Final report appendix 6
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- Impacts Scientific impacts
- Capacity impacts
- Community impacts
- Communication and dissemination activities
- Conclusions and recommendations
- Recommendations
- Attachments Annex 1
- Soil conditions
- Soil moisture and tension
DiscussionThree different types of harvesters were used in the study and based on the IS data 4 to 5 impact points were identified for each, excluding the bunker drop. These impact points occurred where there was a change in direction of the chains or a drop greater than 10 cm leading to the tubers either bumping into each other or the guards surrounding the chains. This lead to impacts ranging from 50 G or 10 cm drops to > 200 G or the equivalent of a 30 cm drop for some of the crops. It is recommended that tubers are not dropped from heights greater than 10 – 15 cm as this is the standard industry bruise height (Blaesing and Kirkwood 2004) but this will differ with the differing susceptibility of cultivars. Our calibrations of bruising in the cultivars Atlantic and Granola against drop height show that the impacts points observed would cause damage to Atlantic but not Granola. The bunker drop had significantly larger G force readings than the harvester readings. The bunker drop consistently produced G force readings > 50 G and three of the crops with > 200 G, indicating that the bunker drop represents a significant damage point for seed potato producers. Three different cultivars were harvested during the study. Using a pendulum bruising device similar to that used by Mathew and Hyde (1997) on WA grown Atlantic and Granola tubers it was found that Atlantic is highly susceptible to bruising (Figure 6.1) whilst Granola was more tolerant (Fig 6.2). This confirms tests done for bruising susceptibility under European growing conditions for both Atlantic and Granola. Atlantic was found to be moderately resistant to external damage and low to medium resistant to internal bruising (European cultivated potato database 2010). Granola on the other hand was found to be resistant to very resistant to external damage and shows medium to very high resistance to internal bruising (European cultivated potato database 2010). Hence growers in WA will need to adjust their machinery according to the variety in which they are harvesting to prevent potential loses associated with bruising. It is recommended that soil temperature at harvest should be between 10 and 18 °C to avoid excess bruising (Blaesing and Kirkwood 2004). The soil temperatures at harvest ranged from 8.4 °C to 18.4 °C during this study and therefore some growers were harvesting outside the recommended guidelines. The results of this study indicate that harvest damage to seed potatoes was in the range of 1.9 to 6.7% for Atlantic. This variability is the result of differences in growth conditions of the plants, mechanical equipment used, operators of the equipment as well as the conditions of the soil at the time of harvest. The majority of damage recorded was in the medium impact range (50-99 G) for all crops. Seed potato growers in WA have several options available to minimise the bruising seen on tubers. The first is to assess impacts by using an IS and to make adjustments to machinery to reduce the size and number of these impacts through physical modifications to their machinery or through refinement of the operating settings. During this study we found an assessment of a harvester would take approximately 3 hours. Other ways to minimise damage includes described removing as much soil as possible on the primary chain and loading the rear cross, elevator and boom chains to capacity so that tubers cushion each other (Blaesing and Kirkwood 2004). Removal of soil on the primary chain is a plausible option for seed potato growers in WA using any one of the three machines examined in this study; it would just require the machine operator to be closely aware of soil moisture content, soil texture and weeds. A more difficult task would be to ensure the chain capacity of tubers as this requires training harvester operators, many of whom are casual backpacker workers, in maintaining chain speed in the harvester whilst determining the optimum level of tubers on the chains and continuing to sort the tubers. ImpactsScientific impactsThe IS survey results show opportunities for growers to develop better harvest management techniques to improve seed potato quality particularly in the area of chain speed. Cultivar susceptibility is a major factor in the level of bruising and mechanical damage that appears on tubers. Different cultivars are grown under WA conditions and the results from this study and previous research reveals that they differ considerably in their susceptibility to bruising. Soil temperature and tuber temperature were found to differ vastly between growers and crops. Although some of this appears to be the result of different soil type it is apparent that soil temperature is managed differently through irrigation in WA and this has an effect on the level of bruising and mechanical damage seen on the tubers. Several growers had large differentials between their minimum and maximum soil temperatures during the crop and this is an area where efficiency can be gained through more education and the use of soil moisture monitoring equipment. Of the damage recorded during harvesting the largest impacts were recorded from the bunker drop to the bin. It was consistently found that the impacts at this site were in the high G force range for the majority of growers. Improvement in the handling of potatoes in this area to minimise impacts would represent a significant step towards reducing mechanical damage of tubers in the WA supply chain. Capacity impactsBy highlighting the areas where damage or potential damage can occur, this study has increased the capacity of WA seed potato growers to produce higher quality seed potatoes. Growers will be more aware of the impact of harvester set-up, variety, soil management and irrigation techniques on the level of mechanical damage seen on tubers and potential this has on yield and market development. Results of the study have been presented to growers. The IS team will be available to WA seed potato growers who wish to assess their harvesting operations. Community impactsThis study will lead to a more efficient and productive seed potato industry for WA. Improved efficiency and productivity will lead to an industry with a reputation as an internationally recognised producer of high quality seed potatoes. Results of this will be increased seed potato sales interstate and internationally. Communication and dissemination activitiesTable 7.4. Analysis of WA seed supply chain communication and dissemination activities.
Conclusions and recommendationsConclusionsThis study was successful in identifying the areas of impact during harvesting that lead to bruising and mechanical damage of potato tubers. Bruising and mechanical damage is variable in WA depending on the cultivar grown, irrigation, soil management, temperature control and harvester type. RecommendationsInvestigate the use of padding material to prevent impacts > 50 G from occurring at the bunker to bin drop. Padding will reduce the drop height of impacts and therefore minimise the level of G forces applied to the tubers and reduce bruising and mechanical damage. Growers will be aided by the use of more soil temperature monitoring equipment to maintain soil temperature between the recommended 10 and 18°C. The monitoring units will provide constant feedback to growers that enable them to manage soil temperature more efficiently using irrigation practices. Soil temperature monitoring units will also aid growers in determining that tuber temperature at harvest is within industry recommendations to prevent further bruising. ReferencesBlaesing D and Kirkwood I (2004) PT01030: Potato Seed Handling and Storage – Implementing Best Practice. Horticulture Australia Limited. European cultivated potato database (2010) Retrieved from http://www.europotato.org/quick_search.php Henderson A & Bennett R (1999) Product Description Language: Potatoes. Agriculture Victoria and Australian Horticultural Corporation. Victoria, Australia. Hyde, GM, Brown, GK, Timm, EJ & Zhang, W 1992, ‘Instrumented sphere evaluation of potato packing line impacts’ Transactions of the American Society of Agricultural Engineers, Vol 35 (1): January - February 1992. pp. 65-69. Lopresti, J & Thomson, G (1998) Instrumented sphere assessment of seed potato grading lines:A summary. ExpHORT 2000 publication Number 41. Department of Natural Resources & Environment Victoria, Australia. Mathew R and Hyde GM (1997) Potato impact damage thresholds. Transactions of the ASAE. 40: 705–709. Molema GJ, Struik PC, Verwijs BR, Bouman A. and Klooster JJ (2000) Subcutaneous tissue discoloration in ware potatoes. 2. Impact measured by an instrumented sphere. Potato Research 43, 225-238. Morris S, Sharp A, Stephens B and Bokshi A (2000) Storage and transport technology for quality, in Potatoes 2000 “Linking research to practice”: Australian potato research, development and technology transfer conference 31 July to 3 August 2000, Adelaide, South Australia. Peters R (1996) Damage of potato tubers, a review. Potato Research. 39: 479-484 Van Canneyt, T, Tijskens, E., Ramon E., Verschoore, R and Sonck, B (2003) Characterisation of a Potato-shaped Instrumented Device. Biosystems Engineering 86 (3), 275–285 AttachmentsAnnex 1:Crop 1The results of the impact severity are presented in Tables 6.2, 6.3 and 6.4. Of the total impacts from the harvester 16 were greater than 50 G which equates to 0.8 ≥ 50 G impact every run on average (Table 6.2). Forty percent of total runs had an impact of medium severity and 15% of runs recorded a high impact. Of the impacts greater than 50 G 81% were in the medium range (50 – 99 G) and the remainder 19% were high (100-149 G) (Figure 6.10). Maximum impact recorded from the harvester was 112 G. Impacts from the harvester bunker to the bin recorded 42 impacts greater than 50 G which equates to 2 impacts >50 G per run on average (Table 6.3). Of the 21 bunker drops 57% were recorded as a medium impact, 19% a high impact and 14% a very high impact. Seventy six percent of impacts greater than 50 G were medium impacts, 17% were high and 7% were very high (Figure 6.10). The highest impact recorded was 181.6 G. When the harvester data and bunker data was combined there were 58 recordings of impacts >50 G (Table 6.4). The percentage breakdown of runs where the various impacts occurred is presented in Figure 6.10. On average it took 49.35 seconds for the Smart Spud™ to travel from the short main web to the drop into the bunker; location 4 on Figure 6.1. At the time of harvest the internal tuber temperature was approximately 18.4°C. Soil conditionsThe topsoil (0-15 cm) was classified as a sandy loam with 73% sand, 19% clay, 8% silt and field capacity (FC) of approximately 30% (v/v). TemperatureThe mean soil temperature at 15 cm was 20.5 °C, (median 20.1 °C) and the range from a minimum of 13.7 °C on the 04/02/10 to a maximum of 28.8 °C on the 28/12/09 (Figure 6.2) 
Figure 6.2. Soil temperature information for crop 1. Soil moisture and tensionMean volumetric soil moisture at 15cm depth on the site was 10.8%, the median 10.3% and it ranged from a minimum of 7.8% on the 07/02/10 to a maximum of 18.8% on the 18/01/10. Key soil moisture data is also available for other depths (attachment). Mean soil tension at 15cm depth on the site was -29.5 kPa, the median -22.8 kPa and it ranged from a minimum of -86 kPa on the 08/02/10 to a maximum of -15.1 kPa on the 13/01/10. Soil tension was less than -40 kPa 15% and -20 kPa 60% of the crop period. Directory: files -> node -> 13922 files -> Pop Warner History files -> North Carolina Inclusion Initiative Mapping Where Children with ieps are Being Served Purpose files -> Fall 2013 Spring 2014 Program Data: Standard 1 Exhibit 4d files -> Hanban – asia society confucius classrooms network 2010 request for proposal files -> Northern England’s set-jetting locations node -> Citizenship usa position Investigator, Howard Hughes Medical Institute node -> Final report project Development of integrated crop management practices to increase sustainable yield and quality of mangoes in Pakistan and Australia 13922 -> Final report appendix 7 Download 1.26 Mb. Share with your friends:
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