., 1980 ); although some exceptions exist ( Clarke, 1990 ; Judd et al., 1989 ), they appear to be tolerated statistically ( Zhang and Robson, 2002 ). Although fruit weight distributions are frequently reported in the literature, fruit firmness
Kareen Stanich, Margaret Cliff, and Cheryl Hampson
I. Lustig and Z. Bernstein
The firmness tester for juicy fruit measures firmness by the compression of the fruit between two parallel surfaces with a measured force until a given applanation area is reached. An improved hydrostatic measuring head for this instrument is described that allows the direct determination of this area instead of the measurement of its diameter in the optical head formerly used. The firmness index is defined as the applied force per unit applanation area. Examples of firmness measurements of Prunus avium L., Vitis vinifera L., and Carica papaya L. are given.
T. J. Facteau, K. E. Rowe, and N. E. Chestnut
Multiple applications (1-3) of 10 and 50 ppm GA3 to ‘Bing’ and ‘Lambert’ (Prunus avium L.) sweet cherries increased fruit firmness and weight, and delayed harvest. Firmness was positively related to dose of GA3 (number of applications × concentration), soluble solids (SS), and In leaf/fruit ratio. GA3 interacted with SS so that the effect of GA3 dose on firmness was increased at higher SS levels. Fruit coloring was delayed by GA3. Chemical name used: gibberellic acid (GA3).
Alicia L. Rihn, Ariana Torres, Susan S. Barton, Bridget K. Behe, and Hayk Khachatryan
, and maintenance firms) as well as production firms (e.g., wholesale nursery, greenhouse, and turfgrass sod producers), and wholesale and retail distribution firms such as garden centers, home stores, mass merchandisers with lawn/garden departments
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.
Claudia Moggia, Yeldo Valdés, Alejandra Arancibia, Marcelo Valdés, Catalina Radrigan, Gloria Icaza, Randolph Beaudry, and Gustavo A. Lobos
physiological firmness loss ( Paniagua et al., 2013 ). Although firmness can vary widely among cultivars ( Cappai et al., 2018 ), it is commonly used to estimate perishability (postharvest potential) of a given lot ( Lobos et al., 2018 ). Instruments to assess
Donna A. Marshall, James M. Spiers, and Stephen J. Stringer
. Factors contributing to splitting in cherries include cultivar differences, water temperature, period of wetting, soluble solids, fruit firmness and turgor, and elasticity of the skin ( Ackley and Krueger, 1980 ; Bullock, 1952 ; Davenport et al., 1972a
Ariana Torres, Susan S. Barton, and Bridget K. Behe
The United States environmental horticulture industry, or green industry, comprises wholesale nursery, greenhouse, and turfgrass sod producers; landscape design, installation and maintenance firms; as well as wholesale and retail distribution firms
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.
Maude Lachapelle, Gaétan Bourgeois, and Jennifer R. DeEll
Firmness is the main attribute that gives an indication of fruit texture and it is often used by producers to evaluate harvest date ( Trillot and Tillard, 2002 ). This quality index can be influenced by many preharvest factors such as season