Improved method for easy and rapid determination of root length of vegetables

We developed an improved method for the determination of the root length of crisphead lettuce (Lactuca sativa L.) and Chinese cabbage (Brassica pekinensis Rupr.). Boiling of soil containing roots and stirring to collect the roots in water reduced the contamination with debris. The time required for removing the debris was shortened by 30% as compared to washing of roots with water. Boiling had no effect on the nitrogen concentration, but resulted in changes of the phosphate, potassium and calcium concentrations of roots. Use of a crosscounter plate shortened by 30% the time required for the line intersect method. The total time required for root length determination from a 1 kg soil sample was only 15.9 min.