Analysis of Different Mechanical Pruning Strategies on the Production of 'Clemenules' Mandarin and its Costs

Abstract

Spain is the sixth citrus producer in the world and the first exporter for fresh consumption. However, the profitability of citriculture is going down due to the increasing production costs and the low prices perceived by farmers. Between farming operations, pruning is done manually, which represent around 12.5% of the total production costs. The objective of this study was to analyse the effect of different mechanical pruning strategies on the production of mandarins variety 'Clemenules' comparing them with manual pruning, and to determine their costs. A trial with a random blocks experimental design with 5 repetitions was carried out in a commercial Clemenules orchard located in Chiva (Valencia). During season 2017, eight pruning strategies were assessed: C (control, no pruning); M (manual pruning, with hand saw and pruning shears); and six mechanical pruning with disc pruner: TEW (Topping, Hedging both sides, East and West), TR (Topping, Manual follow-up), TER (Topping, Hedging Est side, Manual follow-up), TE (Topping, Hedging Est side), EW (Hedging both sides) and E (Hedging Est side). The results of trials showed differences in production and costs between the pruning strategies. C was significantly the most productive with 157 kg/tree; the following more productive were M, EW and E ranging between 128 and 132 kg/tree with no differences between them; and in a third level were all treatments where Topping was carried out (TEW, TE, TER and TR) that oscillate between 72 and 85 kg/tree without significant differences between them. Costs were higher for treatments with manual pruning. Cost for M was 441 €/ha and for the treatments with manual follow-up pruning they oscillated between 459 and 293 €/ha. However, the cost for mechanical pruning ranged between 25 to 110 €/ha depending on the number of machine passes. To get more consistent conclusions, more seasons comparing pruning strategies must be performed.