FRUITING PATTERNS OF NORTHERN-ADAPTED STRAWBERRY POPULATIONS IN A MILD SHORT-DAY ENVIRONMENT

In Canada, dayneutral strawberry cultivars are difficult to breed, partly because the adapted germplasm is not short-day adapted and does not exhibit low dormancy. To overcome this, dayneutral selections need to be found that exhibit these characteristics. As a first step, a northern-adapted population was grown in a mild, short-day environment to find the range of fruiting patterns available. This population consisted of plants grown from crosses between ‘Seascape’ and seven Ontario selections which exhibited a range of fruiting patterns from dayneutral through early to late June-bearing. Seeds from these crosses were germinated, grown as plug plants at 17°C and planted on either 21 September or 5 October 2006 at the Gulf Coast Research and Extension Center. All fruit were picked twice weekly from 17 November 2006 to 10 May 2007. The fruit from each plant were weighed and counted. The seven families showed a continuous distribution of fruiting patterns from plants that fruited more-or-less continuously from mid-November to early May, to others that never fruited. The dates of first fruit after the 9^th week of harvest could be related to the mean daily temperatures at 60 cm above the ground. From this we concluded that flower bud initiation is regulated by the maximum temperature at which flower buds are initiated and is genetically continuous.