Alternate Bearing in Fruit Crops: Causes and Control Measures

Abstract

Alternate bearing (AB) is a phenomenon, common in fruit crops, is a concerned plant or branch or orchard does not bear a regular crop year-after-year rather heavy yields are followed by extremely light yield and vice versa. Based on the alternate bearing index, it is divided in four groups viz., no alternation, less alternate, high alternate, severe alternate. There are mainly two factors are responsible for alternate bearing i.e., exogenous and endogenous factors. Alternate bearing can be managed by cultural practices, selection of rootstocks, and selection of cultivars, chemical application and pruning at right time. Scrutiny of all of the factors are presented in this review to achieve consistent success in induction of flowering in perennial fruit crops. The information may pave way for better regulation of flowering shoots to enhanced fruit productivity in various fruit crops.

Exploring Carbohydrate Concentration Fluctuations in Pistachio (Pistacia vera L. cv Uzun) for Deeper Insights into Alternate Bearing Patterns

“…However, the fruit buds dropped during kernel development during the "ON" years. It has been reported that excessive fruit-bud abscission in pistachio started in June, at the time of embryo development, and increased during July, causing the next year to be the "OFF year" [1,2,6,19].…”

“…Essentially, it involves a cycle of high fruit set (ON) in one year and low fruit set (OFF) in the subsequent year. This pattern leads to excessive fruit set in ON years, leading to non-bearing or smaller fruits in the following year [2]. Fluctuation between ON and OFF years poses financial challenges for producers and consumers and causes significant losses in fruit tree crops.…”

“…However, while these practices alleviate alternate bearing, additional measures are still needed to effectively address this challenge. The effects of carbohydrates, plant growth regulators, phenolic compounds, and polyamines have been studied in the management of AB and, recently, studies on molecular and biotechnological tools have also been started [1][2][3]. However, the extent to which these factors influence AB remains unclear.…”

Ground Management through Grazing in Rainfed Olive Orchards Provides High Olive Yields and Has Other Potential Benefits for Both the Soil and the Farmer

“…The fact that eleven successive olive harvests were conducted in this study, using a total of 30 trees, provided insights into the alternate bearing of olive trees that deserve commentary. Alternate bearing in fruit trees is characterized by a good harvest invariably followed by a poor one, and vice versa, known as "On" and "Off" years, respectively [31,32]. Attempts to explain this alternation have focused on hormonal effects exerted by developing seeds in the current year on the floral induction of buds that would bloom in the following year, with the involvement of gibberellins [33], auxins [31], or phenols [34] suggested.…”