An analysis of the diphenylamine reaction in sap of healthy and leaf roll virus infected potato plants D. PetersF. L. Dieleman OriginalPaper Pages: 279 - 286
Pea early-browning virus and tobacco rattle virus — two different, but serologically related viruses D. Z. Maat OriginalPaper Pages: 287 - 293
Zwartrot in sla, veroorzaakt doorRhizoctonia solani K. VerhoeffEvarien Tijssen OriginalPaper Pages: 294 - 296