ESTABLISHMENT OF A NONDORMANT BLUEBERRY (VACCINIUM-CORYMBOSUM HYBRID)PRODUCTION SYSTEM IN A WARM WINTER CLIMATE

'Gulf Coast', 'Sharpblue', and 'Wannabe' southern highbush blueberry ( Vaccinium corymbosum interspecific hybrid) cultivars were planted at a density of 10,000 plants per ha in southwest Florida to test the feas ibility of a non-dormant blueberry production system. A non-dormant pr oduction system involves application of nitrogen (N) throughout the fa ll and winter, which enables the plants to avoid the normal dormancy c ycle and the concomitant chilling requirement. If successful, this sys tem could extend the production range of blueberry into subtropical an d tropical areas where chilling temperatures are inadequate for tradit ional (dormant) production systems. Nitrogen fertilizer rate (84 to 25 2 kg ha(-1) N in year 1, 168 to 336 kg ha(-1) N in year 2) was evaluat ed for effects on maintaining plant growth and development in this sys tem. Additionally, since organic soil amendments are known to improve blueberry growth, the effects of municipal solid waste (MSW) compost a nd acidic peat on maintaining growth were also evaluated. In general, increasing N rates from 84 to 252 kg ha(-1) (year 1) or 168 to 252 kg ha(-1) (year 2) increased plant canopy volume, leaf retention, and rat e of new vegetative budbreak. There was no consistent effect of N rate s on soil nutrient concentrations, but leaf N increased and leaf Ca de creased as N rate increased. MSW compost incorporation increased P, Ca , Mg, Cu, Fe, Mn, and Zn soil concentrations compared with peat, but h ad no consistent effect on leaf nutrient concentrations. Plant height and canopy volume were consistently greater for plants grown in the MS W compost compared with the peat amendment, but there were no differen ces in leaf retention or vegetative budbreak between the two soil amen dments. Plants in this non-dormant system have shown no deleterious gr owth effects, suggesting that establishing a blueberry planting in a w arm winter climate is feasible under the described conditions.