fresh ‘Anjou’ pear quality. This is an important research question for the pear industry because the potential of increasing commercial viability is dependent on the industry's capability of supplying consistent and optimal quality. Hence, information on
Fruit cullage due to postharvest-expressed diseases and disorders of `Anjou' pear amounted to $1.4–2.4 million annually to northwest growers in 1991–93. Fungal diseases, including Penicillium spp., Botrytis cinerea, and Mucor spp. accounted for the majority of losses. Scald, skin speckling, and scuffing are listed by packinghouse managers as major contributing disorders. A 3-year study has examined reasons for losses and methods to reduce losses through improved postharvest handling. Maturity at harvest, fruit nutrient status, time of packing, temperature management, and improved handling practices provide the basis for cullage.
Superficial scald is a major physiological disorder of ‘Anjou’ pears that occurs after ≥3 or 5 months of cold storage in air or controlled atmosphere (CA), respectively ( Hansen and Mellenthin, 1979 ). The commercial air storage target for ‘Anjou
In the United States, ‘Anjou’ ( Pyrus communis L. ‘Anjou’) winter pear production occurs solely in the Pacific northwestern states of Oregon and Washington. The annual North American production of ‘Anjou’ pear is 11.3 million boxes (20 kg
expected that metabolic differences may reflect elements of light interception, microclimate, fruit development, and ripeness. Materials and Methods Fruit source, ripening assessment, and postharvest treatment. ‘d’Anjou’ pear fruit were harvested on 27 Sept
‘d’Anjou’ pears can develop the peel disorder superficial scald (scald) ( Chen, 2016 ), and this defect can be prevented by 1-MCP application after harvest ( Argenta et al., 2003 ; Calvo, 2003 ; Chen and Spotts, 2006 ). Although 1-MCP treatment
Abstract
Alfalfa greening, (green stain, green mottle, or superficial cork) is a physiological disorder of ‘Anjou’ pear fruit, Pyrus communis L. This disorder is characterized by green streaks, blotches, and specks on the skin occurring most frequently at the stem end; it may also extend to the calyx end where superficial cork is also frequently present. Mineral analysis of the peel and whole fruit of alfalfa greening-affected fruit indicated that the disorder was associated with higher nitrogen, potassium, and phosphorus content but lower calcium levels than normal fruit.
important regions of the HRV to determine if reconsideration of a specimen label solely for ‘Anjou’ pear was warranted. Materials and Methods Expt. 1 (2010–11). Trials evaluating different rates and timings of P-Ca on vegetative and reproductive growth of
Several characteristics of amylases involved in starch degradation were studied in extracts from immature (30 days before harvest) `d'Anjou' pears (Pyrus communis L.). Enzyme activity was not detected until after at least 60 minutes of incubation in frozen or lyophilized tissues. Activity increased significantly after 90 minutes and increased linearly after 2 to 12 hours of incubation. Activity was greater, however, in frozen than in lyophilized tissues. Three buffers (acetate, tris-HCl, and imidazole-HCl) were used at a range of pH levels (4.6-8.2) to ascertain the optimum assay system. Highest specific activity was recorded with acetate buffer at pH 5.6. The Km value in this system was 1.43 × 10-3g·ml-1. Specific activity increased as Ca concentration in the reaction mixture increased from 1 to 15 mm CaCl2 but did not change as Ca concentration increased from 15 to 25 mm CaCl2. The `d'Anjou' pear amylases were purified 5.7-fold using ammonium sulfate fractionation.
Relationships between mineral content and corkspot in `Anjou' pears (Pyrus communis) were evaluated in 1985 and 1986. Although there were no significant relationships between mean preharvest fruit mineraI content and corkspot incidence, the postharvest mineral concentrations of corkspotted and normal fruit were markedly different. Corkspotted and normal pear fruit had different Ca and N : Ca ratios in all types of subsamples (peels, opposing tangential slices with peels, opposing tangential slices without peels, cortical tissue plugs from the area next to the core, cortical tissue plugs from the area just inside of the peel, and the cores including seed), based on either dry or fresh weight. The dry-weight basis also revealed differences in Mg concentrations in both years and in B and K concentrations in 1986. Peel concentrations correlated with other tissues and were the easiest subsample to process. Corkspot was absent in either year, with a peel N: Ca ratio below 6.3. A computer model used mean Ca concentrations and standard deviations to estimate the percentage of pears in each orchard that were less than a given threshold level. When the overall average percentage of arbitrarily defined low-Ca pears was small (< 10%), it was difficult to predict the actual number of low-Ca pears from mean Ca concentrations. Therefore, it may not be realistic to expect strong correlations between mean Ca concentration and the incidence of disorders commonly encountered in Hood River, Ore. This situation occurred even when Ca concentrations of disordered and normal pears clearly differed.