ARS | Publication request: WHOLE CANOPY PHOTOSYNTHESIS OF APPLE TREATED WITH 'SURROUND WP'

Submitted to: American Society for Horticultural Science
Publication Type: Abstract Only
Publication Acceptance Date: July 23, 2001
Publication Date: N/A

Technical Abstract: The purpose of the study was to determine if season-long applications of a reflective, particle film material influenced photosynthesis and fruit size. Four, whole canopy photosynthesis chambers of Mylar R were constructed for 'Empire' apple trees with a volume of -25m3. The treat- ments were a control vs weekly applications of 56 kg/ha of 'Surround WP' (Englehard Corp. Iselin, NJ). All treatments were oversprayed with conventional pesticides. Approximately every three weeks during the growing seasons of 1999 and 2000, measurements were made on two trees of each treatment beginning at 0900 HR and ending at 1500 HR. A CIRAS-1 photosynthesis system (PP Systems, Haverhill, MA) measured carbon dioxide and water vapor fluxes. In 1999 whole canopy photosynthesis was greater for the 'Surround WP' treatments on all sampling dates and on only one date in 2000. Fruit size, adjusted for fruit number, was greater in the 'Surround WP' treatments in both years. Overall, we found that the application of 'Surround WP' increased whole canopy photosynthesis and the increased carbon assimilation was partitioned to fruit.