Year: 2006
Type: article
Abstract: In an attempt to control scab, a 12-year-old apple orchard was treated with suspensions of 5 g/l hydrated \nlime (Ca(OH)2) using overhead irrigation for 15 min. No other fungicides were used. In treatment A, irrigation \nwas started when infection according to Mills had taken place. In treatments B and C, treatment was delayed \nby 6 h and 20 h, respectively. Irrigation was initiated when the scab warning system signaled even very low \ninfection risk, and a total of 62 treatments were applied. At harvest, the fruits of ‘Golden Delicious’ and \n‘Jonagold’ varieties of untreated controls were scabbed, while those of ‘Elstar’, ‘Fiesta’, and ‘Kent’ had no \nvisible scab symptoms. During both conventional and ULO storage for 7.5 months, all control fruits \ndeveloped scab symptoms. All fruits from A, B, and C treatments were free of scab at harvest and after \nstorage. All control trees had scabbed leaves at harvest time; treated trees were free of scab on their upper \nleaf surfaces, while up to 15% of the leaves had at least one scab lesion on their lower surfaces. This was \nattributed to poor wetting of these surfaces by sprinkler irrigation, while the fruits and upper leaf surfaces \nwere fully covered with hydrated lime suspensions. At harvest, leaves and fruits were covered with whitish \ncalcium carbonate residues which could be removed by a brief dip in 20 g/l aqueous citric acid. There were \nno signs of phytotoxicity on either leaves or fruits.
Authors: P. Grimm-Wetzel, Jörg Schönherr
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2231155502