Petiole analysis as a guide to the manuring of sugar beet

Summary

During the 1957 growing season an experiment was carried out to see if the Californian method of tissue testing during the growing season to assess the adequacy of the nitrogen supply for optimum growth was practicable in Great Britain. The experiment was laid out in the form of a latin square with the rates of nitrogen application ranging from 0 to 140 pounds per acre in increments of 35 pounds. Petiole samples were collected and analysed at fortnightly intervals from July 29th to September 23rd. The nitrate-nitrogen content of the petioles was found to increase with increasing rates of nitrogen at any one sample date and to decrease during the growing season. On harvesting in November the response in terms of root yield, whether estimated from the actual plot yields, or the root mean weight with a constant plant population, was only just significant. Greater yield responses from the application of nitrogen would probably have been obtained on a less productive soil, for a yield of 15.5 tons of roots per acre was obtained without the use of any nitrogen.