Scientia Horticulturae 277 (2021) 109793 Available online 22 October 2020 0304-4238/© 2020 Elsevier B.V. All rights reserved. Jojoba pruning: New practices to rejuvenate the plant, improve yield and reduce alternate bearing Silit Lazare a, *, Isaac Zipori a , Yaft Cohen b , Amnon Haberman a , Eitan Goldshtein b , Yonatan Ron a , Ronen Rotschild c , Arnon Dag a a Gilat Research Center, Agricultural Research Organization, Gilat, Israel b Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Center, Rishon-LeZion, Israel c Jojoba Israel, Kibbutz Hatzerim, Israel A R T I C L E INFO Keywords: Alternate bearing Productivity Pruning remote sensing Simmondsia chinensis Topping ABSTRACT Commercial pruning practice in jojoba plantations is traditionally dictated by maintenance requirements only. It enables machine movement between the plants and effcient harvest but is not designed to maximize long-term productivity. In this study, mechanical and manual pruning approaches were tested in two cultivars in a mature jojoba plantation, in comparison to the common practice. These new approaches were designed to enable better light penetration into the canopy, aiming to improve growth and productivity. As jojoba is an alternate bearing crop, the vegetative and reproductive performances were observed over four years, by remote sensing and manual measurements. The pruning type and strategy had a signifcant effect on growth, with a distinction between the two tested cultivars. Top-pruning methods were found to best encourage new branching and yield, while side-pruning practices were less effective. Several treatments, including hedge pruning, attenuated or eliminated the alternation cycle. We conclude that using the proposed pruning practices would be benefcial in jojoba cultivation, and that the specifc method should be suited to the cultivar characteristics. 1. Introduction Jojoba (Simmondsia chinensis) is an industrial crop shrub, originating from the north-American deserts and spread in other arid and semi-arid regions of the world (Al-Widyan and Mu’taz, 2010). It is a dioecious plant, cultivated for its seeds, from which a highly valuable wax is produced (Bakeer, 2019). This wax is generally referred to as "jojoba oil" (S´ anchez et al., 2016). It is used in cosmetics and pharmaceutics, due to its unique features, which are close to those of sebum - the natural human skin oil (Meyer et al., 2008). Jojoba oil is known for its high stability and long shelf-life (Sandha and Swami, 2009). It is used as a lubricant (Nassar et al., 2015), an ingredient of livestock feed (Labib and HA, 2012; Reddy and Chikara, 2010), medicines (Habashy et al., 2005) and toiletries (Oliphant et al., 2011), and as an innovative source for biodiesel (Canoira et al., 2006). Previous studies in Israel revealed that fowering takes place on February-March, and the wax accumulates between March and July (Perry, 2019). The fowers develop on new growth, and fowering buds that were produced during summer or autumn remained dormant until spring time (Benzioni, 2006). In commercial cultivation, the jojoba is defned as an alternate-bearing crop, with cultivar-dependent diversity for this trait (El Mohsen and Allatif, 2015; Purcell et al., 2000). It was found that during "On" years, the vegetative growth stops in summer, while in "Off" years it continues until autumn (Perry, 2019). Alternate bearing is a year-to-year yield fuctuation in fruit crops, hypothysed to be caused by abiotic stress or nutrient resource allocation (Bustan et al., 2011; Krasniqi et al., 2014). This common phytological habit maintains a balance between vegetation and reproduction, both require energy investment and necessary for the plant survival (Gold- schmidt, 2013). One of the main goals of fruit tree breeding and culti- vation practices is to manage the alternate bearing fuctuations, which causes economic instability in orchard farms (Cilas et al., 2011). The best measure currently available to manage alternate bearing is pruning, which modulates the natural ratio between vegetative and reproductive growth (Giulivo, 2011). Pruning is a common and highly valuable practice in tree and shrub cultivation, carried out by either specifcally designed machines or manual labor (Wade and Westerfeld, 2009). The specifc practice differs * Corresponding author. E-mail address: silitl@volcani.agri.gov.il (S. Lazare). Contents lists available at ScienceDirect Scientia Horticulturae journal homepage: www.elsevier.com/locate/scihorti https://doi.org/10.1016/j.scienta.2020.109793 Received 5 May 2020; Received in revised form 10 September 2020; Accepted 13 October 2020