The use of harvesting systems and labourer platforms in the South African deciduous fruit industry

Van der Merwe, Gerrit Johannes (2015-04)

Thesis (MSc)--Stellenbosch University, 2015.

Thesis

ENGLISH ABSTRACT: The impact of harvesting systems and laborer platforms on fruit quality were assessed when harvesting, as well as laborer productivity when performing orchard actions requiring the use of ladders. Harvesting systems and laborer platforms were compared to conventional labor practices. Trials were done on stone and pome fruit farms throughout the Western Cape. Harvesting systems showed potential to decrease bruising on hardy apple cultivars such as Red Chief and Cripps’ Red. However, similar or even higher injury levels were obtained on more sensitive cultivars such as Golden Delicious and Cripps’ Pink. Conventional teams incur little bruising on the hardier cultivars, thus the scope of improvement on these cultivars is small. Conventional teams incur higher injury levels on more sensitive cultivars, leaving much room for improvement. However, due to high harvesting injury levels incurred by teams on the harvesting systems, no improvement was obtained. Conventional teams achieve very high picking productivity outputs for hardy cultivars like Abate Fetel, Red Chief and Cripps’ Red whereas outputs are lower for sensitive cultivars like Golden Delicious and Cripps’ Pink. Harvesting systems reached an upper limit of around 150 kg per picker per hour when strip picking, regardless of cultivar hardiness. This limit stemmed from the misalignment between orchard and machine design, which results in a very inefficient picking action. This limits the number of picking cycles that can be completed in a certain amount of time, which in turn limits the weight of fruit that can be picked in that time. Furthermore, factors such as tree size, shape and uniformity, fruit distribution on the tree, fruit size and quality, orchard floor condition and aspect, labor team dynamics, harvesting incentives, bin condition, operational system employed and harvest logistics all affected the overall productivity and efficiency of the harvesting systems. When performing summer pruning with the aid of a laborer platform, productivity was substantially increased compared to conventional laborers on ladders. Dormant pruning and fruit thinning with laborer platforms also showed potential for increased laborer productivity. The extent of improvement was smaller than for summer pruning and was dependent on the pruning/ thinning strategy employed as well as tree architecture. In general, narrower and younger trees showed larger increases in productivity. Producers should aim to simplify pruning and thinning strategies in order to maximize productivity gains when using laborer platforms while at the same time maintaining good fruit quality and yield. Our study revealed that laborer platforms can increase laborer productivity for certain orchard tasks but substantial gains in harvesting productivity through mechanization is not a possibility in the near future. Our study did, however, allude to the potential gains in productivity that can be made with more efficient management and implementation of conventional harvesting practices. Producing, and more specifically, harvesting deciduous fruit for the fresh market will likely remain a labor intensive process. Therefore it is important that producers focus on investing in labor-related factors such as laborer training, motivation and satisfaction together with the careful implementation of new technologies such as laborer platforms.

AFRIKAANSE OPSOMMING: Die impak van oesstelsels en arbeider-platforms op vrugkwaliteit tydens oes sowel as arbeider produktiwiteit met die uitvoer van boordtake waar traplere gebruik word, is geevalueer. Die oesstelsels en arbeider-platforms is vergelyk met konvensionele praktyke wat op verskeie steen- en kernvrugplase in die Wes-Kaap gebruik word. Oesstelsels het die potensiaal om appel kultivars met 'n lae beseringsgevoeligheid, soos Red Chief en Cripps’ Red minder te kneus. Soortgelyke of selfs hoër vlakke van oesbeserings is waargeneem op sensitiewe kultivars soos Golden Delicious en Cripps’ Pink. Konvensionele plukspanne handhaaf oor die algemeen lae vlakke van oesbeserings op geharde kultivars, wat min ruimte vir verbetering laat. Oesbeserings vir konvensionele spanne op sensitiewe kultivars is egter hoog en laat baie ruimte vir verbetering, maar weens die hoë vlakke van beserings van die spanne op die oesstelsels, is geen verbetering waargeneem nie. Konvensionele plukspanne handhaaf hoë oesproduktiwiteit uitsette op geharde kultivars soos Abate Fetel, Red Chief en Cripps’ Red terwyl oesproduktiwiteit vir sensitiewe kultivars soos Golden Delicious en Cripps’ Pink laer is. Oesstelsels het 'n maksimum plukuitset van 150 kg per plukker per uur behaal tydens skoon-pluk, ongeag kultivar gehardheid. Hierdie beperking ontstaan as gevolg van die onverenigbaarheid tussen boord- en masjienontwerp wat tot 'n baie ondoeltreffende plukaksie lei vir die plukkers. Die onverenigbaarheid beperk die aantal plukbewegings wat 'n plukker kan voltooi binne 'n sekere tyd wat weer die totale massa van die vrugte wat in daardie tyd gepluk word beperk. Boomgrootte, -vorm en –uniformiteit, vrugverspreiding op die boom, vruggrootte en – kwaliteit, toestand en helling van die boordvloer, arbeiderverhoudings, plukker vergoeding, krattoestand, operasionele stelsels wat geïmplementeer word en die organisering van oestyd logistiek het 'n invloed gehad op die produktiwiteit uitsette wat met die oesstelsels behaal is. Die gebruik van 'n arbeider-platform vir somersnoei het arbeider produktiwiteit beduidend verhoog in vergelyking met konvensionele arbeiders op traplere. Wintersnoei en vruguitdunning met arbeider-platforms het ook die potensiaal om arbeider produktiwiteit te verhoog. 'n Kleiner verhoging in produktiwiteit as by somersnoei is waargeneem en het afgehang van die snoei- of uitdun-strategie sowel as boom argitektuur. Oor die algemeen het jonger en smaller bome groter verhogings in produktiwiteit getoon. Ten einde maksimum voordeel te geniet met die gebruik van arbeider-platforms moet produsente poog om snoei- en uitdun-strategieë te vereenvoudig terwyl goeie vrugkwaliteit en opbrengs gehandhaaf word. Ons navorsing het getoon dat die gebruik van arbeider-platforms, arbeider produktiwiteit vir sekere boord-take kan verhoog, maar 'n beduidende toename in oesproduktiwiteit d.m.v. meganisasie blyk nie 'n moontlikheid te wees in die nabye toekoms nie. Ons navorsing het wel gedui op die potensiële toenames in oesproduktiwiteit wat verkry kan word met meer doeltreffende bestuur en implementering van huidige konvensionele stelsels. Die verbou, en meer spesifiek die oes van sagtevrugte vir die varsproduktemark sal waarskynlik 'n arbeidsintensiewe proses bly. Daarom is dit belangrik dat produsente aandag gee aan die opleiding, motivering en bevrediging van arbeiders saam met die implementering van nuwe tegnologie soos arbeider-platforms.

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