Effects of Nitrogen Potassium and Phosphorus Fertilizers on Growth of Cannabis

Abstract

Cannabis (Cannabis sativa L.) is an ingredient in many Thai traditional medicines. Because it was designated as a Category 5 narcotic plant in the Narcotic Drugs Act of 1979, it had not been used as a medicine for a long time. Since February 19, 2019, Thailand had allowed the use of cannabis for medical purposes. The Department of Thai Traditional and Alternative Medicine had grown cannabis for medicinal purposes. Plant nutrition is an important factor in cannabis growth. Therefore, this experiment was interested in studying the effect of nitrogen, potassium and phosphorus fertilizers on the growth of cannabis. The experiment was designed in completely randomly (Completely Randomized Design) for five factors and four replications in each. The five factors consisted of T1 (16-16-32), T2 (16-32-16), T3 (32-16-32), T4 (16-16-16) and T5 (32-16-16). Every factor was treated in equal amount every week (156 g/plant). The first week applied for two grams. It increased amount for two grams every week until harvesting. Growth monitoring showed that T1 (16-16-32) had better growth than other factors. The height, stem size and leaf width were 147.50,1.19 and 11.82 cm, respectively. The best leaf length and greenness were T4 and T5. The results showed that different fertilizers had different effects on growth. This information can be used as a basis for selecting fertilizer formulas to be appropriate for growing cannabis plants, while the leaf length the best leaf greenness resulted from T4 and T5 fertilization. The results showed that different fertilizer formulations had different effects on growth. This information can be used as a basis for selecting fertilizer formulas to be suitable for growing cannabis.