Fruit Splitting Research Articles

Postharvest atemoya fruit splitting during ripening

Abstract Postharvest atemoya ( Annona cherimola Mill, x Annona squamosa L.) fruit splitting started when the respiration rate reached its peak and as ethylene production increased. The splitting coincided with the three-fold increase in total soluble solids. There was an increase in dry matter content of the skin and receptacle and a decrease in dry matter content of flesh. Shrink wrapped fruit had reduced weight loss and fewer and narrower splits. Heating fruit to 47.5 °C, with increasing levels of humidity increased split number and width. The results suggest that osmotic and subsequent turgor changes related to production of neutral sugars during ripening led to a movement of water from the skin and possibly receptacle to the flesh. The increase in receptacle diameter increased the stress on the flesh and skin leading to fruit splitting.

Gibberellic acid sprays, girdling, flower thinning and potassium applications affect fruit splitting and yield in the ‘Ellendale’ tangor

SummaryThis study quantified the effect of fruit set treatments on preharvest fruit splitting, a serious problem in the ‘Ellendale’ tangor, as well as treatments aimed at alleviating fruit splitting incidence. Treatments, during the full bloom period, aimed at increasing fruit set, viz. GA3 sprays and girdling, increased fruit splitting to between 30 to 60% of final yield. This related to a significant shift/delay in the normal fruit drop pattern. Only the girdling treatment during fullbloom significantly (P<0.05) increased final yield. The blossom GA3 sprays increased yield only slightly while the postbloom GA3 sprays, varying from 10 to 20mgl–1, did not affect final yield at all. In this study various approaches to reduce fruit splitting in ‘Ellendale’ tangor were tested: (i) specific chemical and mechanical flower thinning treatments reduced fruit splitting, without adversely affecting yield; (ii) potassium sprays, applied from ten weeks before fullbloom to six weeks after full bloom achieved limited s...

Water deficits at anthesis reduce CO2 assimilation and yield of lychee (Litchi chinensis Sonn.) trees

Ten-year-old 'Tai So' lychee (Litchi chinensis Sonn.) trees growing on a sandy loam soil in subtropical South Africa (latitude 25 degrees S) were watered weekly (well-watered treatment) or droughted from late July until January (drought treatment). After 16 weeks, at which time the trees obtained most of their water from below 150 cm, average soil water content at 0 to 150 cm depth was 14.5 +/- 0.1% in the well-watered treatment and reached a minimum of 7.6% in the drought treatment. At Week 7, minimum leaf water potential (Psi(L)) in the morning and early afternoon declined to -2.6 and -2.8 MPa, respectively, in droughted trees compared with -1.5 and -2.2 MPa, respectively, in well-watered trees. From Week 9, stomatal conductance and net CO(2) assimilation rate ranged from 70 to 300 mmol m(-2) s(-1) and 3 to 13 micro mol CO(2) m(-2) s(-1), respectively, in well-watered trees. The corresponding values for droughted trees were 50 to 180 mmol m(-2) s(-1) and 2 to 6 micro mol CO(2) m(-2) s(-1). Five weeks after rewatering the droughted trees, gas exchange had not recovered to the rate in well-watered trees, although tree water status recovered within a week of rewatering. In the well-watered trees, water use (E(t)) was 26 +/- 1 mm week(-1) with evaporation (E(p)) of 20 to 70 mm week(-1) indicating a crop factor (k(c) = E(t)/E(p)) of 0.4 to 1.2. Before anthesis, tree water status did not affect extension growth of floral panicles or leafy shoots. In contrast, no vegetative shoots were initiated after fruit set in the droughted trees when Psi(L) in the morning declined to -2.5 MPa. Water deficits reduced initial fruit set by 30% and final fruit set by 70% as a result of fruit splitting (41.2 +/- 4.0% versus 10.0 +/- 1.3%). Water deficits did not alter the sigmoidal pattern of fruit growth, but reduced yield from 51.4 +/- 5.5 kg tree(-1) in well-watered trees to 7.4 +/- 3.3 kg tree(-1) in droughted trees.

Postharvest physiology and quality of bitter melon (Momordica charantia L.)

Developing fruits of Momordica charantia, known as bitter melon, bitter gourd or balsam pear, were harvested at horticultural maturity and stored up to 14 days in humidified air at different temperatures. Respiration rates of fruits at 20 and 10 °C were approximately 40 and 15 μl CO2 g−1 h−1, respectively. Ethylene production rates at these temperatures were 0.1–0.3 nl g−1 h−1. Fruits stored for >8 days at 7.5 °C showed severe chilling symptoms (decay, pitting and discoloration) and typical chill-induced respiratory and ethylene production increases after transfer to 15 °C. Fruit quality was best maintained if bitter melon were stored at 10 and 12.5 °C. Fruits at 15 °C continued to develop, showing undesirable changes including seed development, loss of green color, and fruit splitting. Immature fruit maintained postharvest quality better than fruit harvested at the fully developed green stage. Bitter melon stored at 15 °C in controlled atmospheres (21, 5 or 2.5% O2 in combination with 0, 2.5, 5 or 10% CO2) were not different in quality from air-stored fruits at 2 weeks. Fruits stored 3 weeks in 2.5 or 5% CO2 in combination with 2.5% O2 showed greater retention of green color and had less decay and splitting than air-stored fruit.

Influence of orchard production system and cultivar on early productivity of sweet cherry (Prunus avium): effects on tree growth and fruit production and quality

This experiment assessed 3 orchard production systems [Tatura trellis, 1-m within-row tree spacing; palmette trellis, 2-m within-row spacing; freestanding, multiple leader (vase), 3-m within-row spacing] and 2 cultivars of sweet cherry (Prunus avium) (Van, Lambert) to establish the horticultural merits of high density, sweet cherry production. The combination of high tree densities and shallow duplex soils reduced vegetative vigour by 32% compared with the lowest tree density production system. Production systems at the highest tree densities produced the highest cumulative yields to year 7 for both cultivars. Fruit size was not affected by orchard production system; however, the extent of rain-induced fruit splitting may be affected by production systems. Cultivar influenced both yield and susceptibility to rain-induced fruit cracking. Van was earlier to bear fruit than Lambert on all production systems and more resistant to rain-induced fruit splitting.

Chemical Repellents and Plastic Netting for Reducing Bird Damage to Sweet Cherries, Blueberries, and Grapes

We conducted 3 years of field tests comparing two chemicals [methyl anthranilate (MA, a natural compound used as a flavor additive) and Keyplex-350 (a proprietary micronutrient formulation)] that were reported to repel birds to exclusionary plastic netting and nontreated plots. Cumulative fruit damage from birds was monitored on sweet and tart cherry (Prunus avium L. and P. cerasus L.), blueberry (Vaccinium corymbosum L.), and wine grapes (Vitis vinifera × labrusca). Initial MA formulations caused injury to fruit and foliage. Two modified MA formulations with microencapsulation and photooxidation inhibitors provided significant reductions in bird damage and fruit splitting on sweet cherries in one of four experiments. A taste panel could not detect MA residues on sweet cherries at harvest. Bird damage was slightly reduced in MA-treated grapes, but damage to blueberries was similar in MA and control treatments. Keyplex did not deter birds from feeding on fruit and caused blemishes on and an unpleasant flavor in treated fruit. Many bird species were observed feeding on these fruit crops during successive years at the three experimental sites. Although these two chemicals have the potential to deter bird depredation, our work suggests that neither is consistently effective against all the frugivorous species in the northeastern United States. Chemical name used: 2-Aminobenzoic acid methyl ester [methyl anthranilate (MA)].

Fruit splitting in ‘Nova’ hybrid mandarin in relation to the anatomy of the fruit and fruit set treatments

Fruit splitting in the mandarin orange cultivar ‘Nova’ is related to the presence of an open stylar end in the fruit. This opening arises from a cavity present at the base of the style, and is formed in a variable proportion of fruits. The cells at the bottom of this style cavity form a rind-like tissue which develop into a navel structure. The size of this navel is larger in open-stylar end bearing fruits and, accordingly, in split fruit. The number of split fruit per tree is unrelated to the number of fruit set. The application of gibberellic acid (GA 3) has a variable effect on set and splitting depending on its timing. This hormone increases fruit splitting when applied at flowering, but reduces it when applied shortly after the end of the June drop. It has only a minor effect on fruit set.

Hormonal control of splitting in ‘Nova’ mandarin fruit

Fruit splitting, a physiological disorder of peel development in citrus, has been studied in terms of peel thickness and puncturing resistance in ‘Nova’ mandarins. Both features are negatively correlated with splitting. A mixture of G A, and 2,4-D reduced significantly the percentage of affected fruits. The best results were obtained with two applications at 60 and 30 d before the anticipated onset of the disorder. Calcium nitrate applications have similar effects, but were ineffective in orchards with a low natural incidence of splitting.

FACTORS INFLUENCING PREHARVEST FRUIT SPLITTING IN ELLENDALE (C. reticulata).

Preharvest fruit splitting (PFS) is a serious problem in Ellendales, especially in hot, humid climactical areas. In control unsprayed treatments PFS can vary from 14 to 30% of the final yield. Any treatment during the fullbloom (FE) period aimed at increasing fruit set (gibberellic acid (GA) sprays, girdling), increases PFS levels, ranging from 40 to 60% of the final yield. This relates to a significant shift (delay) in the normal fruit drop pattern as compared to untreated trees.We have evaluated various approaches aimed at reducing PFS in Ellendales: potassium treatments, from 10 weeks pre-blossom to six weeks after full-bloom, however, increased PFS levels, possibly due to increasing the initial fruit set levels; flower thinning, both chemical and mechanical, marginally reduced PFS, without adversely affecting yield; post-November drop GA application, 2,4-D and girdling treatments, aimed at stimulation of rind growth (not quantified) increased yields significantly (P&lt;0.05) without concurrent increases in PFS.Cross pollinated trees, and resultant high seed content in the fruit, yielded fruit with thicker rinds, with little or no PFS. GA application at FE reduced fruit seed content and peel thickness and increased PFS.Any treatment causing high initial fruit set increases PFS. Flower: flower and fruit: fruit competition should be reduced early during the fruit growth phase, without adversely affecting final yields.

FACTORS INFLUENCING PREHARVEST FRUIT SPLITTING IN ELLENDALE (C. reticulata).

Preharvest fruit splitting (PFS) is a serious problem in Ellendales, especially in hot, humid climactical areas. In control unsprayed treatments PFS can vary from 14 to 30% of the final yield. Any treatment during the fullbloom (FE) period aimed at increasing fruit set (gibberellic acid (GA) sprays, girdling), increases PFS levels, ranging from 40 to 60% of the final yield. This relates to a significant shift (delay) in the normal fruit drop pattern as compared to untreated trees. We have evaluated various approaches aimed at reducing PFS in Ellendales: potassium treatments, from 10 weeks pre-blossom to six weeks after full-bloom, however, increased PFS levels, possibly due to increasing the initial fruit set levels; flower thinning, both chemical and mechanical, marginally reduced PFS, without adversely affecting yield; post-November drop GA application, 2,4-D and girdling treatments, aimed at stimulation of rind growth (not quantified) increased yields significantly (P&lt;0.05) without concurrent increases in PFS. Cross pollinated trees, and resultant high seed content in the fruit, yielded fruit with thicker rinds, with little or no PFS. GA application at FE reduced fruit seed content and peel thickness and increased PFS. Any treatment causing high initial fruit set increases PFS. Flower: flower and fruit: fruit competition should be reduced early during the fruit growth phase, without adversely affecting final yields.

Cape gooseberry (Physalis peruviana) production systems

Abstract The management and fruit production of cape gooseberries (Physalis peruviana L.) was compared over a range of between-plant spacings from 0.2 to 1.8 m and under different combinations of cultural techniques, including the use of a polythene mulch, trickle irrigation, and planting in raised (20 cm) beds. The relative performance of cape gooseberry seedlings and cuttings was also studied. Plants propagated from cuttings were less vigorous, cropped earlier, and produced more and larger fruit than seedlings, but showed a higher incidence of fruit splitting and a lower soluble solids content. Fruit yield per plant was greatest at between-plant spacings > 0.6 m, but yields per planted m2 were greatest at the closest spacings. Of the cultural techniques used, only the growing of plants through a polythene mulch resulted in consistently increased plant growth and higher fruit yields.

Pistillate Flower and Fruit Abortion in Pecan as a Function of Cultivar, Time, and Pollination

Abstract Abortion of pistillate flowers and fruit was determined in ‘Cherokee’, ‘Success’, ‘Stuart’, and ‘Desirable’ pecans [Carya illinoensis (Wang.) K. Koch]. Abortion occurred in 4 periods during the growth cycle of the fruit. The distinctness and magnitude of the drops varied greatly among cultivars. Total seasonal abortion was inversely related to the alternate bearing tendency of the cultivars. The 1st drop varied inversely with shoot length, the 2nd drop coincided with abortion of nonpollinated flowers and was increased by selling, and the 3rd drop coincided with abortion induced by self-pollination. The majority of fruit loss during the 4th drop followed fruit split or discoloration. This drop correlated with high soil moisture and humidity. However, a lesser drop, from embryo abortion, also is proposed to occur at this time.

Effects of Calcium, Daminozide, and Fruit Maturity on Canned ‘Bing’ Sweet Cherry Quality

Abstract Cherries pitted prior to canning or treated with daminozide had lower drained weights, more total anthocyanin, more turbid syrup, darker Agtron red values, and were softer than nonpitted or nontreated cherries. USDA color grade was higher, but USDA character grade was reduced when cherries were pitted or treated with daminozide. CaCl2 applied as either a 3% dip prior to pitting or as a 1% addition to the syrup increased the firmness, decreased the turbidity of the syrup of pitted and nonpitted cherries, and reduced the number of split fruit in nonpitted cherries. CaCl2 improved the USDA character grade of pitted and nonpitted cherries, and daminozide-treated cherries. Delaying harvest by 8 days reduced drained weight losses, increased total anthocyanin content, pH and soluble solids, and resulted in a darker red canned cherry as measured by the Agtron. CaCl2 compensated for the reduced USDA scores for character caused by pitting or daminozide, increasing character to equal that of nonpitted or nontreated, respectively. Chemical names used: butanedioic acid mono(2,2-dimethylhydrazide) (Daminozide).

Fruit Morphology and Drop of Navel Oranges in Florida

Abstract Some morphological aspects of navel oranges [Citrus sinensis (L.) Osbeck] were studied in 1980 and 1981 on healthy fruit and fruit affected by secondary-fruit yellowing (SFY), stylar-end decay (SED), and fruit splitting, major causes of summer and summer-fall fruit drop in Florida. Fruit affected by SED or splitting were generally larger and had larger styler-end apertures, and those affected by SED had a higher frequency of rind protrusions into primary-fruit locules than healthy fruit. Healthy fruit harvested from the south top of trees were heavier and had larger secondary fruit, stylar-end apertures, and thicker peel than fruit from the northern-bottom canopy position. Some of these characteristics are associated with incidence of SFY, SED, and fruit splitting.

Seasonal Attack Patterns on 'Hamlin' Orange by the Coffee Bean Weevil (Coleoptera: Anthribidae) in Florida

The seasonal attack period of the adult coffee bean weevil, Araecerus fasciculatus (DeGeer) on maturing `Hamlin' orange, Citrus sinensis [L.] Osbeck, was determined. Adult weevils were drawn into the trees in August with the onset of fruit splitting. Consistent and highly significant (p =< 0.01) correlation coefficients were obtained between adult weevil counts and the counts of split fruit on the same trees. Adult activity occurred within the trees for ca. 12-14 weeks from mid-August through November each year between 1978-80. Attacked fruit were first observed between 2-4 weeks after adult activity was recorded within the trees. Most injury to fruit occurred during September-October each year with the amount of weevil injury declining rapidly through November.

Effect of potassium nutrition on fruit splitting in Valencia oranget

SummaryThe effect of K supply on fruit splitting and other quality features was studied in outdoor soil culture of Valencia orange trees on sour orange rootstock. K application reduced splitting, and increased fruit size, peel thickness and fruit acidity. Addition of P to the NK treatment moderated the K effect on acidity.In the K treatments, the leaf K was raised, on an average, from 0.69 to 1.36% and K in the peel from 0.42 to 1.0%. The putrescine content in the fruit peel of trees not receiving K, and split fruits, was significantly higher than in the K-treated trees.

モモおよび日本ナシの果実発育におよぼす胚の破壊とジベレリン処理の影響

The effect of gibberellins on the setting and subsequent growth of peach and Japanese pear fruits has been studied after the embryos were destroyed or the seeds were removed mechanically at different stages of fruit development.1. In the peach, 14-year-old ′Okubo′ trees were used. Among the growth regulators tested, GA3 was only effective on the fruit set and development following destruction of the embryos.2. In young stages of fruit development, that is 5 and 9 weeks after bloom, the application of GA3 to embryo-killed peach fruit resulted in 8 and 6 per cent set of the mature seedless fruit, respectively. In advanced stages, however, embryo destruction 13 weeks after bloom, with or without application of GA3, resulted in 93 and 85 per cent set of the seedless fruit at maturity.3. Injury to the fleshy pericarp without destruction of the embryo had little effect on the rate of fruit set when treated 5 and 9 weeks after bloom.4. Seed removal and gibberellin application to the cut surface of the Japanese pear fruit, cv. ′Shinseiki′ were done at five different stages of fruit development. Only GA4+7, applied as a lanolin paste to the cut surface of seed-removed fruit, was effective in sustaining further growth of the fruit when treated 3 and 5 weeks after bloom.5. At the stage of 7 weeks after bloom, however, not only GA4+7, but also GA3 application began to work effectively to sustain the treated fruit. In late stages subsequent to 9 weeks after bloom, GA3 in lanolin was more effective than G GA4+7 on maintaining the seedless fruit.6. It was also found that a large number of treated fruit were infected with rot and fruit splitting in late stages of fruit development and they abscised before ripening.

Fruit splitting in grapes: Determination of the critical turgor pressure

A technique was devised to measure the internal turgor pressure required for fruit rupture in order to assess resistance to splitting objectively rather than rely solely on field observation. In the laboratory, fruit of uniform maturity and known osmotic potential were immersed in a range of osmotica to create a known turgor pressure at equilibrium. "Critical turgor", the pressure which resulted in 50% of the berries splitting, was approximately 15 atm in grape cultivars prone to splitting and 40 atm in resistant cultivars. Cultural treatments with growth regulators subsequently affected fruit resilience. p-Chlorophenoxyacetic acid lowered critical turgor, while gibberellic acid caused an increase. These laboratory-based observations coincided with field experience. Additional factors in fruit splitting, including berry morphology and anatomy, are discussed.

EFFECT OF GAMMA IRRADIATION ON THE POSTHARVEST PHYSIOLOGY OF FIVE BANANA VARIETIES GROWN IN INDIA

ABSTRACT— Gamma irradiation to 20–40 krad inhibits the ripening changes in preclimacteric bananas without affecting the fruit quality. Both fruit maturity at harvest and post‐irradiation storage temperature markedly influence the response to irradiation. The optimum dose and the maximum tolerable dose varied among the five varieties screened. Ability of the banana fruit to withstand higher doses of gamma irradiation depends on the physiological status of the fruit at time of irradiation. Irrespective of varietal differences, irradiation of preclimacteric bananas to doses above 50 krad resulted in severe skin discoloration and fruit splitting. Irradiation under anoxia did not markedly reduce the radiation injury, suggesting that factors other than ozone formed during irradiation in air may contribute the radiation damage. Fruits on the climacteric could tolerate up to 200 krad but no effect on ripening rate was observed. Ethylene or 2,4‐D could reverse irradiation‐induced inhibition of ripening in bananas. Irradiation seems to decrease the sensitivity of banana fruit to the ripening action of exogenously added ethylene.