Xylem vessels of Prunus persica Batsch (peach) and Juglans regia L. (walnut) are vulnerable to frost-induced embolism. In peach, xylem embolism increased progressively over the winter, reaching a maximum of 85% loss of hydraulic conductivity (PLC) in early March. Over winter, PLC in walnut approached 100%, but the degree of xylem embolism varied during the winter, reflecting the ability of waln...

In a young walnut orchard planted on black walnut rootstock, and stunted as a result of root lesion nematode feeding treatments are being applied in an effort to invigorate tree growth and/or significantly reduce the nematode population. Treatments began in 1989 and include: (1) Spring grafting two paradox seedlings to the existing trees trunk (llinarching")i(2) application of Nemacur 3 nematoc...

Hedgerow walnuts (cv. Chico) that were irrigated at 33 and 66% ETc from 1986-88 suffered marketable nut yield reductions of 32 and 50%. Upon returning these trees to full irrigation in 1989, tree growth and.water relations immediately recovered but yields were little changed. Harvest yields completely recovered this year (after two years of full irrigation). This indicates that hedgerow walnuts...

Common walnut (Juglans regia L) is an economically important species cultivated worldwide for its wood and nuts. It is generally accepted that J. regia survived and grew spontaneously in almost completely isolated stands in its Asian native range after the Last Glacial Maximum. Despite its natural geographic isolation, J. regia evolved over many centuries under the influence of human management...

The infestation of rice moth, Corcyras cephalonica (Lepidoptera: Galleriidae), causes severe losses in postharvest walnuts. Heat has been studied as a phytosanitary treatment to replace chemical fumigation for controlling this pest. Information on kinetics for thermal mortality of C. cephalonica is needed for developing effective postharvest phytosanitary thermal treatments of walnuts. Thermal ...

We bring to the lab the theoretical result of Robinson (1985, RAND Journal of Economics 16: 141 145) that collusion is incentive compatible in the English auction (EN) and not in the firstprice sealed-bid auction (FP) in the case of one-shot interaction. Our data partly confirm Robinson’s prediction: in FP all cartels break down, but a majority of cartels breaks down in EN as well. However, mor...

BACKGROUND Published studies relating pyrethroid use and subsequent mite outbreaks have largely been based on laboratory and field experiments, with some inferring a result of increased miticide use. The present study derived a mathematical model proposed to quantify the effect of pyrethroid use intensity on mite population density. The model was validated against and parameterized with actual ...

Freeze-thaw cycles induce major hydraulic changes due to liquid-to-ice transition within tree stems. The very low water potential at the ice-liquid interface is crucial as it may cause lysis of living cells as well as water fluxes and embolism in sap conduits, which impacts whole tree-water relations. We investigated water fluxes induced by ice formation during freeze-thaw cycles in Juglans reg...

In this study, 36 extracts derived from 29 plant species selected using an ethnobotanical approach were tested for antifungal activity against a taxonomically diverse group of 13 human pathogenic fungi. We compared the inhibitory characteristics of these plant extracts with those of the commonly used antifungals, amphotericin B and ketoconazole, and the plant-derived antifungal, berberine. Seve...

The walnut oil (Juglans regia L.) total lipids (TL) were extracted by the Bligh-Dyer method and the lipid classes have been isolated by chromatographic techniques and they were analyzed by high performance thin layer chromatography (HPTLC)/FID and GC-MS. The oil was found to be rich in neutral lipids (96.9% of total lipids) and low in polar lipids (3.1% of total lipids). The neutral lipid fract...