Testing Birdsfoot Trefoil, Lotus corniculatusL., For Varietal Purity III The Use of N‐dimethylaminossuccinamic Acid to Induce Varietal Differences1

The possibility of using chemicals to accentuate varietal differences in birdsfoot trefoil was investigated. Preliminary experiments with several chemicals showed that foliar applications of N‐dimethylaminosuccinamic acid (B‐995) could be used to cause ‘Empire’ plants to differ from ‘Viking’ and common European plants in growth habit, stem number and stem length. Treated Empire plants were shorter or more nearly recumbent than Viking or European plants. Results of using this chemical on greenhouse grown plants varied from one time of the year to another. Growth chamber experiments were conducted to determine what environmental conditions were responsible for this variation. Long photoperiods or low light intensity did not reduce the effectiveness of the chemical. High dark period temperatures or light from incandescent bulbs did reduce its effectiveness. A combination of high dark period temperature with low light intensity or with light from incandescent bulbs drastically reduced the effect of the chemical. Under these conditions increasing the concentration of B‐995 did not increase its effectiveness. One or 2 additional foliar sprays at 3‐day intervals did increase its effectiveness