The Use of Biostimulants in High-density Olive Growing: Quality and Production

Abstract

Due to the increase of high-density holdings, especially of olive trees, the nutritional requirements of the plants are higher per unit area, which implies that a greater contribution of fertilizers to the soil is needed. Opting for fertilizers of inorganic origin will produce an increase in the pollution of the soil. In the face of this possible soil contamination, our aim is to analyze the effect of biostimulants as an alternative to chemical fertilizers, to steadily produce and maintain high quality standards during the life of the crop. Our objective is using more environmentally friendly products in order to satisfy one of the most important demands from both consumers and the authorities. In this study, we carried out five different treatments in addition to a control treatment with a supply of NPK, from inorganic products, which are used to control fertilization with a solution obtained from seaweed extracts. These treatments were applied in two crop cycles for two of the most important varieties in the current olive tree growing scenario: Arbequina and Koroneiki. Hernández-Hernandez et al.; AJAAR, 10(4): 1-11, 2019; Article no.AJAAR.49116 2 This study was developed in the farm Pozohondo, which is located in a crop zone by the Palancia river (Castellón, Valencia, Spain), in the southeast of the Iberian Peninsula, where the olive trees were established in a high-density system with a planting framework of 4 x 1.5 m. We ensured an exhaustive control of the nutritional needs of the holding by using a fertigation system. We could notice differences in the productions of each applied treatment, avoiding any possible biases through the additional control of 100 randomly selected olives from each of the samples. There is an improvement in the set of physical characteristics of the olives with the treatment that provides amino acids and extra potassium based on amni acids. We analyzed the quality of the olive oil obtained from the production of each treatment by measuring the fatty acids, tocopherols and polyphenols contents. We also carried out an organoleptic tasting analysis following the rules of the International Olive Committee (IOC). We observed an improvement with regard to the rest of treatments in the pomological parameters of the olives when applying the potassium and amino acid biostimulant, while the quality of the oils was not affected by the type of fertilization applied in each treatment. Original Research Article

Productivity and Fruit Quality Influenced by Bioestimulant in Olive under Hot and Arid Environment of Mexico

“…Adaptation from [22] The values found in fruit weight and pulp-pit ratio are similar to those reported by previous research in 'Manzanilla' under similar agro environmental conditions [33]. The little or no response of the application of biostimulants to improve olive fruit quality is in accordance with that reported by [17,18] using different types of biostimulant on different olive tree varieties. Olive fruit size and pulp-pit ratio are important characteristics for table olive production.…”

“…Actually modern fruit trees physiology is focused on the stimulation of plant cell development and fruit production using bioestimulant. Foliar and soil applications with different types of biostimulants during flowering and fruit set in olive trees have increased fruit set, productivity and fruit quality [14,15,16,17], increase in oil content and quality [15,16], also improved fruit quality by advancing and uniforming fruit ripening [15,18].…”

Inorganic and organic foliar fertilization in olives

“…Investigations with olive trees sprayed with humic acid at the beginning of the fruit set, led to a higher yield, fruit size and weight, and pulp/pit ratio (Haggag et al 2013). An improvement in the set of physical characteristics of the olives after the application of amino acids and extra K has been also observed (Hernández-Hernandez et al 2019). Other studies have shown the potential of an extract obtained from the aquatic duckweed (Lemna minor L.), with a high content of phenolic acids, phenols and flavonoids, to act as a biostimulant in olives, improving the leaf photosynthetic activity and chlorophyll content, plant growth and nutritional status (Regni et al 2021).…”

Sustainable Olive Culture under Climate Change: The Potential of Biostimulants

“…For the Alcygol biostimulant, an increase of carotenoids and a reduction of peroxide value and total phenols was observed, while with the use of Nectar intense, the monounsaturated fatty acids (MUFAs) and carotenoids increased but the polyunsaturated fatty acids (PUFAs) decreased. Hernández-Hernandez et al [140] showed that the application of biostimulants based on algae and amino acids supplemented with nutrients on olive plants from the cvs 'Chemlali' and 'Arbequina' (in high density orchards) improved fruit weight but not alter oil quality (e.g., fatty acids, polyphenols and tocopherols). In olive orchards, the application of A. nodosum reduced olive oil acidity (%) but improved to levels of total phenols [4].…”