Chilling requirement for seed germination and phenological observations on peach cultivars

Abstract

RESUMO Necessidade de frio para estratificação das sementes e observações fenológicas em cultivares de pessegueiroEm regiões de clima subtropical, os modelos e métodos propostos para avaliação da necessidade de frio das fruteiras de clima temperado não apresentam, muitas vezes, resultados satisfatórios. Isto demonstra a necessidade do desenvolvimento de alternativas para se estimar a necessidade de frio dessas plantas. Este trabalho teve como objetivo analisar as correlações entre os dados fenólogicos e a necessidade de frio das sementes de 18 cultivares de pessegueiro e um cultivar de nectarineira. Para realização dos estudos de correlação, foram realizados dois experimentos, separadamente, sendo o primeiro por acompanhamento das características fenológicas em campo e, o segundo, com o estudo da necessidade de frio acumulado, para germinação de 50 e de 100% das sementes, de cada cultivar. Houve correlação significativa entre o número de dias necessários para o início do florescimento (r = 0,70**, 0,55*) e plena floração (r = 0,72**, 0,73**) e o número de unidades de frio acumulado, para germinação de 50 e de 100% das sementes estratificadas. O número de dias para o início da brotação e fim da dormência apresentou correlação significativa com o número de unidades de frio acumulado, para 50 e 100% de germinação (r = 0,48*, 0,50*, respectivamente). Received:12/06/2012; Accepted: 28/11/2012 Chilling requirement for seed germination and phenological observations on peach cultivarsIn subtropical climate areas, the models and methods proposed to evaluate the chilling requirement of temperate fruit crops often do not provide satisfactory results, thus calling for the development of alternative techniques. The aim of this study was to evaluate the correlations between some phonological traits and chilling requirement for seed germination of 18 peach cultivars and one nectarine cultivar. Two experiments were installed separately for the correlation studies. In experiment 1, the phenological traits were observed in the field, while in experiment 2, the chilling requirement for 50 and 100% seed germination of each cultivar was assessed. The number of days for beginning of bloom (r = 0.70**, 0.61**) and full bloom (r = 0.72**, 0.76**) were both significantly correlated with the number of chilling units for 50% and 100% germination of seeds. The number of days for beginning of budding and dormancy break were both significantly correlated with the number of chilling units for 50% and 100% germination (r = 0.48*, 0.50*, respectively). However, the same significant effect for these phenological traits was not found between chilling units and 50% germination of seeds, as well as between chilling units and harvest dates.

Optimization of germination and initial quality of seedlings of Prunus persica tree rootstocks

“…In this case, exposure to cold is required to break dormancy and activate peach seed germination (Wagner Júnior et al, 2013). Seeds not exposed to the adequate conditions for overcoming dormancy may not germinate or may produce abnormal seedlings, with physiological symptoms of dwarfism.…”

Robust PLS models for soluble solids content and firmness determination in low chilling peach using near-infrared spectroscopy (NIR)

“…In temperate regions peach trees (Prunus persica L.) require exposure to chilling temperatures during the winter to overcome the rest period, after which normal bud break and development can occur (Campoy et al, 2011;Viti et al, 2010). The duration of chilling length required to bud break of a given cultivar is known as the chilling requirement of that particular cultivar (Wagner Júnior et al, 2013), and it varies greatly from 1050 h in 'Contender' to 600 h in 'LaFeliciana' (Parker and Werner, 2015). On the other hand, in subtropical and tropical regions the cultivation of peach trees is possible due to agronomic innovations and the development of low chilling cultivars, which require low exposure to chilling temperatures (100 to 200 h).…”

Influence of Shade and Bed Types on Attaining Optimum Temperature for The Germination of Peach (Prunus Persica L. Batsch) Seeds at Holetta, Central Ethiopia

“…We present the result for the influence of shade and bed type for a mean temperature of 2017 and 2018 growing seasons in Table 1. There was no significant difference in mean temperature between treatments under tree shade on a flatbed (S1B1) ( 16 (Sharma & Singh, 1978;Bewley et al, 2013;Americo et al, 2013). Overall treatments located out of shade both on the flat and sunken bed recorded significantly higher temperatures followed by those treatments in the shade and the control as stated in Figure 1.…”

“…Here the highest GSI is recorded for S1B1 (1.90) followed by S1B2 (1.82) even if there is no statistical difference between them. This variation might be because of the length of periods that the seeds we exposed to stratification (Finch-Savage, 2004;Rawat et al, 2010), and also be cues the genetic component that can influence entire population of seed or individual seeds within a seed lot (Geneve, 2003;Americo et al, 2013).…”

“…Peach (Prunus persica L. Batsch) requires low temperature to break the dormancy of seeds and buds resulting in seed germination and flowering (Americo et al, 2013). The low temperature triggers internal mechanisms that change the nature and level of growth regulators involved in the dormancy's control processes (Kester et al, 1977).…”