Pythium in established alfalfa. Don C. Norton. 1

Some size an shape relationships between tree stems and crowns. Graeme P. Berlin. 7

Influence of leaf-blade removal on seed weight of oats. K.J. Frey. 17

Fatty acid carboxylation by extracts of Nocardia corallina. C.L. Baugh, D.S. Bates, G.W. Claus and C.H. Werkman. 23

Host specialization in Pythium graminicolum. R.O. Hampton and W.F. Buchholtz. 43

Inhibitory and lethal effects of three seed protectants against Pyhium debaryanum. W.L. Staudinger and W.F. Buchholtz. 67

Stand and nodulation of alfalfa from seeds pelleted with high dosages of Arasan. M.V. Desai and W.F. Buchholtz. 79

Vulnerability of soil structure research an a new approach in Belgium. L, De Leenheer. 87