Whole fruit mineral element composition and quality of harvested ‘Delicious’ apples¹

Abstract

Wellspur Delicious' apple trees received preharvest foliar sprays of CaCl 2 at rates of 0, 5.9 or 19.6 kg Ca/ha. season. Fruits of uniform size (7.65 to 8.05 cm diameter) were harvested on a single date and were allowed to ripen at 19°C or were placed in controlled atmosphere storage for five months and then allowed to ripen at 19°C. Fruit quality indices were measured at various times during ripening. The CaCl 2 sprays failed to influence fruit mineral element composition, skin color, soluble solids, titratable acidity, firmness, bitter pit or watercore. At all times during ripening, fruit skin color, soluble solids, titratable acidity and firmness were independent of whole fruit Ca, Mg, K, N and P concentrations, and whole fruit Mg/Ca, K/Ca, (K+Mg)/Ca, K/(Ca+Mg), N/Ca and P/Ca concentration ratios. Fruits with and without bitter pit had identical whole 1 Department of Horticulture and Landscape Architecture Paper No. 88-26. Contribution from the College

Pre‐harvest application of calcium to control black heart disorder in Mauritius pineapples during low‐temperature storage

“…Watkins et al 19 reported that foliar application of soluble calcium salts increases firmness and reduces bitter pit and senescent breakdown in apples. In contrast, Davenport and Peryea20 observed no effect of foliar calcium application on fruit mineral element composition or post‐harvest quality of apples. Beverly et al 21 reported that to increase calcium supply to developing fruit topical spray must be applied to the fruit surface so as to be absorbed directly.…”

Effect of Naphthalene Acetic Acid and Calcium chloride on pre-harvest drop and quality of ‘Red Delicious’ apple.

“…Bramlage et al (1979) found 'McIntosh' fruit firmness at harvest increased slightly with increased flesh calcium concentration; however, the firmness of 'McIntosh' apples did not appear to be influenced by preharvest sprays of calcium or other commercially available calcium mixtures (Bramlage et al 1985). Similarly, preharvest calcium sprays did not affect the calcium content or fruit firmness of other cultivars, such as 'Wellspur Delicious' (Davenport and Peryea 1990). Peryea 1991 concluded that in some cases, preharvest calcium sprays seem to be effective only when applied very often (18 times during the growing season).…”

Vpliv tal in foliarnega gnojenja s kalcijem na kakovost plodov jablane (Malus domestica Borkh.) ’Jonagold’

“…Zaradi lažje primerjave s priporočenimi vsebnostmi za dobro skladiščenje plodov, smo podatke za plodove ob obiranju v obeh sezonah preračunali še na svežo maso plodov in spet ocenili vsebnosti kalcija v plodovih glede na normative, ki so postavljeni na enoto sveže mase plodov. Tudi v sveži masi plodov so bile količine kalcija v plodovih zadovoljive, saj so presegale najnižjo priporočeno mejo za dobro skladiščenje: 4-5 mg Ca/100 g sveže mase plodov (Davenport, 1990). Ta kriterij je bil v literaturi najpogosteje uporabljen, obstajajo pa še drugi.…”

“…V letu 1998 učinkov na omenjeno razmerje ni bilo. Raese (1996) in Davenport (1990) sta kot kriterij za dobre skladiščne sposobnosti plodov določila razmerje K/Ca, ki je manjše od 30. V obeh sezonah so imeli kontrolni plodovi največje razmerje in so se statistično značilno razlikovali od Kalgana in Calciogreena v letu 1997 in od Caltracka v letu 1998 (preglednica 2).…”

“…Večina strokovnjakov (npr. Davenport, 1990;Raese, 1996;Krivorot, 1998;Bergmann, 1988 in drugi) je večkrat poudarila, da sama vsebnost kalcija v plodovih ne pove zadosti, zato je potrebna analiza plodov tudi na vsebnost magnezija in kalija (pa tudi drugih elementov), ker nam daje bolj kompleksno informacijo o kakovosti plodov.…”