Desenvolvimento Vegetativo de Cesalpinea ferrea e Anadenanthera macrocarpa: I - Estimativa das Temperaturas Cardinais

Abstract

<jats:p>Resumo A temperatura do ar influencia o desenvolvimento vegetativo e a duração da fase de muda de espécies florestais, uma vez que regula as reações fotoquímicas e bioquímicas da fotossíntese, e por isso é considerada a principal variável meteorológica. O objetivo deste trabalho foi estimar as temperaturas cardinais (basal inferior, ótima e basal superior), que determinam os limiares em que ocorrem desenvolvimento vegetativo, e estimar o filocrono de duas espécies florestais na fase de muda. Para isso, foi instalado um experimento a campo, sob delineamento inteiramente casualizado, em esquema fatorial (2 x 12), sendo duas espécies florestais nativas (pau-ferro - Caesalpinia ferrea Mart. ex. Tul. Var. leiostachya Benth e angico-vermelho - Anadenanthera macrocarpa (Benth) Brenan) e doze épocas de semeadura, com cinco repetições por tratamento. Os valores das temperaturas cardinais para o pau pau-ferro foram: 12,8 °C, 20,7 °C e 46,3 °C e para o angico-vermelho foram: 10,3 °C, 23 °C e 45,5 °C. Já o filocrono médio estimado para o pau-ferro foi de 56,9 °C dia folha-1 e de 163,8 °C dia folha-1 para o angico-vermelho, mostrando que o angico-vermelho necessita de mais energia para promover o desenvolvimento vegetativo quando comparado ao pau-ferro.</jats:p>

Phenological stages of the ‘Paluma’ guava tree in a region of subtropical climate according to the BBCH scale

“…To quantify the heat unit requirements, and consequently, to determine the exact moment of the occurrence of the ∑ where: GDD = Growing degree-days (°C day); Tmed = medium air temperature (°C), obtained by the arithmetic mean data from the automatic weather station (Figure 1); Tb = base temperature (12 °C) (Salazar et al 2006); i = start date of the development stage; n = end date of the development stage, both considering the dates of occurrence of the BBCH general scale (Table 1). This method of heat unit accumulation considers the medium air temperature and the cardinal base temperature (Tb), below which development does not occur (Martins et al, 2019;Silva et al, 2020).…”

“…The guava tree (Psidium guajava L.) belongs to the Myrtaceae family and is native to the central region of the American continent (Singh, 2018;Silva et al, 2020). Due to its ability to adapt to different edaphoclimatic conditions, the guava species is cultivated in different locations around the world (Salazar et al, 2006).…”

Thermal and photoperiodic requirements of the seedling stage of three tropical forest species

“…The seedling stage of plant growth is the most sensitive and least tolerant to climatic conditions and extremes (Morin et al 2010;Rawal et al 2014;Ferreira et al 2019a, b;Silva et al 2020;Fagundes et al 2021;Martins et al 2022b), especially to air temperature variability (Costa and Streck 2018;Florêncio et al 2019;Reis et al 2021). Gradual or abrupt changes in climate can alter physiological processes, and if persistent, can change morphological and phenological patterns (Bahuguna and Jagadish 2015; Reis et al 2021) and impact seedling quality and survival.…”

“…Air temperature and photoperiod are critical factors for seedling development of tropical forest species (Rawal et al 2014;Ferreira et al 2019a, b;Freitas and Martins 2019;Silva et al 2020;Martins et al 2022b, c). Air temperature influences physiological and metabolic activities, photosynthesis and photorespiration, the transport of solutes, and the balance between transpiration and water consumption (Freitas et al 2017;Ferreira et al 2019a;Martins et al 2022b).…”

“…TT can be calculated using different methods (Rosa et al 2009;Daibes et al 2019;Freitas and Martins 2019), but all require air temperature and the cardinal temperatures, which are called base (T b ), optimum (T opt ), and maximum (T B ) temperatures. These thermal thresholds (T b , T opt and T B ) are specific for each tropical forest species and establish the temperature ranges at which a seedling can develop (Freitas et al 2017;Ferreira et al 2019a, b;Silva et al 2020). Each TT method can result in different thermal time values, especially when air temperature is below the T b or above the T B of the species (Rosa et al 2009;Ferreira et al 2019a;Freitas and Martins 2019), thus affecting the phyllochron values (Rosa et al 2009;Martins et al 2022c).…”