THE EFFECTS OF THE IMPOSITION OF HERBICIDE STRIPS ON THE NUTRIENT UPTAKE, YIELD AND STORAGE QUALITY OF APPLES IN A PREVIOUSLY GRASSED COX ORCHARD

Effects of establishing narrow (0.9 m) and wide (1.8 m) herbicide strips in a previously grassed orchard were investigated from 1971 to 1976. Effects of three N fertiliser regimes (0, 62.5 and 125 kg ha^-1) were also studied.
Removal of grass and fertiliser application resulted in acidification of the surface (0–15 cm) soil and an accumulation of nitrate N at 30–45 cm depth.
Herbicide use and N application was associated with improved N uptake by leaves and fruits but P levels were depressed particularly in leaves.
Adopting herbicide strips tended to increase fruit yield and improve tree growth; fertiliser application produced a similar response.
The incidence of bitter pit was lower in N fertiliser treatments compared with nil application and also tended to be reduced in fruit from the herbicide strip plots.
Although in 1975 these beneficial effects of high N supply could be interpreted via effects on fruit size and Ca concentration, in 1976 the latter parameters were similar in all treatments.
In 1975 low Ca fruits from grass and nil N plots were more susceptible to senescent and low temperature breakdown.
Fruit red colour was reduced by herbicide and N fertiliser application.

Weeds and Herbicides, XXI IHC

P.A. Johnson, D.S. Johnson

https://doi.org/10.17660/ActaHortic.1983.136.6