Conditioning alleviates reduced yield of smaller plugs of 'Albion' strawberry (Fragaria X ananassa Duch.) in oil-season plasticulture production

摘要

The influences of plug size, planting density, and mulch colour on responses to photoperiod and nitrogen conditioning of 'Albion' strawberry (Fragaria x ananassa Duch.) plants were evaluated in off-season field production in New Jersey, USA. Three different sized plug plants (7.6 cm square pots, 24-cell plug trays, or 50-cell plug trays) were conditioned with natural days (ND, natural daylength) or long days (LD, natural daylength supplemented with 24 h incandescent radiation) for one week followed by ND plus 100 ppm nitrogen (N) for 4 weeks or LD plus 800 ppm N for 4 weeks. Plants were then established in plasticulture on black, white, or silver mulch. In a second experiment, plug plants (439 cm(3) ) were conditioned with LD and nitrogen then established in plasticulture on black, white, or silver mulch at 3 planting densities (0.46, 0.23, and 0.16 m(2) center dot plant(-1) (2, 4, and 6 plants center dot m(-2) )). Fruit were harvested from August through October in both experiments. Conditioning enhanced off-season fall production. White plastic enhanced survival, productivity, and fruit size and larger plugs were more productive than smaller ones. If smaller plugs are desired, conditioning prevents the reduction in yield observed with non-conditioned smaller plugs.