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Registro Completo |
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Biblioteca(s): |
Embrapa Semiárido. |
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Data corrente: |
27/07/1995 |
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Data da última atualização: |
20/11/2018 |
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Autoria: |
BOHART, G. E.; NEY, W. P.; HAWTHORN, L. R. |
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Afiliação: |
George E. Bohart, Utah State University; William P. Nye, Utah State University; L. R. Hawthorn. |
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Título: |
Onion pollination as affected by different levels of pollinator activity. |
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Ano de publicação: |
1970 |
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Fonte/Imprenta: |
Logan: Utah State University, Agricultural Experiment Station, 1970. |
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Páginas: |
57 p. |
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Descrição Física: |
il. |
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Série: |
(State University. Agricultural Experiment Station. Bulletin, 482). |
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Idioma: |
Inglês |
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Conteúdo: |
According to Jones (1937), the pollination of onion (Allium cepa Linnaeus) is effected mainly by insects that visit the nectaries at the base of the three inner tamens. Muller (1833) and Jones (1937) stated that cross-pollination is the rule, although self-pollination between flowers of the same umbel is undoubtedly of frequent occurrence. Muller (1883) and Hayward (1938) reported that the flowers are imperfectly proterandrousthe anthers of the inner whorl of stamens dehisce before those of the outer. Both whorls dehisce before the stigma is receptive. Moll (1953) stated that the normal receptive period of the stigma is 3 days. Several investigators have noted that onion flowers are visited freely by many kinds of insects, including honey bees. (Apis melli/era Linnaeus) (Muller, 1883; Jones and Emsweller, 1934; Shaw et. at. 1935; Kordakova, 1956). For this reason, it has often been taken for granted that pollination is not a limiting factor in onion seed production in spite of the tremendous variation known to occur in yields from different fields, seasons, and cultural practices (Morse, 1923; Hawthorn, 1951). The recent development of hybrid seed grown on male-sterile inbreds pollinated by male-fertile inbreds has intensified the pollination problem. Pollinating insects are required to disseminate pollen over 6 to 12 or more rows from two pollen parent rows Complicating problems are the supposed relative unattractiveness of malesterile plants to pollen-collecting insects and the possibility that their receptive period will not coincide with the pollen dehiscence period of the pollen parents. Another problem, and one particular to the Treasure Valley of Idaho and Oregon (the most important onion seed producing area in the U. S.) has been the great increase in alfalfa seed production, resulting in thousands of acres of alfalfa bloom which drain off populations of honey bees and other pollinators. Finally, increased use of insecticides has reduced the populations of pollinators. In Treasure Valley, the widespread use of Dylox (sometimes called Dipterex) for alfalfa insect control has probably had a particularly disa strous impact on dipterous pollinators. In 1958, we started a 4-year program to learn more about the pollination factor as it affects onion seed production. In the following discussion, the methods, conditions, and results for each year will be treated separately, and a general discussion will follow. Handling of the plots and methods of measurement were the same from year to year unless otherwise stated. 1958 Methods and Materials Location White farm, northeast bench, Logan, Utah. Treatments The three treatments (randomized within the row of plots) were as follows: (1) Plots caged to admit only tiny insects; (2) plots without cages (open pollination); and (3) plots caged to enclose a small (four-frame) colony of honey bees. The cages (Pedersen et aI., 1950) were 21.5 feet long, 11 feet wide, 6 feet high, and covered with 12-mesh clear lumite screen. As soon as flowering began in late June, the cages were erected and the hives of bees installed. Plot layout In 1958, there were 12 plots that measured 10 x 20 feet arranged in a single row. Each plot contained five rows, each planted with 40 onion bulbs. The rows were 2 feet apart, and the plants were spaced ab()ut 6 inches apart in the rows. The center row was plante:! with U-16-3-10- 2B, a male-fertile inbred line. The other four rows were planted with the following three male-sterile inbreds: B-1900A, B-2147A, and B-2267A. Two rows of the B-2267 A were planted in each plot and the positions of all the male-sterile rows were randomized. More than one male-sterile line was used merely because we were unable to obtain enough bulbs of a single line. When the bulbs were obtained, we anticipated that male sterility would be complete, but at least a small amount of pollen was present in all of the lines. MenosAccording to Jones (1937), the pollination of onion (Allium cepa Linnaeus) is effected mainly by insects that visit the nectaries at the base of the three inner tamens. Muller (1833) and Jones (1937) stated that cross-pollination is the rule, although self-pollination between flowers of the same umbel is undoubtedly of frequent occurrence. Muller (1883) and Hayward (1938) reported that the flowers are imperfectly proterandrousthe anthers of the inner whorl of stamens dehisce before those of the outer. Both whorls dehisce before the stigma is receptive. Moll (1953) stated that the normal receptive period of the stigma is 3 days. Several investigators have noted that onion flowers are visited freely by many kinds of insects, including honey bees. (Apis melli/era Linnaeus) (Muller, 1883; Jones and Emsweller, 1934; Shaw et. at. 1935; Kordakova, 1956). For this reason, it has often been taken for granted that pollination is not a limiting factor in onion seed production in spite of the tremendous variation known to occur in yields from different fields, seasons, and cultural practices (Morse, 1923; Hawthorn, 1951). The recent development of hybrid seed grown on male-sterile inbreds pollinated by male-fertile inbreds has intensified the pollination problem. Pollinating insects are required to disseminate pollen over 6 to 12 or more rows from two pollen parent rows Complicating problems are the supposed relative unattractiveness of malesterile plants to pollen-collecting insects an... Mostrar Tudo |
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Palavras-Chave: |
Apicultor. |
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Thesagro: |
Abelha; Cebola; Polinização. |
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Thesaurus Nal: |
Bee pollen; Pollination; Pollinators. |
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Categoria do assunto: |
O Insetos e Entomologia |
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Marc: |
LEADER 04627nam a2200241 a 4500
001 1142393
005 2018-11-20
008 1970 bl uuuu 00u1 u #d
100 1 $aBOHART, G. E.
245 $aOnion pollination as affected by different levels of pollinator activity.
260 $aLogan: Utah State University, Agricultural Experiment Station$c1970
300 $a57 p.$cil.
490 $a(State University. Agricultural Experiment Station. Bulletin, 482).
520 $aAccording to Jones (1937), the pollination of onion (Allium cepa Linnaeus) is effected mainly by insects that visit the nectaries at the base of the three inner tamens. Muller (1833) and Jones (1937) stated that cross-pollination is the rule, although self-pollination between flowers of the same umbel is undoubtedly of frequent occurrence. Muller (1883) and Hayward (1938) reported that the flowers are imperfectly proterandrousthe anthers of the inner whorl of stamens dehisce before those of the outer. Both whorls dehisce before the stigma is receptive. Moll (1953) stated that the normal receptive period of the stigma is 3 days. Several investigators have noted that onion flowers are visited freely by many kinds of insects, including honey bees. (Apis melli/era Linnaeus) (Muller, 1883; Jones and Emsweller, 1934; Shaw et. at. 1935; Kordakova, 1956). For this reason, it has often been taken for granted that pollination is not a limiting factor in onion seed production in spite of the tremendous variation known to occur in yields from different fields, seasons, and cultural practices (Morse, 1923; Hawthorn, 1951). The recent development of hybrid seed grown on male-sterile inbreds pollinated by male-fertile inbreds has intensified the pollination problem. Pollinating insects are required to disseminate pollen over 6 to 12 or more rows from two pollen parent rows Complicating problems are the supposed relative unattractiveness of malesterile plants to pollen-collecting insects and the possibility that their receptive period will not coincide with the pollen dehiscence period of the pollen parents. Another problem, and one particular to the Treasure Valley of Idaho and Oregon (the most important onion seed producing area in the U. S.) has been the great increase in alfalfa seed production, resulting in thousands of acres of alfalfa bloom which drain off populations of honey bees and other pollinators. Finally, increased use of insecticides has reduced the populations of pollinators. In Treasure Valley, the widespread use of Dylox (sometimes called Dipterex) for alfalfa insect control has probably had a particularly disa strous impact on dipterous pollinators. In 1958, we started a 4-year program to learn more about the pollination factor as it affects onion seed production. In the following discussion, the methods, conditions, and results for each year will be treated separately, and a general discussion will follow. Handling of the plots and methods of measurement were the same from year to year unless otherwise stated. 1958 Methods and Materials Location White farm, northeast bench, Logan, Utah. Treatments The three treatments (randomized within the row of plots) were as follows: (1) Plots caged to admit only tiny insects; (2) plots without cages (open pollination); and (3) plots caged to enclose a small (four-frame) colony of honey bees. The cages (Pedersen et aI., 1950) were 21.5 feet long, 11 feet wide, 6 feet high, and covered with 12-mesh clear lumite screen. As soon as flowering began in late June, the cages were erected and the hives of bees installed. Plot layout In 1958, there were 12 plots that measured 10 x 20 feet arranged in a single row. Each plot contained five rows, each planted with 40 onion bulbs. The rows were 2 feet apart, and the plants were spaced ab()ut 6 inches apart in the rows. The center row was plante:! with U-16-3-10- 2B, a male-fertile inbred line. The other four rows were planted with the following three male-sterile inbreds: B-1900A, B-2147A, and B-2267A. Two rows of the B-2267 A were planted in each plot and the positions of all the male-sterile rows were randomized. More than one male-sterile line was used merely because we were unable to obtain enough bulbs of a single line. When the bulbs were obtained, we anticipated that male sterility would be complete, but at least a small amount of pollen was present in all of the lines.
650 $aBee pollen
650 $aPollination
650 $aPollinators
650 $aAbelha
650 $aCebola
650 $aPolinização
653 $aApicultor
700 1 $aNEY, W. P.
700 1 $aHAWTHORN, L. R.
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| 14. |  | ALVARENGA, R. C.; BORGHI, E.; GONTIJO NETO, M. M. Integração lavoura-pecuária-floresta. In: PEREIRA FILHO, I. A.; RODRIGUES, J. A. S. (Ed.). Sorgo: o produtor pergunta, a Embrapa responde. Brasília, DF: Embrapa, 2015. cap. 16, p. 267-279. (Coleção 500 perguntas, 500 respostas).| Tipo: Capítulo em Livro Técnico-Científico |
| Biblioteca(s): Embrapa Milho e Sorgo. |
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| 19. | | ALVARENGA, R. C.; GONTIJO NETO, M. M.; KLUTHCOUSKI, J. O milho na integração lavoura-pecuária. In: CRUZ, J. C.; MAGALHAES, P. C.; PEREIRA FILHO, I. A.; MOREIRA, J. A. A. (Ed.). Milho: o produtor pergunta, a Embrapa responde. Brasília, DF: Embrapa Informação Tecnológica; Sete Lagoas: Embrapa Milho e Sorgo, 2011. cap. 17, p. 269-278. (Coleção 500 perguntas, 500 respostas).| Tipo: Capítulo em Livro Técnico-Científico |
| Biblioteca(s): Embrapa Arroz e Feijão; Embrapa Milho e Sorgo. |
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