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Publication
Germinação de diferentes cultivares de bermuda
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| 25.79 MB | Adobe PDF |
Advisor(s)
Abstract(s)
Em climas mediterrâneos, como o Algarvio, a Cynodon dactylon (Bermuda), além de bem-adaptada a altas temperaturas do Verão, permite poupar água que é um recurso cada vez mais escasso e, é uma das relvas mais resistente aos períodos de seca (Zhang et al., 2019), mantendo a sua cor verde. Esta é uma espécie com muito potencial para a adaptação às alterações climáticas.
A implantação de relvados de Bermuda, por semente, no início da estação quente é um problema pois esta precisa de altas temperaturas para germinar e, várias cultivares, têm uma baixa percentagem de germinação. Há pouca informação disponível para as cvs existentes no mercado. Estudou-se a germinação das sementes das cultivares de bermuda, (‘Nova Relva’, ‘Sultan’, ‘A. P. Jordão’, ‘Rocalba’, ‘Mónaco’ e ‘Arden’), atualmente fáceis de adquirir no mercado português, a 3 temperaturas 15ºC, 25ºC e 30ºC. Testou-se também o efeito da estratificação (a -1ºC e 4ºC) na germinação posterior a 25ºC, tentando saber se teria um efeito benéfico. Foram feitos um ensaio preliminar (sem repetições) e um completo sobre as temperaturas de germinação, e um ensaio exploratório (também sem repetições) sobre o efeito da estratificação.
Para os valores testados, quanto mais altas as temperaturas de germinação melhores as taxas de germinação. A 15ºC as melhores taxas de germinação foram obtidas de uma forma consistente com a bermuda genérica comercializada pela Nova Relva (≈28%) e com a cv Sultan (≈23%). A bermuda genérica comercializada pela A. P. Jordão também germinou bem no ensaio final (≈28%). As cvs Rocalba e Mónaco germinaram mal a 15ºC (≈10% e 1,5%, respetivamente) parecendo ser as cvs com piores germinações a esta temperatura.
A estratificação das sementes a baixas temperaturas não teve efeitos deletérios na germinação, sugerindo qua a sementeira precoce, antes do aparecimento das temperaturasconvenientes para germinação, não está fora de causa. Além disso, parece ter efeitos benéficos nas cvs a Mónaco e Nova Relva, nas quais a sua taxa de germinação parece significativamente aumentada com a estratificação.
Os dados obtidos podem ser depois utilizados, junto com as temperaturas do solo registadas nas várias zonas de Portugal Continental para estabelecer orientações sobre as épocas de sementeira.
In Mediterranean climates, such as the Algarve, Cynodon dactylon (Bermuda) is well adapted to high summer temperatures, allows a better water management, which is an increasingly limited resource, and is the most resistant to periods of drought (Zhang et al., 2019). Installing Bermuda grass by seed at the start of the warm season is a problem as it needs high temperatures to germinate and several cultivars have a low germination percentage. There is almost no information available about the cvs in the market. This study analyzes the seed germination on Bermudagrass cultivars, (‘Nova Relva’, ‘Sultan’, ‘A. P. Jordão’, ‘Rocalba’, Mónaco’ e ‘Arden’) easy to find in the Portuguese market, at three different temperatures: 15ºC, 25ºC e 30ºC. The effects of stratification were tested as well (at -1ºC and 4ºC) with germination at 25ºC. A preliminary trial (without repetitions) and a complete trial about germination temperature were made, and an exploratory trial (without repetitions) about stratification was also performed. For the temperatures tested, the higher the germination temperatures the better the germination rates. At 15ºC the best germination rates were consistently obtained with the common bermuda commercialized by Nova Relva (≈28%) and with ‘Sultan’ (≈23%) . The common Bermuda commercialized by A. P. Jordão also germinated well in the final trial (≈28%). The ‘Rocalba’ and ‘Mónaco’ cvs germinated poorly at 15ºC (≈ 10% and 1,5% respectively) and seem to be the cvs with the worst germination at these temperatures. The seed stratification at low temperatures had no deleterious effects on germination, suggesting that early seeding, before the right temperature/season for germination, is not out of question. Also, it seems to have beneficial effects on some cvs such as Mónaco and Nova Relva, in which their germination rate seems to be significantly increased by stratification. The data obtained can be used together with the soil temperatures, recorded in the various areas of mainland Portugal, to establish guidelines for sowing time.
In Mediterranean climates, such as the Algarve, Cynodon dactylon (Bermuda) is well adapted to high summer temperatures, allows a better water management, which is an increasingly limited resource, and is the most resistant to periods of drought (Zhang et al., 2019). Installing Bermuda grass by seed at the start of the warm season is a problem as it needs high temperatures to germinate and several cultivars have a low germination percentage. There is almost no information available about the cvs in the market. This study analyzes the seed germination on Bermudagrass cultivars, (‘Nova Relva’, ‘Sultan’, ‘A. P. Jordão’, ‘Rocalba’, Mónaco’ e ‘Arden’) easy to find in the Portuguese market, at three different temperatures: 15ºC, 25ºC e 30ºC. The effects of stratification were tested as well (at -1ºC and 4ºC) with germination at 25ºC. A preliminary trial (without repetitions) and a complete trial about germination temperature were made, and an exploratory trial (without repetitions) about stratification was also performed. For the temperatures tested, the higher the germination temperatures the better the germination rates. At 15ºC the best germination rates were consistently obtained with the common bermuda commercialized by Nova Relva (≈28%) and with ‘Sultan’ (≈23%) . The common Bermuda commercialized by A. P. Jordão also germinated well in the final trial (≈28%). The ‘Rocalba’ and ‘Mónaco’ cvs germinated poorly at 15ºC (≈ 10% and 1,5% respectively) and seem to be the cvs with the worst germination at these temperatures. The seed stratification at low temperatures had no deleterious effects on germination, suggesting that early seeding, before the right temperature/season for germination, is not out of question. Also, it seems to have beneficial effects on some cvs such as Mónaco and Nova Relva, in which their germination rate seems to be significantly increased by stratification. The data obtained can be used together with the soil temperatures, recorded in the various areas of mainland Portugal, to establish guidelines for sowing time.
Description
Keywords
Relvados Cynodon dactylon Temperatura Germinação Escarificação das sementes Resistência