• Energy Research
• 2021-2025close

ABSTRACT This study aimed to characterize the occurrence, duration, and intensity of the flushes of vegetative growth in two peach cultivars of Prunus persica L. Batsch, grown as a pioneer endeavor at a high-altitude tropical climate site in the State of Minas Gerais, Brazil. The observational experiment was carried out in 2017/18 and 2018/19 on the ‘Tropic Beauty’ and ‘BRS Kampai’ cultivars by an evaluation of the number and duration of flushes of vegetative growth during the year over two cycles. The number of fruit-bearing shoots, total number of leaves and shoot length were also assessed. At harvest, fruit load and diameter were determined and grouped into diameter ranges. The number of hours recorded at different temperature ranges, 25.1 °C, were summed separately and divided into daily and nightly periods. The peach tree has an unusual vegetative growth pattern when cultivated in a tropical area, which occurs in two flushes, with the first flush occurring from budbreak to fruit harvest between June and Sept, forming short shoots (less than 10 cm), with early shoot growth cessation, with a limited leaf number that can potentially diminish the supply of carbohydrates to the fruit, leading to smaller growth. The second flush occurs after harvest, between Oct and Dec, when there is an increase in daily temperature and precipitation, and no competition with fruits. Notabily, these second flush shoots grow with greater vigor and regularization of the growth cycle, forming fruit-bearing shoots with abundant leaf and flower buds for the next production cycle.

Conventional fruit-tree farming systems are highly productive and strongly dependent on external inputs, including pesticides, fertilisers, and water. To reduce this dependence, various initiatives have been developed in past decades, such as Integrated Fruit Production, Organic Farming, and more recently, Agroecology which is strongly inspired by research in ecology. These initiatives include plant diversity as the main driver to improve the sustainability of the orchard. Plant diversity can either be planned (choice of productive and not productive species) or associated (unintentional) and at different scales (within the cultivated plot and/or the surrounding landscape). To increase plant biodiversity, companion, i.e., mostly non-productive, plants can be either herbaceous, bushes, or trees. The interest of plant diversity to improve the sustainability of agrosystems is documented from three points of view: composition, structure, and function. First, companion plants have to fulfil precise functions within the system, such as sustaining nitrogen provisioning (e.g., herbaceous legumes between fruit-tree rows), hosting natural enemies of main pests, or attracting herbivore insects outside the orchard. Recent works on agroecology analyze fruit-tree based agrosystems documenting fruit production and the various “services” (e.g., mitigation of CO2 emission, soil nitrogen availability) companion plants can provide. Second, to optimise plant functioning, it is necessary to define rules of plant assemblage at spatial (e.g., distance between plants) and temporal (e.g., plantation at the same time period or not) levels. Based on a literature survey and current experiments, we will show that agrosystems that combine trees grown for fruit and possibly for timber or firewood and agricultural crops, i.e., fruit-tree based agroforestry systems (FT-AFS), provide promising results in the temperate climate context, including the Mediterranean zones. Further, the introduction of plants providing pest regulation services opens to challenging perspectives toward friendly fruit-tree-based agrosystems.