The Use of Compost Increases Bioactive Compounds and Fruit Yield in Calafate Grown in the Central South of Chile

Abstract

Different concentrations of compost applied as organic fertilizer can modify productive, quality, and chemical parameters in several fruit tree species. The objective of this study was to determine the effect of increasing applications of compost on physiological, productive, and quality parameters in calafate fruit during the seasons of 2018–2019 and 2019–2020. The study was conducted on a commercial calafate orchard using a randomized complete block design with four treatments (CK: no compost application, T1: 5 Ton ha−1, T2: 10 Ton ha−1, and T3: 15 Ton ha−1), each with four repetitions. The results did not show statistical significance for stomatal conductance (Gs), quantum yield of PSII, or photosynthetic active radiation (PAR) within treatments. As for fruit yield, a statistical difference was found between the control treatment and T1, which were lower than T2 and T3 in both seasons. The trees reached a higher leaf area index with T2 in both seasons. The highest antioxidant capacity was obtained with T3 and T2 for the first and second season, respectively. Polyphenols and total anthocyanin production showed statistical significance, with a higher content at the second season with T2. It is concluded that the dose under which yield, quality, and nutraceutical content of calafate fruit are optimized is the one used in T2, 10 Ton ha−1.

Preharvest Applications of Oxalic Acid and Salicylic Acid Increase Fruit Firmness and Polyphenolic Content in Blueberry (Vaccinium corymbosum L.)

“…The maximum, minimum, and average air temperature ( • C) of the study site was recorded every 30 min during the whole development of the crop, using Key Tag automatic sensors (Key Tag Recorders, USA). In parallel, the average soil temperature ( • C) was measured with a digital thermometer (Multi Thermometer, Shanghai, China) at a depth of 0.2 m. Photosynthetic photon flux density (PPFD, µmol m −2 s −1 ) was quantified according to the method proposed by Pinto-Poblete et al [26] and Pinto-Morales et al [27] using an AccuPAR LP-80 ceptometer (Decagon Devices, Washington, DC, USA), which delivers the average of 80 quantum sensors. Leaf temperature was measured during 1 d of fruit harvest with a portable OS-30p fluorometer (Opti-Sciences, Hudson, NH, USA) [28].…”

“…Total anthocyanins were determined by a differential pH technique according to the methodology described by Pinto-Morales et al [27], where the molecular weight and molar absorbance of the anthocyanin pigment present in the highest proportion were used to calculate the total anthocyanin content. Data were expressed as mg 100 g −1 FW [36], a compound found in greater proportion in blueberry [31].…”

“…The readings in the spectrophotometer were determined at 515 nm, and the standard curve used was 0.0008× + 0.0272 and R 2 = 0.99. The results were expressed as µmol Trolox equivalent (TE) 100 g −1 FW [27].…”

Improving Blueberry Fruit Nutritional Quality through Physiological and Genetic Interventions: A Review of Current Research and Future Directions

“…Important blueberry traits for consumers, and therefore for breeders, include freshness, flavour, texture (firmness), and shelf life [ 13 , 14 ]. Another key focus is to improve fruit nutritional quality by increasing bioactive compounds content [ 15 ], which is strongly influenced by environmental factors such as light, temperature and water availability [ 16 , 17 ]. Knowledge of the environmental factors and growing conditions that positively influence bioactive accumulation will provide an opportunity to develop agronomic practices that can enhance the nutritional quality of blueberry fruits.…”

Plant Performance and Soil Microbial Responses to Irrigation Management: A Novel Study in a Calafate Orchard

“…Despite its functional and nutritional properties, it is only grown in the wild, without cultural management to improve its phytosanitary status, and longevity of branches or shoots [4], which leads to a low fruit production per plant, resulting in total production of calafate fruit in Chile that did not exceed 1 t in 2019 [5]. In this context, to stimulate its productive development, in 2017, the first commercial orchard was established in the central-southern zone of Chile, for domestication and development of agronomic management [6]. Pinto-Morales et al [6] pointed out that agronomic management is being addressed, but the implementation of commercial orchards brings new questions, such as how the interaction of these agronomic managements is altering soil biological properties.…”