Bitter Pit Development Research Articles

Incidence of bitter pit in relation to the calcium content of apples: Calcium distribution in the fruit

AbstractThe distribution of calcium at harvest, its subsequent redistribution within the fruit during storage in air at 2.8°C and bitter pit development in samples of Cox's Orange Pippin apples picked at intervals during September and October were investigated. The distribution of calcium in the fruit changed on the tree and during storage. The percentages of pitted apples, assessed in January, were poorly related to calcium concentrations in the whole fruit or in any fruit zone at harvest. Redistribution of calcium from the mid and outer cortical tissues to the core zone was followed, at longer intervals over successive picks, by the appearance of bitter pit lesions. The earliest‐picked sample was less affected by bitter pit than samples picked later in September. The least bitter pit occurred in samples picked in October, after the climacteric rise in respiration, and these fruits were apparently less subject to fluctuations in calcium concentrations during storage.

Bitter pit reduction in ‘Cox's Orange Pippin’ apples by controlled and modified atmosphere storage

Controlled and modified atmospheres reduced bitter pit in New Zealand ‘Cox's Orange Pippin’ apples stored for 5 weeks at 2°C. Fruit from orchards that had received calcium sprays during the season were stored in an integral container maintained with a gas atmosphere of 3% CO 2 plus 3% O 2, and had less than 6% bitter pit. In comparison, air-stored fruit from the same orchards had up to 26% bitter pit. Polyethylene bags containing different numbers of 9-mm holes were tested for their effectiveness in influencing bitter pit development. The incidence of bitter pit that developed during storage was progressively reduced from 50% to less than 5% as the number of holes per bag decreased. Fruit in polybags had less weight loss, higher firmness and improved quality compared with air-stored fruit. Practical problems relating to commercial use of polybags for bitter pit control are discussed.

Possible roles of calcium and ammonium in the development of bitter pit in apple

Apple trees (Malus pumila Mill. var. domestica Fuji/Malus prunifolia rootstock) showed a high susceptibility to bitter pit when supplyed with ammonium salt instead of nitrate (control) in the nutrient solution. When apple fruit was affected by bitter pit, a lower calcium as well as a higher nitrogen and ammonium‐nitrogen contents was observed in the fruit flesh near the calyx end. The activity of the mitochondrial Ca2+‐uptake of the fruit flesh near the calyx end was higher when the tree was grown with ammonium salt than when grown with nitrate. Both the activities of succinate: cytochrome c oxidoreductase and the mitochondrial Ca2+‐uptake per g of tissue were higher in affected fruit than in healthy fruit. Each of chlorpromazine, N‐(6‐aminohexyl)‐5‐chloro‐l‐napthalenesulfonamide (W‐7) and N‐(6‐aminohexyl)‐l‐naphthalenesulfonamide (W‐5), calmodulin antagonists, was infiltrated into the fruit for 20 min under reduced pressure (about 1 × 104 Pa). Few days later, numerous bitter pit‐like spots were observed in both fruit treated with W‐7 and chlorpromazine, while only a few spots were observed after the infiltration with W‐5, a less potent calmodulin antagonist. A possible mechanism for the occurrence of bitter pit is discussed.

Response of Young ‘Topred Delicious’ Apple Trees to Orchard Floor Management and Fertilization

Abstract Growth of ‘Topred Delicious’ (Malus domestica Borkh)/Malling Merton (MM) 111 apple trees during the first 5 years in the orchard was significantly affected by the orchard floor management system. Trees grown in a mowed sod were smaller and had a significantly lower yield efficiency (kg/cm2) than those grown under cultivation or a herbicide strip system. N source or rate did not influence growth or average yield/tree; fruit size and bitter pit development were significantly greater where a complete fertilizer (10N-4P-8K) was applied. N increased tree growth under sod but not under a cultivated or herbicide strip managment system. Growth response in the first year was increased when larger-sized trees were planted under a weed-free management system and trees were headed to 76 cm.

Supplementing the Nutrition of Bramley’s Seedling Apple with Phosphorus Sprays II. Effects on Fruit Composition and Storage Quality

SummaryFour sprays of 1% KH2 P04 applied between mid-June and mid-July in each of three years consistently increased the P concentration in cv Bramley’s Seedling apples at harvest and reduced the incidence of senescent breakdown in the fruit after storage in air at 1.5°C for 32 weeks. Similar reductions in low temperature breakdown were recorded in two of the three years in air storage and in the third year in fruit stored in 8% CO2 at 3.5°C for 45 weeks. Phosphorus sprays also reduced the incidence of superficial scald and core flush in certain years. Although sprays applied between mid-July and mid-September also increased fruit P content the reduction in breakdown was negligible. In one trial KH2 PO4 sprays also increased the K concentration in the fruit and this was associated with the development of bitter pit in the stored fruit. Ca(H2 PO4)2 applied at an equivalent rate of P also increased fruit P concentrations and reduced the level of breakdown in store. The tendency of P sprays to increase the i...

Calcium analysis and the prediction of bitter pit in apple fruit

Abstract Calcium concentrations of Cox's Orange Pippin apple fruit, determined on plugs of cortical tissue, measured in fruit 3 weeks before commercial harvest, and in different districts, different seasons, and by 2 laboratories, were found to be closely related to subsequent development of bitter pit. Data from an extensive survey in Nelson orchards showed that calcium analyses before harvest could be used reliably to predict the risk of bitter pit developing in any line of fruit.

The effect of Ca and Mg treatments on the physiology, chemical composition and bitter-pit development of ‘Cox's Orange’ apples

‘Cox's Orange’ fruits were treated on the tree at weekly intervals with high concentrations of either Ca or Mg solutions. The concentration of these elements in the treated fruits was considerably increased. Ca treatment completely prevented the development of bitter pit, reduced respiration and solute leakage, and increased fruit firmness and titratable acidity. The effect of Mg on the investigated fruit characteristics was different in the two years under consideration, which possibly can be explained by the highly different Ca Mg ratios obtained in the two years.

Transport of calcium in apple trees and its penetration into the fruit

Abstract Factors affecting the movement of calcium in apple trees and the roles played by xylem and phloem in its distribution to leaves and fruits are discussed in relation to the development of bitter pit.

The Predominant Role of Calcium as an Indicator in Storage Disorders in Cleopatra Apples

SummaryExperiments with Cleopatra apple trees growing on Mailing 7 rootstocks in pot culture were conducted over a period of seven years. The trees were subjected over the years to a wide variety of treatments related to the nutrient supply, consisting of various levels and combinations of calcium, magnesium, phosphorus, nitrogen and potassium. The study considered the influence of nutrition on the mineral element composition of the fruit and on the storage disorders bitter pit, breakdown, scald and fungal rotting. Statistical analysis of the results indicated a predominant role for calcium in inhibiting bitter pit development, and also showed that calcium was the only mineral element of importance as an indicator of other storage disorders. Under conditions of adequate nutrition, a direct role for magnesium and potassium is unlikely. Principal component analysis, followed by varimax rotation of the first three component axes, proved to be a most useful mathematical technique for studying interrelationshi...

Studies on volatile compounds produced by apples in relation to the development of bitter pit

AbstractApples affected with bitter pit had higher levels of most volatile organic compounds than sound fruit. Reducing the susceptibility of fruit to pit by the application of calcium sprays also resulted in reduced levels of most volatiles. However, it appears that the volatiles are not causatively associated with pit as they did not cause an increase in the incidence of pit when added to the fruit.A significant positive correlation between pre‐harvest levels of acetaldehyde and development of pit was found but the extent of the remaining variation precluded the use of the method for commercial grading of fruit for pit susceptibility.

Effect of 2,3,5-Triiodobenzoic Acid on Bitter Pit and Calcium Accumulation in ‘Northern Spy’ Apples1

Abstract Spraying ‘Northern Spy’ apple trees with 50 ppm TIBA 2 weeks after petal fall reduced the accumulation of Ca in the fruit and increased the amount of bitter pit. The greatest incidence of bitter pit was associated with the Ca content of the fruit during the middle of the growing season. Calcium accumulated rapidly during the period of cell division and seed development, and again 2 to 3 weeks before harvest. The late influx of Ca may explain the development of less bitter pit in storage in late harvested apples than in apples harvested immature.

Calcium Levels of ‘Golden Delicious’ Apples Sprayed with 2,3,5-Triiodobenzoic Acid1

Abstract ‘Golden Delicious’ apple trees sprayed with 50 ppm 2,3,5-triiodobenzoic acid (TIBA) 28 days after bloom had pitted fruit at harvest, but comparable control trees had none. The appearance of the pits on the fruit was similar to bitter pit. TIBA decreased the fruit Ca content and increased fruit B content. Decrease in Ca content by TIBA probably caused the development of bitter pit on the fruit.

The effects of calcium and other minerals on incidence of bitter pit in Cox's orange apples

Abstract Sprays containing calcium, magnesium, potassium, phosphorus, nitrogen, boron, iron, strontium, tungsten, and vanadium were tested for their effect upon bitter pit development in stored apples (Cox's Orange). Only calcium nitrate significantly altered the incidence of pit, both tree sprays and post-harvest fruit sprays of this compound reducing incidence of bitter pit consistently. Later sprays tended to be more effective than early ones, but the most effective treatment was calcium nitrate (6 lb/100 gals) applied fortnightly throughout the season. No damage occurred, even at concentrations of 10 lb/100 gals.

Studies on bitter pit in relation to mineral nutrition (preliminary report)

MORI and ABB(6) noted that susceptibility of apple fruit to bitter pit was increased by high potassium and low nitrogen supply, MORI and YAMAZAICI(9) have shown that bitter pit increased in proportion to potassium supply in solution culture experiment. It has been reported that excessive absorption of nitrogen increased susceptibility of apple fruit to bitter pit(7, 8). These results suggest that the cause of bitter pit may be attributable to deficiency of calcium or magnesium. It was shown, however, that magnesium has no effect on the development of bitter pit, even when severe deficiency was observed(11). Therefore emphasis should be put on calcium nutrition. In this preliminary study, bearing trees were grown in solution culture. For the experiment of effect of calcium deficiency on incidence of bitter pit was used Rall's variety, which is most susceptible to this disorder. When the trees were grown for two years in the solution from which calcium was eliminated, all fruits were severely affected by bitter pit at harvest time. For the experiment of magnesium or calcium deficiency, Jonathan variety which is least susceptible to bitter pit was used. Pitting was severer on the fruits on trees growing in the solution from which calcium was eliminated than on those of the standard solution, while no effect of magnesium supply was observed.