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Avocado is one of the most in-demand fruits worldwide and the trend towards its sustainable production, regulated by international standards, is increasing. One of the most economically important diseases is root rot, caused by Phythopthora cinnamomi. Regarding this problem, antagonistic microorganism use is an interesting alternative due to their phytopathogen control efficiency. Therefore, the interaction of arbuscular mycorrhizal fungi of the phylum Glomeromycota, native to the Peruvian coast (GWI) and jungle (GFI), and avocado rhizospheric bacteria, Bacillus subtilis and Pseudomonas putida, was evaluated in terms of their biocontrol capacity against P. cinnamomi in the “Zutano” variety of avocado plants. The results showed that the GWI and Bacillus subtilis combination increased the root exploration surface by 466.36%. P. putida increased aerial biomass by 360.44% and B. subtilis increased root biomass by 433.85%. Likewise, P. putida rhizobacteria showed the highest nitrogen (24.60 mg ∙ g⁻¹ DM) and sulfur (2.60 mg ∙ g⁻¹ DM) concentrations at a foliar level. The combination of GWI and Bacillus subtilis was the treatment that presented the highest calcium (16.00 mg ∙ g⁻¹ DM) and magnesium (8.80 mg ∙ g⁻¹ DM) concentrations. The microorganisms’ multifunctionality reduced disease severity by 85 to 90% due to the interaction between mycorrhizae and rhizobacteria. In conclusion, the use of growth promoting microorganisms that are antagonistic to P. cinnamomi represents a potential strategy for sustainable management of avocado cultivation. Full article

Avocado (Persea americana Mill.) is a tropical fruit that has gained immense popularity worldwide due to its unique flavor, nutritional value, and numerous health benefits. The growth and maturation of avocados are influenced by various environmental and climatic factors. Temperature is one of the most critical factors, as it plays a significant role in various physiological processes of this fruit. This study aimed to investigate the effect of air temperature on avocado development and assess the harvest maturity period (determined by the dry matter content) of Fuerte, Zutano, and Hass, the most common avocado varieties, grown in Western Crete, Greece. Fruit samples collected from avocado orchards in five regions of Western Crete were subjected to dry matter analysis during the ripening period for the years 2017 to 2022. Maturation time is determined based on the EU regulation for dry matter concentration. The results of this study revealed that dry matter concentration can be affected by both very high summer temperatures and low temperatures during the ripening period. Specifically, high temperatures during the summer months can have a significant impact on avocado development and result in a reduced dry matter concentration. On the other hand, low temperatures during the maturation stage can slow down enzymatic activity and metabolic processes, resulting in delayed ripening and a prolonged time to reach optimal maturity. This delay in maturation and reduced dry matter concentration can significantly affect the harvest timing, as growers may need to wait for the avocados to develop the desired characteristics before they can be harvested. Our findings are the first data on avocado maturation (dry matter concentration) in relation to temperature and provide valuable insights into harvest maturity period of avocado cultivation in Crete and other regions with similar Mediterranean climatic conditions. Full article

The study of flavors and fragrances is a topic of rising interest from both marketing and scientific perspectives. Over the last few years, the cultivation of avocados has accelerated in Greece, with production levels elevated by 300%. There has been increasing attention from a number of growers and consumers on avocado oil, the volatiles of which form a key part of consumers’ purchase decisions. A previously unevaluated Zutano cultivar was chosen for this study. Extraction of the pulp oil was performed during three phases of ripening using Soxhlet and ultrasound techniques. Headspace-solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC–MS) were utilized in order to analyze the isolated volatile fraction. At least 44 compounds, including mainly terpenoids (61.7%) and non-terpenoid hydrocarbons (35.9%), presented in the Zutano variety, while (1S,6S,7S,8S)-1,3-dimethyl-8-propan-2-yltricyclo[4.4.0.02,7]dec-3-ene (a-copaene) and (1R,9S,Z)-4,11,11-trimethyl-8-methylenebicyclo[7.2.0]undec-4-ene (β-caryophyllene) were in higher abundance. The composition of the volatiles was unaffected by the extraction techniques but was influenced by the ripening stage. Thus, during maturation, the volatile fraction fluctuates, with a significantly higher abundance of terpenoids during the fourth day of the ripe stage, whilst it decreases during over-ripening. These findings demonstrate that the Zutano variety can be used to produce an aromatic oil and hence could be used, among others, as an ingredient in cosmetic products. Full article