Fruit cracking (also known as growth cracks or fruit splitting) is a major physiological disorder that can cause significant economic losses in a wide variety of fruit including tomato ( Solanum lycopersicon ), cherry ( Prunus avium ), apple ( Malus
Juan Pablo Fernández-Trujillo, Gene E. Lester, Noelia Dos-Santos, Juan Antonio Martínez, Juan Esteva, John L. Jifon and Plácido Varó
Annick Moing, Christel Renaud, Hélène Christmann, Lydie Fouilhaux, Yves Tauzin, Anne Zanetto, Monique Gaudillère, Frédéric Laigret and Jacques Claverie
Rain-induced fruit cracking is a limiting factor for sweet cherry (Prunus avium L.) growers in many production areas. Although many studies have concerned this complex phenomenon, the basic mechanisms involved in fruit cracking remain unclear. We re-examined the relations between osmotic potential and cracking susceptibility in cherry fruit by comparing the osmotic contribution of the major metabolites separately in flesh and skin, in four cultivars (with different levels of susceptibility to cracking) at four stages of development. Several differences were observed between flesh and skin revealing compositional gradients in the fruit tissues. Acidity and malate concentrations were higher in flesh than in skin for all stages. The absolute value of osmotic potential was higher but the contribution of the sum of sugars to osmotic potential was lower in flesh than in skin. As determined using fruit immersion test, `Fermina' and `Regina' were less susceptible to fruit cracking than `Lapins' and `Brooks'. At commercial maturity when fruit susceptibility to cracking was highest, no clear difference appeared between `Brooks' and `Lapins' compared to `Regina' and `Fermina' for flesh or skin osmolarity and for the contribution of the major sugars or organic acids to skin and flesh osmotic potential.
The environmental and physiological causes of cracking or splitting of soft fruits and citrus as they ripen are not well understood. This paper explores factors contributing to radial cracking in tomatoes, gives suggestions for prevention of cracking, and suggests directions for future research. Fruit cracking occurs when there is a rapid net influx of water and solutes into the fruit at the same time that ripening or other factors reduce the strength and elasticity of the tomato skin. In the field, high soil moisture tensions suddenly lowered by irrigation or rains are the most frequent cause of fruit cracking. Low soil moisture tensions reduce the tensile strength of the skin and increase root pressure. In addition, during rain or overhead irrigation, water penetrates into the fruit through minute cracks or through the corky tissue around the stem scar. Increases in fruit temperature raise gas and hydrostatic pressures of the pulp on the skin, resulting in immediate cracking in ripe fruit or delayed cracking in green fruit. The delayed cracking occurs later in the ripening process when minute cracks expand to become visible. High light intensity may have a role in increasing cracking apart from its association with high temperatures. Under high light conditions, fruit soluble solids and fruit growth rates are higher. Both of these factors are sometimes associated with increased cracking. Anatomical characteristics of crack-susceptible cultivars are: 1) large fruit size, 2) low skin tensile strength and/or low skin extensibility at the turning to the pink stage of ripeness, 3) thin skin, 4) thin pericarp, 5) shallow cutin penetration, 6) few fruits per plant, and 7) fruit not shaded by foliage. Following cultural practices that result in uniform and relatively slow fruit growth offers some protection against fruit cracking. These practices include maintenance of constant soil moisture and good Ca nutrition, along with keeping irrigation on the low side. Cultural practices that reduce diurnal fruit temperature changes also may reduce cracking. In the field, these practices include maintaining vegetative cover. Greenhouse growers should maintain minimal day/night temperature differences and increase temperatures gradually from nighttime to daytime levels. For both field and greenhouse tomato growers, harvesting before the pink stage of ripeness and selection of crack-resistant cultivars probably offers the best protection against cracking. Areas for future research include developing environmental models to predict cracking and exploring the use of Ca and gibberellic acid (GA) sprays to prevent cracking.
Jinwook Lee, James P. Mattheis and David R. Rudell
‘Gala’ apple strains are susceptible to stem-end fruit cracking at harvest ( Fallahi et al., 2013 ) and during storage ( Lee et al., 2013 , 2016 ). The incidence of stem-end fruit cracking at harvest is influenced by several factors such as
Peter J. Nitzsche, C.A. Storlie, W.P. Cowgill Jr. and W. Tietjen
Fruit cracking in tomatoes is a serious problem, particularly when trellis culture is used. Past studies indicate that fruit cracking is associated with fluctuating soil moisture levels. Soil moisture variations are influenced by irrigation practices, and an irrigation regime employing frequent applications of water will lessen variations in soil moisture. A field study was initiated to study the effect of trickle irrigation regime on fruit cracking in `Celebrity' tomatoes (Lycopersicon esculentum Mill). In the three treatments used, soil was allowed to dry to 10-20, 50-60, and 100-110 centibars of tension, respectively, between watering and then was irrigated to field capacity. These tension levels corresponded with soil moisture levels of field capacity (10-20 cb), 20% of available water depleted (50-60 cb), and 40% of available water depleted (100-110 cb). Yield measurements indicated that the driest treatment (100-110 cb) significantly reduced the percent of radially cracked fruit. This treatment also significantly lowered the total yield, in terms of both fruit number and weight. There was no significant effect, however, on marketable fruit yield due to irrigation treatments. Further field studies are required to determine the optimum irrigation program to reduce fruit cracking.
M.M. Peet and D.H. Willits
Excess irrigation water was provided to spring crops of bag-grown greenhouse tomatoes (Lycopersicon esculentum Mill.) to test the effect on radial fruit cracking. Varied numbers of emitters were placed in bags filled with soilless medium to provide different amounts of irrigation water. In 1990, all emitters provided water containing nutrient solution, but in 1992, the extra water added in one treatment did not contain nutrient solution. In both years, the percentage of cracked fruit was 20 percentage points higher in the treatments receiving more water. The increase in cracking was similar whether or not nutrient solution was added to the extra water. There also were some effects of the extra water on yield. Fruit count per plant was slightly higher (9.5%) when extra water was provided without nutrient solution, but was the same when nutrient solution was added to the extra water. Fruit weights per plant were 18.6% higher in 1990 when watering was increased. In 1992, fruit weights were similar, except for the treatment where the extra water provided did not contain nutrient solution. Fruit weight in this treatment was 19.7% higher than in the other treatments. In both crops, the percentage of cracking increased as linear and quadratic functions of cluster positions, i.e., there was more cracking in the upper clusters. In greenhouse situations, growers should consider water reduction when experiencing high levels of fruit cracking and as a precautionary measure when harvesting from the upper clusters. Providing excess water to greenhouse-grown tomatoes may be a viable technique for screening cultivars or for conducting research on practices to reduce cracking.
R.E. Byers, D.H. Carbaugh and C.N. Presley
Submerging `Stayman' apples in nonionic and anionic surfactant-water solutions caused increased water uptake and fruit cracking. The primary sites of water uptake were lenticels and injured areas of the fruit cuticle. Fruit cracking caused by submerging fruit in 1.25 ml X-77/liter surfactant was used to predict the natural cracking potential of `Stayman' strains and apple cultivars in the field. Submerging apples in aqueous pesticide mixtures did not Increase fruit cracking or water uptake. Fruit cracking and uptake of surfactant-water were not correlated between apple cultivars. In a surfactant-water bath, `Starkrimson Delicious' absorbed more water than `Stayman', `York', `Jonathan', and `Golden Delicious'; no `Starkrimson Delicious' fruits cracked, but 32% to 80% of the other cultivars did. In field tests, four airblast spray applications of GA4+7 in July and Aug. 1987 reduced fruit cracking from 56% to 21%, and five applications In July, Aug., and Sept. 1988 reduced fruit cracking from 93% to 75%. In 1987, daminozide reduced cracking, but, in 1988, neither daminozide, NAA, nor Vapor Gard alone reduced cracking. However, in 1988, a combination treatment of GA4+7, daminozide, NAA, and Vapor Gard reduced fruit cracking from 93% to 22%. Also, two scorings of the trunk with a carpet knife reduced fruit cracking 22%. Chemical names used: alkylaryl polyoxyethylene alcohol glycol (X-77); butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); naphthaleneacetic acid (NAA); di-1-p-methene (Vapor Gard); gibberellic acid (GA4+7).
Takashi Ikeda, Kunio Okano, Yuka Sakamoto and Shin-ichi Watanabe
This study was undertaken to investigate the water relations of tomato (Lycopersicon esculentum Mill.) fruit cracking for single-truss tomato plants. The tomato plants were cultured on a closed hydroponic system in greenhouse. Water status of culture solution and plant tissues was measured with psychrometers. Water potential of the culture solution for the stressed plant was changed from -0.06 MPa (control plants) to -0.36 MPa at 24 days after anthesis. Hardness of the fruit skin was not different significantly between the stressed plants and the control plants. Fruit cracking occurred frequently in the control plants, but not in the stressed plants. Water potential gradient between the tissue of fruit flesh and water source for the control plants was bigger than that of the stressed plants. Turgors were increased at the tissues of fruit flesh and fruit skin at the control plants between predawn and morning but not at the stressed plants. These results indicated that the water potential gradient and the increased turgor in these tissues might be a trigger for the occurrence of fruit cracking on single-truss tomato plants.
Tara Auxt Baugher, Kendall C. Elliott and D. Michael Glenn
Three growth suppression treatments were compared during 1991 to 1993 on `Stayman' apple (Malus domestica Borkh.) trees grown in the T-trellis and the MIA trellis systems. All treatments—root pruning, K-31 fescue (Festuca arundinacea Schreb.), and K-31 fescue plus root pruning—suppressed tree growth compared to the nontreated control, but results were inconsistent between years and systems. Sod or sod plus root pruning reduced terminal shoot length in both systems in 2 out of 3 years. Root pruning decreased shoot length in the T-trellis in 1992. Sod decreased trunk cross-sectional area in the T-trellis in 1993. Treatments did not affect 3-year average yield efficiency but did appear to increase biennial bearing. Sod, with or without root pruning, decreased fruit cracking in the T-trellis 69% and 42%, respectively, in 1992, and sod plus root pruning decreased cracking in the MIA trellis 50%. Sod reduced fruit diameter in the T-trellis in 1992. Secondary effects of growth suppression treatments included increased light penetration and improved fruit color. Sod decreased leaf N and Mg and increased leaf P, K, and Cu. The Oct. 1993 stem water potential gradient from root to canopy was more negative in the sod plus root pruning treatment, and the osmotic potential of rootsucker leaves in the combination treatment was greater than in the control, indicating that sod plus root pruning alters the distribution of water within a fruit tree.
Masahiko Yamada, Akihiko Sato and Yasuo Ukai
Environmental variance components were estimated for calyx-end fruit cracking in pollination-constant and nonastringent cultivars and selections of Japanese persimmon (Diospyros kaki Thunb.). The cracking value of a tree in a cultivar or selection (genotype) (X) was evaluated as the number of fruit that cracked divided by the total number (25) of fruit evaluated from each tree. Because the mean value of X was correlated with the variance of X, analyses of variance were performed using its square root value. The variance associated with genotyp× year interaction was the largest of environmental variance components. The variances associated among years and among trees within genotypes were very small. The mean percentage of cracked fruit in evaluation for 10 years was 3% for `Fuyu', 11% for `Matsumotowase-Fuyu', and 12% for `Izu'. On the basis of the environmental variance components obtained, it is proposed that all offspring genotypes exhibiting a phenotypic cracking incidence of less than 20% and 11% should be selected in single-year and three-year evaluations, respectively, when those genotypes are evaluated using 25 fruits from a single tree, in order to successfully select all genotypes with an genotypic incidence of less than 3%.