Monthly Archives: November 2024

STFS mtg this Sat (Nov 9th 10 AM) zoom-only is free for all to attend and begins with Claire Yost’s (WSU NWREC researcher) presentation: Regulated deficit irrigation (RDI) conserves water but has limited impact on cider apple fruit and juice quality. Hmmm…Can Claire’s talk help me smartly water my dessert apple trees?

Even if you don’t grow orchard blocks of cider apples, you may be able to glean juicy advice from Claire’s talk on strategies for wisely watering your backyard dessert apple trees.

Zoom connect info:

Join Zoom Meeting via computer or other “smart” deivce:

https://us02web.zoom.us/j/83554223958?pwd=nDOnpHppyhgaKY0t729AxoqULPebPz.1

Meeting ID: 835 5422 3958

Passcode: 319884

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Join Zoom Meeting via the humble phone:

Dial by your location

• +1 253 205 0468 US

• +1 253 215 8782 US (Tacoma)

Same Meeting ID & Passcode as above.

Find your local number: https://us02web.zoom.us/u/keDBwvkMPx

Presentation Synopsis (written by Claire Yost)

My presentation will be on my research thesis titled: Regulated deficit irrigation (RDI) conserves water but has limited impact on cider apple fruit and juice quality. RDI is an irrigation management strategy in which the tree is intentional kept in a water deficit, meaning tree water needs (evapotranspiration) exceed water inputs (irrigation and rain). RDI is widely used in wine grapes to conserve water, limit vegetative growth, and improve fruit and juice quality attributes. These positive changes can decrease economic inputs through reducing irrigation and pruning costs. Additionally, fruit and juice attributes such as tannins are increased, leading to a higher value crop. To our knowledge, RDI has not been done in cider apples yet and our research sought to see if cider apples would respond similarly to wine grapes to RDI treatments in Washington state across four cultivars. Furthermore, we evaluated the efficacy of monitoring methods for RDI, which can be used in various irrigation management strategies. These strategies included weather based models, soil moisture and plant water status monitoring.

Here is the complete abstract if you wanted a longer synopsis. (written by Claire Yost) The United States has experienced a resurgence in cider apple (Malus domestica Borkh.) production, with Washington State as the leading apple producer. However, the cider industry is experiencing several challenges, including orchards struggling to meet the demand for cider-specific cultivars, new orchards sometimes having insecure access to irrigation water or only access to high-cost municipal water, and cidermakers trying to differentiate their product in an increasingly crowded market. This project evaluated whether regulated deficit irrigation (RDI) could (1) conserve water while maintaining yield, and (2) increase fruit and juice quality to help producers differentiate their products. The first study evaluated the effects of RDI on tree physiology, fruit yield and quality, and net returns in a partial budget analysis, while the second focused on RDI impacts on juice quality. Trees of four cultivars (Dabinett, Golden Russet, Nehou, and Porter’s Perfection) were managed with either RDI or control irrigation treatments at two distinct locations: Mount Vernon and Wenatchee, WA. In Mount Vernon, no water stress (ψstem) was detected in the trees managed with RDI, though apple weight and fruit phosphorous decreased by 3.9% and 12.5%, respectively, while fruit firmness increased by 1.2% for fruit from trees managed with RDI. In Wenatchee, a decrease in ψstem in trees managed with RDI led to reductions in fruit size (diameter and weight) in both cultivars, bloom density in ‘Golden Russet’, and leaf nutrients (N, P, K, Cu) in ‘Nehou’, as well as increased firmness for both cultivars. Fruit weight decreased by 15.5% and 33.1% for apples from ‘Golden Russet’ and ‘Nehou’ trees managed with RDI, respectively, though there was no corresponding decrease in yield, at least not one that was statistically detectable (P = 0.724 and P = 0.297, for ‘Golden Russet’ and ‘Nehou’, respectively). Irrigation was reduced by 100% in Mount Vernon and in Wenatchee, 40% and 27%, for ‘Golden Russet’ and ‘Nehou’, respectively. These water reductions resulted in a net gain of $347 per hectare with RDI if irrigation was scheduled using a publicly available online tool based on a calculated water balance. However, if irrigation was scheduled based on ψstem for RDI but with the online tool for business-as usual irrigation, the extra labor associated with measuring ψstem resulted in a net loss of $295 per hectare if RDI was implemented. The second study found no changes in juice quality for fruit from trees managed with RDI in Mount Vernon, but in Wenatchee, there was an increase in specific gravity and soluble sugars. However, implementing RDI did not increase total tannins or total phenolics in the juice at either location, nor did it result in meaningful differences in the phenolic profiles of the juice.