تکنولوژی های خلاق و متداول برای هرس محصول: یک بررسی Current and innovative technologies for pruning harvesting: A review

1. Introduction Residues of permanent crops in Europe are a substantial reservoir of renewable biomass for energy and industrial use. The * Corresponding author. 10.6 Mha currently covered by permanent crops generate 13 Tg (oven-dry basis) of pruning. However, the rational use of this biomass source is being hindered [1,2]. Firstly by an increase in surfaces, and a conversion from traditional to intensive systems is forecast as well as a growing demand for fuel biomass [1,3e5]. Secondly, there are various barriers tied to the use of prunings and the development of a sustainable logistic chain to produce energy from it [6,7]. Pruning (branches and shoots of fruit trees) is considered a problem rather than an opportunity and, hence, it is not used or incorrectly disposed of [8]. Environmental concerns regarding the use of fossil fuel and their depletion have boosted a cultural change in the sustainable use of renewable sources. As a result, the formulation of more strict regulations regarding pruning in most European countries [2] has led to a renewed interest in pruning recovery. Over the last fifteen years several scholars have identified cost-effective technologies for harvesting, processing and delivering pruning residues. In fact, harvesting is a key stage that influences the product quality, the type of logistics chain and the economic sustainability of the pruning supply chain. In reality, over the years, many machine manufacturers have developed dedicated implements for collecting pruning residues [9e14]. Equipment that facilitates the harvesting and processing of agricultural pruning is already available on the market and many manufacturers offer different models that are tailored to specific harvesting chains. The aim of the present work is to provide a thorough overview of the technologies available for harvest pruning, from basic equipment to the state of the art.