Slant‐Board Culture Methods for Root Observations of Red Clover 1

Red clover ( Trifolium pratense L.) plants were grown to the flowering stage cultured on slant boards that were either irrigated continuously with a recirculating nutrient solution or watered twice daily when the roots were covered with bags of perlite. One irrigation system serviced many slant boards that were continuously wetted, whereas slant boards with perlite bags functioned independently. The latter method is best suited for treatments that might contaminate the irrigation system, such as pathogen treatments, and when several plant growth chamber or greenhouse environments are utilized. Both methods resulted in root systems that were free of solid substrate, readily available for treatments, and larger than comparable plant roots grown in soil. A weighing method that estimated water displacement provided a nondestructive measurement of roots and shoots of intact plants.