Loading...
Publication
Adaptação da fenologia do pessegueiro a uma escala numérica : estudo preliminar
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 2.46 MB | Adobe PDF |
Authors
Abstract(s)
Com o objetivo de estudar a fenologia do pessegueiro com base em escalas numéricas, foram acompanhados 3 pomares de pessegueiro na região da Beira Interior (cada pomar com uma diferente cultivar), durante 4 anos. A fenologia do pessegueiro foi inicialmente registada de acordo com os estados fenológicos de Baggiolini (1952). O crescimento do fruto foi acompanhado pela medição dos diâmetros e posterior elaboração de uma curva de crescimento em dupla sigmoide. Para estudar a influência das temperaturas no desenvolvimento do gomo e do fruto, utilizou-se o somatório das temperaturas médias positivas (> 0oC) a partir do início do ano. Posteriormente, adaptou-se uma escala numérica de 1 (estado 1 – intumescimento do gomo) a 16 (data da colheita), permitindo o ajustamento de um modelo fenológico em função do somatório dos graus.dia, que se mostrou altamente significativo (P < 0,001) e com uma precisão elevada (R2 ≈ 99%). Este modelo permitiu caracterizar todo o período de desenvolvimento reprodutivo do pessegueiro, tendo-se verificado diferentes somatórios de graus-dia do início do ano até ao estado 1 e somatórios de graus.dia idênticos, para a mesma cultivar e local, do estado 1 à plena floração e do estado 1 à colheita . Este facto só foi possível porque o modelo permitiu fazer coincidir a contagem do somatório dos graus.dia com o início da atividade do gomo (estado 1), sugerindo a possibilidade de fazer previsões sem necessidade de estabelecer valores fixos para a data de início do somatório dos graus.dia e para a respetiva temperatura base.
Abstract: Peach phenology adaptation to a numeric scale. Preliminary study. To study peach phenology with numeric scales, 3 different peach orchards, which one with a different cultivar, were monitored during 4 years at “Beira Interior” region of Portugal. At first, peach phenological stages were recorded as in Baggiolini (1952). To elaborate a growth curve (double sigmoid), the fruit diameter was measured. To study the influence of temperatures on bud and fruit development, the sum of mean positive temperatures from 1st January was used. Afterwards, a modified numeric scale from 1 (stage 1 - bud swelling) to 16 (harvest date), allowing to fit a phenological model as a function of the sum of degree.days, which proved to be highly significant (P < 0.001) and efficient (R2 ≈ 99%). This model allowed to characterize all the peach reproductive development period, with different sums of degree.days from the beginning of the year to stage 1 and identical sums of degree.days, for the same cultivar and location, from stage 1 to full bloom and to stage 1 to harvest. This fact was only possible because the model has made possible to match the count of the sum of degree.days with the beginning of the activity of the bud (stage 1), suggesting the possibility of making predictions without establishing fixed values for the moment to start accounting the degree.days and the respective base temperature.
Abstract: Peach phenology adaptation to a numeric scale. Preliminary study. To study peach phenology with numeric scales, 3 different peach orchards, which one with a different cultivar, were monitored during 4 years at “Beira Interior” region of Portugal. At first, peach phenological stages were recorded as in Baggiolini (1952). To elaborate a growth curve (double sigmoid), the fruit diameter was measured. To study the influence of temperatures on bud and fruit development, the sum of mean positive temperatures from 1st January was used. Afterwards, a modified numeric scale from 1 (stage 1 - bud swelling) to 16 (harvest date), allowing to fit a phenological model as a function of the sum of degree.days, which proved to be highly significant (P < 0.001) and efficient (R2 ≈ 99%). This model allowed to characterize all the peach reproductive development period, with different sums of degree.days from the beginning of the year to stage 1 and identical sums of degree.days, for the same cultivar and location, from stage 1 to full bloom and to stage 1 to harvest. This fact was only possible because the model has made possible to match the count of the sum of degree.days with the beginning of the activity of the bud (stage 1), suggesting the possibility of making predictions without establishing fixed values for the moment to start accounting the degree.days and the respective base temperature.
Description
Dissertação apresentada à Escola Superior Agrária de Castelo Branco do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Engenharia Agronómica.
Keywords
Prunus persica Fenologia do pessegueiro Modelo fenológico Escala numérica Somatório de graus.dia Peach phenology Phenological model Numeric scale Sum of degree.days