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Persea americana, cv. Hass has become an important crop in Colombia due to increased exports to European markets; however, the avocado is a climacteric fruit sensitive to chilling injury, reducing its shelf-life and affecting commercialization abroad. This research aimed to evaluate the effect of 1-methylcyclopropene, ethylene, and intermittent warming on chilling injury and postharvest behavior of avocado cv. Hass. Five treatments were evaluated: Control; Intermittent warming cycles of 4 days at 2 °C + 1 day at 18 °C; Intermittent warming cycles of 7 days at 2 °C + 1 day at 18 °C; 1-methylcyclopropene, and ethylene. The fruits were stored for 29 days at 2 °C and then up to 14 days in the shelf-life period. The intermittent warming treatment 4-days cycles reduced chilling injuries. However, this treatment increased weight loss, respiration, epidermal color index, and electrolyte leakage during the storage period at 2 °C. Intermittent warming showed that Hass avocado fruit ripens faster, regardless of the application of ethylene in the shelf-life period. The results indicated that intermittent warming reduced the chilling injury, the treatment with 1-methylcyclopropene delayed ripening but it is not recommended for avocado cv. Hass when stored at 2 °C because the chilling injury is not reduced. [ABSTRACT FROM AUTHOR]

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• Ethylene regulates processes associated with fruit ripening in cape gooseberry. • 1-methylcyclopropene is an inhibitor of ethylene perception in cape gooseberry. • 1-methylcyclopropene can act as a competitive inhibitor of the ACO enzyme. • 1-methylcyclopropene can directly inhibit ethylene biosynthesis. Theoretical and experimental studies were conducted to determine the role of 1-MCP in the biosynthesis of ethylene in cape gooseberry fruits (Physalis peruviana L.), ecotype Colombia. A completely randomized experimental design was used with 3 treatments: ethylene (1000 μL ethephon L−1), 1-MCP (1 μL L−1), and a control with no applications. At 1, 6 and 11 days after treatment, volatile compounds, firmness and color were measured. The enzymatic activities of ACC oxidase (E.C. 1.14.17.4) and histidine kinase (HK, E.C. 2.7.13.3) were also determined in vitro. Subsequently, molecular docking studies with the enzymes, their respective substrates and 1-MCP were carried out. It was found that 1-MCP decreased the emission of volatile esters, color index, loss of firmness, and ACC oxidase and histidine kinase activities. Results indicated 1-MCP acted as a competitive inhibitor of ACC oxidase and as a noncompetitive inhibitor of HK. The coupling free energy was higher for 1-MCP in both the ACC oxidase (8.31) and the HK (4.22), compared to their respective substrates. The results also suggested that 1-MCP was able to decrease both the biosynthesis and activity of ethylene in cape gooseberry fruits. [ABSTRACT FROM AUTHOR]

• Regulated deficit irrigation improvements water use efficiency in pear trees. • Moderate water deficits during filling did not affect quality in pear fruit. • Regulated deficit irrigation is recommended for pear crops in tropical conditions. Depletion of water resources, high water costs and increased demand require improvements in the efficient use of water. The objective of this experiment was to determine the effect of regulated deficit irrigation (RDI) on pear fruit quality (Pyrus communis cv Triunfo of Viena), which was compared to control irrigated plants at 100 % crop evapotranspiration (ETc) under tropical conditions. The irrigation treatments consisted of the application of water regimes corresponding to 74 % and 48 % ETc in the T2 treatment and 60 % and 27 % ETc in the T3 treatment in 2014 and 2015, respectively, during the period of rapid fruit growth. The irrigation reduction in T2 and T3 during this period represented a water savings of 26.4 % and 39.6 % in 2014 and 51.7 % and 72.8 % in 2015, respectively. In production, the Number of fruits per tree and distribution of fruits by size during the two years did not have significant differences between the treatments. The RDI did not affect fruit firmness, pigments (Chlorophyll and carotenoids), color index, content of phenols, sugars or acids at harvest, but there were important water savings. The respiration rate was lower in 2015, with RDI 60 %. Therefore, RDI is an efficient irrigation technique recommended for pear production under tropical conditions. [ABSTRACT FROM AUTHOR]