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ARS Home » Southeast Area » Poplarville, Mississippi » Southern Horticultural Research » Research » Publications at this Location » Publication #353362

Title: Effect of Phosphorous Acid and Pruning Height on Renovated ‘Woodard’ Blueberry

item STAFNE, ERIC - Mississippi State University
item Smith, Barbara

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: N/A

Technical Abstract: Phosphorous acid is a fungicide that may have other plant health-inducing properties. A previous study showed greater vigor in blueberry plants treated with phosphorous acid. In the current study, old, unproductive ‘Woodard’ rabbiteye blueberries were selected for renovation in 2017. The bushes had not been pruned or otherwise managed in several years. To test the hypothesis that adding phosphorous acid treatments (Agri-Fos) to the renovation process, three treatments were used; no addition of phosphorous acid, phosphorous acid applied as a drench at renovation pruning, and monthly foliar applications of phosphorous acid after renovation pruning and the following year. Two pruning height treatments were also done on July 14; bushes were pruned at ground level and bushes pruned at 50 cm. end of season shoot number was significantly different between the 50 cm cut and the ground level cut (35.6 50 cm vs. 21.1 ground). However, shoot length was greater for the ground cut (74.6 cm) vs. 50 cm cut (65.8 cm). Shoot diameters were not significantly different. Other factors such as first bud push after pruning and crop load rating were not significant. Interesting, phenological development recordings of flower stage did not differ at stages 2-4, but were different from 5-7. The 50 cm cut flower development was earlier by 9 days at stage 5, 10 days at stage 6, and 5 days at stage 7. None of the phosphorous acid treatments differed. More time may be needed to ascertain any differences among those treatments as it is not a direct, but rather induced, effect.