P.A. Gallagher
As peas can obtain most, if not all of their nitrogen requirements by symbiotic nitrogen fixation by Rhizobium pisi, little attention has been given to the effects of nitrogen supply on growth and yield of peas. However, some workers have shown that variation in the supply of nitrogen can effect the yield of peas and the rate at which they mature. Terman and Murphy (1) showed that nitrogen fertilisers tended to delay maturity. Hollis (2) found that as nitrogen fertiliser use was increased, vegetative growth was more vigorous, but yields of peas were decreased. He showed that if nitrogen was limited just before harvest, nitrogen was redistributed within the plant and this resulted in faster maturation. Klacan and Berger (3) reported that the supply of nitrogen was critical up to and including the pod swelling stage. They found that if nitrogen supply was reduced at this stage, seed production was increased and vegetative growth was reduced.

An investigation into the nitrogen requirements of peas was commenced in 1963 and in this work a study was made of the effects of nitrogen on the maturity of peas as measured by tenderometer values.

Gallagher, P.A. (1973). THE EFFECT OF NITROGEN ON TENDEROMETER VALUES OF PEAS. Acta Hortic. 27, 184-188
DOI: 10.17660/ActaHortic.1973.27.21

Acta Horticulturae