Plant stress measurement Plant stress measurement Plant stress measurement is the quantification of environmental effects on plant health. When plants are subjected to less than ideal growing conditions, they are considered to be under stress. Stress factors can affect growth, survival and crop yields. Plant stress research looks at the response of plants to limitations and excesses of the main abiotic factors (light, temperature, water and nutrients), and of other stress factors that are important in particular situations (e.g. pests, pathogens, or pollutants). Plant stress measurement usually focuses on taking measurements from living plants. It can involve visual assessments of plant vitality, however,
Natural foods the term if the food does not contain added color, artificial flavors, or synthetic substances." Furthermore, the FDA has not developed any rules or regulations on the defining features of what qualifies a product as "natural." The FDA does reference a definition of "natural" in their informal policy (Ref. 53) that defines "natural" as "nothing artificial or synthetic (including colors regardless of source) is included in, or has been added to, the product that would not normally be expected to be there." The Food, Drug, and Cosmetic Act prohibits labeling that is false or misleading. The USDA's Agricultural Marketing Service