durometer to measure husk softening of black walnuts. However, there is a paucity of information on the relationships between husk softening, harvest date, and kernel size and color for black walnut cultivars. Therefore, the objectives of this study were to
Scott A. Brawner and Michele R. Warmund
Troy A. Larsen* and Christopher S. Cramer
Current onion varieties that are grown in New Mexico were developed for hand harvesting and not for mechanical harvesting. In order for onion production in New Mexico to remain a viable commodity, firmer onion varieties need to be developed for mechanical harvesting. In this study, bulb firmness of onions was examined in short and intermediate-day onion entries comparing a qualitative `finger pressure' method with a digital FFF-series durometer. After harvesting and curing of the onion bulbs, dry outer scales were removed before durometer measurements were taken at two perpendicular points on the vertical center axis of the bulb. Following the durometer measurements, bulb firmness was rated by `finger pressure' applied to multiple points on the vertical center axis. For intermediate and late-maturing entries, durometer measurements and firmness rating were positively correlated in a strong fashion (r = 0.77 to 0.87). Early maturing entries, NMSU 02-25 and NMSU 02-03 both had high durometer averages and firmness ratings. `NuMex Crimson' and `NuMex Crispy' had the highest durometer averages and firmness ratings among intermediate maturing entries while `NuMex Solano' and NMSU 01-06 had the highest among late maturing entries. From our results, the durometer can be useful in providing a quantifiable measure of bulb firmness.
Scott A. Brawner, Michele R. Warmund, and Mark V. Coggeshall
A study was conducted to: 1) evaluate the use of a durometer for determining husk softening and the date of black walnut harvest and 2) elucidate the relationship between husk hardness, kernel color and weight, and date of harvest. Thirty nuts were randomly collected weekly from mature `Sparrow', `Emma K', `Kwik Krop', and `Football' trees from 1 Sept. to 13 Oct. 2004. Husk denting, hardness, and color measurements were recorded immediately after harvest. Husk denting is the method commonly used by growers to determine the optimum time of harvest. Nuts were then hulled within 48 hours and the in-shell fresh weights were recorded. After drying under natural conditions for 5 weeks, kernel color and weights were assessed. On 15 Sept., 99% of `Sparrow' husks dented with a mean durometer value of 54. On 29 Sept., ≥99% of `Emma K' and `Kwik Krop' husks dented with mean durometer values of 63 and 68, respectively. By 13 Oct., 80% of `Football' husks dented with a mean durometer value of 74. From the first harvest date to the time of maximum denting, kernel weight and color (L*, hue values) of `Sparrow' and `Emma K' generally increased. The L* and hue values of `Kwik Krop' were inversely related to increased kernel weight over time. Kernel color of `Football' remained relatively constant as kernel weight increased over time.
Troy A. Larsen* and Christopher S. Cramer
New Mexico onion production will begin using mechanical harvesters in the near future in order to stay competitive in today's market. Past onion breeding objectives have focused on improving onions for hand harvesting instead of mechanical harvesting. Our breeding program is starting to evaluate germplasm for bulb firmness. The objectives of this study were to evaluate hybrid lines for their bulb firmness, to compare two methods of measuring bulb firmness, and to compare bulb firmness using two different production schemes. Bulb firmness of spring-transplanted and spring-seeded intermediate-day hybrid breeding lines was measured using a digital FFF-series durometer and a subjective rating of firmness achieved by squeezing bulbs. Bulbs were rated on a scale of 1 (soft) to 9 (hard). In general, these hybrid lines produced very firm to hard onions whether the lines were transplanted or direct-seeded. Bulb firmness of these lines measured with the durometer was greater when the lines were direct-seeded (74.9) than when transplanted (73.5). Conversely, when firmness was measured with our subjective rating, transplanted onions exhibited slightly greater firmness (8.9) than direct-seeded onions (8.8). For both transplanted and direct-seeded onions, durometer readings were weakly correlated in a positive fashion with our subjective rating. In general, durometer readings gave a greater spread in firmness measurements with a range of 69.6 to 77.8 in firmness values. Subjective ratings of bulb firmness ranged from 8.5 to 9.0. Depending on the firmness of evaluated breeding lines, our subjective rating system should be adjusted to better distinguish firmness differences between bulbs.
Frank Kappel, Bob Fisher-Fleming, and Eugene Hogue
The relationship between the objective assessment of analytical measures of sweet cherry (Prunus avium L.) fruit quality and the corresponding sensory panel rating was studied. The optimum size, based on average fruit weight, for sweet cherries was 11 to 12 g. A nine-row or 29- to 30-mm-diameter sweet cherry would be the equivalent industry standard. When two separate panels were conducted with overlapping samples, panelists had similar results for optimum fruit size. The optimum color is represented by the #6 color chip of the prototype of the Centre Technique Interprofessionnel des Fruits et Légumes (CTIFL) scale (#5 in new commercial CTIFL chart). A fruit firmness between 70 and 75 using a Shore Instrument durometer was considered optimum. Minimum soluble solids concentration (SSC) for sweet cherries was between 17% and 19% and optimum pH of the juice was 3.8. The optimum sweet–sour balance was between 1.5 and 2 (SSC/ml NaOH).
Mark V. Coggeshall
husk softness on kernel color for multiple cultivars, Warmund and Coggeshall (2006) correlated durometer data, which evaluated husk softness (elasticity), with kernel color using a handheld spectrophotometer for five black walnut cultivars harvested
Nihad Alsmairat, Carolina Contreras, James Hancock, Pete Callow, and Randolph Beaudry
the four replicates. Fruit firmness was determined as resistance to deformation using a durometer (Type 00; Shore Instruments, Jamaica, NY) fitted with a 2.4-mm diameter hemispherical probe and imparting a force of 0.49 N (50 g-force) per millimeter
Louise Ferguson and Sergio Castro Garcia
of durometers of two types: type A for softer materials and type D for harder materials ( Wikipedia, 2014 ). Shore 60A padding has roughly the same rubber parameters as car tire tread. Second, there is a strongly positive relationship between the