Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 3/28/2006
Publication Date: 7/1/2008
Citation: Bryla, D.R., Kaufman, D., Strik, B. 2008. Effects of irrigation method and level of water application on fruit size and yield in red raspberry (Rubus idaeus L.) during the first year of full production. HortScience. 43:1112.
Technical Abstract: A study was done to determine the effects of irrigation method and amount of water application on production and fruit quality in red raspberry. Two cultivars, 'Meeker' and 'Coho', were irrigated by overhead sprinkler or subsurface drip at 50, 100, and 150% of the estimated crop evapotranspiration (ETc) requirement. To adjust for differences in evaporation and application efficiency, approximately 75% more water was applied by sprinklers than by subsurface drip. All measurements were made in 2007 during the first year of full production. Total yields ranged from 11.0-13.2 t/ha, depending on treatment, in 'Meeker', and 11.7-14.2 t/ha in 'Coho'. Yield was 13% higher, on average, in plants irrigated by subsurface drip than in those irrigated by sprinklers. Yield was also affected by the level of water application, although only in plants irrigated by subsurface drip. With subsurface drip, yield increased by 17% from 50% to 100% ETc and decreased by 6% from 100% to 150% ETc. Yield with sprinklers, in contrast, differed by only 4% among each level of irrigation. In general, plants irrigated by subsurface drip produced larger fruit (‘Coho’ only) and more fruit per cane ('Meeker' and 'Coho') than those irrigated by sprinklers. Average fruit size in 'Coho' was 4.3 g per berry with subsurface drip and 4.0 g per berry with sprinklers, while average size in ‘Meeker’ was 3.6-3.7 g per berry regardless of irrigation method. Fruit size was also influenced by irrigation level, with plants producing larger fruit when irrigated at 100 and 150% ETc than at 50% ETc. Lower yield and fruit size with sprinklers than subsurface drip was related to lower soil and plant soil water status due to a limited ability to use the sprinklers during harvest (26 June to 24 July). Soil water content measured during this time averaged 21-28% when irrigated at 50% to 150% ETc by subsurface drip but only 15-18% when irrigated by sprinklers. Consequently, by peak harvest, plant water potentials were -0.3 to -0.5 MPa lower in plants irrigated by sprinklers than in those irrigated by subsurface drip.