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  • Author or Editor: Larry K. Hammett x
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Abstract

Summer application of succinic acid-2,2,dimethylhydrazide (SADH) followed by an (2-chloroethyl)phosphonic acid (ethephon) application 1 month before normal harvest to ‘Starkrimson Delicious’ trees resulted in highly-colored, firm fruits with storage quality for 28 weeks if harvested 20 days after ethephon application. Ethephon application to ‘Golden Delicious’ trees 1 month before normal harvest resulted in soft, over-ripe fruits when harvested 10, 20 or 30 days after treatment. Firmness of ethephon-treated ‘Golden Delicious’ fruits rapidly declined in storage.

Open Access

Abstract

Form, rate, and date of late-season soil application of N and foliar applications of CaCl2 to ‘Jewel’ sweet potatoes (Ipomoea batatas (L.) Lam) did not influence root yield, cracking, and mineral, carbohydrate, carotene or ascorbic acid concentrations. Use of CaCl2 foliar sprays and Ca(NOSS3)2 as a top dressing did not increase root Ca levels, firmness, or reduce the incidence of root cracking.

Open Access

Abstract

‘Jewel’ sweet potato transplants were held in refrigerated storage at 4.4°, 8.9°, 13.3°, 17.8°, or 26.7°C for 7 or 14 days before planting. Some treatments received a fungicide dip before storage. Maximum plant survivability and root yield were obtained from transplants held for 7 days at 13° to 18°. Ambient storage (26.7°) greatly reduced transplant survivability. Fungicide treatment had no influence on plant stand.

Open Access

Abstract

Methyl 3,6-dichloro-o-anisate (disugran) applied as a pieharvest apple spray gave significant increases in soluble solids in ‘Golden Delicious’ apple fruit. Sugar enhancement with ‘Starkrimson Delicious’ was not significant but an enhancement trend was indicated. Other maturity indices were not influenced by disugran application.

Open Access

Abstract

Interest in the use of molded plastic bins for harvesting and storing sweet potatoes prompted a study of their suitability as curing and storage containers. The airflow resistance characteristics of the containers in question were measured and compared with similarly measured characteristics of conventional wooden crates. The plastic bins were found to offer significantly higher resistance to airflow than did the conventional wooden crates, with the airflow through the wooden crate being 1.4 to 2.6 times greater, depending upon orientation, under the same test conditions.

Open Access

Abstract

Gaseous mixtures of O2 + CO2 in N2 or ethylene in air were held in glass or plastic syringes for up to 30 hr under different temperatures and conditions. Concentration changes in the gases were followed over time to determine the best method to hold gas samples until analyses. At 25°C, ethylene loss was less from glass than plastic syringes. Twenty minutes at 25° was the maximum holding time before a statistically significant change in concentration occurred for 10 μl·liter−1 ethylene samples in plastic syringes. Plastic syringes absorbed ethylene. Ethylene loss from plastic syringes at 25° was linear within the constraints of the experiment over 30 hr, with the loss of 10 μl·liter−1 ethylene being more rapid than loss from 1 μl·liter−1. Carbon dioxide and O2 levels changed less from glass than plastic syringes at 25°. Holding ethylene or CO2 + O2-filled syringes under saturated NaCl or MgSO4, respectively, did not influence the change in CO2 or ethylene level from the syringes. The change in O2 concentration was less in plastic syringes held in a MgSO4 solution than plastic syringes held in air.

Open Access

Abstract

Oryzalin (3,5-dinitro N4, N4-dipropylsulfanilamide), oryzalin/chloramben (3-amino-2,5-dichlorobenzoic acid) combinations, and diphenamid (N,N-dimethyl-2,2-diphenylacetamide) were evaluated for their influence on root quality of sweet potato [Ipomoea batatas (L.) Lam.] at harvest and during storage. Mineral analysis and foliage dry matter were evaluated with no significant differences observed between the oryzalin rates, diphenamid, and the controls. Soluble carbohydrates, reducing carbohydrates, ascorbic acid, and carotene content were not influenced by the herbicidal treatments. Intercellular space values were all within an acceptable range at harvest storage. The 3 rates of oryzalin utilized were not detrimental to quality and comparable to the diphenamid, weedy control, and cultivated control treatments.

Open Access

Abstract

Blueberry plants (Vaccinium corymbosum L. cv. Wolcott) under a constant-flow gravity system in the greenhouse were able to utilize either NO3-N or NH4-N and maintained a healthy growth status for 2 growing seasons.

Open Access

Abstract

‘Jewel’ sweet potatoes [Ipomoea batatas (L.) Lam] were grown for 2 seasons on an Orangeburg loamy sand soil with 3 N sources, 3 K rates, and 2 N rates. NH4NO3 and Ca(NO3)2 were equivalent in influence on root quality at harvest and storage, but NaNO3 significantly reduced root dry matter content. With an increase in N rate from 101 to 202 kgN/ha, weight loss during storage increased and carbohydrate levels, dry matter content, and root intercellular space values decreased. An increase in K applications from 70 to 280 kg/ha reduced root dry matter content.

Open Access

Abstract

The amino acid, organic acid, and free sugar contents as determined by gas-liquid chromatography, of ‘Wolcott’ fruit were not influenced quantitatively or qualitatively by different ratios of NH4-N and NO3-N applied in nutrient solution via a constant-flow gravity drip system to blueberries planted in sand. The amino acids detected in order of decreasing concn in the ‘Wolcott’ fruit were: tyrosine, glutamine, lysine, glutamic acid, tryptophane, gamma-aminobutyric acid, histidine, arginine, aspartic acid, alanine, serine, leucine, cysteine, threonine, isoleucine, valine, proline, and glycine. Citric acid was the predominant organic acid accompanied by lesser concn of shikimic and quinic acids. Fructose was the free sugar present in greatest concn in the fruit followed by beta-glucose and alpha-glucose. Sucrose was present at extremely low concn. The sugar/acid ratio of the ‘Wolcott’ fruit was not influenced by the N nutrient treatment.

Open Access