Fruit cracking in litchi (Litchi chinensis): An overview

Abstract

Litchi (Litchi chinensis Sonn.), an arillate fruit species of China origin, possessed a unique structure comprising thin and leathery pericarp that enclosed the aril as its edible part. Fruit cracking is a serious physiological disorder in litchi that occurs during its growth and development, and causes significant loss of economic yield. Fruit cracking in litchi coincides with a period characterized by high day temperature (35-40°C) and low relative humidity (60%). It entails the implicated roles of both internal and external factors. Besides climatic effects, abnormal development of the skin during early fruit growth promotes the disorder. In this context, a concept, ball skin versus bladder effect was theorized to describe the relationship between a pre-grown skin and a growing aril. To further conceptualize the problem, Zig-zag Unfolding model was developed which decipher the role of spongy tissue in pericarp extensibility necessary for preventing pericarp cracking. Cracking occurs during the final stage of fruit growth when the aril develops and exerts pressure on the inactively growing pericarp. Thus, a balance between turgor pressure from the expanding aril and the mechanical structure and elasticity of skin is indispensable to prevent fruit cracking. Fruit cracking can be controlled by application of calcium nitrate (0.5 - 1%), borax (0.4 - 0.8%), Zn (0.4%), GA3 (10 ppm) alone or in combinations assured with timely irrigation, mulching, bagging of fruit bunches, use of shade nets and growing cracking resistant cultivars.

Molecular mechanisms involved in fruit cracking: A review

“…So, the cuticle weakening in ripe fruits can cause severe economic losses by developing several visual cuticle-associated traits which are dependent of the interaction among the cuticle and environment and/or the development stage of the fruit (Petit et al, 2017;Lara et al, 2019). Among the several visual cuticle-associated traits can be included fruit color in tomato (Gonzali and Perata, 2021), fruit cracking in sweet cherry (Lane et al, 2000;Simon, 2006;Rehman et al, 2015), tomato (Domıńguez et al, 2012), pomegranate (Singh et al, 2020), grape (Sahadev et al, 2017) or litchi (Marboh et al, 2017), brightness in tomato (Petit et al, 2014), russeting in apple (Knoche et al, 2011;Straube et al, 2021) and pear (Zhang et al, 2020;Zhang et al, 2022), and browning in pear (Franck et al, 2007) and litchi (Jiang et al, 2004). The thickness and chemical composition of fruit cuticle is another factor in cuticle-associated traits, presenting a high variability according fruit tree species, cultivars, and fruit development (Knoche and Lang, 2017;Zarrouk et al, 2018).…”

Progress in Fruit Cracking Control of Gibberellic Acid and Abscisic Acid

“…In addition, the regulation of phytohormone and plant growth regulators (PGRs) are very vital factors of cracking due to the growth and development of fruits cannot be separated from the regulation of phytohormones. The homeostasis of endogenous phytohormones plays a vital role in the normal growth of the pericarp, and its imbalance may cause fruit cracking or splitting [37][38][39][40]. PGRs which have similar functions to the endogenous plant hormone are well known and also have a certain effect on fruit cracking.…”

Effect of Water Sprinkling over Tree Canopy on Fruit Cracking, Quality and Yield of Litchi Fruits

“…Fruit cracking in litchi coincides with a period characterized by high day temperature (35-40°C) and low relative humidity (60%). It entails the implicated roles of both internal and external factors [1].…”