Regulation of fruit abscission: Horticultural interventions and plant responses

ABSTRACT
Many perennial fruit trees typically bear an abundance of flowers and the resulting fruit set can be
either excessive (apple) or extremely low (mango). In both cases, the regulation of flower/ fruit(let)
abscission by mainly bloom or post-bloom thinning chemicals is necessary to maximize crop value
and tree performance.
The causes of fruit abscission are numerous, ranging from failure of fertilisation, biotic stress (pest
injury and disease damage), to abiotic stress with specific plant-environment interactions caused e.g. by high ambient temperature, water deficiency and shade conditions. These numerous stressors resulting in mainly carbohydrate and hormonal imbalances; endogenous plant factors that ultimately affect fruit abscission.
The induction of the fruit abscission process is thought to be governed by plant hormones.
Regulation of phytohormone biosynthesis by exogenously applied hormone-type plant growth
regulators has been extensively investigated to promote or inhibit fruit set. Reduced carbohydrate
supply may also be involved in fruit abscission, particularly at times of strong fruitlet growth
coinciding with shoot growth when young leaves still expand rapidly.
However, despite great research effort, our factual understanding of the underlying specific
abscission mechanisms is still limited. This review attempts to offer some explanation on how the
abscission process in apple and mango is inhibited or promoted by signals formed within the plant in response to a complex combination of plant status, environmental cues and crop management. The focus is given to the role of phytohormones, carbohydrates and related gene activation.

Details

Activity type

Organising/holding industry group meeting/event

Activity work package

Secure sustainable fruit production

Activity number

UHOH-WP1-A10

Activity contact

Prof. Dr. Jens Wünsche

Activity partner

Universität Hohenheim

Activity country

Germany

Last edit

02-11-2017

Event

Event location

Stuttgart