TESTING ORCHARD SOILS FOR TREATMENTS TO CONTROL APPLE REPLANT PROBLEMS IN BRITISH COLUMBIA, CANADA

In greenhouse tests for the effects of soil treatments on the growth of apple seedlings in 101 soils, growth, was increased >50% and >100% respectively by monoammonium phosphate (11–55–0) at 1.5g/L, in 76 and 55 of the soils, by a fumigant or fungicide in 63 and 34 soils, and by a fumigant or fungicide + 11–55–0 in 93 and 81 of the soils.
The greatest increase with 11–55–0 alone was 520%, and with 11–55–0 + a biocide it was 718%. Growth was poor (4.8 to 5.8cm) with or without fertilizers or biocides in three calcarious soils until the soils were acidified.
Growth was good (19.9 to 26.5 cm) and not improved with treatments in 5 soils which had high N and P analysis.

Biocides which improved growth in 20% to 50% of the soils included dazomet, formalin, mancozeb, metam, methyl bromide and 1,3-dichloropropene ± methyl isothiocyanate ± 17% chloropicrin.
Peat was beneficial in many soils.
Some animal manures were beneficial in some but damaging to growth in other soils.

Workshop on Replant Problems with Fruit Trees

John T. Slykhuis

https://doi.org/10.17660/ActaHortic.1988.233.11