No 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.

2 Two cultivars of geranium (Pelargonium × hortorum) were grown under five different fertilizer regimes, 50, 100, 200, 300, or 400 mg·L −1 nitrogen (N). The two cultivars were chosen to represent a dark-colored leaf cultivar, 'Tango Dark Red' and a light-colored leaf cultivar, 'Rocky Mountain Dark Red'. Tissue samples were collected and analyzed for the content of 11 elemental nutrients every two weeks for a period of 12 weeks. The dark-colored leaf cultivar contained higher nutrient concentrations, with the exception of magnesium, sulfur, iron, and copper, than the lightcolored leaf cultivar. Compared to concentrations previously published for geraniums, concentration ranges observed in this study were narrower. In addition, this study accounted for differences in concentrations over the entire crop cycle and reflects levels associated with current fertilization practices.

Gerbera liners of 'Festival Light Eye Yellow' were transplanted one plant per 5-inch pot. Plants were fertilized with one of six constant liquid fertilizer levels (50, 75, 100, 200, 300 or 400 mg•L-1 N) for 8 weeks. Plants were harvested at week 2, 5 and 8 after transplanting. Recently fully expanded leaves were sampled and analyzed for the concentration of 11 nutrients (N,

Core Ideas Leaf tissue nutrient concentration survey values do not exist for greenhouse CBD‐hemp. Growers can use these ranges as a nutrient management tool for CBD‐hemp stock plants. Different leaf tissue nutrient concentrations have been found in CBD‐hemp cultivars. There are no researched nutrient recommendations specific to greenhouse CBD‐hemp. CBD‐hemp products have great market potential.