Cuticular Cracking on Nectarine Fruit Surface: Spatial Distribution and Development in Relation to Irrigation and Thinning

Abstract

<jats:p>Investigations on “natural” cuticular cracks were conducted on nectarine fruit [<jats:italic>Prunus persica</jats:italic> (L.) Batsch var. <jats:italic>nucipersica</jats:italic> (Suckow) C.K. Schneid.]. A method for quantifying the cuticular crack surface area on a whole fruit basis was proposed. By using a stratified sampling design, the spatial distribution of the cuticular cracks over three regions (stylar end, peduncle, and cheek), their morphology, and the estimation of the total proportion of cuticular cracks on the fruit were studied. These features were examined during fruit development and in response to several fruit growing conditions corresponding to various crop loads and irrigation regimes. Cuticular cracks on nectarine fruit occurred during the final rapid fruit growth stage. Larger fruit presented higher cuticular crack densities in the apical regions than in the cheek regions. Thin and larger cuticular cracks occurred continuously during fruit development. Cuticular cracks represented 10% to 12.5% of the fruit surface area for well irrigated or low crop load trees, whereas they covered less than 4.5% for the heavy crop load and water deficit treatments. Cheek regions largely contributed to the total cuticular crack surface area (&gt;60%), regardless of the fruit growing conditions. After irrigation was restricted, cuticular crack development was limited. A positive relationship was established between the cuticular crack surface area per fruit surface area and the fruit fresh weight.</jats:p>

Fruit Splitting in Citrus

“…In 'Navel' orange, as the D/H ratio reduced, a lower incidence of fruit splitting occurred (De Cicco et al 1988). In 'Nova mandarin', the percentage split fruit reached a maximum when the D/H ratio increased from 1.21 to 1.23 during fruit growth ( As reported for other crack-prone crops such as tomato (Peet 1992) and nectarine (Gibert et al 2007), a reduction in irrigation rate during periods of rapid fruit growth, without stressing the tree, holds promise in reducing the likelihood of fruit cracking and splitting. By reducing water supply during stage II of fruit development, fruit splitting was reduced in 'Murcott' mandarin (Goldschmidt and Galili 1992).…”

“…In addition, as suggested in citrus (Coit 1915), high-volume irrigation after a period of water stress has been shown to result in the development of cracks in prune (Milad and Shackel 1992), tomato (Peet 1992), and nectarine (Gibert et al 2007). Cultural practices encouraging excessive fruit growth, such as high irrigation during the period of rapid fruit growth of nectarine (Gibert et al 2007) as well as pruning and thinning of tomato plants in a similar developmental phase (Peet 1992), can lead to the development of cracks of the fruit surface. In terms of mineral nutrient deficiency, cracks develop due to boron (B) deficiency in apricots (Benson 1994) and calcium (Ca) deficiency in cherry (Meheriuk et al 1991) and tomato (Huang and Snapp 2004).…”

“…A high percentage of split fruit occurred at very high crop loads and little or no splitting in years of low crop loads (Gilfillan and Stevenson 1984). However, an increase in the disorder was expected at lower crop loads in tomato (Peet 1992) and nectarine (Gibert et al 2007), which can be explained by the higher growth rate of individual fruit at lower crop loads and an inability of the fruit epidermis to accommodate for the increase in fruit volume created by these higher growth rates.With an increase in the number of fruit per tree, a linear increase in the interfruit competition for water and assimilates is expected. Lenz and Cary (1969) reported a decrease in fruit size and, more importantly, a decrease in rind thickness of citrus fruit with an increased crop load per tree.…”

“…This disorder occurs most notably in apple (Visai et al 1989), apricot (Benson 1994), cherry (Belmans andKeulemans 1996), grape (Considine and Kriedemann 1972), nectarine (Gibert et al 2007), prune (Milad and Shackel 1992), and tomato (Peet 1992) (Table 4.2). Although similarities in certain causal factors as well as certain aspects of the physiological development of the phenomenon exist between these crops and citrus fruit, unique anatomical features of citrus fruit as well as physiology of fruit development separate the phenomenon in citrus from other crops.…”

“…Heavy rainfall during the (Gibert et al 2007); increased fruit size (Gibert et al 2007) Lowering irrigation during rapid fruit growth (Gibert et al 2007) Prune Excessive irrigation following water stress (Milad and Shackel 1992) Consistent water supply (Milad and Shackel 1992) Tomato Excessive irrigation following water stress (Peet 1992); insufficient nutrition (Huang and Snapp 2004); low crop load (increased growth rate) (Peet 1992); harvest at pink stage (late) (Peet 1992) Use of crack-resistant cultivars (Sperry et al 1996); consistent water supply (Sperry et al 1996); GA (Peet 1992) and Ca (Huang and Snapp 2004) application; harvest at green mature stage (early) (Peet 1992) period of rapid fruit growth in apricot (G€ ulS sen et al 1995), grape (Clarke et al 2010), as well as tomato (Peet 1992) and at harvest in cherry (Belmans and Keulemans 1996) correlates as a causative factor of the phenomenon in citrus fruit (Wager 1939). In addition, as suggested in citrus (Coit 1915), high-volume irrigation after a period of water stress has been shown to result in the development of cracks in prune (Milad and Shackel 1992), tomato (Peet 1992), and nectarine (Gibert et al 2007). Cultural practices encouraging excessive fruit growth, such as high irrigation during the period of rapid fruit growth of nectarine (Gibert et al 2007) as well as pruning and thinning of tomato plants in a similar developmental phase (Peet 1992), can lead to the development of cracks of the fruit surface.…”