Orchard Field Research Articles

Impact of agricultural land use on N and P concentration in forest-dominated tea-cultivating watersheds

The increase in nitrogen (N) and phosphorus (P) and the decrease in dissolved silica (DSi) in aquatic environments attributed to human activities has been the focus of many studies. The resultant increases in the N/DSi and P/DSi ratios have been associated with the disturbance and deterioration of aquatic ecosystems. We investigated the impact of land use on riverine N and P as well as their ratio to DSi in 4 mountainous forest-dominated tea-cultivating areas in Shizuoka, central Japan. More than 50% of the drainage basins investigated were under forested land, while the land under tea (Camellia sinensis) fields varied from 0 to 18% and orchard fields reached up to 30% in some cases. The total nitrogen (TN) concentration was 5 mg L−1 at maximum, the majority of which was dominated by nitrate-N. An increase in the tea field area (%) within the basin resulted in significant increase in the TN concentration (p < 0.001) and in a considerably higher impact factor of 0.1–0.2 for the tea field. Orchard fields also affected the TN concentration in corresponding areas. An increase in the tea field area significantly contributed to an increase in the TN/DSi mole-based ratio. These results indicated that tea fields are a major source of riverine N. To maintain the TN/DSi below the critical level (TN/DSi ratio <1.0), tea fields should be cultivated only in a maximum of 30% of the watershed area, and the TN concentration should be limited to 2.5 to 4.0 mg L−1. Based on the level of precaution (TN/DSi <0.3), the TN concentration should be strictly limited to less than 1 mg L−1, which is identical to the Japanese critical standard for environmental conservation of lakes and coastal seas. On the other hand, TP concentrations were almost always below 0.1 mg L−1 and the TP/DSi ratios were considerably lower than the critical level (TP/DSi <0.07). Excess N load in the tea-cultivating watersheds might accelerate the P shortage in aquatic ecosystems. N concentration should be reduced to prevent future problems. In most of our mountainous tea-cultivating watersheds, 1 mg L−1 of TN concentration could be achieved, and generally a minimum of 2.5 to 4.0 mg L−1 should be achieved. To reduce the riverine TN concentration, the fertilizer N rate should be reduced by using modern practices to enhance N fertilizer use efficiency, such as slow-released coated urea combined with cultivar selection, without producing inferior quality tea leaves.

지형에 따른 전북지역 과수원 토양의 물리화학적 특성

지형에 따른 전북지역 과수원 토양의 물리화학적 특성과 중금속 함량을 조사하기 위해 재배면적과 과수종류에 따라 110개 지점을 선정하여 실시하였다. 전라북도 과수원 분포지형은 곡간 및 선상지, 구릉 및 산악지, 산록경사지, 하성평탄지, 홍적대지 하해혼성평탄지였으며, 구릉 및 산악지가 가장 많은 46.0%을 차지하고 있었다. 곡간 및 선상지의 토성은 사질식양토가 66.6%였고, 구릉 및 산악지는 토성이 고르게 분포하고 있었다. 용적밀도, 공극률 및 경도는 지형에 따라 차이가 없었고, 유효수분상수는 홍적대 지에서 19.5%로 가장 높았다. 토양 pH와 EC는 하해혼성평탄지에서 가장 높았고, 유기물, 유효인산, 치환성 K, Ca, Na은 지형에 따라 차이가 없었고, 치환성 Mg은 하해혼성 평탄지에서 <TEX>$3.5cmol_c\;kg^{-1}$</TEX>으로 가장 높았다. 토양 pH와 유기물은 과수에 따라 적정수준을 보였지만, 유효인산, 치환성 K, Ca 등은 적정 수준보다 높아 적절한 양분관리가 필요하다. 지형과 과수에 따라 중금속함량은 우려기준을 초과한 경우는 없었다. This study looked into 110 sites of orchard fields to investigate the relationships between the physical and chemical properties of soils, including heavy metal contents, and the topographic characteristics of the fields in Jeonbuk province. The topographic distribution of orchard fields in Jeonbuk province was local valley and fans, hilly and mountains, mountain foot slopes, alluvial plains, diluvium, and fluvio-marine deposits. Forty-six percent (46%) of total orchard fields were located in the hilly and mountains. Soil texture of the local valley and fans was mostly sandy clay loam, and the soil texture of other topographical sites were varied. Bulk density, porosity, and soil hardness were not different among the various topographic sites. The content of plant available water was the highest (19.5%) in the sites of diluvium. Soil pH, electrical conductivity (EC), and exchangeable <TEX>$Mg^{2+}$</TEX> content were the highest in the sites of fluvio-marine deposits, whereas the contents of soil organic matter (SOM), available phosphorus, and exchangeable <TEX>$Ca^{2+}$</TEX>, <TEX>$K^+$</TEX>, and <TEX>$Na^+$</TEX> were not significantly different among the topographic sites. Also, soil pH and SOM content were generally in optimal ranges for the fruit plants in the orchard fields, but other values were mostly higher than those in optimum. In addition, the contents of heavy metals were much lower than the levels of Soil Contamination Warning Standard.

전북지역 과수원의 토양특성이 미생물 분포에 미치는 영향

This study was conducted to investigate impacts of soil properties on microbial distribution in Jeonbuk orchard fields. Soil samples were collected from 110 sites cultivated with different fruit plants. The population of aerobic bacteria and fungi and the content of soil microbial biomass carbon (C) were found to increase with increasing silt content in the soils. Different activity of dehydrogenase was not observed among the different textures of soil. Microbial distribution, amount of microbial biomass C, and dehydrogenase activity in the soils were not significantly different among the topographic sites. However, in pear and grape fruit plant fields, coliform group of bacteria was found in relatively higher population, 133.0x10 3 CFU g -1 and 107.4x10 3 CFU g -1 , respectively. Microbial groups were simplified and their density was reduced with increasing the cultivation periods of fruit plants. The soil microbial distribution was proportionally correlated with some of soil properties such as soil pH, soil organic matter (SOM) content, and exchangeable Mg content; in particular, the population of Bacillus sp. was proportionally correlated with soil pH and exchangeable Mg content. The amounts of microbial biomass C and the dehydrogenase activity in the soils were significantly correlated with the contents of SOM and exchangeable Ca ion (p<0.01).

State of pesticide residue in litchi orchard soils in Guangxi and Fujian, China

荔枝收获完毕后在广西壮族自治区及福建省荔枝主产区采集210 个荔枝园土壤样本, 检测了甲霜灵、代森锰锌、多菌灵、溴氰菊酯、氯氰菊酯、三氟氯氰菊酯、敌百虫、乐果和敌敌畏等9 种荔枝常用农药的含量。结果显示, 多菌灵是广西和福建荔枝园土壤最常检出的农药, 检出率分别为48.1%和84.0%。广西荔枝产区土壤代森锰锌、敌百虫和乐果均未检出, 其他5 种农药检出率均低于10%。福建荔枝产区甲霜灵和氯氰菊酯检出率均为24.0%, 其他6 种农药均未检出。广西荔枝产区土壤未检出或只检出1 种农药荔枝园分别占采样荔枝园的48.6%和38.4%, 福建荔枝产区分别占56.0%和8.0%; 检出2 种农药的广西荔枝园占11.4%，福建占32.0%。广西荔枝园土壤平均含量最高的农药为氯氰菊酯(5.0 μg·kg^-1), 敌敌畏次之(1.9 μg·kg^-1), 其他4 种检出农药不超过1.0 μg·kg^-1。福建荔枝园土壤平均含量为多菌灵(0.77 μg·kg^-1)>甲霜灵(0.65 μg·kg^-1)>氯氰菊酯(0.48μg·kg^-1)。虽然福建荔枝园土壤农药残留比广西普遍, 但两地荔枝园土壤农药残留仍属轻微。

Analyses of environmental factors around orchard fields damaged by Japanese black bear and construction of bear damage hazard map

Analyses of environmental factors around orchard fields damaged by Japanese black bear and construction of bear damage hazard map

Variations of soil organic matter in typical orchard regions

在黄土高原、胶东半岛和北京郊区果园选择11个采样区, 按照5~10年、10~15年和15年以上3个园龄段, 利用GPS定位系统, 共采集0~20 cm表层土壤样品99份, 并在取样果园附近选择普通农田作为对照采集土壤样品33份, 测定了果园与普通农田土壤的有机质含量, 并从果园土壤有机质数量特征、果园与农田差异特征以及有机质随园龄段变化特征3个方面进行统计分析。研究结果表明: 胶东半岛栖霞和北京郊区果园土壤有机质含量较高, 黄土高原宝塔较低。与农田相比, 60%多的果园土壤有机质未发生显著变化, 明显提高的果园不到30%, 明显降低的果园不到10%; 土壤有机质发生变化的果园, 平均提高0.62%, 平均降低0.20%; 随园龄增加, 两个样点果园土壤有机质明显提高, 其他果园变化不显著。在优质高产果园区, 果园土壤有机质提高归因于施用有机肥、果园种草、青草或秸秆还田。总体上看, 典型区域果园土壤有机质高低值差异较大, 土壤有机质含量普遍不高, 果业持续发展能力较低。

자주식 심토환경 개선기 개발(1) - 과수원의 토양 다짐 특성 및 심토 관리 실태 -

This study was carried out to investigate the present status of subsoil compaction, and subsoil compaction management in orchard as a basic study for developing a self-propelled explosive subsoiler. Subsoil compaction was evaluated using the soil penetration resistance. Soil cone index was measured using the DIK 5520 type cone penetrometer in several fruit farms such as apple, pear, peach and grapes during growing seasons of these fruit in Jecheon, Gamgok, Choongju, Cheonan and Hwasung areas. Most of the subsoil managing machinery were either explosive type or digging type attached to the tractor or power tiller and turning radius of this machine was more than 3-5 m. Many of the farmers wanted to use the subsoiler which can put lime into soil and rupture soil at the same time. For most of the orchard fields, soil penetration resistance in vehicle traffic area was increased quickly and reached about 1.0 MPa in 5 cm soil depth. As the soil depth increased to 15-20 cm, cone penetration resistance reached about 2.0-2.5 MPa which restricted root growth seriously. Thus it was concluded that one of the main reason for increasing the soil compaction in orchard fields is agricultural vehicle traffic. In the vicinity of fruit trees, compaction is not so serious compared to that of the vehicle traffic area, but as the soil depth increased to 20-25 cm, in most of the orchard fields soil penetration resistance reached about 2.0-2.5 MPa which is the root growth-limiting value. Considering the rooting depth of fruit trees which ranged 30-60 cm for apple, pear and peach, and 20-30 cm for grape, it is necessary to loosen the subosoil and improve the subsoil conditions using subsoiler.

Pulse Jet Orchard Heater System Development: Part I. Design, Construction, and Optimization

The objective of this six-year project was to develop a more efficient and effective supplemental orchard field heater technology. In addition to being low-cost and mobile, these devices should be useable with or without wind machines, reduce labor requirements, and greatly reduce air pollutants compared to conventional orchard heating systems. The new generation orchard heaters that were developed in this process are portable, auto-regulating, horizontal pulse jet engines (combustors) with no moving parts. These devices utilize air ejector technology to reduce the temperature of the high-velocity combustion stream by thoroughly mixing it with the surrounding ambient (cold) air, producing a net effective temperature increase of only 2°C to 5°C above ambient. Buoyant forces of warm air are therefore small, and fewer heaters would be needed. The design achieved pressure oscillations that were free of combustion instabilities, and amplitudes were maximized for high exhaust jet velocities for deep hot jet penetration and mixing into the surrounding cold air. The overall size and weight of the heater system were minimized while maintaining optimum operation. Finally, anti-phase operation of paired heaters for noise level reduction from 130 dB to near 75 dB was achieved by implementing optimized silencing plenums at the inlet and exhaust of the paired heaters.

Pulse Jet Orchard Heater System Development: Part II. System Scaling and Application

This article reports the results of a six-year project in which an efficient and effective supplemental orchard field heater system was successfully developed. In addition to being low-cost and mobile, the criteria met by this system design included: (1) usage with or without wind machines or as stand-alone units, (2) reduced labor requirements, and (3) reduced air pollutants compared to conventional supplemental, fossil fuel combustion orchard heating systems. The resulting new generation heaters were portable, auto-regulating, horizontal pulse jet engines (combustors) with no moving parts. Scaling criteria were formulated and utilized for fabrication of various sizes of portable horizontal pulse jet engines optimized for stable operation. Scale-up parameters for multiple sizes of these combustor systems for agricultural heating and frost protection purposes were both theoretically and qualitatively described. Theoretical and empirical approaches resulted in similarity parameters that played an important role in the scale-up for field applications. The scaled and optimized heater prototypes were constructed and field tested. Experimental results confirmed the applicability of using both gaseous and liquid propane as fuel supplies. Detailed field testing showed that mixing of warm air by the high-velocity exhaust stream into cold air (0 to 4 m height) was quite effective in reducing buoyant heat losses. Pulse jet heater prototypes were also tested under orchard conditions and found to circumvent the many disadvantages of conventional oil and liquid propane (LP) gas orchard heating systems, especially when used in combination with wind machines.

Tillage and tractor traffic effects on soil compaction in horticultural fields used for peri-urban agriculture in a semi-arid environment of the North West Province, South Africa

Urban and peri-urban agriculture is becoming increasingly important as a source of income and food for the urban population in South Africa. This study was prompted by concerns of city authorities that soil compaction in horticultural fields that used conventional tillage practices with tractors was, not only limiting the performance of fruit and vegetable crops, but also affecting the quality of water resources. The extent of soil compaction in selected fields used for peri-urban agriculture within the city of Mafikeng was quantified by measuring soil penetrometer resistance and bulk density in the profiles of four adjacent fields (vegetable, orchard, vineyard and unploughed control) but with different tillage traffic systems over 14 years. Soil organic carbon and water content of the profiles were also measured. Tractor traffic was used for seedbed preparation and weeding respectively in the vegetable and orchard fields while the vineyard was not heavily trafficked. A field that remained unploughed over the same period was used as control. Higher soil compaction was more evident in the orchard and vegetable fields compared with the vineyard. The location of compacted layers within the profiles was related to the nature of tractor traffic applied. There was subsoil compaction in the orchard and vegetable fields while shallow compaction was observed in the vineyard. The maximum penetrometer resistance and depths were: unploughed land (1500 kPa at 42 cm), vineyard (1587 kPa at 5.0 cm), vegetable field (2315 kPa at 30.0 cm) and orchard (2550 kPa at 20 cm). The unploughed and untrafficked soil profile had the largest soil water content and the least penetrometer resistance. The trafficked fields had significantly greater ( P = 0.05) bulk density than the unploughed land. Apart from tractor traffic the small organic matter content and the hard-setting behavior of the soil could have exacerbated the compaction. It was concluded that tillage practices are diminishing the quality of soils used for horticulture production in peri-urban areas of the study area. The compacted soil profiles were considered to have the potential of contributing to increased runoff and soil erosion and subsequent sediment concentration in surface water courses around the city. The study recommends that controlled tillage and other management strategies, especially those that increase the organic matter content of the soils, be adopted to not only ameliorate the existing compaction, but also sustain the productivity of the soils used for urban agriculture and the water resources in this semi-arid environment.

Assessing canopy PRI for water stress detection with diurnal airborne imagery

A series of diurnal airborne campaigns were conducted over an orchard field to assess the canopy Photochemical Reflectance Index (PRI) as an indicator of water stress. Airborne campaigns over two years were conducted with the Airborne Hyperspectral Scanner (AHS) over an orchard field to investigate changes in PRI, in the Transformed Chlorophyll Absorption in Reflectance Index (TCARI) normalized by the Optimized Soil-Adjusted Vegetation Index (OSAVI) (TCARI/OSAVI), and in the Normalized Difference Vegetation Index (NDVI) as function of field-measured physiological indicators of water stress, such as stomatal conductance, stem water potential, steady-state fluorescence, and crown temperature. The AHS sensor was flown at three times on each 2004 and 2005 years, collecting 2 m spatial resolution imagery in 80 spectral bands in the 0.43–12.5 μm spectral range. Indices PRI, TCARI/OSAVI, and NDVI were calculated from reflectance bands, and thermal bands were assessed for the retrieval of land surface temperature, separating pure crowns from shadows and sunlit soil pixels. The Photochemical Reflectance Index, originally developed for xanthophyll cycle pigment change detection was calculated to assess its relationship with water stress at a canopy level, and more important, to assess canopy structural and viewing geometry effects for water stress detection in diurnal airborne experiments. The FLIGHT 3D canopy reflectance model was used to simulate the bi-directional reflectance changes as function of the viewing geometry, background and canopy structure. This manuscript demonstrates that the airborne-level PRI index is sensitive to the de-epoxidation of the xanthophyll pigment cycle caused by water stress levels, but affected diurnally by the confounding effects of BRDF. Among the three vegetation indices calculated, only airborne PRI demonstrated sensitivity to diurnal changes in physiological indicators of water stress, such as canopy temperature minus air temperature (Tc–Ta), stomatal conductance (G), and stem water potential (ψ) measured in the field at the time of each image acquisition. No relationships were found from the diurnal experiments between NDVI and TCARI/OSAVI with the tree-measured physiological measures. FLIGHT model simulations of PRI demonstrated that PRI is highly affected by the canopy structure and background.

Soil compaction by tractor tillage in horticultural fields at Molelwane research farm, Mafikeng, North West Province

The study was prompted by concerns that soil compaction in horticultural fields at the University research farm was limiting the performance of fruit trees and vegetable crops after fifteen years of conventional tillage with tractors. Soil penetrometer resistance and bulk density were measured in the profiles of three adjacent fields (vegetable, orchard & vineyard). Over the years, tractor traffic was used in the vegetable field and orchard for seedbed preparation and weeding respectively, while the vineyard was not trafficked. Higher soil compaction was evident in the orchard and vegetable fields compared to vineyard. The location of compacted layers within the profiles was related to the nature of tractor traffic. There was subsoil compaction in the orchard and vegetable fields while shallow compaction was observed in the vineyard. Apart from tractor traffic, low organic matter content and the hardsetting behavior of the soil could have exacerbated the compaction. It was recommended that controlled traffic and deep ripping should be adopted, to not only ameliorate the existing compaction, but also sustain the productivity of the soils.

Detection of water stress in orchard trees with a high-resolution spectrometer through chlorophyll fluorescence in-filling of the O/sub 2/-A band

A high spectral resolution spectrometer with 0.065-nm full-width half-maximum was used for collecting spectral measurements in an orchard field under three water stress treatments. The study was part of the FluorMOD project funded by the European Space Agency to develop a leaf-canopy reflectance model to simulate the effects of fluorescence. Water deficit protocols generated a gradient in solar-induced chlorophyll fluorescence emission and tree physiological measures. Diurnal steady-state chlorophyll fluorescence was measured from leaves in the field between June and November 2004 using the PAM-2100 fluorometer to study the effects of water stress on chlorophyll fluorescence. Spectral measurements of downwelling irradiance and upwelling crown radiance were conducted with the narrow-band spectrometer, enabling the canopy reflectance to be obtained at subnanometer spectral resolution and permitting the evaluation of the fluorescence in-filling effects on reflectance in trees under water stress conditions. Diurnal and seasonal measurements showed consistently lower steady-state fluorescence (Ft) and quantum yield /spl Delta/F/Fm' in water-stressed trees, yielding mean values of Ft=0.38 (well-irrigated) and Ft=0.21 (water-stressed trees). The agreement between Ft and water potential showed that steady-state fluorescence could be used to detect differences in water stress levels, with determination coefficients ranging between r/sup 2/=0.48 and r/sup 2/=0.81 for individual dates. Analysis in the 680-770-nm range showed that the chlorophyll fluorescence in-filling in the O/sub 2/-A band at 760 nm is sensitive to diurnal variations of fluorescence and water stress, yielding r/sup 2/=0.76 (well-watered treatment), r/sup 2/=0.89 (intermediate stress treatment), and r/sup 2/=0.7 (extreme stress treatment), demonstrating the close relationships between Ft and in-filling at the crown level.

Resistência específica do solo de um pomar frutícola relacionada ao manejo entrelinhas e intensidade de tráfego

Orchard production traffic demands have characteristics that is called controlled traffic. Tractors and its machines, always use the same tracks in each of their passage. Not only this negative condition, but the fact that the irrigation used is usually excessive, it leads to a highly potential condition to enhance over-compaction in Alto Valle region in Argentina. This paper is part of a thesis refered to the possibility of introducing changes in the manner of the phytosanitary applications are done. These changes consist in leaving the fixed calendar method to the one proposed by the Integrated Orchard Production program of the INTA. In an apple orchard field, on two soil conditions, with and without grass, traffic corresponding to a whole year management passages of a tractor and it sprayer were simulated for both systems. Penetration resistance was assessed before and after traffic, and related to induced compaction. Over-compaction values were measured more frequently on non-grassed soil if control plot was considered. Edaphic reology was different for each soil condition after traffic was applied. Traffic decreases due to Integrated Orchard Production management and were of significant importance if a sustainable system is the target.

Chemical Changes in Agricultural Soils of Korea: Data Review and Suggested Countermeasures

The monitoring of chemical properties, including heavy metals, in soils is necessary if better management and remediation practices are to be established for polluted soils. The National Institute of Agricultural Science and Technology initiated a monitoring study that investigated fertility and heavy metal contents of the benchmarked soils. The study covered paddy soils, upland soils, and horticultural soils in the plastic film houses, and orchard soils throughout the Korea from 1990 to 1998. Likewise, 4047 samples of paddy and 2534 samples of plastic house in 1999 and 2000 were analyzed through the Soil Environment Conservation Act. Soil chemical properties such as pH, organic matter, available phosphate and extractable calcium, magnesium and potassium contents, and heavy metal contents such as cadmium, copper, lead, zinc, arsenic, mercury, and cobalt contents were analyzed. The study showed that the average contents of organic matter, available phosphate, and extractable potassium rapidly increased in plastic house soils than in upland or paddy soils. Two kinds of fertilizer recommendation systems were established for the study: the standard levels by national soil average data for 77 crops and the recommendation by soil test for 70 crops. Standard nitrogen fertilizer application levels for cereal crops changed from 94 kg/ha in 1960s, 99 kg/ha in 1970s, 110 kg/ha in 1980s to 90 kg/ha in 1990s. The K2O-fertilizer also changed from 67 kg/ha in 1960s, 76 kg/ha in 1970s, 92 kg/ha in 1980s, and only 44 kg/ha in 1990s. In rice paddy fields, the average contents of Cd, Cu, Pb, and Zn in surface soils (0-15 cm depth) were 0.11 mg kg(-1) (ranged from 0 to 1.01), 4.70 mg kg(-1) (0-41.59), 4.84 mg kg(-1) (0-66.44), and 4.47 mg kg(-1) (0-96.70), respectively. In the uplands, the average contents of Cd, Cu, Pb, Zn, and As in surface soils (0-15 cm depth) were 0.135 mg kg(-1) (ranged from 0 to 0.660), 2.77 mg kg(-1) (0.07-78.24), 3.47 mg kg(-1) (0-43.00), 10.70 mg kg(-1) (0.30-65.10), and 0.57 mg kg(-1) (0.21-2.90), respectively. In plastic film houses, the average contents of Cd, Cu, Pb, Zn, and As in surface soil were 0.12 mg kg(-1) (ranging from 0 to 1.28), 4.82 mg kg(-1) (0-46.50), 2.68 mg kg(-1) (0-46.50), 31.19 mg kg(-1) (0.19-252.0), and 0.36 mg kg(-1) (0-4.98), respectively. In orchard fields, the average contents of Cd, Cu, Pb, Zn, As, and Hg in surface soils (0-20 cm depth) were 0.11 mg kg(-1) (ranged from 0-0.49), 3.62 mg kg(-1) (0.03-45.30), 2.30 mg kg(-1) (0-27.80), 16.60 mg kg(-1) (0.33-105.50), 0.44 mg kg(-1) (0-4.14), and 0.05 mg kg(-1) (0.01-0.54), respectively. For polluted soils with over the warning content levels of heavy metals, fine red earth application, land reconsolidation and soil amelioration such as lime, phosphate, organic manure, and submerging were recommended. For the countermeasure areas, cultivation of non-edible crops such as garden trees, flowers, and fiber crops; land reformation; and heavy application of fine red earth (up to 30 cm) were strongly recommended. Land use techniques should be changed to be harmonious with the environment to increase yield and income. Soil function characteristics should be taken into account.

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This work was motivated by previous pheromone trap tests for Conogrthes sp. and C. punctiferalis in which small numbers of Pleuroptia chloropahanta males were unexpectedly trapped. Formulations of (E)-10-hexadecenal (E10-16: Ald), (Z)-10-hexadecenal (Z10-16: Ald), n-hexadecanal (n-16: Ald) or (E)-10-hexadecenol (E10-16: OH) alone or in various combinations were tested as attractants for male moths of P. chloropahanta in different plantations. In chestnut and peach orchard field tests in 1994, E10-16: Ald alone was attractive to the males but binary mixtures of E10-16: Ald and 5 to 50% of Z10-16: Ald were not attractive. Trap catches by a binary mixture of E10-16: Ald and E10-16: OH in 1995 was very low and not different from that of a 4-component mixture for C. punctiferalis. In field tests of two Japanese white pine plantations of in 2001, 36 P. chloropahanta males were caught by traps baited with E10-16: Ald alone. Conclusive results, that is, exclusive attraction by E10-16: Ald were also obtained by field trap tests in plantations of Paulownia tomenyosa and Syrax abassia, host plants of this species. These results strongly suggest (E)-10-hexadecenal is effective as a sex attractant for monitoring P. chloropahanta and this compound may be one of the sex pheromone components of this species.

Distribution, occurrence and characterization of entomopathogenic fungi in agricultural soil in the Palestinian area.

The occurrence of entomopathogenic fungi was investigated in irrigated vegetable fields and citrus orchards soils, over a nine-month period (April-December 1999), using the Galleria bait method (GBM). Entomopathogenic fungi were found to occur in 33.6% of the soil samples studied, with positive samples yielding 70 fungal isolates, belonging to 20 species from 13 genera. Conidiobolus coronatus was the most frequent and abundant entomopathogenic species recovered, comprising 31.4% of the total number of isolates. Soil pH, soil moisture content and the geographical location had minor or no effect on the isolation of entomopathogenic fungi in the fields studied. On the other hand, organic matter content of soil, and vegetation type were found to significantly affect the occurrence of entomopathogenic fungi in soil habitats, with orchard fields yielding larger numbers of isolates than vegetable fields. Using Koch's postulates the pathogenicity of fungal isolates to Galleria larvae was found to range from 16-100% (mortality rate). Isolates of C. coronatus proved to be the most virulent isolates recovered. The effect of media and temperature on mycelial growth rate, conidial production and conidial germination of six entomopathogenic fungal species (C. coronatus, Entomophaga grylli, Erynia castrans, Hirsutella jonesii, Paecilomyces farinosus and Sporodiniella umbellata) was also studied. Mycelial growth rate, spore production and spore germination were significantly affected by media, temperature and isolates. In view of the present results, C. coronatus appears to be a good candidate for pest control in agricultural soils, as it has a wide tolerance to agricultural practices, has frequently been isolated from both vegetable and orchard fields, and is characterized by high mycelial growth rate, conidial production and conidial germination.

樹園地における非選択性茎葉処理除草剤の連用による雑草草種の変化

樹園地における非選択性茎葉処理除草剤の連用による雑草草種の変化

Field-Based Monitoring of Agricultural Workers for Overexposure to Cholinesterase-Inhibiting Pesticides

ABSTRACT We report on our experience utilizing the EQM TestMate OP field cholinesterase test kit in monitoring orchard pesticide applicators and field workers in Washington State. The kit provides immediate results of plasma and acetyl cholinesterase as well as hemoglobin adjusted acetyl cholinesterase. The kit utilizes blood obtained by finger-stick sampling, is extremely portable, battery powered and is very simple to operate. Compared to baseline values obtained prior to the start of exposure, at each visit, approximately 7-8% of monitored workers were identified as having cholinesterase activity level changes consistent with significant inhibition. Applicators had significantly lower levels from field workers. None of these workers had complaints of symptoms. Among those with either plasma or acetyl cholinesterase depression we found explanations other than pesticide exposure for depression in two of seven. One had an artifactually high baseline value, a second had recently been started on isoniazid and had developed drug induced hepatitis. In a third worker with depression, activity of a venous sample drawn at the same visit revealed no depression, suggesting that the fingerstick value was probably low due to dermal contamination. Workers and employers appreciated the speed with which results were provided. We encountered a major technical problem when after baseline collections the kits were recalled because of a faulty filter. Upon return we found that the kit read consistently higher than prior to the recall. We also found that in an unexposed control group, baseline values were depressed due to the effect of the cold testing environment on the TestMate. The TestMate holds the promise of being a simple, rapid, accurate method for testing cholinesterase in the field. Technical corrections to the kit are necessary and a standardizing mechanism needs to be developed to assure calibration of the kit from visit to visit.

Studies on the Improvement and Maintenance of Soil Physical Properties of a Hardened Soil in an Orchard Field

Studies on the Improvement and Maintenance of Soil Physical Properties of a Hardened Soil in an Orchard Field