<b>Adaptability and stability of reproductive and vegetative phases of peach trees in subtropical climate

Abstract

ABSTRACT. The peach tree (Prunus persica) is a fruit species native to temperate climates that requires a chill during its hibernal period to overcome dormancy. However, due to genetic breeding, varieties are currently grown in subtropical and tropical regions where there are low occurrences of chill during this phenological stage. This study evaluated the adaptability and stability of the reproductive and vegetative phases of peach tree cultivars in a subtropical climate. An experiment was designed in randomized blocks with split time plots, with 23 peach tree cultivars and four replications, with each replication consisting of one plant and four shoots. The years of evaluated (plots) and the cultivars (subplots) were considered to be treatments. The relative rates of budburst (RRB), flowering (RRF), shoot formation (SF) and fruit set (FS), average time of budburst (ATB) and flowering (ATF), duration of budburst (DB) and flowering (DF) and number of hours with temperatures below 7.20°C were evaluated during the experimental period. The cultivars 'Bonão', 'Ouromel-4', 'Libra' and 'Maciel' demonstrated greater adaptability during the vegetative phase, whereas'Ouromel-4' and 'Libra' demonstrated greater adaptability and stability during the reproductive phase of peach trees in a subtropical climate.Keywords: Prunus persica, fruit set, shoot formation, chill requirement.Adaptabilidade e estabilidade de fases reprodutivas e vegetativas de pessegueiros em clima subtropical RESUMO. O pessegueiro (Prunus persica) é uma frutífera de clima temperado e necessita de frio durante o repouso hibernal para superar a dormência, entretanto, atualmente é cultivado em regiões subtropicais e tropicais, onde há menor ocorrência de frio durante essa fase fenológica. Este trabalho teve como objetivo avaliar a adaptabilidade e a estabilidade das fases vegetativa e reprodutiva de cultivares de pessegueiro em clima subtropical avaliando os estádios de brotação e floração. O delineamento utilizado foi em blocos casualizados com quatro repetições e quatro ramos por repetição, em esquema de parcelas subdivididas no tempo, no qual as parcelas representam o tempo (2 ciclos produtivos) e as subparcelas as cultivares (23). Foram avaliados a duração da brotação (DB) e floração (DF), o tempo médio de brotação (ATB) e floração (ATF), a quantidade de gemas vegetativas brotadas (RRB) e floríferas brotadas (RRF), a formação de ramos (SF) e frutificação efetiva (FS) e o número de horas com temperatura abaixo de 7,2ºC e 12ºC, e acima de 20ºC durante o período experimental. As cultivares 'Bonão', 'Ouromel-4', 'Libra' e 'Maciel' apresentam maior adaptabilidade e estabilidade da fase vegetativa e 'Ouromel-4' e 'Libra' apresentam maior adaptabilidade e estabilidade da fase reprodutiva de pessegueiro sob clima subtropical. Palavras-chave:Prunus persica, frutificação efetiva, formação de ramos, requerimento em frio.

Determination of Potential Pollinizer Grafted Pear Hybrids (Pyrus communis × Pyrus pyrifolia) for Subtropical Regions in Brazil

“…The plant material was collected during 2015 and 2016 in Lavras, Brazil located at latitude 21º14′ S, longitude 45º00′ W, and at an altitude of 841 m above mean sea level. The climate of the experimental site is classified as Cwa (subtropical climate, with cold and dry winter and hot and humid summer) (Souza et al, 2017). Seven Pyrus communis × Pyrus pyrifolia hybrid cultivars were evaluated: Cascatense, Centenária, D'água, Primorosa, Seleta, Tenra, and Triunfo (Table 1).…”

Influence of Temperature on the Development of Peach Fruit in a Subtropical Climate Region

“…The phenological study was carried out in six plants per cultivar and monitored every day right after the dormancy period from the beginning of flowering (BF) until the end of harvest (EH) in the plant as a whole. For the fruit development analysis, the phenological stages were related to the GDD during the productive cycle (Table 1): (I) beginning of flowering (BF), corresponding to 5% of open flowers; (II) full bloom (FB), when 50% of flowers are opened; (III) end of flowering (EF), when over 75% of flowers are opened and the petals of flowers begin to fall; (IV) end of harvest (EH), referring to the period of the final harvest of fruits, where they are in the senescence stage; and productive cycle (PC), which is the chronological time in days from FB to EH, according to Souza [20]. Table 1.…”

Simultaneous selection of peach rootstocks by mixed models

“…The longevity, economic and environmental viability of a peach orchard (Prunus persica L.) are directly correlated with the rootstock that is used, as well as the grafting affinity between the cultivar and rootstock (Reig et al, 2019). The recommendation of superior peach genotypes should meet the minimum criteria that allow inferring about the genotypic potential in the cultivation environment (Souza et al, 2017). In this context, the preference for rootstock cultivars with superior characteristics that result in better fruit quality and greater adaptability and production stability is of great interest.…”