Determination of the optimal harvest time for hemp plantations in controlled greenhouse conditions

The purpose of the research is to evaluate the optimal concentration curve of Hemp plantations (Cannabis spp); the study considers the six main Cannabinoids found in the plant under controlled greenhouse conditions. The methods applied in the present work are experimental research types with the analytical method with statistical evaluation. The experiment was carried out in Jacksonville, Montevideo, Uruguay, during the agricultural year 2019-2020. Were evaluated 47 plants of the cultivar Romalex in each of its three parts (high, medium, and low), corresponding to five (05) mothers that were sampled for six consecutive weeks; having carried out a total of 846 analyzes, the plants were sown at a density of 1.3 plants per m2, for the measurement the High Performance Liquid Chromatography (HPLC) method was used. The data were subjected to analysis of variance (ANOVA), and the measurements were compared using the Friedman test with a probability of error of 5%. It was found that the middle part of the plant has a mean value of 8.19% of total Cannabidiol CBD with a standard deviation of ± 1.49. The lower part of the plant has a mean of 7.56% of total CBD, with a standard deviation of ± 1.55. The upper part of the plant has an average of 8.91% of total CBD with a standard deviation of ± 1.05 and concentrates its highest percentage of total CBD at the third week.