45 dias) e dois tamanhos de bulbos, T1 (6,9 cm de diâmetro) e T2 (4,8 cm). A vernalização contribuiu para o aumento do rendimento de sementes. Quanto maior o período de tratamento, maior o percentual de umbelas com flores, o número de hastes florais, o número total de cápsulas e de cápsulas com sementes. Estes componentes promoveram maior rendimento de sementes por umbela, tanto em número como em peso, apresentando os períodos de 35 e 45 dias como os mais favoráveis. No entanto, no rendimento de sementes por planta, prevaleceu apenas a superioridade do período de 45 dias. O potencial fisiológico das sementes não foi afetado pelos tratamentos, tendo sido observados resultados acima de 80,0% no teste de primeira contagem e acima de 90,0% no percentual de germinação, independentemente do tratamento. O tamanho do bulbo maior (T1) apresentou efeito significativo apenas no número de hastes florais e de flores fecundadas, que contribuíram para o maior rendimento de sementes por planta, quando comparado ao tamanho T2.

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Potential of Onion Seed Production in a Tropical Environment

Cited by 3 publications

References 0 publications

Flowering and Seed Development in Onion—A Review

Flowering and Seed Development in Onion—A Review

Vernalization and Gibberellic Acid Response in Summer Onion’s (Allium Cepa L.) Reproductive Phases

Vernalização em bulbos e efeito no rendimento e potencial fisiológico de sementes de cebola

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