New technologies and systems for high quality citrus fruit production, labor-saving and orchard construction in mountain areas of Japan

Abstract

Novel technologies have been necessary for improving fruit quality and productivity of citrus, labor-saving and orchard conservation on steep slope lands since aging of growers and decrease in the number of successors is remarkable in mountain areas of southwestern Japan. The purpose of this paper is to introduce new technologies for improving citrus production that have been developed in recent years. A new fruit quality control system using drip irrigation and liquid fertilization technique combined with year-round plastic mulching was developed, and it enables high quality and stable citrus fruit production. Water and/or nutrient solution is automatically supplied through drip tubes that are laid under the mulching sheets to give adequate water stress, so as to improve sugar and acid content of fruit. A new transportation system for steep sloping citrus orchards, which is a combination of the monorail system and contour narrow paths, was suggested. A small walking cultivator was developed to explain the procedure of narrow path excavation. After introducing the narrow path, working hours for fertilizer and chemical herbicide application were reduced. Disaster prevention mapping of citrus orchards on slope lands was developed based on computer-aided seepage estimation and topographic data. The mapping can show zones of both ascending flow and descending flow of underground water during heavy rains in citrus orchards. The mapping is considered to be effective for the management of orchards and prevention of erosion on slope lands.

Utilization of a Biodegradable Mulch Sheet Produced from Poly(Lactic Acid)/Ecoflex®/Modified Starch in Mandarin Orange Groves

“…However, it is unsuitable to keep the soil very dry for the entire period [ 12 ]. Usually, the mulch drip method is adopted for the moisture control, however the cost of the apparatus is expensive [ 13 ]. Indeed, the change in the moisture uptake of soil in MS-3,6,1 represents the ideal condition.…”

A Method for High-Quality Citrus Production Using Drip Fertigation and Plastic Sheet Mulching

“…In order to eliminate the disadvantages of sheet mulching, a novel method was proposed in 2000 for using drip irrigation in conjunction with year-round sheet mulching (Morinaga et al 2004a(Morinaga et al , 2005(Morinaga et al , 2010 (Fig. 1).…”

Sheet-mulching Cultivation Promotes the Number of Floral Buds via Up-regulation of <i>Citrus Flowering Locus T</i> Expression in Two Citrus Cultivars, ‘Haraguchi-wase’ (<i>Citrus unshiu</i> Marcow.) and ‘Harehime’ (<i>C.</i> spp.)

“…High-quality mandarin fruit is defined as medium sized fruits with a high sugar content (12% or more) and appropriate acid (about 1%) in Japan (Morinaga et al, 2005). In this study, since 'Haraguchi-wase' Satsuma mandarin and 'Harehime' fruits with alldrying treatment conformed to this fruit size and had a high Brix% and citric acid content, we considered that Fruit shape index was expressed by transverse diameter divided by longitudinal diameter.…”