Influence of air-assistance on spray application for tomato plants in greenhouses

Protected horticulture production represents one of the most important agricultural businesses in Southern Europe. However, many problems related to the lack of mechanisation, intensive use of pesticides, and, in some cases, undesirable residues on food, have not been solved yet. In this context, application technology is a key factor for the improvement of the efficacy and efficiency of plant protection products. Spray guns and knapsack sprayers are the most common technologies that have been used for this purpose. However, several studies have demonstrated that, compared with spray guns, the use of vertical boom sprayers in greenhouses improves spray distribution and reduces labour costs and operator exposure. The main objective of this study was to evaluate the influence of air-assistance on spray application in conventional tomato greenhouses. For this purpose three different spray conceptions were evaluated: 1) a modified commercial handheld trolley sprayer with two air assistance concepts; 2) a self-propelled sprayer; and 3) an autonomous self-propelled sprayer with remote control. All the sprayers considered were evaluated in terms of absolute and normalised canopy deposition, uniformity of distribution, and losses to the ground. In addition, the vertical liquid and air velocity distributions of the sprayers were assessed and compared with the canopy profiles and spray depositions. Yellow tartrazine (E-102 yellow) was used as a tracer for deposition evaluation. The results indicated that increasing the air velocity does not increase the efficiency of a spray application. In general, the modified handheld trolley sprayer showed the best results in terms of deposition and uniformity of distribution, especially at the lowest air assistance rate. These results were confirmed with evaluation of the uniformity of the air and liquid distribution.     

A spray technique for mass release of eggs of Micromus tasmaniae Walker (neuroptera: Hemerobiidae)

Laboratory and glasshouse tests showed that eggs of Micromus tasmaniae Walker (Neuroptera: Hemerobiidae) can be sprayed at 206 kPa pressure with a specially developed compressed-air sprayer without impairing viability. The effects of five materials (agar, sucrose, gelatin, plant glue and xanthan gum) in water solution on egg hatching were tested and xanthan gum solution (0·03%) was selected as a suitable liquid medium for suspending the eggs and making them adhere to potato foliage. Egg losses during spraying may be greatly affected by wind drift, the amount of exposed soil (which is related to the stage of foliage development) and other environmental factors. The possibility of a spray technique for mass release of M. tasmaniae eggs in the biological control programme for potato pests is discussed.     

Use of netting and whitewash spray to protect papaya plants against Nivun Haamir (NH)-dieback disease

A disease causing the decline of papaya (Carica papaya) plants was noticed in the Jordan Valley in 1982. The disease caused severe yellowing of the upper leaves and dieback of the apex. The disease was not transmissible mechanically and continued efforts to associate viruses and viroids have so far been unsuccessful. Epidemiological observations suggested that the disease is airborne and probably caused by a mollicute. In order to test this hypothesis, plots were covered by an insect-proof net and with white nets providing 15, 30 and 50% shade. The 30%, 50% and insect-proof nettings provided complete protection, and the 15% netting reduced disease incidence to <2%, compared with>37% in the uncovered control plot. Spraying plants at weekly intervals with a commercial whitewash solution was also found to be effective in reducing disease incidence. The advantages of using a range of netting field treatments as a simple means for obtaining information on the epidemiological nature of a new disease are described.     

A simple non-destructive technique for healthy and diseased leaf area assessment of potato plants

Summary A method for assessing the leaf area of potato plants was based on the number of leaves coinciding with imaginary vertical lines descending from a horizontal grid of points above the plant or crop canopy. Leaves seen through each vertically aligned pair of holes in a perforated double table, covering the midpoint of the exposed area, were counted and moved aside one by one, until the ground was seen. For both green and diseased surfaces the leaf area, or its horizontal component, was calculated as the product of sum of records and the grid cell size. Tested against a destructive method, the technique worked equally well for healthy and diseased leaf area of potato plants infected byPhytophthora infestans. The theoretic estimate of the standard error for a single measurement was derived as the geometric mean of the leaf area and the grid cell size. The method is also suitable forLAI of crop stands.     

Local and systemic control of powdery mildew (Leveillula taurica) on pepper plants by foliar spray of mono-potassium phosphate

A foliar spray of 1% (w/v) solution of the fertilizer mono-potassium phosphate (MKP) (KH₂PO₄) on the upper surfaces of lower leaves of greenhouse-grown peppers induced local and systemic control against Leveillula taurica, as compared with control plants. This protection was expressed by a reduction in the leaf area covered with sporulating colonies and in conidial production on leaf tissue, 24 or 48 h post-treatment, when MKP was applied on lower leaves of plants that had been exposed to the source of inoculum. Foliar application of MKP, initiated before or after exposure to heavily diseased plants as the source of inoculum, was effective in controlling powdery mildew. Application of MKP efficiently suppressed powdery mildew as expressed by inhibition of the development of new sporulating colonies, as well as the conidial production of the fungus on infected tissue. Microscopic examination indicated destruction of both hyphae and conidial structures on MKP-treated leaves. The efficacy of MKP in controlling powdery mildew on greenhouse-grown plants was compared with a sterol-inhibiting systemic fungicide. Both treatments significantly inhibited powdery mildew as compared with non-treated control plants, although the fungicide-based treatment seemed to be slightly more effective (not significant) in controlling the disease. Phosphate solutions were not phytotoxic to plant tissue and did not affect the yield, as compared with the fungicide treatment. However, a lower yield was recorded for the non-treated control plots because of mildew infection on leaves. These data indicate that MKP spray may be applied as an alternative practice for the control of powdery mildew in peppers.     

农杆菌介导法将β—1,3—葡聚糖酶基因导入油菜的研究初报

将克阼的烟草β－１,３－葡聚糖酶基因插入双子叶植物高效表达载体ｐＢｉｎ４３８中,构建了植物表达载体ｐＢＬＧ。利用农杆菌介导法,将此抗真菌基因导入甘蓝型双低油菜品种Ｈ１６５中,得到了抗卡那霉素的再生植株,并探讨了影响油菜分化的几个要素。结果表明：乙酰丁香酮及硝酸银等物质对油菜分化及绿苗的形成具有重要作用; 采对卡那霉素十分敏感,提高卡那霉素浓度可可能将一部分转化体淘汰,对８株再生株株进行了ＰＣＲ检测     

国家玉米工程技术研究中心(吉林)简介

为了充分发挥吉林省优越的玉米优势 ,配合“九五”科技攻关重中之重项目“玉米大面积高产综合配套技术研究开发与示范”课题 ,形成全国的玉米技术集散地和辐射源 ,成为全国最大的玉米产业网络 ,国家科委批准依托吉林省农科院成立了“国家玉米工程技术研究中心 (吉林 )”。国家玉米工程技术研究中心 (吉林 )的总体目标是 :立足玉米主产区 ,面向全国 ,走向世界。通过依托单位 ,采取承接委托、合作开发、技术转让等途径 ,引入国内外玉米新品种 ,开展以优化品种为中心的玉米工程化综合配套技术研究 ,形成玉米技术集散基地和转移网络 ,加速技术转…     

可建水仙茶制作工艺初探

可建水仙茶产自福建省建瓯市迪口镇可建村,该茶条索紧结,叶端扭曲,色泽油润暗砂绿,香气浓郁,具兰化清香,滋味入口细滑纯厚回甘,汤色油亮清澈橙黄,叶底厚软黄亮,叶缘朱砂红边或红点,品质优异,有“一叶赢得万户春”的美誉。上世纪60～70年代,可建水仙茶曾远销日本及东南亚国家,受到当地人民的青睐。为了迎合现代人的品茶口味,2004年,迪口镇可建茶厂选用可建水仙茶试制清香包揉型茶叶初获成功。现将可建水仙茶制作工艺简介如下。     

A rapid screening technique for drought resistance in potato (Solanum tuberosum L.)

Summary The reduction in growth in the dark of leaf dises floated over polyethylene glycol 6000 solution of water potential −0.4 MPa, relative to the growth of similar leaf dises floated over water for the same period, varied in the range 10–87% in 28 genotypes. The growth reductions in the genotypes tested were in general agreement with what is known about their drought resistance. Publication No. 906, Central Potato Research Institute, Simla.     

A method for raising brown planthopper (BPH), Nilaparvata lugens (Stal)

To get mass population of the BPH, a good method for raising BPH is needed. In this paper, a convenient method was recommended.     

Modelling the spray deposition and efficacy of two mineral oil-based products for the control of California red scale, Aonidiella aurantii (Maskell)

The pattern and quantity of pesticide deposition may affect the efficacy of pesticide treatments. In this study we evaluated under laboratory conditions the efficacy of two petroleum-derived spray oils (PDSO) (Laincoil^®, an nC21 oil with a content of 83% w/v, Oil A, and Sunspray Ultrafine^®, an nC21 with a content of 85% w/v, Oil B, both with an unsulfonated residue of 92%) applied at 1.5% concentration at five volumes (0.5, 1, 2, 3 and 4 ml) against different stages of Aonidiella aurantii Maskell (Homoptera: Diaspididae). In parallel, we characterized the deposition pattern of treatments resulting from these five volumes and two PDSOs. The objective was to model deposition characteristics and efficacy as a function of the deposited volume in order to determine the optimum volume per unit surface that should be applied to control this pest. Different models that depend on the developmental stage and relate to the efficacy of the treatment as a function of the deposited volume have been obtained for both PDSOs, thus providing a scientific basis for product efficacy comparison. Furthermore, our results are also relevant to find an adequate trade-off between sprayed pesticide volume and expected efficacy.     

A new variety of Salvia macrosiphon (Lamiaceae) for Iran

In this study, Salvia macrosiphon Boiss. var. longiflora Kharaz. is reported for the first time as one of the new varieties of Salvia macrosiphon in Iran. The morphological characters of this variety have been described in details.     

Sterile insect technique (SIT) in the near east — a transboundary bridge for development and peace

Mediterranean fruit fly, Ceratitis capitata (Wied.), is a major pest of fruits and vegetables throughout the region, reduces yield of marketable fruit and limits exports. The Arava Medfly Eradication Project (AMEP) was initiated in 1997, and serves as a pilot effort to begin implementing the sterile insect technique in the Near East. It could become a model for future implementation of the proposed EASTMED project, a plan conceived and planned by the International Atomic Energy Agency in 1994–1995 with input of regional experts. The target area lies in the Arava Valley between the Dead Sea and the Red Sea. AMEP activities include host mapping, population monitoring and suppression followed by weekly releases of sterile flies. This project will lead to permanent establishment and maintenance of Medfly free areas. In addition, new technologies are being tested under local conditions. This includes use of tsl male-only strains of medflies, aerial releases with a chilled insect release machine, female attractants and new trap designs. At present, the project relies upon long-distance shipping of pupae from Madeira, Portugal and Guatemala rather than local sources. The medfly population on the Israeli side of the Arava valley, was monitored in 132 trimedlure loaded traps. It dropped by July 1999 to 0.04 flies per trap per day from the pre-eradication level of 0.71 flies per trap per day in July 1998. In June 1999, only 19% of the traps captured wild flies as compared to 40% of the traps in June 1997. As medfly does not respect international boundaries, transboundary co-operation is a key factor for successful implementation. Current project status and plans for future expansion within Israel, Jordan and the Palestinian Authority will be presented.     

一种提取悬铃叶苎麻(B.tricuspis (Hance) Marino)花序 RNA的方法

应用改良CTAB法提取苎麻属野生种悬铃叶苎麻(Boehmeri.tricuspis(Hance) Marino)的花序RNA,通过1.2%琼脂糖凝胶电泳,测定分析260nm和280nm处的吸光值发现,应用该法提得的RNA完整性好,得率高;对其反转录产物进行AFLP分析表明,每一特定引物组合均能产生稳定清晰的条带,且在各引物间有差异.认为所提 RNA符合分子生物学实验要求.另外,本文还对提取RNA过程中应注意的一些事项进行了讨论.     

一种提取悬铃叶苎麻（ B. tricuspis （Hance） Marino）花序RNA的方法

应用改良CTAB法提取苎麻属野生种悬铃叶苎麻（Boehmeri．tricuspis（Hance）Marino）的花序RNA，通过1．2％琼脂糖凝胶电泳，测定分析260nm和280nm处的吸光值发现，应用该法提得的RNA完整性好，得率高；对其反转录产物进行AFLP分析表明，每一特定引物组合均能产生稳定清晰的条带，且在各引物间有差异。认为所提RNA符合分子生物学实验要求。另外，本文还对提取RNA过程中应注意的一些事项进行了讨论。     

Solanum microdontum (PI 558098): A diagnostic host plant for potato virus A

Solanum microdontum (PI 558098) develops diagnostic symptoms when inoculated with plant sap containing potato virus A (PVA). The symptoms consist of local lesions (2–4 mm), followed by systemic necrosis of leaf veins, bronzing of leaf surface, and leaf drop. Symptoms develop in a temperature range of 20–29 C with 4 to 8 Klux light intensity of 14 h daylength. Local lesions are visible within 1 wk of inoculation and can be caused by PVA containing sap dilutions of up to 1:100. Plants multiplied by shoot cuttings as well as those produced from true potato seed are equally sensitive. True potato seed production occurs under normal greenhouse conditions in cross-pollinated plants.     

A glasshouse progeny test for resistance to gangrene (Phoma foveata)

Summary Tubers were obtained from 80 glasshouse-grown seedlings of each of twelve progenies, inoculated withPhoma foveata Foister, and the mean percentage of infected tubers recorded. There was a good correlation (r=0.798) between this assessment and that made previously on field-grown tubers of eleven of the progenies. A gangrene test on glasshouse-grown tubers is suggested as a more rapid means of identifying progenies with useful levels of resistance.     

Performance of Cry1A.105-selected fall armyworm (Lepidoptera: Noctuidae) on transgenic maize plants containing single or pyramided Bt genes

Cry1A.105 is a Cry protein expressed in some transgenic Bacillus thuringiensis (Bt) maize products. In this study, performance of five populations of fall armyworm, Spodoptera frugiperda (J.E. Smith), were evaluated on four non-Bt and eight commercial and experimental Bt maize hybrids/lines (hereafter referred as maize products). The five insect populations included one Cry1A.105-susceptible strain, two Cry1A.105-resistant strains, and two F₁ heterozygous genotypes. The eight Bt maize hybrids/lines consisted of five single-gene Bt maize products containing Cry1A.105, Cry2Ab2, Cry1F, or Cry1Ab protein, and three pyramided Bt maize products expressing Cry1A.105/Cry2Ab2, Cry1A.105/Cry2Ab2/Cry1F, or Cry1Ab/Vip3A for targeting aboveground lepidopteran maize pests. In the study, neonates of each population were tested on leaf tissues in the laboratory and whole plants in the greenhouse. Cry1A.105 and Cry1F maize killed 92.2–100% susceptible larvae in both test methods, while resistant larvae survived well on these two maize products. Performance of the two F₁ populations on Cry1A.105 and Cry1F maize varied between the two test methods. In leaf tissue bioassay, Cry1Ab maize was marginally effective against the susceptible population. In contrast, few live larvae and little leaf injury from any of the five populations were observed on Cry2Ab2 and the three pyramided Bt maize products. The results of this study showed evidence of cross resistance of the Cry1A.105-resistant S. frugiperda to Cry1F and Cry1Ab maize, but not to the Bt maize products containing Cry2Ab2 or Vip3A. Data generated from this study will be useful in developing resistance management strategies for the sustainable use of Bt maize technology.     

Fabrication of homogeneous multi-walled carbon nanotube/poly (vinyl alcohol) composite films using for microwave absorption application

Poly (vinyl alcohol) (PVA)/multi walled carbon nanotubes (MWNT) nanocomposite films were fabricated and their microwave absorption behavior were evaluated using vector network analyzer in the frequency range of 8–12 GHz (Xband). The uniform, stable dispersion and well oriented MWNT within the PVA matrix were achieved through using sodium dodecyl sulfate (SDS) as dispersing agent. The surface morphology of the PVA/SDS/MWNT films was examined by scanning electron microscope (SEM). The SEM analysis of the film samples revealed the uniform appearance in the whole surfaces of the fabricated composite films. However, some roughness on the surface was observed due to the presence of MWNT in the film structure. The PVA/SDS/MWNT films show significant increase in microwave absorption which is improved by increasing the MWNT content. The PVA/SDS/MWNT nanocomposite film sample with MWNT loading of 10 wt% showed the maximum and the relatively high microwave absorption of 28.00 dB at the frequency of 8.6 GHz.