YIELD LOSSES IN BARLEY, WHEAT AND POTATOES ASSOCIATED WITH FIELD POPULATIONS OF LARGE FORM LONGIDORUS-LEPTOCEPHALUS

Three field experiments made during 1975‐77, in North and South Yorkshire, investigated the influence of ‘large form’Longidorus leptocephalus upon the yield of spring barley, winter wheat and second early potatoes. Longidorus populations ranged from undetectable levels to 2375/litre soil. At one site estimates of nematode numbers were made twice, and gave a close agreement between the ranking order of plots. Significant negative correlations between numbers of L. leptocephalus and yield suggested that this nematode impaired the yield of these crops. For each 200 LongidoruslX of soil the estimated reductions in yield were 0–25 t/ha of barley, 0–13 t/ha of wheat and 0–55 t/ha of potatoes. Copyright © 1979, Wiley Blackwell. All rights reserved