Search Results

You are looking at 11 - 20 of 75 items for

  • Author or Editor: L. L. Morris x
Clear All Modify Search
Open access cc by nc nd

D. L. Cawthon and J. R. Morris

Abstract

Fruits were collected on weekly intervals in 1980, beginning at fruit set (ovary shatter) and continuing through harvest. Additional samples collected at harvest in 1980 and veraison in 1981 were sorted into preveraison green, postveraison green, and ripening categories. Seed number per berry was directly related to accumulation of 14C-photosynthate, fresh weight, and dry weight. Seed number had little relationship with berry content of indoleacetic acid (IAA), abscisic acid (ABA) or percentage of acidity. Percentage of soluble solids was not affected by seed number prior to veraison, but after veraison, percentage of soluble solids and intensity of juice color were inversely related to seed number. Nonripe fruit at the time of harvest had fewer seeds per berry, and fruit containing an immature seed did not accumulate ABA or enter veraison. IAA levels were similar in ripening and nonripening fruit. IAA declined to basal levels by about 55 days after peak bloom. ABA began to increase after 65 days from peak bloom and berry changes associated with veraison occurred after 72 days.

Open access cc by nc nd

J. R. Morris and D. L. Cawthon

Abstract

Single and split applications of (2-chloroethyl)phosphonic acid (ethephon) at different concentrations to ‘Concord’ grapes(Vitis labrusca L.)did not influence maturation. When ethephon was applied 8 days prior to harvest, abscission was enhanced and postharvest alcohol accumulation was reduced when fruit was shaken from the vine and held at 30°C for up to 24 hours.

Open access cc by nc nd

J. R. Morris and D. L. Cawthon

Abstract

A site was prepared with 2 distinctly different soil depths and a vineyard of ‘Concord’ grapes (Vitis labrusca L.) was established with in-row spacings of 1.52, 1.83, 2.13, 2.44, and 3.05 m. Wider in-row vine spacings resulted in increased vine yields on deeper soils to the point that yields per meter of cordon and per hectare were not reduced; but yield per meter of cordon and per hectare was reduced on the shallow soil when in row vine spacings exceeded 2.44 m. There were few effects on juice quality from either soil depths or in-row vine spacings.

Open access cc by nc nd

J. R. Morris and D. L. Cawthon

Abstract

Firm-fruited strawberries (Fragaria × ananassa Duch.) for processing can be mechanically harvested, properly handled and then held for up to 48 hours at 24°C for 7 days at 1.7° without excessive quality loss. High mold count and a reduction in other quality attributes occur after 96 hours at 24°. Ripe fruit held for 48 hours at 24° and then processed was acceptable to a sensory panel. The effects of overwrapping appeared to be limited to quality changes associated with dessication. Benomyl treatment had a suppressing effect on mold count and reduced loss of soluble solids.

Open access cc by nc nd

Dennis P. Murr and Leonard L. Morris

Abstract

Mushrooms [Agaricus bisporus, (Lange) Sing.] stored at 10° and 20°C showed a sigmoid pattern of growth while at 0°C growth was retarded. The postharvest growth exhibited at 10° and 20°C could be related to a decrease in free a-amino N while at 0°C there was a significant increase in the level of free a-amino N during storage. Protease activity in the tissue increased at all 3 temperatures. It is suggested that postharvest maturation of mushrooms is supported by utilization of low molecular weight nitrogenous compounds formed through increased protein degradation. Mushrooms stored at 20°C toughened and matured faster than those stored at 10° or 0°C. Increases in discoloration during storage appeared to be correlated with decreases in total phenols and with increases in o-diphenol oxidase (o-DPO) activity. The relationship of these biochemical changes to postharvest maturation of mushrooms is discussed.

Open access cc by nc nd

Dennis P. Murr and Leonard L. Morris

Abstract

Controlled atmosphere (CA) storage prolonged the shelf life of mushrooms (Agaricus bisporus, [Lange] Sing.) if the O2 concentration was 9% or the CO2 concentration was 25 or 50%. Concentrations of 2 to 10% O2 stimulated pileus expansion and stipe elongation with maximal stimulation of growth occurring at 5% O2. Levels of CO2 above 5% markedly inhibited growth, even after air was substituted for the CO2 treatment. Five percent CO2 stimulated stipe elongation and suppressed pileus expansion. Protein degradation, as indicated by protease activity and the level of a-amino N in the tissue, increased during postharvest maturation of mushrooms. As in starving bacteria, it is suggested that the main physiological function of proteolysis in the postharvest maturation of mushrooms is as a source of C and N.

Open access cc by nc nd

N. L. Wade and S. C. Morris

Abstract

Fruit of muskmelon (Cucumis melo L.) were treated with 0–104 mg/liter of the fungicides: benomyl (methyl-1-[butylcarbamoyl]-2-benzimidazole carbamate); etaconazole (l-{[2-(2,4-dichlorophenyl)-4-ethyl-1,3-dioxolan-2-yl]-methyl}-1 H-1,2,4-triazole); fenapanil (1-butyl-1-phenyl-1 H-imidazole-1-propanenitrile); imazalil (1-[2-allyloxyl-2-(2,4-dichlorophenyl)ethyl]imidazole); and prochloraz (l-{N-propyl-N-[2-(2,4,6-trich-lorophenoxy) ethyl]}carbamoyliinidazole). Damage from Fusarium rots, Geotrichum and Rhizopus soft rots, and Alternaria surface blemish was assessed. Fenapanil, imazalil, and prochloraz had the most useful range of fungicidal activities. Prochloraz was the most efficacious fungicide tested, expressed as disease control per unit concentration of active ingredient.

Open access cc by nc nd

Adel A. Kader and Leonard L. Morris

Abstract

A reflectance spectrophotometer (Agtron E5-W) was found to be a useful laboratory tool for nondestructive determination of tomato fruit color as an indicator of ripeness classes and changes in ripeness in postharvest studies. Values obtained represent the average green and red color hues of the whole fruit which is rotated dueing the measurement.

Free access

D.A. Devitt, R.L. Morris, and L.K. Fenstermaker

We investigated foliar damage to five landscape species sprinkler irrigated with either reuse water or one of five synthesized saline waters that contained elevated single salts mixed with Colorado River water, all having similar electrical conductivities. The experiment allowed us to compare the impact of elevated concentrations of Na, Mg, Ca, Cl, and SO4 on an index of visual damage (IVD), tissue ion concentrations, and spectral reflectance. Waters containing elevated concentrations of MgCl2 or NaCl caused greater foliar damage than did MgSO4, Na2SO4, CaSO4, or reuse water, as recorded in higher IVD values (p < 0.05). Privet and elm were damaged to a greater extent (higher IVD values) than were desert willow, guava and laurel (p < 0.05). Higher IVD values were recorded for all species irrigated with the MgCl2 waters, with mortality recorded in privet. Tissue nutrient concentrations were correlated with the IVD values. In the case of guava, 61% of the variability in the IVD could be accounted for based on N, P and K (P < 0.01). On a treatment basis, the single salts added to the municipal water showed little correlation with the IVD values, except in the case of MgCl2, where Mg was included in the regression equation (r 2 = 0.82, P < 0.01, IVD↑ as S04↓, Mg and P↑). Eleven different spectral indices separated based on treatment and/or species (P < 0.05). In elm, 70% of the variability in the IVD could be accounted for by including Red Edge, Normalized Difference Vegetation Index (NDVI) and Water Band Index (WBI)/NDVI. A mixed response was observed to a post 30-day irrigation rinse in an attempt to reduce IVD values. Based on our results, care should be given to monitoring not only the EC (and osmotic potential) but also the ionic composition when saline waters are blended with other water sources, with the aim of minimizing the concentration of Mg, Cl, and Na.

Open access cc by nc nd

J. R. Morris, L. D. Ray, and D. L. Cawthon

Abstract

Succinic acid-2,2-dimethylhydrazide (daminozide) applied at 1800 ppm to 10-year-old ‘Babygold-5’ and ‘Babygold-8’ peach trees (Prunus persica (L.) Batsch) at pit hardening advanced fruit maturity and increased tolerance of low soluble solids fruit by improving flesh color. Fruit softening, the disappearance of flesh chlorophyll, and reductions in puree viscosity were the primary benefits obtained from the application of daminozide. Daminozide advanced maturation generally, rather than concentrating the fruit into a more uniform maturity class. Flesh color and acidity were highly correlated with loss of fruit firmness of both control and daminozide-treated fruit, but daminozide treated fruit improved in flesh color more rapidly than control fruit as firmness decreased. Acidity remained consistently higher for treated fruit at all firmness levels. The mechanism by which daminozide advanced maturity did not appear to be active during postharvest holding of these clingstone cultivars. Further ripening as a result of postharvest storage of both treated and control fruit occurred at about the same rate during a 2, 4 or 6 day period at 18°C.