THE EFFECT OF DEFICIT IRRIGATION ON THE FLOWERING BEHAVIOUR OF TWO DAY-NEUTRAL AND ONE EVERBEARING STRAWBERRY CULTIVAR

To determine the effect of deficit irrigation on the flowering behaviour of day neutral and everbearing strawberries, three cultivars (‘Albion’, ‘Evie 2’ and ‘Portola’) were exposed to one of three irrigation regimes; 100% (control), 80% (mild stress), 60% (severe stress) evapotranspiration (ETp) for a period of five weeks. The plants were then allowed to reach maximum water capacity before drought stress treatments were repeated for a further five-week period. Irrigation was adjusted daily in accordance with changes in potential evapotranspiration; calibration coefficients were determined weekly by changes in weight of the pots over a 24-hour period. The number of flowers and berries produced was recorded twice weekly and results are presented for flower numbers over a 12-week period. Application of either the mild or severe deficit treatments did not advance flowering in any of the cultivars tested. A mild stress had no effect on the flower numbers but the severe stress caused a reduction in number up to eight weeks after the deficit treatments. However following the recovery period there was no effect on flower quantity.