Characterization of Nutrient Disorders of Cannabis sativa

Abstract

Essential plant nutrients are needed at crop-specific concentrations to obtain optimum growth or yield. Plant tissue (foliar) analysis is the standard method for measuring those levels in crops. Symptoms of nutrient deficiency occur when those tissue concentrations fall to a level where growth or yield is negatively impacted and can serve as a visual diagnostic tool for growers and researchers. Both nutrient deficiency symptoms and their corresponding plant tissue concentrations have not been established for cannabis. To establish nutrient concentrations when deficiency or toxicity symptoms are expressed, Cannabis sativa ‘T1’ plants were grown in silica sand culture, and control plants received a complete modified Hoagland’s all-nitrate solution, whereas nutrient-deficient treatments were induced with a complete nutrient formula withholding a single nutrient. Toxicity treatments were induced by increasing the element tenfold higher than the complete nutrient formula. Plants were monitored daily and, once symptoms manifested, plant tissue analysis of all essential elements was performed by most recent mature leaf (MRML) tissue analysis, and descriptions and photographs of nutrient disorder symptomology were taken. Symptoms and progressions were tracked through initial, intermediate, and advanced stages. Information in this study can be used to diagnose nutrient disorders in Cannabis sativa.