Search

Nearly half (45%) of the U.S. peach production is sold through the fresh market sector, making post-harvest disinfectant washing treatments a critical step for reducing surface microorganisms. This...

Potato breeding requires a long and laborious study as a based on phenotypic and genotypic selection studies due to its tetraploid and heterozygous plant structure. This research was made to show that the variety development can be faster with molecular assisted breeding. In this research, a short breeding program was applied in order to develop new varieties by taking high dry matter content and PVX resistance as the main criterion. The research was carried out between 2014-2019 and 16.000 F1 potato seeds were used as a genetic material. A hard and effective selection breeding, breeder field observation and PVX markers based on tuber and plant characteristics were selected. In this research, fresh market, French fry and chips variety candidates which have high dry matter content, PVX resistant and higher tuber yield compared to commercial varieties have been developed. According to the results of the research; special breeding programs with two selection criteria can be used to shorten the potato breeding time and commercial candidate varieties with superior properties can be developed. Superior lines that showed to be carrying the markers are strongly recommended to be used by breeders to develop new PVX extreme resistance potato varieties.

As availability of skilled harvest labour is in decline, the sustainability of fresh market apple production in the USA is threatened. A mass mechanical harvesting of apples offers an alternative and promising solution. In addition to harvester design elements, it is important to understand the key canopy parameters of apple trees as they are closely integrated and interact with each other during the harvest process. In this study, the impact of eleven canopy parameters on mechanical harvesting were investigated for vertically-trained “Scifresh” and V-trellis grown “Envy” trees during harvesting trials. A supervised machine learning algorithm with weighted k-nearest neighbours (kNN) was adopted to analyse our canopy datasets. Overall, 2678 ground-truth data points (apples) were classified into two binary classes of fruit removal status: “mechanically harvested” and “mechanically unharvested” apples. For the training dataset (85%), the adopted algorithm achieved overall prediction accuracies of 76–92% and 62–74% for “Scifresh” and “Envy”. With the remaining 15% dataset, the overall test accuracies were 81–91% on “Scifresh” but only 36–79% on “Envy”. The principal components analysis (PCA) was adopted to determine the key canopy parameters by calculating the coefficients of principal components (PCs). The PC1–PC5 explained at least 80% of the data variance. By assuming a coefficient greater than 0.5 as being highly relevant, fruit load per branch, branch basal diameter, and shoot length were the most relevant among all. These results provide guidance for growers in canopy management that could improve efficiency of a mechanical harvesting system.

HighlightsThree shaking methods and vibratory harvesting systems were evaluated and compared.Multi-year field evaluations were performed with up to six cultivars trained to formal architectures.The updated semi-automated system achieved the highest fruit removal efficiency and the best fruit quality.Abstract. Apple is the most economically important agricultural crop in Washington State. In 2018, Washington State produced ~3.3 billion kg of apple, accounting for approximately 63% of U.S. production. Fresh-market apple is currently harvested manually, requiring large numbers seasonal semi-skilled workers for a small harvest window. To overcome the increasing challenges of uncertain labor availability and raising labor costs, a promising mechanical harvesting system, using a targeted shake-and-catch approach, is under development at Washington State University. This study evaluated the system by analyzing its fruit harvest efficiency and fruit quality with three shaking methods, i.e., continuous non-linear, continuous linear, and intermittent linear shaking, on up to six apple cultivars trained to formal tree architectures. Results showed that intermittent linear shaking achieved 90% fruit removal efficiency for ‘Scifresh’ cultivar, while continuous linear shaking achieved only 63% removal efficiency for ‘Gala’. This study also compared three vibratory systems: a hand-held system, a hydraulically driven system, and a semi-automated hydraulic system. The semi-automated system achieved the highest fruit removal efficiency (90%), followed by the hand-held (87%) and hydraulic (84%) systems, mainly due to the different shaking methods employed. However, the differences were statistically insignificant. Fruit catching efficiency varied among the harvesting systems, with the hand-held system achieving the highest efficiency (97%), followed by the hydraulic (91%) and semi-automated (88%) systems. Among the three tested technologies, the prototype semi-automated system achieved the highest level of mechanization, as well as high fruit removal efficiency and the best fruit quality. Because the semi-automated system did not include an auto-positioning function, positioning its shaker head took about eight times longer (~103 s) than the actual shaking time (~13 s), which suggests that a fully automated system is desirable to further increase productivity. This study showed that the shake-and-catch approach has great potential for practical adoption in harvesting of fresh-market apple and therefore can have a positive economic impact on the U.S. apple industry. Keywords: Automation in apple production, Bulk mechanical harvest, Semi-automated system, Shaking method, Time efficiency.

Attractive appearance is highly desirable for fresh market red-skinned potatoes. Red potatoes derive their skin color from anthocyanins. Some growers attempt to enhance red potato skin color by treating vines with the synthetic auxin 2,4-D. In this study, 2,4-D was applied twice at early bloom stage to ‘Red Norland’ potatoes and tubers were harvested weekly until plants senesced. 2,4-D rapidly increased anthocyanin quantity and altered anthocyanin composition. Average tuber mass at the final harvest was less for the 2,4-D-treatment than untreated controls. Elevated anthocyanin content resulting from 2,4-D persisted through 3 months storage. 2,4-D-treated potatoes did not differ from untreated controls in the number and depth of red pigmented cells in the phellem. Thus, changes in periderm cell division and expansion may not contribute to the 2,4-D response of ‘Red Norland’. Instead, the data suggest that 2,4-D application initiated a rapid change in anthocyanin accumulation that persisted into storage.

Five fresh market potato cultivars commonly grown in western Washington were evaluated against Potato virus Y (PVY) O, NTN, and N-Wi using inoculated PVY-free plantlets in the greenhouse in 2015 and successive generations of seed tubers from foliar inoculated plants in 2016, 2017, and 2018. Mosaic displayed strongly on all cultivar by strain combinations, except All Blue by PVYO. Russet Burbank and Yukon Gold infected with PVYO had highest area under symptom progress curve values for leaf drop across all cultivars and years. Yields mostly were lowest for PVYO. More cracked tubers developed on G3 tubers in the field than greenhouse G2 or G1 plants. Chieftain infected with PVYO and PVYNTN, and Yukon Gold with PVYN-Wi had marked increases in tuber cracking by 2018. Cracking began at early plant growth stages; seed tuberborne rather than current season infections had higher cracking incidence; cracking became prevalent with succeeding seed tuber generations; cracking did not contribute to tuber weight loss during storage; and, PVY and tuber cracking substantially impacted yield.

Clustered regularly interspaced short palindromic repeats (CRISPR)-driven traits are commonly introduced into tomato (Solanum lycopersicum) in less than a year. Although CRISPR technology is highly suitable for rapid incorporation of new traits into plants with superior breeding backgrounds, the usefulness of these traits must be demonstrated prior to large-scale distribution of any new variety possessing them. The jointless pedicel trait is crucial for stem-free harvest of tomato fruits and is therefore an essential requirement for developing low-labor tomato varieties. We aimed to evaluate the effect of CRISPR-driven jointless pedicel trait on the yield and horticultural traits of fresh-market tomatoes. We conducted field trials during three consecutive seasons using three related genotypes of two elite fresh-market tomatoes, namely a jointed pedicel tomato, a CRISPR-driven jointless pedicel mutant of the jointed pedicel tomato, and a conventionally-bred jointless pedicel near isogenic line (NIL) to the jointed pedicel tomato. Field evaluations confirmed that the total and medium-, large-, or extra-large-size fruit yields of the CRISPR-driven mutants were not statistically different for those corresponding to their backgrounds and that the fruit yield stratified by fruit size might be varied under different growth conditions. We did not observe any negative correlation between the genotype and the fruit/abscission joint detachment force for any of the genotypes under study.

Harvest of fresh market, southern highbush blueberries (SHB) is labor intensive and costly, leading to a demand for alternative harvest methods. Recent research has shown potential for mechanically harvesting blueberries with minimal bruising by using a modified over-the-row (OTR) harvester. For two harvests, SHB cultivars Optimus and Vireo were either hand-harvested (HH) or mechanically harvested (MH) by two commercial harvesters, one unmodified with standard hard-catch surfaces (HCS) or by the other modified with soft-catch surfaces (SCS). For Harvest 1, fruit from all harvest methods were hand-sorted into the following categories: blue fruit (marketable), red fruit, green fruit and culls. Samples from each cultivar and treatment were then held at 24 °C overnight, and the following day firmness and impact bruise severity were determined. Harvest 2 had identical harvest treatments, however, the fruit were sorted on a commercial packing line prior to packing in clamshells (n = 16). A subsample was held overnight as in Harvest 1 for bruise severity rating, while the remaining fruit were stored at 1 °C for 14 days (d). Although percent marketable fruit was more affected by cultivar than harvest method, determination of bruise severity revealed the benefit of harvest with SCS over HCS for both cultivars. The former had 16–26% severe bruising, compared to 27–40% for the latter, HH had 1–4%. During storage, HH fruit remained firmer than HCS and SCS, which were similar. After 14 d, firmness for “Optimus” was 239 N (HH), 157 N (HCS and SCS) and for “Vireo” it was 189 (HH), 155 N (HCS and SCS). Fruit weight loss increased during storage (1.1–4.4%), but there was no difference due to catch plate surface. SSC, TTA and Ratio were not affected by catch surface type or storage period within cultivar. Using modifications such as “soft” catch surfaces on currently available OTR harvesters reduces impact bruise damage, however, impacts incurred during commercial packing operations can negate this effect. MH for fresh market blueberries may provide an economical alternative for blueberry growers, however, with current technology, the fruit should be utilized within a week of harvest.

Polyhalite (PH), a naturally occurring multinutrient fertilizer containing potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), has improved tomato (Solanum lycopersicum L.) product...

Naranjilla (Solanum quitoense Lam.) and tamarillo (S. betaceum Cav.) are two important perennial solanaceous crops grown in Ecuador for the fresh market and juice production. Viruses infecting tamarillo and naranjilla are currently poorly studied, and no clean stock program exists in Ecuador. Here, we report a new virus, provisionally named as naranjilla mild mosaic virus (NarMMV) (genus Tymovirus, family Tymoviridae), isolated from naranjilla grown in an orchard in Pichincha Province, Ecuador. The complete genome of the virus consists of 6,348 nucleotides and encodes three open reading frames typical for members of the genus Tymovirus. Phylogenetically, Chiltepin yellow mosaic virus, Eggplant mosaic virus, and the recently characterized naranjilla chlorotic mosaic virus (NarCMV) were found to be the closest relatives of NarMMV. Unlike NarCMV, the new virus induced mild mosaic in naranjilla and more severe symptoms in tamarillo. Similar to NarCMV, NarMMV was unable to systemically infect potato. Virus surveys found NarMMV prevalent in naranjilla production areas of two provinces of Ecuador, especially where hybrid cultivars of naranjilla were cultivated. NarMMV was also found in field-grown tamarillo. The new virus cross-reacted with antibodies developed against NarCMV. Hence, this antibody will be useful for its field diagnosis using enzyme-linked immunosorbent assay or immunocapture reverse transcription polymerase chain reaction in future virus-free certification programs.

Potato culinary evaluation is an integral component of a breeding programme to determine suitability of new cultivars to specific end-uses. In most breeding programmes, quality assessment is conducted after a few generations of field selection on tubers collected from the field or from storage conditions. In order to optimize selection procedures, we analysed the relationship between specific gravity of potato tubers and quality evaluation traits as well as the effects of field selection parameters in clones that are intended for fresh market and processing uses. A total number of 237 advanced breeding clones were analysed over three consecutive years in the potato breeding programme at Agriculture and Agri-Food Canada (AAFC). Principal component analysis (PCA) and linear mixed-effects model fit by maximum likelihood indicated that parameters used in field selection significantly contributed to specific gravity and culinary components. Specific gravity also contributed significantly to culinary traits related to acceptable quality of baked, boiled and French-fried products. However, such relationship was not observed for chip quality. Significant associations were found between field selection parameters, such as maturity, early vigour, top vigour, early harvest, tuber size and tuber appearance and culinary components related to French fry and chip quality, but not for quality of baked and boiled products. Broad-sense heritability estimates for various culinary evaluation traits ranged from 57 to 92%. The results suggest that specific gravity and culinary traits should be incorporated in early or intermediate generation selection parameters in order to optimize selection gains for specific end-uses.

Potato (Solanum tuberosum) production generally requires added nitrogen (N), which is costly and potentially environmentally damaging. One path to limiting N application is breeding N efficient potatoes. Effective use of nitrogen, across crops, is typically characterized in terms of yield. However, tuber quality characteristics affect potato marketability, especially for red fresh market potatoes. While optimal N rates maximize yield, the genotype-specific effect of N on tuber quality traits is unclear. In order to highlight quality traits effected by N, identify germplasm with lower N requirements, and determine optimal N rates for red-skinned clones, we conducted a variable N rate experiment over two years in Minnesota. Eight red fresh market genotypes were grown in RCB factorial design with five nitrogen application rates ranging from 0 to 81.6 kg/ha. Best linear unbiased estimates were calculated for yield, skin color, skin set, and tuber shape. The models for yield and quality traits included significant genotype by N rate interaction effects, suggesting that there is variation in the way clones respond to N. Established varieties were more responsive to added N than breeding lines. Similarly, established varieties tended to produce more oblong tubers under higher N conditions, while the breeding lines remained round. Color traits also responded to N in a genotype-specific way, while the interaction effect for other traits depended on unmeasured environmental factors. No clone exhibited increased yield above the 54.4 kg/ha rate. Our results suggest that the 81.6 kg/ha rate produced less favorable phenotypes for all traits.

Uma das razões para a baixa demanda de amoras do mercado no Brasil é o sabor ácido da fruta fresca. Os frutos da cultivar BRS Cainguá, recém-lançada, têm um sabor melhor e uma forma muito atraente. Made available in DSpace on 2020-03-19T16:42:26Z (GMT). No. of bitstreams: 1 BRS-Caingua.pdf: 421542 bytes, checksum: d92f0561aa7e0654e88030e36f66315e (MD5) Previous issue date: 2020

Comprehensive understanding of bruise damage caused by apple-to-apple impacts is beneficial to design a low-impact fruit capturing mechanism for mass (shake-and-catch) harvesting, as well as to design other fruit handling devices. This study quantified the bruising severity in ‘Jazz’ apples induced by different levels of impact upon various fruit surface locations. Impact experiments were carried out to analyze bruising patterns in three zones in a fruit surface, i.e., middle/cheek-to-top/stem, middle-to-middle and middle-to-bottom/calyx. Moving fruit and stationary fruit were impacted using a pendulum-type test device, and an equivalent drop height of fruit was calculated to provide a more practical measure for designing a catching surface. In each impact zone, seven different levels of impacts were applied respectively at seven different locations on the fruit surface. Those locations were evenly distributed along the circumferential direction in each of the three zones, and moving fruit was replaced after each impact test. The United States Department of Agriculture (USDA) standard was then used to estimate percentages of fruit in the Extra Fancy Class 1 (no bruising), Extra Fancy (a bruising area diameter ≤ 12.7 mm) and Fresh Market (a bruising area diameter ≤ 19 mm) grades. Results showed that fruit bruising severity increased in a non-linear manner with increasing drop height. It was also found that there existed significant differences in fruit bruising severity between stationary and moving fruit under different fruit-to-fruit impact zones. The bottom zone showed the least bruising sensitivity, followed by the middle zone which was statistically similar to the same in the top zone. The results suggested that the free drop height need to be

Fruit texture and firmness are important cues of blueberry quality for the fresh market. These attributes contribute to consumer acceptance, resistance to bruising during harvesting and transportation, and shelf-life. Thus, fruit firmness and texture are major priorities for blueberry breeders, producers and distributors. In this study, the discriminative power of texture analysis was examined using penetration tests with different probes and double compression for texture profile analysis (TPA). Mechanical parameters taken from the force deformation curves used to dissect texture subcomponents in blueberries that are associated with specific tissue layers. Principal component analysis (PCA) allows to filter and identify mechanical parameters that significantly discern the most variation amongst 24 blueberry genotypes and showed that texture in this crop is multi-trait and cultivar-dependent. Texture analysis was used also on blueberries stored over six weeks to identify mechanical parameters that could be used as predictors for long shelf life. Additionally, the mechanical parameters were correlated with dynamometer data to determine the utility and accuracy of a simple handheld device to measure fruit firmness in blueberries. This study provides a framework for the identification and characterization of the subcomponents of texture in highbush blueberry.

Economically solvent fresh-market potato production is predominantly dependent on the ability to efficiently produce consistent tuber quality and high yield, and the ability to meet first-to-market demand with early-season potatoes. Unfortunately, these two qualifiers often work against each other in terms of production management. In response, we studied integrated potato vine management programs that support timely early-season potato harvest. Vine management with a flail chopper, roller, and flame burner used alone or followed by diquat was evaluated when initiated 21 or 14 d prior to harvest in 2015 and 2016. Potato varieties included ‘Yukon Gold' and ‘Dark Red Norland'. Potato leaf and stem management, as well as tuber skinning, stolon separation, grade, and yield were quantified. Among mechanical methods, potato leaf and stem management were poor when vines were rolled or mowed but better when flail chopped. In general, vine management and tuber skin set was better when treatments were initiated 21 d prior to harvest as opposed to 14 d. Vine management, tuber skin set, and yield were comparable when potato vines were flail chopped followed by flame burning and where diquat was applied twice, offering a viable program for smaller scale or organic production.Nomenclature: Diquat; potato, Solanum tuberosum L.

Fresh market southern highbush blueberries are typically hand-harvested which requires an extensive labor force over a relative short period of time. With rising production costs and labor availability issues, interest in mechanical harvesting options is increasing. In 2017, an over-the-row (OTR) harvester was modified to reduce purchase cost while making hand labor more efficient. The picking heads were removed and dual worker stations were added on each side of the unit. Handheld olive shakers were suspended at each station. Experimental catch plates were installed on one side of the OTR harvester and soft, inclined surfaces over the rigid conveyors on both sides. &lsquo, Meadowlark&rsquo, and &lsquo, Farthing&rsquo, blueberries were harvested with this system and compared to those manually harvested by a commercial harvest crew. Samples from each harvest method were then commercially cooled and mechanically harvested fruit were commercially packed to determine packout data. Fruit firmness, bruise severity and composition were determined after one day at room temperature (22 &deg, C) and after seven and fourteen days of storage at 1 &deg, C. Average packout was very high for mechanically harvested fruit, 87% for &lsquo, and 91% for &lsquo, Initial firmness of both cultivars was lower for mechanically harvested fruit (208 g/mm) than hand-harvested fruit (243 g/mm). Fruit from the three treatments softened during storage, and although &lsquo, remained firmer than &lsquo, during storage, there were no differences due to catch surfaces. Hand-harvested fruit had no severe bruising (&gt, 20% of cut surface area) at harvest, increasing to 2% after seven days, while mechanically harvested fruit from both fruit collection surfaces had 3% initial severe bruising that increased to 22% during storage. &lsquo, had slightly higher soluble solids content and significantly higher total titratable acidity compared to &lsquo, Additional modifications must be made to the next-generation OTR harvester to further reduce blueberry harvest and handling impacts.

Made available in DSpace on 2020-12-12T01:53:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Potassium (K) is the most taken up and removed nutrient by potato (Solanum tuberosum L.), and has a great influence on tuber yield and quality. This study was performed to evaluate the effects of three rates (100, 200, and 400 kg K2O ha–1) and two timings of application of K (single application at planting furrow and split application of 50% at planting furrow plus 50% at hilling), as potassium chloride, as well as a control (without K application) on the plant nutrition and tuber yield and quality of potato ‘Agata’ grown in tropical clay soils. The split application of K fertilizer had little influence on plant nutrition and tuber yield and quality. The influence of K fertilization on increasing K and reducing Ca and Mg concentrations in the leaf was more significant in soil with low exchangeable K. In this soil, the maximum tuber yield (33.6 Mg ha–1; 107% higher than the control) was obtained with an estimated rate of 325 kg K2O ha–1, while in the soils with medium and high exchangeable K, the tuber yield was increased between 22 and 34% and only up to a rate of 200 kg K2O ha–1. The critical leaf K concentration to reach 95% of the maximum yield was 29.3 g K kg–1, but there was an extreme increase in the tuber yield even with K rates that provided leaf K concentrations above this limit. Potassium fertilization increased the firmness and reduced soluble solids and protein in tubers. São Paulo State Univ. (UNESP) College of Agricultural Sciences Dep. of Crop Science, Av. Universitária, 3780, Lageado Experimental Farm São Paulo State Univ. (UNESP) Center of Tropical Roots and Starches (CERAT), Av. Universitária, 3780, Lageado Experimental Farm Agronomic Institute of Paraná (IAPAR), Rod. do Café, km 496, Av. Presidente Kennedy, s/no, P.O.Box 129 São Paulo State Univ. (UNESP) College of Agricultural Sciences Dep. of Crop Science, Av. Universitária, 3780, Lageado Experimental Farm São Paulo State Univ. (UNESP) Center of Tropical Roots and Starches (CERAT), Av. Universitária, 3780, Lageado Experimental Farm

Meloidogyne chitwoodi (Columbia root-knot nematode, CRKN) can cause serious damage in potato production systems, decreasing tuber value in the fresh market and processing industries. Genetic resistance to CRKN was first identified from the wild diploid potato species Solanum bulbocastanum accession SB22 and was successfully introgressed into tetraploid potato breeding material. To expand the base of genetic resistance, 40 plant accessions representing nine wild potato species were screened for their resistance to M. chitwoodi. Greenhouse screening identified fifteen clones from S. hougasii, one clone from S. bulbocastanum, and one clone from S. stenophyllidium with moderate to high levels of resistance against three isolates of M. chitwoodi. Geographical mapping showed that the resistance sources identified in this and previous studies primarily originated in the states of Jalisco and Michoacan in west-central Mexico. These new sources of resistance will be introgressed into elite potato populations to facilitate the development of potato cultivars with durable resistance to M. chitwoodi.

Pomerelle Russet is an early maturing fresh potato variety, which produces moderately high early-season (95–110 days after planting) yields of long tubers with brown-russet skin. It is notable for its very attractive, smooth tubers and resistances to internal and external defects with a high percentage of U.S. No. 1 tubers. Fresh merit ratings for Pomerelle Russet in trials conducted in Idaho, Oregon and Washington were consistently higher than Russet Burbank and Russet Norkotah. Early harvest yields for Pomerelle Russet are generally comparable to Russet Norkotah with a higher percentage of U.S. No. 1 tubers. Compared to Russet Burbank and Russet Norkotah, Pomerelle Russet has greater resistance to Potato mop-top virus, soft rot, corky ringspot and tuber infections from late blight. It also has higher protein and vitamin C concentrations than Ranger Russet, Russet Burbank and Russet Norkotah, indicating that it can provide an enhanced level of dietary protein and vitamin C relative to these standard potato varieties. Pomerelle Russet has moderate specific gravity and good resistance to sugar ends. It also has moderately long dormancy, about 30 days shorter than Russet Burbank. Average post-harvest processing ratings for Pomerelle Russet were similar to Ranger Russet and greater than Russet Burbank. Pomerelle Russet also has maintained acceptable fry color for about 180–200 days in storage at 8.9 °C, indicating potential for processing out of mid-term storage, with improved fry color uniformity relative to industry standards. However, its primary use appears to be as a high quality, early fresh variety.

The state of Washington is the biggest fresh market apple ( Borkh.) producer in the U.S., and the state’s annual apple production has exceeded 60% of the national production. Due to the extensive labor requirements for harvesting fresh market apples, there is burgeoning demand for mechanical harvest solutions. Our transdisciplinary studies on mechanical harvest systems for apples have shown that fruit removal efficiency (FRE) with a vibratory system can be improved with precision canopy management. In this study, we evaluated the effect of precision pruning strategies on FRE in two groups (106 and 107, respectively) of randomly selected horizontal branches of ‘Jazz/M.9’ apple trees in a commercial orchard. Fruiting lateral branches were pruned to either shorter than 15 cm (guideline 1, G1) or 23 cm (guideline 2, G2). Harvest tests were conducted using a shake-and-catch harvester prototype developed by Washington State University with a fixed vibrating frequency of 20 Hz and shaking duration of 5 s. FRE for branches treated with G1 was significantly higher (91%) than FRE for branches treated with G2 (81%). We recorded a negative relationship between FRE and lateral shoot length. FRE was up to 98% when shoots were shorter than 5 cm, and FRE was only 56% for shoots of 25 cm or longer. We developed a shoot diameter-to-length index (S-index) to better understand the effect of shoot size on FRE. FRE was as high as 98% when the S-index was greater than 0.15. In addition, mechanically harvested fruit quality was assessed by categorizing the fruit into Extra Fancy, Fancy, and Downgrade fresh market classes based on USDA standards; however, no significant difference was found between the two treated groups. These results suggest that pruning lateral fruiting branches to less than 15 cm or to an S-index greater than 0.03 is required to achieve FRE of 85% with no negative impacts on fruit quality. Keywords: Canopy management, Fresh market fruit, Fruit removal efficiency, Mechanical harvest, Shoot pruning severity.

[EN] A designed lightweight experimental shaker successfully used to collect ornamental oranges has been tested to harvest fresh market citrus. The aim of this study was to evaluate the removal efficiency and operational times of this experimental device compared to an orchard trunk shaker. Three different collecting systems were studied. 'Caracara' citrus trees were tested. Removal efficiency, vibration parameters, fruit and tree damages, and fruit quality were measured. A high-speed camera was used to record operational times and determine cumulative removal percentage over vibration time. The canvases on the ground reduced the severe fruit damages but were not useful to protect against light damages. The experimental shaker produced a higher percentage of slightly damaged oranges. No significant differences in removal efficiency were found between the two harvesting systems. However, removal efficiency using the experimental device could be reduced by 40 percent and working time increase by more than 50 percent when access to the main branches was difficult. In agreement with previous results, the curve representing the branch cumulative removal percentage in time followed a sigmoidal pattern. A model was built showing that during the first 5 s more than 50 percent of the fruits were detached, This research has been fund by the European Agricultural Fund for Rural Development and cofounded by the Ministerio de Agricultura, Pesca y Alimentacion (project GO "Avances tecnologicos para la modernizacion y la sostenibilidad en la produccion de citricos CITRUSTECH").

Reveille Russet (ATX91137-1Ru) is a uniform, medium-early, high yielding, high pack-out, fresh market russet cultivar, with wide adaptability, released by Texas A&M AgriLife Research in 2015. It resulted from a cross of Bannock Russet(♀) and breeding clone A8343–12(♂). Reveille Russet produces attractive, oblong tubers, with medium russeting, white flesh and excellent culinary qualities. It has a lower incidence of internal defects and a higher percentage of marketable tubers in the 170 to 284 g and 284 to 510 g (6 to 10 oz. and 10 to 18 oz.) size classes than Russet Norkotah. Reveille Russet is resistant to hollow heart, second growth and blackspot bruise. It also stores longer and tends to wound-heal to a lighter brown color upon skinning during harvest and/or handling than Russet Norkotah.

Plums, sweet cherry, and sour cherry trees were spaced 4.5 m × 1.5 m to be trained to “Y” and “V”-trellising systems for mechanical harvesting, with a canopy contact harvester, attending to obtain fruits meeting the requirements of the fresh fruit market. The applied trellising systems were compared with the standard central leader system at the same spacing. The most of trellised trees grew less vigorously than the standard trees, and after 3 years of training, the trees were suitable for mechanical harvesting with the harvester designed at the Research Institute of Horticulture in Skierniewice. The trellised trees were able to set as many fruitlets as those grown in the form of central leader and gave a comparable yield, but differences between cultivars were significant. Light interception in the third year after planting was lower for trees of sour cherry and plum growing in the “Y”-20° and “V” in comparison to the trees with central leader. Illumination of trellised canopies at the level of 0.7 and 1.5 m was the most favorable in “V” system when compared to control and “Y” training systems. Cost of construction for the trellising systems of stone fruits calculated per 1 ha was two times higher when compared with the standard system.

Infield pre-sorting is intended to remove processing-grade (inferior) fruit that are not suitable for the fresh market, so that growers can handle sorted apples differentially in postharvest storage and packing to achieve cost savings. To achieve this goal, we developed an apple infield grading and sorting system, in which fruit singulation, rotation, and transportation are achieved by using simple, compact pitch-variable screw conveyors, fruit grading (for size and color) is accomplished with a low-cost imaging system, and fruit sorting is done by using paddle sorters. Experiments were conducted for ‘Red Delicious’ and ‘Golden Delicious’ apples to evaluate the overall performance of the infield grading and sorting system in terms of grading repeatability (i.e., chances of each apple that would be graded into the same quality grade in multiple runs and different lanes), bruising damage, and sorting accuracy (consistency between the imaging-based grading results and destinations). Results showed that the grading repeatability rates of the system were above 90 % and 81 % for intra- and inter-lane grading, respectively. The system achieved above 99 % sorting accuracy for the system throughputs of 7.5, 9.0, and 10.5 fruit s−1, while 100 % of sorted apples were graded Extra Fancy and 55 % or higher of the apples incurred no bruising damage during the grading and sorting process. The infield grading and sorting system is compact and robust in performance, and it can meet commercial infield sorting needs.

Broccoli is a vegetable grown worldwide due to its good nutritional properties. The harvest of this product is done selectively by hand depending on their size and state of maturation for both fresh market and agri-food industry. The final aim of our work is the development of a machine that is able to automatically harvest only those broccoli heads that have the size and ripeness suitable for the agri-food industry, besides discarding those overripe or with diseases. One critical element in such a machine is a vision system that locates and classifies the broccoli heads present in photographic images, to trigger later a cutting module. In this paper, we present an approach to that vision system, based on deep learning techniques. The proposed algorithm, running in a relatively cheap hardware, is able to work in real time, locating broccoli heads in 640 × 480 px digital images, and classifying then into harvestable, immature and wasted classes. Tested with images taken in real conditions, with many heads partially hidden by leaves, the system was able to correctly locate and classify up to 97% of the cases presented in the test set.

The physiological disorder referred to as pressure flattening is a cause of significant economic losses in the storage of Irish potatoes (Solanum tuberosum L.) intended for use in the fresh market. As the flattened area on each tuber becomes larger in diameter or becomes more depressed the USDA quality grade, and therefore the market value of the potatoes is reduced. Experiments were conducted to identify at-harvest which potato lots within and among cultivars were likely to pressure flatten earlier or more severely. The use of an instrumented penetrometer or texture analyzer to measure peak load required for periderm deformation at harvest appears to anticipate correctly the majority of fields from which tubers are more likely to have severe pressure flattening at six months’ storage duration. At-harvest texture analysis appears to segregate varieties according to susceptibility to deformation based on cultivar specific factors that play a role in pressure flattening development during storage. The Pearson correlation coefficient (R2=0.5481) indicates that there is a correlation between tuber texture at harvest and pressure flattened area on the tuber following storage. Testing of tubers from different fields and cultivars as the potatoes are loaded into storage, may allow growers to identify and ship potatoes that are more susceptible before they develop significant pressure flattening.

Fresh market apples are picked manually around the world. To reduce dependence on seasonal labour and minimise harvest costs, shake and catch harvesting methods have been investigated (no commercialised product). During shaking, certain amount of fruits could not be detached primarily due to insufficient level of transferred energy. The primary goal of this study was to investigate the efficiency in detaching fruit from different locations of tree branches in modern trellis-trained trees. A fruit location index was formulated and estimated to identify the location of targeted apples on a branch by considering the geometric dimensions of fruit bearing twig (twig index) and excited branch (branch index). A dynamic test system was developed to measure the response of fruit under certain shaking modes. The weights of twig index and branch index were optimised with maximizing R2 of regression model between fruit acceleration and fruit location index. This study indicated that the fruit location has a critical influence on fruit detachment with shaking. Test fruits (‘Envy’ variety) could generally be detached within 5 s of shaking when fruit acceleration was higher than 5 g, and the corresponding fruit location indices were 0.071, 0.06, and 0.061 in three test frequencies. Harvesting tests showed that over 90% of fruits with location index greater than 0.06 were detached under 20 Hz shaking. Fruit quality assessment was not included in this study. The study provided baseline knowledge and information for improving the fruit canopy management practices to obtain high fruit removal efficiency.

In 2016, Russet Norkotah was the second most widely grown potato variety in the US; however, recent research has identified alternatives with excellent production economics. During 2011–2013, fresh market variety research was conducted in the Columbia Basin of central Washington, a long-season production region. Russet Norkotah was compared to five varieties–Classic Russet, Mountain Gem Russet, Russet Burbank, Targhee Russet, and Teton Russet–and four sub-clonal strains–CO-3, CO-8, TX-278, and TX-296–derived from Russet Norkotah. Each variety was evaluated for early- (104 days between planting and vine kill) and late- (150 days between planting and vine kill) harvest tuber size profile, grade, and yield, grower economic value, susceptibility to blackspot bruise and shatter bruise, emergence, stem and at-harvest tuber numbers, tuber length-to-width ratios, and quality. When harvested early, Classic Russet and Mountain Gem Russet produced 30% and 15% more gross revenue than Russet Norkotah, respectively. All other varieties and Russet Norkotah strains except CO-3 produced as much early-harvest gross revenue as Russet Norkotah. CO-3 early-harvest revenue was close to 50% lower than that of Russet Norkotah. All varieties and Russet Norkotah strains produced significantly greater late-harvest yields and gross returns than Russet Norkotah. Late-harvest gross revenue for Targhee Russet and Mountain Gem Russet was 38% and 34% higher than Russet Norkotah, respectively. Classic Russet, Mountain Gem Russet, Targhee Russet, and Teton Russet had significantly more shatter bruise following the late harvest than Russet Norkotah and all Russet Norkotah strains. Russet Burbank was among the most susceptible to blackspot and Targhee Russet the least, with 32% and 2.1%, respectively. If bruising is mitigated, Mountain Gem Russet, Classic Russet, and Teton Russet may be suitable alternatives to Russet Norkotah and Russet Norkotah strains for both early and late harvests.

Currently, fresh market apples are picked manually around the globe, which has become a challenge due to the decreasing availability of labor and the high associated cost. To reduce harvest cost and dependence on human labor, researchers and growers have been seeking mechanical solutions for decades. However, the high rate of harvest-induced fruit damage has been an obstacle to commercializing these technologies. To achieve a desirable level of fruit quality with mechanical harvesting, a new shake-and-catch system with two catching buffers for reducing fruit impact was developed and evaluated in this study. The system provides localized harvesting by shaking targeted tree limbs and catching the detached fruits directly under the limbs. To test the performance of the catching device, a series of laboratory tests was conducted using an impact recording device. The results showed that the impact force of falling fruit and the number of impacts decreased dramatically when using a catching surface with buffers compared to using a catching surface without buffers. A harvesting test was performed with ‘Jazz‘ apple trees trained to vertical fruiting wall architecture. The system achieved fruit removal efficiencies of 84%, 86%, and 92% for shaking frequencies of 15, 20, and 25 Hz, respectively. The corresponding collection efficiencies were 99%, 98%, and 93%. The system achieved the highest quality grade (Extra Fancy) for 85% of the harvested fruits when the limb was shaken at 15 Hz and fruits were collected using a catching surface tilted at an angle of 25°. With this level of performance of the prototype system, this study showed that the developed shake-and-catch system offers a promising solution for mechanical harvesting of ‘Jazz‘ apples, with potential extension to other apple varieties grown in modern fruiting wall architectures.

Currently, fresh market apples are harvested manually in the U.S. and around the world. Because of increasing labor shortages and costs, there is a critical need for developing mechanical harvesting techniques. Mass harvest using a shake-and-catch system is a potential solution for addressing this issue. Selecting suitable materials that can provide adequate cushioning for apples could help to reduce fruit bruising during mechanical harvesting. To gain an understanding of how cushioning materials can absorb impacts on fruit, an experimental study was conducted to investigate the bruise response of apples to different impact levels. A specially designed pendulum impact platform was used to conduct the tests. Three types of cushioning materials (polyurethane foam) covering an aluminum plate were used as the impact surfaces, and the bare aluminum plate was used as the control surface. Polyurethane foams with the same thickness but different firmness ratings (at 25% deflection) were used to exert impacts on stationary apples sitting freely on a horizontal surface. In this study, seven different impact levels were applied at three impact zones (top, middle, and bottom) of ‘Jazz‘ apples. Impact tests were repeated 50 times for each impact level at each zone. The results showed that no bruising resulted when apples were impacted at ≤22 N with the bare aluminum plate regardless of the impact zone. The non-bruising impact level increased to 95, 160, and 160 N after 12.7 mm thick foam cushions with firmness ratings of 2.1, 4.8, and 9.7 to 11 kPa (foams 1, 2, and 3, respectively) were used to cover the aluminum plate. Based on USDA grades, 100% of the apples maintained Extra Fancy quality at 50, 115, 171, and 180 N when impacted by the bare aluminum plate and by the plate covered with foams 1, 2, and 3, respectively. The tolerable impact levels to maintain 100% of apples within the fresh-market quality threshold were 95, 189, 230, and 232 N, respectively. These results showed that the foams with firmness ratings of 4.8 kPa and 9.7 to 11.0 kPa (foams 2 and 3) provided better cushioning for apples, as the fruit tolerated a substantially higher level of impact compared to using the bare aluminum plate or foam 1. The results also showed that the difference between foams 2 and 3 was very slight, which could indicate that a cushioning material with a firmness rating of 4.8 kPa or higher could provide sufficient cushioning for apples.

Cucumber (Cucumis sativus L.) yield quantity and quality can be improved. Estimates of combining ability are useful in determining breeding value of cucumber lines by suggesting the appropriate use in breeding to generate new hybrids with high yield and quality. The research was conducted to estimate general and specific combining ability and heterosis in seven inbred lines proposed for cucumber breeding according previous research. The highest early yield specific combining ability (SCA) and general combining ability (GCA) were related to lines B10 and B12 and crosses B12 × A0 and B10 × A4. Lines A11 and B12 had the highest positive and negative cull yield GCA and the crosses A0 × B10 and A0 × B12 had the highest negative cull yield SCA. Lines B10, A4, and B12 and crosses B12 × A0, B10 × A11, and B10 × A4 had the highest positive marketable yield GCA and SCA. Lines B10 and A4 and crosses B12 × A0, B10 × A11, and B10 × A4 had the highest positive total yield GCA and SCA. Lines B10, B12, and A11 an...

Citrus melanose, caused by Diaporthe citri, is a major disease of fresh market grapefruit which is controlled primarily by preventive applications of copper fungicides. The goal of this research was to improve melanose control without increasing the total amount of metallic copper utilized. Disease control was assessed in field experiments for 3 years using one, two, three, or four applications of copper fungicides in which the same total amount of metallic copper was applied per season in each program. Melanose was severe in 1995 and 1997, and the four-application schedule provided better control than the one-, two-, or three-application programs. In 1996, disease pressure was low and all programs and fungicides provided equally effective control. Analysis of copper residues on the fruit indicated that loss of protection was attributable more to increase in fruit surface area when fruit were growing rapidly than to removal of copper by weathering. On larger, slower-growing fruit, loss of copper residues was apparently due to both factors. Economic evaluation of improved packouts of fresh market fruit and additional application costs indicated that net returns would be increased by $650 to $1,250 per hectare during years in which melanose was severe when the four-spray program was compared to a single spray.

During summer 2012, symptoms of a new leaf spot disease were observed in several commercial fields in Treviglio (Bergamo, northern Italy) on plants of curly (Cichorium endivia var. crispum) and Bavarian (C. endivia var. latifolium) endive (Asteraceae). This crop is widely grown in the region for fresh market. The first symptoms on leaves of affected plants consisted of small (1 mm) black-brown spots of irregular shape, later coalescing into larger spots, up to 10 to 15 mm diameter. Eventually, spots were surrounded by a yellow halo. Particularly, affected tissues rotted quickly under high moisture. Disease severity was greatest at 75 to 90% RH and air temperature between 23 and 30°C, where affected tissues rotted quickly. This disease resulted in severe production losses. On one farm in particular, three different fields totaling 2 ha, 5 to 13% of the plants were affected. Diseased tissue was excised, immersed in a solution containing 1% sodium hypochlorite for 60 s, rinsed in water, then placed on potato dextrose agar (PDA) medium, containing 25 mg/liter of streptomycin sulphate. After 5 days, a fungus developed producing a whitish-orange mycelium when incubated under 12 h/day of fluorescent light at 23°C. The isolates obtained were purified on PDA. On this medium, they produced hyaline elliptical and ovoid conidia, rarely septate, measuring 5.0 to 9.0 × 1.7 to 3.9 (average 6.0 × 2.9) μm. Conidia were born on phialides, single, clavate, and 2.8 × 1.4 μm. Such characteristics are typical of Plectosphaerella sp. (1,2). The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 (3) and sequenced. BLAST analysis of the 530-bp segment obtained from C. endivia var. crispum isolate PLC28 and of the 527-bp from C. endivia var. latifolium isolate PLC 30, respectively, showed 99% similarity with the sequence of Plectosphaerella cucumerina (anamorph Plectosporium tabacinum), GenBank EU5945566. The nucleotide sequences of isolates PLC 28 and PLC 30 have been assigned the GenBank accession numbers KC293994 and KC293993, respectively. To confirm pathogenicity, tests were conducted on 30-day-old C. endivia plants. C. endivia var. crispum cv Myrna and C. endivia var. latifolium cv. Sardana plants, grown in 2-liter pots (1 plant per pot, 10 plants per treatment) were inoculated by spraying a 106 CFU/ml conidial suspension of the two isolates of P. cucumerina, prepared from 10-day-old cultures, grown on PDA. Inoculated plants were maintained in a growth chamber at 25 ± 1°C and 90% RH for 5 days. Non-inoculated plants, only sprayed with water, served as controls. All plants inoculated with the two isolates, showed typical leaf spots 7 days after the artificial inoculation, similar to those observed in the field. Later, spots enlarged and leaves rotted. Non-inoculated plants remained healthy. P. cucumerina was reisolated from inoculated plants. The pathogenicity tests were conducted twice with identical results. This is, to our knowledge, the first report of P. cucumerina on endive n Italy, as well as worldwide. Due to the importance of the crop in Italy, this disease can cause serious economic losses. References: (1) A. Carlucci et al. Persoonia 28:34, 2012. (2) M. E. Palm et al. Mycologia 87:397, 1995. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

Improved blueberry mechanical harvesting (MH) equipment that maintains fresh market quality are needed due to rising costs and decreasing availability of laborers for harvesting by hand. In 2017, a modified over-the-row (OTR) blueberry harvester with experimental catch surfaces and plates designed to reduce fruit bruising was evaluated. The catch surfaces were made of neoprene (soft catch surface, SCS) or canvas (hard catch surface, HCS) and compared to hand-picked fruit (control). Early- and early/mid-season &lsquo, Duke&rsquo, and &lsquo, Draper&rsquo, respectively, were evaluated in Oregon, while late-season &lsquo, Elliott&rsquo, Aurora&rsquo, were evaluated in Washington. Harvested berries were run through commercial packing lines with fresh pack out recorded and bruise incidence or fresh fruit quality evaluated during various lengths of cold storage. The fresh pack out for &lsquo, were 83.5% and 73.2%, respectively, and no difference was noted between SCS and HCS. &lsquo, fruit firmness was highest among MH berries with SCS, but firmness decreased in storage after one week. Firmness was highest among hand harvested &lsquo, followed by MH with SCS. For &lsquo, fruit firmness was the same across harvesting methods. &lsquo, exhibited more bruising than &lsquo, but bruise ratings and the incidence of bruising at &le, 10% and &le, 20% were similar between hand and MH &lsquo, with SCS after 24 h of harvest. &lsquo, berries had similar bruise ratings after 24 h between hand harvesting and MH with SCS, while &lsquo, showed more bruise damage by MH with both SCS and HCS than hand harvested fruit. Although our studies showed slightly lower fresh market blueberry pack outs, loss of firmness, and increased bruise damage in fruit harvested by the experimental MH system compared to hand harvested fruit, higher quality was achieved using SCS compared to HCS. We demonstrated that improved fresh market quality in northern highbush blueberry is achievable by using modified OTR harvesters with SCS and fruit removal by either hand-held pneumatic shakers or rotary drum shakers.

Harvest is one of the most challenging production tasks in apple production. It is a labor-intensive operation, and mechanization has been slow in development for a myriad of reasons. With increasing labor costs and decreasing availability of harvest employees, researchers have been focusing on mechanical apple harvest technologies. Studies on semi-automatic harvesters, harvest robots, and harvest-assist platforms target development of mechanical apple harvesting. Semi-automatic harvesters for fresh market apples have not been commercialized due to unacceptably high incidence of apple bruising. Harvest robots have not been commercialized due to their high costs and low efficiency. Apple harvest-assist platforms are a technology that has the potential to be more widely commercialized based on the current research.

The U.S. apple industry is facing difficulties because apple production costs have been continuously increasing. Three factors contribute to this situation: close dependence on a large seasonal workforce, increasing labor costs, and decreasing availability of agricultural employees. Apple harvest is the most labor-intensive operation during the production season. An economical apple harvest-assist unit prototype targeting fresh market apples was designed and field tested, aimed at increasing harvest efficiency, reducing harvest-related injuries, and increasing the potential labor pool through decreased working strength requirements. This harvest-assist unit focused on apples in the top of the canopy, which typically require use of ladders for conventional harvest. The unit was field tested for two years, with the first year focusing on identifying the components that caused apple bruising, and the second year focusing on identifying the performance of this unit. After being identified as the major component causing apple bruising, the distributor (a rotating disk used to distribute apples evenly in the bin) was improved and then tested in the second-year experiment. Apple downgrade incidence was reduced to 0% using an optimized distributor rotation speed of 28 rpm. For the apples located in the upper portion of the trees, the harvest-assist unit increased apple harvest efficiency (apples picked per second) by 95% compared with the conventional apple harvest method using ladders.

Field experiments were conducted to determine the critical period for weed control (CPWC) in nongrafted ‘Amelia’ and Amelia grafted onto ‘Maxifort’ tomato rootstock grown in plasticulture. The establishment treatments (EST) consisted of two seedlings each of common purslane, large crabgrass, and yellow nutsedge transplanted at 1, 2, 3, 4, 5, 6, and 12 wk after tomato transplanting (WAT) and remained until tomato harvest to simulate weeds emerging at different times. The removal treatments (REM) consisted of the same weeds transplanted on the day of tomato transplanting and removed at 2, 3, 4, 5, 6, 8, and 12 WAT to simulate weeds controlled at different times. The beginning and end of the CPWC, based on a 5% yield loss of marketable tomato, was determined by fitting log-logistic and Gompertz models to the relative yield data representing REM and EST, respectively. In both grafted and nongrafted tomato, plant aboveground dry biomass increased as establishment of weeds was delayed and tomato plant biomass decreased when removal of weeds was delayed. For a given time of weed removal and establishment, grafted tomato plants produced higher biomass than nongrafted. The delay in establishment and removal of weeds resulted in weed biomass decrease and increase of the same magnitude, respectively, regardless of transplant type. The predicted CPWC was from 2.2 to 4.5 WAT in grafted tomato and from 3.3 to 5.8 WAT in nongrafted tomato. The length (2.3 or 2.5 wk) of the CPWC in fresh market tomato was not affected by grafting; however, the CPWC management began and ended 1 wk earlier in grafted tomato than in nongrafted tomato.

Tomato is one of the most economically important vegetable crops in the world. Objective of this study was to determine the genetic diversity of tomato based on its horticultural traits. Seventy-one tomato genotypes were planted and grown in two replications with randomized complete block design for two years. Diversity analysis produced six distinct clusters based on average-linkage method. Five principal components (PC) explained more than 92% of the phenotypic variation. Clusters produced in this analysis can be of importance for breeding programs developing specific fruit types based on consumer’s demand.

An online choice experiment was conducted to investigate U.S. consumer preferences for attributes of fresh market strawberry fruit. Using a latent class logit model, three different groups of consumers are identified: “Balanced Consumers,” “Experience Attribute Sensitive Consumers,” and “Search Attribute Sensitive Consumers.” This information on consumer segmentation can help the fresh market strawberry industry identify target markets, and provides valuable information to breeders, growers, and retailers to prioritize fruit attributes in their breeding, growing, or product sourcing decisions.

Fresh market spinach has one primary herbicide, cycloate, which does not control all weeds. Previous studies demonstrated that cycloate PRE followed by (fb) phenmedipham at the four-leaf spinach stage is a safe and effective treatment. However, this treatment is not useful for the main growing season of fresh spinach due to its short crop cycle and the 21-d preharvest interval requirement of phenmedipham. This study evaluates the potential to use the combination of cycloate PRE fb phenmedipham on two-leaf spinach. Greenhouse and field studies were conducted in 2014 using three spinach varieties with low (‘Nordic' and ‘Sardinia') and high (‘Regal') tolerance to phenmedipham. Greenhouse studies revealed that phenmedipham at 90 g ai ha−1was safe to Regal when applied at the two-leaf stage. Sardinia was more susceptible to phenmedipham injury under high (310 W m−2) light conditions than low (258 W m−2) light conditions. Impact of time of day on phenmedipham safety was evaluated in the field: day-long exposure to high light intensity following morning applications vs. evening applications fb exposure to low light intensity. Injury estimations taken 3 d after treatment (DAT) were lower for evening than for morning applications. Nonetheless, injury 11 DAT and spinach yield evaluations found no differences between morning and evening applications. Subsequently, cycloate (1,700 g ha−1) PRE fb phenmedipham (90 and 180 g ha−1) applied in the evening at the two-leaf stage was evaluated. A reference treatment was cycloate PRE fb phenmedipham (270 g ha−1) at the four-leaf stage. Treatments with cycloate fb two-leaf phenmedipham at 90 and 180 g ha−1were safe to spinach and improved weed control compared to cycloate alone. Cycloate fb 180 g ha−1phenmedipham at the two-leaf stage reduced weed biomass by 88% compared to cycloate alone. This level of weed control was similar to the reference treatment. Results here show that phenmedipham applied at the two-leaf stage is safe to fresh market spinach and it has the potential to be used during most of the fresh spinach growing season.

The few available herbicides for fresh market spinach do not provide adequate weed control, and there is need for additional herbicide tools. Phenmedipham is registered for use in processing spinach but not in fresh spinach, because of potential injury and the short interval between application and spinach harvest. The objectives of this study were to evaluate the tolerance level of fresh spinach varieties to phenmedipham and evaluate the impact of light intensity on tolerance of spinach to phenmedipham. In the greenhouse, nine spinach varieties were treated with phenmedipham (0.55 kg ai ha−1). Spinach varieties exhibited a wide range of tolerance, and dry weights of treated plants ranged from 40 to 78% compared to the nontreated control. Based on the phenmedipham tolerance screen, two varieties with low (Nordic) and high (Regal) tolerance to phenmedipham were treated, then exposed to half (shaded) and full (nonshaded) sunlight. Nonshaded Nordic treated with phenmedipham had 65% lower dry weight compared to similarly treated plants grown under shade, suggesting that spinach tolerance to phenmedipham was mainly affected by light intensity. Measurements of electron transfer intensity in photosystem II also showed tolerance to phenmedipham that varied among spinach varieties and light intensity. The maximum values of electron transfer in photosystem II of Regal treated with phenmedipham were higher than those of similarly treated Nordic. In the field, phenmedipham was applied under varied light and temperature conditions. The impact of light intensity on yield of treated spinach was greater than the impact of temperature. Phenmedipham applied under high light conditions was more injurious than when applied under low light conditions. Results from this study can contribute to successful integration of phenmedipham into currently used fresh spinach weed management, which in turn can allow more efficient production of this crop.

Mountain Gem Russet is a potato variety notable for having both high early and full-season yields of oblong-long, medium-russeted tubers with higher protein content than those of standard potato varieties. Mountain Gem Russet has greater resistance to soft rot, tuber late blight, growth cracks and second growth than Russet Burbank. Mountain Gem Russet produced greater total and U.S. No. 1 yields than Ranger Russet and Russet Norkotah in early-season trials conducted in Idaho, Oregon and Washington over a 3 year period. In full-season trials conducted in five western states over a 4 year period, average total and U.S. No. 1 yields for Mountain Gem Russet were almost always higher than Ranger Russet and Russet Burbank, with specific gravities averaging between these two standard cultivars. It maintains acceptable reducing sugar concentrations and fry quality when stored at 8.9 °C and has displayed a high level of fry color uniformity from tuber stem to bud end providing good potential for early processing. High fresh merit ratings and taste panel sensory scores comparable to Russet Burbank indicate good fresh market potential for Mountain Gem Russet. It was released in 2015 by the USDA-ARS and the Agricultural Experiment Stations of Idaho, Oregon, and Washington, and is a product of the Pacific Northwest Potato Variety (Tri-State) Development Program.

This article reviews the research and development progress of mechanical harvest technologies for fresh market apples over the past decades with a focus on the predominant technologies of shake-and-catch, robots, and harvest-assist platform methods. In addition, based on the review it points out the bottlenecks and future trends of these three technology categories. Major progress in the shake-and-catch method is related to theoretical studies on the effective removal of apples and catching mechanisms to minimize bruising. The unacceptable bruising conditions hinder the shake-and-catch method from commercial application. Two startups of apple harvesting robots are in the stage of commercializing their products based on vacuum and three-finger end-effectors, respectively. Economic benefits, as well as technology reliability and robustness of both robots, are pending for validation before they are on the market. In addition, a key obstacle faced by both robots before commercial use is to find a solution to pick apples grown in clusters. Harvest-assist platforms are gradually adopted by apple growers, but at a very low rate due to their doubts on economic benefits. Validation of harvest-assist platforms’ economic benefits and incorporation with more functions (e.g., sorting) would enhance their adoption. With the rapid development of sensing and automation technologies, such as novel sensors, embedded systems, and machine learning algorithms, and the progress in new tree canopy structures that are friendlier for fruit visibility and accessibility, it is believed the robots for fresh market apple harvest would be realized and commercialized in the near future. Currently, more efforts should be invested in analyzing and validating the economic benefits of harvest-assist platforms, as well as adding more functions to the harvest-assist platforms, to increase their application rate for the benefit of the apple industry.

In 2016, severe pod distortion and leaf mottling in green beans (Phaseolus vulgaris) for the fresh market (Figs. 1-2; isolate Q5288) occurred in the Fassifern production area in south Queensland, Australia. Disease incidence in crops was…

Background Accumulation and stability of tomato lycopene markedly depends on the cultivar, plant growing and storage conditions. To estimate lycopene in open-field cultivated processing and fresh market tomatoes, we used a calibrated spectral reflectance portable sensor. Results Lycopene accumulation in fruits attached to the plant, starting from the Green ripening stage, followed a sigmoidal function. It was faster and reached higher levels in processing (cv. Calista) than fresh market (cv. Volna) tomatoes (90 and 62 mg kg-1 fresh weight, respectively). During storage at 12, 20 and 25 °C, Red tomatoes retained about 90% of harvest lycopene for three weeks. Pink tomatoes increased lycopene during the first week of storage, but never reached the lycopene values of Red tomatoes ripened on the vine. Storability at 12 °C retaining the highest quality in red tomatoes was limited to 14 and 7 days for Calista and Volna cultivars, respectively. Conclusion Significant differences in lycopene accumulation and stability between processing and fresh market tomatoes were established by examining with time the very same fruits by a non-destructive optical tool. It can be useful in agronomical and post-harvest physiological studies and can be of interest for producers oriented to the niche nutraceutical market. © 2018 Society of Chemical Industry.

Peter Wilcox is a new, medium-maturing, purple-skinned, yellow-fleshed potato cultivar for the fresh market. Peter Wilcox also produces light-colored chips, although it is being released primarily as a fresh market potato because of its skin and flesh colors. Tubers are attractive, smooth, with dark purple-skin, oblong shape and moderate size. Yellow-flesh intensity is equal to or slightly darker than Yukon Gold. Marketable yields of Peter Wilcox have averaged 78–97 % of various standard cultivars in multiple years of testing. Specific gravity of Peter Wilcox was lower than Yukon Gold, but higher than standard red-skin cultivars it was compared to at numerous locations. Hollow heart and internal heat necrosis in Peter Wilcox tubers have generally been less than in standard cultivars; however, slight purple-streaks in the flesh have occasionally been reported in Maine. Peter Wilcox is moderately resistant to powdery scab. It is susceptible to late blight, early blight, potato virus Y, Verticillium wilt, and common scab. Peter Wilcox is a publicly released cultivar.