Adult pciiod
G«>«vihpc*iOd
Ule jpan of plant
FIGURĘ 8-5 Ciungc nf suwcptibiliry of plant parts with agc. In pattcm I. plam* are łuscrpriblc onlr in rlte uagcs of nuMmuui gmwrh (la) or m thc c.trlicst stages *>f growth llb). In paltem II. plams ire imurptiWr orły jltcr they rcacli maiunty, and susccptihility inocaso, with sencsccncc. In pattetn III, plant* arr *ov.eptiblc whilc vcry young and agam nfterthcy rcach inaturity. |Alter Populcr (1978).|