Dwarf apple tree growth and yield under several non-herbicidal ground management systems were compared. Six ground cover systems were established in two newly planted orchards. After two growing seasons, trees in the straw mulch and geotextile mulch treatments had larger trunk cross-sectional areas and more shoot growth than trees in the red fescue and insectary plant cover treatments. Growth of trees under the manure mulch and cultivation treatments was intermediate. When four of the systems were established along rows of five-year old trees in an existing orchard, the increase in trunk cross-sectional area over two growing seasons was greatest for trees in the manure mulch and straw mulch followed by tose in geotextile mulch, trees in the red fescue grew least. The use of a mulch, such as straw or geotextile, has a favourable effect on growth and has potential for use in organic orchards.

No description available.

An alternative to herbicides in dwarf apple orchards (Malus pumila Mill.) is the use of mulches. Research objectives were to compare several mulch systems (Festuca rubra L., Lupinus albus L. plus Daucus carota L.; straw, manure compost, geotextile) with soil cultivation as to soil physical properties and plant nutrient levels in soils, leaves and fruit. Studies carried out in 1992 and 1993 on three dwarf apple orchards on the Macdonald Campus of McGill University showed that straw mulch increased soil water contents and exchangeable K, but reduced exchangeable Mg compared to Festuca mulch. Straw mulch reduced soil temperatures in summer relative to geotextile or cultivation. Festuca reduced leaf N contents but increased leaf P contents-elative to geotextile treatments. Soil nitrate N contents were correlated with soil water contents, and the ratios N/Ca and K/Ca in the fruit were unaffected by treatment. Straw and geotextile mulches increased soil water content and nitrate-N levels during peak sowing periods and thus were the superior treatments.

No description available.