Nutritional Disorders of Florists’ Crops

Abstract

Nutrient disorders result from chemical imbalances in plants caused by prolonged insufficient or excessive concentrations of elements in plant tissue. Nutrient deficiencies develop when an essential element is below the critical concentration required for growth and development. Nutrient phytotoxicity occurs when an element, essential or nonessential, is present at concentrations higher than what the plant can metabolize. Both conditions can cause abnormal growth and development. Generalization of nutrient disorder symptoms in floriculture crops is complex because the response to nutrient concentration is specific to the plant genetics. Visual diagnosis of nutrient disorders in the field is conducted by matching nutrient function and mobility to distribution and characteristics of symptoms. Nutrient deficiencies in plants may result from insufficient nutrient levels at the root zone, interactions with other elements, or reduced absorption caused by other growth factors not directly related to nutrition. Diagnosticians can provide immediate on-site corrective recommendations based on visual diagnosis. However, recommendations should be adjusted when nutrient analyses become available. Nutrient management begins with planning a nutrient program based on water quality, growing media properties, and crops' requirements (genetics and growth stage). In general, corrective procedures for deficiencies include a single foliar or drench application of the element or adjustment of the pH or fertilization program. Corrective options for nutrient toxicity include discontinued application of the element, increased leaching with clear water, changed or blended water source (if water source is the problem), pH increase, or use of antagonistic elements to reduce uptake.