Authors: Kuldeep Singh, Gururaj Mathapati
Fruit cracking:
“The physical failure of the fruit skin” occurs in the form of fractures in the skin or cuticle that typically doesn’t penetrate the flesh. Splitting is more extreme form of cracking that penetrates deep into the pulp. Cracked fruits are susceptible to disease of storage and their storage and shelf life are shorter. Fruit cracking occur during fruit growth, development and ripening. Also, it can occur during postharvest in some fruits, mostly attributable to the environmental conditions of storage. Fruit cracking commonly found in sweet cherry, plum, apricot, apple, litchi, pomegranate, citrus, banana, avocado, grape, persimmon, peach, tomato, pistachio, fig etc.
Research obstacles:
- Erratic in occurrence (year and location).
- Poor correlation with weather and soil condition.
- Variable fruit to fruit susceptibility.
- Distinct genetic difference.
- Fruit cracking is difficult to study, even in controlled conditions, because we lack experimental methods to induce cracking.
- No. of factors responsible fruit cracking
Type of fruit cracking
- There are many types of fruit cracking based on species:
- Longitudinal or burst cracking
- Ring or concentric cracking
- Crazing or russeting
- Star or radial cracking
- Core failure
- Radical cracking is developed from the radical section of stem towards the fruit center.
- Concentric cracking is appeared on fruit that leads to cracking in a single fruit which is known as concentric e.g., sweet cherry
- Crazing or russeting a minute hairline cracks invisible to naked eyes cover the 25% of fruit surface. e.g., Tomato, Apple.
Factor influencing fruit cracking
- There are many factors that influence fruit cracking:
- Physiological and biochemical factor: water uptake by the fruit, water potential, dynamics of fruit growth, Hormones and Enzymes.
- Nutritional deficiency
- Genetic factor: Gene expression, Varietal susceptibility
- Physiological and biochemical factors
- Water uptake by the fruit:
- Water potential:
- Fruit growth and development:
- Cultivar susceptibility to cracking varies with the stage of fruit development (Christensen, 1973). For example Sweet cherry presents a double-sigmoid pattern, three distinctive growth phases:
- Phase I -: is characterized by the rapid division of mesocarp cells.
- Phase II -: characterized by embryo development and endocarp hardening.
- Phase III, characterized by cell enlargement resulting in the final fruit size (critical moment for cracking).
- As cell enlargement progress in the mesocarp, the elastic capacity of the cuticle is exceeded due to high fruit internal pressure during Phase III, which increases the incidence of cuticle fractures resulting higher water flux into the fruit (Knoche et al., 2001).
- Hormonal Imbalance:
- Gibberellic acid
- Gibberellic acid is responsible for cell division and enlargement. GA3 applications also increase firmness of crack-prone cherry (Cline and Trought, 2007). In citrus, GA3 increases rind resistance to pressure and delay of chlorophyll breakdown (McDonald et al., 1987). Cline and Trought reported that application of GA3 reduced cracking in cherry. In litchi, spraying of GA3 (25 and 50 ppm) reduced fruit cracking.
- Abscisic acid
- Yilmaz and Ozguven found that the ABA content of the peel is higher in cracked fruits than in the peel of non-cracked fruits of litchi.
- (Sharma and Dhillon 1998) observed that ABA content in pericarp is higher in cracking fruits than in the healthy fruits of litchi.
- Enzymes
- Pectin esterase (PE) and polygalacturonase (PG) are the key enzymes involved in the process of plant pectin degradation. Cellulose (EG) is one of the key enzymes involved in cellulose degradation. β-galactosidases (β-Gal) reduce the levels of cell wall galactosyl residues in ripening tomato fruits. Xyloglucan endotransglycosylase (XET) catalyses the transglycosylation of xyloglucan, the major hemicelluloses polymer, which is thought to mediate cross-linking of cellulose microfibrils in cell walls and is proposed to be involved in the control of cell wall relaxation .
- Nutrient deficiency:
- Calcium:
- Calcium is a structural component of cell membranes and walls. It has role in the processes of cell division and growth. Fruit tissues are supplied with Ca+2 bytranspiration stream which translocate Ca +2 directly from the soil solution. If the xylem sap is poor in Ca+2 or transpiration rate of the fruit is poor, inadequate level of Ca+2 supplied to the fruit. Low calcium concentration in pericarp cells is correlated with fruit cracking in tomato and litchi. Application of calcium chloride (3%) reduced cracking in pomegranate (Punica granatum L.). Calcium develop thicker epidermal and sub-epidermal layer of cell wall in grape and decrease berry cracking under critical turgor pressure.
- Boron:
- Boron has role in the synthesis of pectic substances, its application checks fruit cracking in apple. In young trees, boron deficiency causes fruit cracking in pomegranate. 0.2% boron spray to control fruit cracking in pomegranate.
- Other nutrients
- Imbalances in potassium (K) and phosphorous (P) can contribute to thin or weak rind and increase chances of splitting in citrus. Increased leaf P-content, a decrease in rind thickness in contrast, an increase in leaf K-content, increase in rind thickness and coarseness.
Genetic factors:
- Gene expression:
- Expansins are proteins in cell wall that can promote wall loosening and weakening during cell expansion. Expansins isolated from Litchi (Yong et al., 2006), Apple (Wakasa et al., 2003), Peach (Hayama et al., 2001), Tomato (Brummell et al., 1999) and showed correlation with fruit development. In apple MdEXPA3 is mainly appeared during fruit enlargement (Wakasa et al., 2003).
S. No | Fruit | Expansins | Reference |
1. | Apple | MdEXPA1, MdEXPA2, MdEXPA3, MdEXPA4, MdEXPA5, MdEXPA6 | Wakasa et al., 2003 |
2. | Peach | PpExp1, PpExp2, PpExp3 | (Hayama et al., 2001), |
3. | Litchi | LcExp1 and LcExp2 | (Yong et al., 2006), |
- Varietal susceptibility
S.No | Fruit | Susceptible Variety | Tolerant variety |
1. | Apple | Golden Russet, Fuji, Gala | |
2. | Avocado | Bacon, Zutano, Lamb Hass, | Hass |
3. | Cherry | Bing, Sam, Hartland, Cashmere, Vega, Tieton | Lapins, Regina, Lapins, Kordia, Celeste |
4. | Grape | Ribier, Thompson Seedless, Ruby Seedless & cardinal | Emperor |
5. | Mandrin | Owari, Hybrid-: Nova, Ellendale, Orlando. | |
6. | Litchi | Nuomici, Dehradun (27.4%), Muzaffarpur (16.8%), | Culcutta, Huaizhi |
7. | Pomegranate | Malas-e-Saveh | Bedana Bosec, Khog, Jalore Seedless, Wonderful. |
8. | Sweet Orange | Valencia, Hamlin, Navelina, Washington Navel, Frost, Olinda. | |
9. | Pistachio nut | Khanjari, Shahpasand | Pesteh Garmeh, Badami Sefid |
Reference:
Brummell DA, Harpster MH, Dunsmuir P (1999) Differential expression of expansin gene family members during growth and ripening of tomato fruit. Plant Mol Biol 39:161–169
Christensen JV (1972) Cracking in cherries iv. Physiological studies of the mechanisms of cracking. Acta Agric Scand 22:153–162
Cline, J.A., and M. Trought. 2007. Effect of gibberellic acid on fruit cracking and quality of Bing and Sam sweet cherries. Can. J. Plant Sci. 87:545–550
Hayama H, Shimada T, Ito A, Yoshioka H, Kashimura Y (2001) Changes in the levels of mRNAs for putative cell wall-related genes during peach fruit development. Sci Hortic 91:239–250
Knoche M, Peschel S (2002) Studies on water transport through the sweet cherry fruit surface: VI. Effect of hydrostatic pressure on water uptake. J Hortic Sci Biotechnol 77:609–614
McDonald, R.E., P.E. Shaw, P.D. Greany, T.T. Hatton, and C.W. Wilson. 1987. Effect of gibberellic acid on certain physical and chemical properties of grapefruit. Trop. Sci.
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Sharma SB, Dhillon DS (1998) Endogenous levels of abscisic acid in relation to fruit cracking in Litchi (Litchi chinensis Sonn.), Agricultural Science Digest, India, 8(1):55–58
Torres, C.A., J.A. Yuri, A. Venegas, and V. Lepe. 2009a. Use of a lipophilic coating pre-harvest to reduce sweet cherry ( Prunus avium L.) rain-cracking. 15-19 p. VI International Cherry Symposium, Renaca, Chile. 15-19 November. International Society for Horticultural Sciences (ISHS) and Facultad de Agronomía e Ingeniería Forestal, Departamento de Fruticultura y Enología, Pontificia Universidad Católica de Chile (PUC), Viña del Mar, Chile.
Wakasa Y, Hatsuyama Y, Takahashi A, Sato T, Niizeki M, Harada T (2003) Divergent expression of six expansin genes during apple fruit ontogeny. Eur J Hortic Sci 68:253–259
Yong W, Wangjin L, Jianguo L (2006) Differential expression of two expansin genes in developing fruit of cracking-susceptible and resistant litchi cultivars. J Am Soc Hortic Sci 131(1):118–121
Young HW (1958) Inheritance of fruit cracking. Tomato Genet Coop 8:38
Yilmaz, C., and A. I. Ozguven. "Hormone physiology of preharvest fruit cracking in pomegranate (
Punica granatum L.)." X International Symposium on Plant Bioregulators in Fruit Production 727. 2005
About Author / Additional Info:
I am currently pursuing Ph.D. in Fruit and Horticultural Technology from IARI, New Delhi.