The 2012 ASHS Annual Conference

We applied reflective fabric (Extenday™) to alleyways of pear orchards to investigate the influence of fabric on canopy light interception and distribution, fruit set, fruit growth rate, average fruit size, yield, fruit firmness, and postharvest quality.  Sites included a multi-leader ‘d’Anjou’ orchard planted at 269 trees/ha (2009–2011; Oregon) and a hedgerow ‘Bartlett’ orchard at a density of 633 trees/ha (2011; California).  We evaluated two treatments at both sites:  No Fabric [NF], and Fabric applied prior to full bloom (FB) through harvest [FS].  For ‘d’Anjou’ we included two additional treatments:  Fabric applied prior to (FB) and removed 75 days after full bloom (DAFB) [F-75], and Shade, 60 % shade-cloth applied 60 DAFB through harvest in 2009 and 2010 only.  Weekly ‘d’Anjou’ fruit growth rate was not affected by the fabric treatments relative to NF in any year, but significantly reduced for shaded fruit.  Final fruit size of ‘Bartlett’ and ‘d’Anjou’ was similar among treatments, with the exception of shade-treated fruit which were smaller.  Total ‘d’Anjou’ tree yield in year one was significantly greater for fabric treatments compared to NF (c.a., 27% and 21% for FS and F-75, respectively ), but not significantly different between fabric treatments, indicating that increased tree yields were a function of greater fruit number.  2011 ‘Bartlett’ yield (P = 0.19) and fruit number (P = 0.16) were higher for FS than NF, but not significantly; however, yield efficiency was significantly higher (~30) with Fabric. In year 2, a significant yield increase relative to NF was observed for FS (11%), but not F-75 (3%) in ‘d’Anjou’.  Severe freeze and wind events limited d’Anjou' production in 2011 (i.e., ~40% of 2009 and 2010 yields), irrespective of treatments. For ‘d’Anjou’, we observed higher yields and light interception for Fabric treatments in the lower exterior, mid and interior canopy.  Relative to NF, ‘Bartlett’ FS had significantly more fruit in the upper canopy on both the north and south sides the tree.  At harvest, fruit maturity was advanced by several days for both ‘d’Anjou’ and ‘Bartlett’ FS treatments relative to NF.  Slightly greater levels of soluble solids were observed in FS ‘d’Anjou’ fruit, but not ‘Bartlett’.  Shaded ‘d’Anjou’ fruit had lower sugar content than other treatments.  Postharvest quality of ‘d’Anjou’ fruit was not affected by treatments in all three years.  Relative to NF, total 3-year projected per acre ‘d’Anjou’ returns were increased by $2,600 and $4,800 for FS and F-75, respectively.