At what boron concentration in irrigation water does it become toxic for most crops?

✅Explanation:
-Boron is an essential micronutrient for plants but becomes toxic at elevated levels in irrigation water.
-Safe limits: Most crops can tolerate boron levels up to 1.0 ppm, though this tolerance varies between species.
-Toxicity threshold: When boron levels exceed 1.0 ppm, it is considered toxic to most crops, especially sensitive ones like citrus, beans, and nuts.
Boron Toxicity
-​Boron is essential to the normal growth of all plants, but the amount required is low.
-If it exceeds a certain level of tolerance depending on the crop, then boron may cause injury.
-The range between deficiency and toxicity of boron for many crops is narrow.
-In order to sustain an adequate supply of boron to the plant at least, 0.02 ppm of boron in the irrigation water may be required.
-However, to avoid toxicity, boron levels in irrigation water should, ideally, be lower than 0.3 ppm.
-Higher concentrations of boron will likely require that the intended crop type must first be evaluated with respect to its boron tolerance of 4 ppm.