PLANT HEALTH * Symptoms: Typical first symptoms of nitrogen deficiency are light green foliage and overall stunting of plants. You can also see wilting and dead and/or yellow leaf margins. NITROGEN PHOSPHORUS POTASSIUM SULFUR CALCIUM MAGNESIUM BORON COPPER IRON MANGANESE MOLYBDENUM ZINC ALUMINUM 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 Figure 1. The relationship between nutrient availability and pH. 8.0 8.5 9.0 9.5 10.0 * Detection: Measuring/monitoring the electrical conductivity (EC) of nutrient solutions can help prevent nitrogen deficiency. Adjust EC levels when they are low or high. * Cure: Identify the source and correct it. This may mean adding more nitrogen to nutrient solutions. It may also mean that an antagonistic nutrient is excessive in the nutrient solution. CALCIUM DEFICIENCY * Cause: Calcium deficiency can be caused by under fertilization, nutrient imbalance or low pH. It is also related to moisture management, high temperature and low airflow. Calcium is a mobile nutrient and is transported through the plant in water-conducting tissues. Fruit and leaves compete for water. Low relative humidity and high temperatures can result in increased transpiration rates and movement to leaves. In this scenario, calcium deficiency can develop in fruit. * Symptoms: Calcium deficiency symptoms commonly start out as brown leaf margins of new plant growth or on the bottom of the fruit. Great examples of this are tipburn in lettuce and blossom end rot in tomato and pepper. As VIEW WHAT'S NEW IN THE 2022 Guide to Cannabis Production GET THE LATEST INSIGHTS & PRODUCT INFORMATION in the fourth annual Guide to Cannabis Production. The greenhouse industry continuously expands its production on a variety of plants, from flowers to vegetables, and also cannabis. LEARN MORE ABOUT: * Maximizing Your Greenhouse * An Enlightened Look at Lighting * Industry Continues Growth * Plus more VISIT GPNMAG.COM/CANNABIS-GUIDE TO DOWNLOAD YOUR COPY Extreme acidity Very strong acidity Strong acidity Medium acidity Slight acidity Very slight acidity Slight alkalinity Moderate alkalinity Strong alkalinity Very strong alkalinityhttp://www.GPNMAG.COM/CANNABIS-GUIDE