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  • Author or Editor: J. M. McDougald x
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Abstract

Apple trees, Malus domestica Bork., cv. Spartan, were grown in pots of quartz sand supplied with nutrient solutions and treated with 8, 4, 2 or 1 meq/1 Ca with all other nutrients constant. Fruit was stored and analyzed for 3 years. Twenty-five percent of the fruits from the 1 meq/1 Ca treatment developed senescent breadown of the flesh after storage but only 1% were affected from the 8 meq/1 Ca treatment. Three-year average Ca concentration in the fruit ranged from 131 ppm in the 1 meq/1 Ca treatment to 178 in the 8 meq/1 Ca treatment. Incidence of breakdown increased through the storage season from October until April when little further increase occurred through June. Magnesium and K concn in the fruit increased with decreasing Ca supply in the nutrient solution.

Open Access

Abstract

‘Spartan’ apples from 29 orchards were dipped in 4% calcium chloride Solution at harvest Senescent breakdown was reduced from an average of 8.3% in the undipped fruit to 2.7% in the dipped fruit Firmness was increased by 0.38 kg (0.84 lb.) and Ca concentration in the fruit flesh by 76 ppm by the dip.

Open Access

Abstract

Fruits of ‘Spartan’ apple were dipped in solutions of commercial CaCl2 after harvest to increase their Ca concentration. Fruits were stored until the following June, then the flesh was analyzed for Ca. Undipped fruit contained 203 ppm Ca and fruit dipped in 4% CaCl2 (wt/vol) contained 278 ppm Ca, dry weight basis. When surfactants were added to the CaCl2 solution, the Ca concentration in dipped fruit was 230 to 250 ppm. When thickeners and surfactants were added, the Ca concentration in dipped fruit was 373 to 825 ppm. These results indicate that surfactants reduce the uptake of Ca by fruit from dips but thickners with surfactants increase it

Open Access

Abstract

The concentration of Ca in the flesh was closely related to the amount of breakdown in individual apples in 5 lots of ‘Spartan’ apple (Malus sylvestris Mill.) collected over 2 years. Correlation coefficients of 0.9 were obtained using log Ca and linear breakdown or log Ca and log breakdown. The amount of breakdown calculated for the 5 lots by the 2 equations was 100 percent at 70 ppm Ca, from 46 to 100 percent at 100 ppm Ca, from 3 to 12 percent at 150 ppm Ca and less than 2 percent at 200 ppm.

Open Access