Lead arsenate was used on orchard soils as a pesticide from 1900 to 1960. An in vitro method has been used to determine the bioaccessiblity of Pb in soils contaminated by Pb paint, fossil fuel combustion, and metallurgical industries. The Pb fraction that is potentially bioavailable from orchard soils, however, has not been reported. Potential reductions in availability of Pb and As as a result...

Aspects of the incidence and spread of the citrus disease huanglongbing (HLB) in relation to the vector Diaphorina citri population fluctuation were studied from January 1999 to December 2001 seasons in a 0.8 ha citrus orchard at Jemukan (1° 33'N, 110° 41'E), Southwest Sarawak in Malaysia. In relation to insecticide and horticultural mineral oils (HMOs) use, levels of HLB infection rose quite r...

`Kent' mango (Mangifera indica L.) ̄owers were sampled in an orchard in the coastal plain of Israel during the 1997 ̄owering season. Effective pollination rate was determined at two stages of the fertilization process: (a) pollen germination on the stigma; (b) pollen-tube penetration into the ovule. Pollination rates were negligible during the ®rst part of the ̄owering season (31 March to 18 Ap...

Insect-pathogenic fungi are important natural enemies of insect pests but their dynamics in the soils of different agroecosystems are incompletely understood. In the present study, the seasonal occurrence and species diversity of insect-associated fungi in soil were investigated by baiting soil samples with larvae of Galleria mellonella. The survey included insect-pathogenic fungi, opportunisti...

In this study we focus on the invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), which has a strong dispersal capacity and has had a significant impact on several cropping systems, including peach (Prunus persica (L.)). Management of H. halys has relied on intensive insecticide use, and thus a better understanding of its dispersal behavior may assist in dev...

Although whiteflies Tetraleurodes perseae (Nakahara) (Hemiptera: Aleyrodidae) are considered a secondary pest of avocado crops, their presence and the damages that they cause can decrease crop vigor and affect production. The objective of the present work was to determine the population fluctuation and altitudinal distribution of the T. perseae Nakahara whitefly in avocado trees, as well as to ...

ABSTRACT Apple replant disease typically is managed through pre-plant application of broad-spectrum soil fumigants including methyl bromide. The impending loss or restricted use of soil fumigants and the needs of an expanding organic tree fruit industry necessitate the development of alternative control measures. The microbial community resident in a wheat field soil was shown to suppress compo...

Photosynthetic light acclimation of leaves can result from (i) changes in mass-based leaf nitrogen concentration, Nm, (ii) changes in leaf mass:area ratio, Ma, and (iii) partitioning of total leaf nitrogen among different pools of the photosynthetic machinery. We studied variations in Nm and Ma within the crowns of two peach (Prunus persica L. Batsch) trees grown in an orchard in Portugal, and ...

Abstract Visible and near infrared (VIS-NIR) spectroscopy is a non-destructive, fast, practical reliable technique to determine maturity quality attributes in apple fruit. However, the effects of cultivar growing conditions on predictive performance equipment must be determined before its commercial application industry. This study was carried out evaluate efficiency VIS-NIR portable spectromet...

During the past year, we reared and released approximately 40,000 parasites of the Guthion-resistant strain of walnut aphid parasite, Trioxys pallidus, into a walnut orchard near Red Bluff, CA. Parasites were recovered three times during the season following release and results of bioassays indicate the resistant strain has established and persisted through its first field season in this orchar...