Our efforts are concentrated on quantifying spatial variability for tree vigor, yield, fruit quality, and profit. We use aerial photography to quantify tree vigor. For mechanically harvested hazelnuts, a prototype weight based yield monitor has been evaluated. This approach may also work for quantifying yield in mechanically harvested sweet cherries. For perishable hand-harvested crops, the GPS locations for individual bar-coded bins can be used to calculate bin density and estimate yield. Bar codes can also be used to track quality in the packing-house. Since profit depends on yield, size, and packout, it is not always intuitively obvious which areas of an orchard are most profitable. Defining which areas are most profitable, and identifying the problems associated with low-profit areas (poor yield, small size, storage loss, bruising, culls, etc) is an important step. Identifying areas producing fruit that stores poorly is a high priority. An evaluation of low- and high-profit areas may lead to alternate management plans. Anything from investing in more supervision of harvest labor and initiating different pruning regimes to attempts to obtain more uniform tree vigor can be evaluated. By delineating test areas with GPS boundaries, profit data in future years can quantify the success of different management approaches. For example, concentrating expensive inputs on the portion of trees (30% of total) that may produce the majority of gross returns, while not even harvesting fruit from regions (1% to 5% of total) that consistently produce poor quality fruit may be a sound strategy.
Najib Assi and M. Joseph Ahrens
Previous investigations have shown that severe injury and bruising result from impacts, compression, and vibration scuffing during transport. Work specifically on vibration has focused on damage caused by “micro impact” and not true vibration. Our study looked at true vibration-imparted energy and analyzed the effects of force and frequency.
Mature green tomato fruit were secured to a platform and energized with a vibration cell at different frequencies and force for 0, 10, 20, 30, 40, 50 and 60 minutes. The fruit were then allowed to ripen at 20C. Ethylene and respiration rates were determined along with general condition for two weeks.
Ethylene production and respiration rate increased initially and remained high with increasing force and length of treatment. Fruit vibrated for 40, 50, and 60 m developed an uneven ripening pattern. When the control fruit were red, the vibrated fruit showed blotchy ripening. In addition, the ripening rate was slower, although respiration and ethylene production were higher. However, when the control fruit were full red to overripe, the blotchy ripening disappeared in the treatments, but they never developed as deep a red as the controls. We are continuing to investigate vibrational effects on gel breakdown and membrane integrity
Ria T. Leonard, Terril A. Nell, Jim E. Barrett, and David G. Clark
The traditional use of poinsettias has been as potted plants. A new poinsettia variety, `Winter Rose Dark Red', is performing well as a cut flower, lasting 2 to 3 weeks. Various postharvest handling procedures were examined, including stem processing methods at harvest, storage and transit conditions, as well as handling practices at the wholesale, retail, and consumer levels, to determine the best handling practices to maximize quality and longevity. At harvest, traditional latex controlling techniques, such as dipping stems in 95% ethanol for 10 min and burning or boiling stem tips were tested. Stems wilted faster when dipped in ethanol or burned. The woody nature of the stem contains little latex compared to traditional varieties; thus, no latex-controlling methods are needed or beneficial. After harvest, there was no benefit found in hydrating stems in a commercial hydration solution compared to plain water. Transport and/or storage conditions between 10 to 15 °C for 3 to 4 days maximized longevity. Chilling injury occurred when transported at 4 °C. Leaves and bracts wilted when stored dry in a box, but recovered within 12 to 24 h when stored for 2 days. Leaves abscised after exposure to short-term wilting but no bract abscission occurred. Storing stems in a 10% bleach solution prevented wilting and reduced bacterial growth. Bracts were sensitive to mechanical injury during transit, resulting in bruising lesions on the bracts, which increased sensitivity to bract edge burn. Stems declined faster when maintained in a floral preservative compared to water during the consumer phase.
Peter M.A. Toivonen, Frank Kappel, Sabina Stan, Darrell-Lee McKenzie, and Rod Hocking
A convenient and reliable method that used a specially designed tool to apply a uniform bruising force in situ was developed to assess the relative susceptibility to fruit surface pitting in sweet cherry. Assessment of pitting with a visual scale after 2 weeks of 1 °C storage was found to be in close agreement with measurements of pit diameter. Using this method `Bing' showed the greatest susceptibility to pitting in both years of the study and `Bing', `Lapins', and `Sweetheart' cherries showed a decline in susceptibility as fruit matured. The predictive value of fruit firmness at harvest, fruit respiration at harvest, and weight loss in storage was assessed in relation to the severity of pitting. The model to best describe pitting was found to include all three physiological variables (firmness, respiration, and weight loss). While an acceptable model was obtained when combining all three cultivars, the best models were achieved when each cultivar was considered separately. It was concluded that there are likely unmeasured variables involved in determining susceptibility to pitting. Hence the best approach to predicting pitting susceptibility is the application of the pit-induction method described in this work.
Ibrahim I. Tahir, Eva Johansson, and Marie E. Olsson
To decrease the unfavorable effects of herbicides on human health and on the environment, new sustainable mulching methods have been developed. These methods aim to impede weed growth and also result in good yield and high fruit quality. The objective of the present study was to investigate the effects of the replacement of conventional methods (chemical treatments or mechanical) with different groundcover material systems (GCMSs) that use aluminum, bark and black polypropylene on 'Aroma' apple (Malus domestica) fruit maturity and quality, and fruit resistance to bruising and decay. The experiment was carried out from 1995 to 2001. Compared with conventional mulching methods, aluminum mulching was found to control annual weeds more effectively, to increase soil temperature, light reflection, yield, and fruit weight, to decrease bruise occurrence, to intensify and saturate the red coloration of apples, and to increase firmness and acid and sugar contents, resistance to storage disorders and decay after storage and shelf life. The other two used GCMSs, bark and black polypropylene also influenced many yield and quality parameters. However, less positive influences on the different parameters were found for bark compared with aluminum, and the use of black propylene was not favorable compared with the conventional mulching methods. Generally, decreased starch content at early picking dates was found for apples grown with GCMSs, indicating an earlier ripening for these apples compared with apples grown with a conventional mulching system. In summary, aluminum mulching was found to be the best alternative mulching method for production of 'Aroma' apples.
J.D. Hansen, M.L. Heidt, M.A. Watkins, S.R. Drake, J. Tang, and S. Wang
Quarantine regulations require domestic sweet cherries (Prunus avium) exported to Japan to be treated to control codling moth [Cydia pomonella (Lepidoptera: Tortricidae)]. The current procedure, methyl bromide fumigation, may be discontinued because of health, safety, and environmental concerns. To examine a potential alternative method, `Bing' sweet cherries were each infested with a codling moth larva, submerged in a 38 °C water bath for 6 minutes pretreatment, then exposed to various temperatures generated by radio frequency and held at that temperature for different times: 50 °C for 6 minutes, 51.6 °C for 4 minutes, 53.3 °C for 0.5 minutes, and 54.4 °C for 0.5 minutes. Insect mortality was evaluated 24 hours after treatment and fruit quality was evaluated after treatment and after 7 and 14 days of storage at 1 °C. No larvae survived at the 50 and 51.6 °C treatments. Fruit color of non-infested cherries was darkened as temperature increased. Stem color was severely impacted after 7 days of storage, even in a warm water bath of 38 °C for 6 minutes, as was fruit firmness at the same treatment. Fruit quality loss increased after 14 days of storage, compared to after 7 days of storage. The amount of pitting and bruising of cherries increased with temperature and again this increase was more evident after 14 days of storage.
B.A. Edmunds and G.J. Holmes
Methods of packing and handling sweetpotatoes are important for mitigating postharvest losses due to decay. The goal of this work is to take a critical look at the packing and handling processes in North Carolina (NC) sweetpotato packinghouses. Similar surveys are being conducted in Louisiana and Mississippi as part of a multi-state project. The survey is inclusive of all packingline operations including sequence of machinery components, length and speed of the packingline, decay control products/strategies used, and impact (bruising) measurements. Packingline impacts are quantified and characterized using a SmartSpud. This instrumented device is placed on the packingline where it is conveyed alongside sweetpotatoes, measuring the impact forces exerted and sending the data via a radio signal to a handheld personal digital assistant (PDA). The information on the PDA is downloaded onto a computer where the results can be displayed in more detail and analyzed. Packinghouse personnel respond well to this visual display and willingly spend one hour being interviewed, discussing the results of the survey, learning about the trouble spots on their lines, and getting advice on how to reduce potential injuries. About 15 out of 30 NC packinghouses have been surveyed (this includes all of the high-volume packinghouses). We typically found the largest impacts (30–70 G) occurring during dumping and at unprotected conveyor changes. Packinglines vary in length from 88 ft to 277 ft with run time varying from 3.5 min to >10 min. Lines all share the same basic components (dump, eliminator, brushbeds, sizer, etc.) with layout and design modified to suit individual needs and space requirements. A variety of decay control methods are in use with about one half of packers surveyed routinely applying the fungicide Botran.
J.H.M. Barten, J.W. Scott, and R.G. Gardner
Pointed blossom-end morphology may be used to reduce blossom-end scar size in large-fruited, fresh-market tomatoes (Lycopersicon esculentum Mill.). The usefulness of this characteristic has been limited due to persistence of pointedness on mature fruit, resulting in postharvest bruising, and to close association of pointedness with leaf curl, which may increase foliar disease problems. The inheritance of pointedness in three breeding lines (NC 140, Fla 890559-24, and Fla 894413-1) and four accessions with previously described blossom-end morphology genes [LA 2-5 with persistent style (pst), LA 986 with beaky (bk), LA 1787 with beaky-2 (Bk-2), and LA 2353 with nipple tip (n)] was investigated. In F1 s and F2s of crosses with wild types, some pointedness was observed in heterozygotes, but the level of expression was generally close to wild type expression, except for LA 986. Consequently, Bk-2 in LA 1787 was renamed bk-2. F1 complementation tests were difficult to interpret. Wild types segregated in F2s of all complementation crosses, except for LA 986 × LA 2-5, a result indicating the presence of the same gene in these two accessions. Three new nipple-tip genes were named; n-2 in NC 140, n-3 in Fla 890559-24, and n-4 in Fla 894413-1. None of the seven accessions tested had significant leaf curl. Early identification of mutant plants by the shape of the stylar base in flowers at anthesis was reliable only for bk. Various blossom-end morphology genes may be backcrossed into otherwise desirable breeding lines, and complementing parents may be intercrossed to obtain optimal smoothness in the hybrid without undesirable pointed mature hybrid fruit.
Eunkyung Lee, Steven A. Sargent, and Donald J. Huber
proportion of visibly damaged tomatoes increased from 15% before to 35% after dumping ( O'Brien et al., 1972 ), while internal bruising increased from 5.2% to 23.8% for tomatoes sampled from the float tank and the grading table, respectively ( Sargent et al
Carol A. Miles and Jaqueline King
In this 2-year study of ‘Brown Snout’ specialty cider apple (Malus ×domestica) grafted onto Malling 27 (M.27) and East Malling/Long Ashton 9, we compared weight of total harvested fruit, labor hours for harvest, tree and fruit damage, and fruit and juice quality characteristics for machine and hand harvest. Machine harvest was with an over-the-row small fruit harvester. There were no significant differences due to rootstock; however, there were differences between years for most measurements. Weight of harvested fruit did not differ because of harvest method; however, harvest efficiency was 68% to 72% for machine pick and 85% to 89% for machine pick + clean-up weight (fruit left on trees and fruit knocked to the ground during harvest) as compared with hand harvest. On average for the 2 years, hand harvest required 23 labor-hours per acre at a total cost of $417, while machine harvest required 5 labor-hours per acre at a cost of $93. There were no differences due to harvest method on damage to spurs (four to eight spurs damaged per tree) or limbs (0.5–0.8 limbs damaged per tree). Although there were also no differences due to harvest method on fruit bruising (100% for both harvest methods in this study), 10% of fruit were sliced and 4% of fruit were cut in half inadvertently with machine harvest, and none were sliced or cut with hand harvest. Harvest method had no effect on fruit quality characteristics, specifically, soluble solids concentration (SSC), pH, specific gravity, titratable acidity (malic acid equivalents), or percent total tannin, when fruit was pressed immediately after harvest or stored for 2, 3, or 4 weeks before pressing. Juice quality characteristics were affected by storage, and SSC increased 11% in 2011 (3 weeks storage), and 12% and 18% in 2012 (2 and 4 weeks storage, respectively). Similarly, specific gravity increased both years after storage, 1% in 2011, and 1% and 2% in 2012 (a 1% increase in juice specific gravity corresponds to a potential 1.3% increase in alcohol by volume after fermentation for cider). Both years, juice pH tended to decline when fruit was stored (0.01 pH units in 2011, 0.06–0.12 pH units in 2012). Overall, cider apple harvest with an over-the-row small fruit machine harvester used four times less labor than hand harvest, yield reached 87% that of hand harvest (when clean-up yield was included), and juice quality characteristics were not negatively affected. These results suggest that machine harvest may be suitable for cider apples if equipment is available and affordable.