Canadian Forest Service Publications
Nutritional and sexual responses of jack pine to ammonium nitrate and gibberellins. 1999. Fogal, W.H.; Larocque, G.R.; Lopushanski, S.M.; Schooley, H.O.; Anderson, M.L.; Edwards, I.K.; Coleman, S.J.; Wolynetz, M.S. Forest Science 45 (1): 136-153.
Issued by: Laurentian Forestry Centre
Catalog ID: 16848
Availability: PDF (request by e-mail)
The nutritional and sexual responses of jack pine (Pinus banksiana Lamb.) seed orchard trees to NH4NO3 fertilization and GA4/7 foliar sprays were examined in seedling and grafted orchards at an Ontario location where soils were low N acidic sandy loams and in a Saskatchewan grafted orchard on high N calcareous sandy clay loams. High seed strobilus abortion and low pollen strobilus production and seed yields characterized the Saskachewan trees. NH4NO3 fertilizer increased soil NH4+ and NO3- at both locations, current-year needle N and Mg in Ontario, Fe in Saskatchewan, and Ca at both locations, seed strobilus initiation and seed yields in Ontario; it decreased K in Saskatchewan. GA4/7 increased needle senescence and current-year needle N and P at both locations, K at Saskatchewan, seed and pollen strobilus initiation in Ontario, seed strobilus initiation and abortion in Saskatchewan, and seed yields per tree in Ontario; it decreased Ca at both locations, Mg at Saskatchewan, and diameter increments the year following treatments in Ontario. NH4NO3 and GA4/7 treatments did not interact for strobilus counts. Sexual expression varied with clones in Saskatchewan but not with families in Ontario. Clones interacted with GA4/7 but not NH4NO3 for seed strobilus intiation.