EDITORIAL

The section on "Plant Breeding, Genetic Resources and Molecular Biology" presents reports on the tropical species cacao (Theobroma cacao), cassava (Manihot esculenta) and the cape gooseberry (Physalis peruviana), which have known, documented genetic variability, which is useful for breeding species in terms of performance, quality and adaptation. In cacao, of the 39 clones evaluated in three environments of the departments of Arauca and Santander, the 95 ICS clone behaved as a resistant plant to "moniliasis or thrush" caused by Moniliophthora roreri, considered the most limiting disease of the cacao bean produced in Colombia and other countries in the tropics. Meanwhile, in cassava, by studying families from irradiated seeds, promising mutants were found for tolerating postharvest physiological deterioration and variability in the granule and pulp properties. In addition, a significant variation was observed in the analysis of the agronomic performance of a collection of 54 cape gooseberry plants, especially the feral materials with Brix values of 14.7°.

On the topic of "Propagation and Tissue Culture", progress was made in the practices of plant propagation for the species Vaccinium alaternoides and Disterigma floribundum, from the Ericaceae family, known for their high potential to benefit human health, and as a source of antioxidant properties and phenols. This contribution is important because about 600 species of neotropical Ericaceae are native but very little has been published on their use, therefore, there are no crops but rather spontaneous populations in highland ecosystems, but given the added value, they could be a potential source in horticultural and medicinal development.

In contribution to the development of species of food security under the scheme to improve production efficiency in high-altitude agro-ecosystems, the "Crop Physiology" section presents the evaluation of the diploid potato variety Criolla Colombia in response to the nutrient application of phosphorus and potassium. Furthermore, the effects of magnetic field application on germination and seedling growth in maize (Zea mays) were analyzed to modify some of the plant physiological processes and stimulate their development, the application of this methodology provides for better seed quality in the establishment of the crop, and can also be an option for the regeneration of collections preserved in germplasm banks. The application of proteomics in studies of stress in plants provides further contributions, providing a new approach in identifying proteins of interest and functional analysis of the plant genome and its relationship with the environment, the present case study refers to water and salt stress in cereals of economic importance. Finally, this section presents an analysis of the global energy crisis and the role played by Brazil in this issue, especially when you look at the protection of ecosystems. In this scenario, Brazil plays a key role by being a leader in the production of biofuels from vegetable sources of soybean (Glycine max) and Jatropha sp. Vegetable species grown in the high tropics are frequently affected by devastating slugs and snails, for this reason, in the "Crop Protection" section, the effects of different management practices for the crops lettuce and broccoli on slugs were evaluated, essentially, the results indicated that the use of metaldehyde and beer traps are alternatives to use in an integrated management program to reduce the population of this pest. Moreover, in the "Postharvest Physiology and Technology" section, methods were sought to optimize the effects of temperature and citric acid concentration in the osmotic dehydration of pineapple (Ananas comosus) in sucrose solutions.

"Soils, Fertilization and Water Management" contributes to the presentation of soil quality indicators, considering their biochemical function in the formation and degradation of organic matter and nutrient recycling, as well as, analyzing the effect of soil chemical properties on the crop yield that in the case of fertilization is site specific, to permit the observation of the temporal and spatial variability of these properties and crop yield. In contrast, in degraded areas with erosive soils an alternative is planting exotic and native tree species using different doses of calcium (CaCO₃) as a corrective. Finally, the section presents the analysis of the climate threat facing the agro-ecosystems in the agricultural areas of the Andean departments of Cundinamarca and Boyacá.

In "Economics and Rural Development", the articles published in this issue broadly outline strategic issues from regional experiences with case issues on participation and innovation being key to development, marketing channels and margins in the dairy chain, rural education and rural territorial heritage recognition, each topic presents a particular case such as rurality in Medellin, the marketing of milk in the Sugamuxi province, the rural school in the Tenza Valley and characterization of production systems for Andean tubers in the Boyacá department. The gained knowledge reflects participatory processes for the characterization of production systems with improvement of territorial heritage, to enhance the particulars and know how in production.

The contents of this issue of the journal are expected to contribute to agriculture development and receive consideration from the scientific community, academia and the productive sector. The work done by the experienced editors, translators and designers for the publication of our magazine Agronomía Colombiana deserves a mention of gratitude.

Gustavo A. Ligarreto M.

Editor