Loading...
Publication
Estudo da floração e polinização do abacateiro, no Algarve
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 4.66 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
O abacateiro possui características únicas a nível da floração. Apesar das flores serem
hermafroditas, apresentam um mecanismo sequencial das suas funções reprodutivas,
primeiro abrem como femininas e depois, numa segunda abertura, são funcionalmente
masculinas, dificultando a autopolinização. Este mecanismo denomina-se sincronia
dicogâmica protogínica. Dependendo do momento do dia em que isso ocorre, os
abacateiros são classificados em dois grupos, grupo A e grupo B, que quando colocados
em conjunto no mesmo pomar, permitem a polinização entre si. As condições
meteorológicas, nomeadamente a temperatura, humidade relativa e nebulosidade
modificam o comportamento de ambos os grupos, principalmente, hora de início e
duração de cada uma das fases da flor.
Uma vez que a maior parte dos estudos sobre floração e polinização em abacateiro têm
sido conduzidos em zonas com características edafoclimáticas diferentes das do Algarve,
é necessário estudar estes processos, com vista a desenvolver conhecimento e técnicas
culturais que permitam aumentar a produtividade dos pomares.
Considerando que a cultivar 'Hass' (grupo A) é a mais valorizada comercialmente,
aparecendo como cultivar principal em quase todos os pomares portugueses, com
polinizadoras do grupo B, foi definida como objetivo avaliar a pertinência da instalação
de árvores polinizadoras e a compatibilidade entre 'Hass' e 'Ettinger', 'Bacon' e 'Zutano'.
Assim, avaliou-se o seu comportamento floral, através da observação ao longo do dia,
durante vários dias, registando o número de flores abertas e seus estágios fenológicos.
Os resultados obtidos mostram que a abertura das flores da cultivar ‘Hass’ na fase
feminina se concentra principalmente entre as 11 e as 14 horas, podendo apresentar
sobreposição com a fase masculina da mesma cultivar. Verificou-se que nos dias mais
frios a abertura das flores era mais tardia e permaneciam abertas durante mais tempo. Nas
cultivares polinizadoras a abertura das flores na fase masculina é variável, sendo a cultivar
‘Bacon’ a que apresenta uma maior sobreposição com a ‘Hass’ ao longo do dia. Verificouse
também que há uma forte correlação entre a produção do ano anterior e o estado
fenológico no início dos lançamentos reprodutivos, havendo um claro atraso nas árvores
cuja produção foi mais elevada.
Study on avocado flowering and pollination in the Algarve The avocado has unique characteristics in terms of flowering. Although the flowers are hermaphrodite, they present mechanisms that do not allow self-pollination. The flowers open twice, first as female, then close and, in a second opening, are functionally male. This mechanism is called protogynic dicogamous synchrony. Depending on the cultivar, the flowers open in the female phase in the morning or in the afternoon. Avocado trees are classified according to their floral behavior in two groups, group A and group B, which allow cross-pollination between them. Changes in temperature, relative humidity and cloudiness modify the behavior of both groups, namely, time of onset and duration of each phase of the flowering. Since most of the studies on flowering and pollination in avocado have been conducted in areas with different soil and climatic characteristics than in the Algarve, it is necessary to study these processes under our conditions, in order to develop knowledge and farming techniques to increase the productivity of orchards. Considering that the cultivar 'Hass' (group A) is the most commercially valued, appearing as main cultivar in almost all Portuguese orchards, with pollinators of group B, it was defined as an objective to evaluate the pertinence of the installation of pollinating trees and the compatibility between 'Hass' and 'Ettinger', 'Bacon' and 'Zutano'. Thus, it was evaluated its floral behavior, through observation throughout the day, during several days, registering the number of open flowers and their phenological stages. The results show that the opening of the flowers of the cultivar 'Hass' in the female phase is mainly concentrated between 11 and 14 hours, and may overlap with the male phase of the same cultivar. It was found that in the coldest days the opening of the flowers was later and remained open for a longer time. In pollenizers, the flower opening in the male phase is variable, with the cultivar 'Bacon' having the greatest overlap with 'Hass' throughout the day. It was also found that there is a strong correlation between the production of the previous year and the phenological state at the beginning of the reproductive launches, with a clear delay in the trees whose production was higher.
Study on avocado flowering and pollination in the Algarve The avocado has unique characteristics in terms of flowering. Although the flowers are hermaphrodite, they present mechanisms that do not allow self-pollination. The flowers open twice, first as female, then close and, in a second opening, are functionally male. This mechanism is called protogynic dicogamous synchrony. Depending on the cultivar, the flowers open in the female phase in the morning or in the afternoon. Avocado trees are classified according to their floral behavior in two groups, group A and group B, which allow cross-pollination between them. Changes in temperature, relative humidity and cloudiness modify the behavior of both groups, namely, time of onset and duration of each phase of the flowering. Since most of the studies on flowering and pollination in avocado have been conducted in areas with different soil and climatic characteristics than in the Algarve, it is necessary to study these processes under our conditions, in order to develop knowledge and farming techniques to increase the productivity of orchards. Considering that the cultivar 'Hass' (group A) is the most commercially valued, appearing as main cultivar in almost all Portuguese orchards, with pollinators of group B, it was defined as an objective to evaluate the pertinence of the installation of pollinating trees and the compatibility between 'Hass' and 'Ettinger', 'Bacon' and 'Zutano'. Thus, it was evaluated its floral behavior, through observation throughout the day, during several days, registering the number of open flowers and their phenological stages. The results show that the opening of the flowers of the cultivar 'Hass' in the female phase is mainly concentrated between 11 and 14 hours, and may overlap with the male phase of the same cultivar. It was found that in the coldest days the opening of the flowers was later and remained open for a longer time. In pollenizers, the flower opening in the male phase is variable, with the cultivar 'Bacon' having the greatest overlap with 'Hass' throughout the day. It was also found that there is a strong correlation between the production of the previous year and the phenological state at the beginning of the reproductive launches, with a clear delay in the trees whose production was higher.
Description
Keywords
Dicogamia Floração Hass Polinização Protoginia