长武塬区苹果园和农田相互转换的深层土壤水环境效应

研究长武塬区苹果园和农田相互转换后0~1 000 cm土壤含水量特征，分析了苹果园土壤干燥化和苹果园转换为农田后土壤水分的恢复效应。结果表明：2、7、17、23、29 a苹果园200~1 000 cm的平均土壤含水量分别为22.8%、21.4%、16.8%、15.4%、14.9%。500~1 000 cm土层中，29 a苹果园平均土壤含水量（14.5%）高于23 a的果园（13.3%）；17~29 a的苹果园均表现为轻度干燥化；基于苹果园和农田转换后土壤水分变化情况估算，苹果园最大种植年限为21 a。苹果园转换为农田1、5、10 a后，农田200~1 000 cm土层土壤含水量分别为：15.3%、15.7%和16.2%，恢复到土壤稳定湿度以上的土层厚度分别为140 cm（1 a）、220 cm（5 a）和400 cm（10 a）。     

沼肥对苹果生物性状的试验初报

笔者对苹果施用沼肥后的生物性状进行了长达4a的对比试验研究，采取对比设计法，在叶、枝、花、果等器官的相关指标取得了极为明显的效果，在果业生产上有极好的推广价值。     

苹果试管苗不定根起源及其发育状况的研究

利用光学和扫描电子显微镜观察结果表明,经琼脂生根培养基诱导产生的长富—2苹果 (Malus pumila Mill.) 试管苗的不定根起源于维管形成层。这种不定根发育不良,根表面缺乏根毛,内部解剖构造为典型的初生结构。为避免因不定根吸收、运输能力差而影响试管苗移栽成活,宜采用通透性良好的基质进行瓶内或瓶外生根,可诱导出优质不定根。     

木垒县旱地春小麦生产潜力初探

本文通过对旱地春小麦生产潜势及生产潜力的系统分析,揭示了影响提高春小麦产量的限制因子,明确了该县春小麦潜在的最高产量及可能达到的产量水平,同时提出了切合当地实际的增产途径,为将春小麦产量提高到一个新的水平提供了理论依据。     

灭菌肥Ⅰ型涂治苹果树腐烂病效果

试验于１９９２～１９９４年在山东和北京的６个地区，１４个苹果园进行。田间试验表明，用灭菌肥Ⅰ型５０倍液涂治苹果树腐烂病患处，平均治愈率可达９０％以上，比对照２％福美砷当年平均治愈率提高７．２２─２９．５１％，周年平均治愈率提高１８．０５％～３２．３９％，愈伤组织宽度增加３．０３％～２９．２３％。室内试验表明，灭菌肥Ⅰ型最低抑菌剂量１０００倍，抑菌面积可达２２８９．０６ｍｍ２。     

Comparative studies of strains of infectious bovine rhinotracheitis virus isolated from latently infected calves

Three strains (479 C, 778 TL, 982 LE) of infectious bovine rhinotracheitis (IBR) virus isolated from latently infected calves were compared with the prototype strain of IBR virus (LA strain) in studies which included restriction endonuclease analysis, experimental infection, and reciprocal cross protection tests in cattle. From the restriction endonuclease analysis it appeared that the 3 "latent" viruses were derived from the same isolate, and that it differed slightly from the LA strain. However, latency does not seem to have affected the pathogenicity or the immunogenicity of the virus. This is demonstrated by the identical clinical and virologic response of calves subjected to experimental infection with the various strains under study, and by the finding that when the LA strain and a "latent" strain (982 LE) were tested in cross protection tests in cattle, they proved to be mutually protective.     

Pelargonium flower-break and pelargonium line pattern viruses in the Netherlands; purification,antiserum preparation,serological identification,and detection in pelargonium by ELISA

Two viruses, detected frequently in the Netherlands in pelargonium, were identified by serology and test plant reactions. Antisera were prepared and an ELISA procedure was developed to detect the viruses in pelargonium.One of the viruses, PFBV-N, proved to be pelargonium flower-break virus. With the antiserum to PFBV-N, it could be detected reliably throughout the year inPelargonium zonale Springtime Irene.The other virus, PLPV-N, was serologically closely related to pelargonium line pattern virus (PLPV) and to pelargonium ring pattern virus (PRPV), as were an old virus isolate from Saturnus, collected in the Netherlands in 1971 (L128), and PLPV isolates from Yugoslavia (PLPV-Y) and Denmark (PLPV-D). There were only minor differences in host-plant reactions between the virus isolates. Based on these tests, PLPV and PRPV are considered as isolates of the same virus, for which, for practical reasons, the name pelargonium line pattern virus is proposed.PLPV could be reliably detected by ELISA inP. zonale Springtime Irene and Amanda throughout the year with only a few exceptions. InPelargonium peltatum Tavira, however, reslts were erratic due to uneven distribution of virus in the plant. Best results were obtained when petioles of fully expanded leaves were tested.     

苹果渣替代麦麸饲喂雏鸡效果试验

选用400只商品代尼克红母雏,随机分为4组,每组100只,设5个重复,每个重复 20只。试验组日粮分别由基础日粮和用风干未发酵苹果渣粉、半干发酵苹果渣粉、膜发酵苹果 渣粉分别替代基础日粮中5％的麸皮。试期为6周。结果显示,添加半干发酵苹果渣粉组和膜 发酵苹果渣粉组试鸡6周龄平均体重及日增重显著高于喂基础日粮的对照组和风干未发酵苹 果渣粉组(P<0．05),喂基础日粮的对照组略高于风干未发酵苹果渣粉组,差异不显著 (P>0．05)。表明发酵苹果渣粉对雏鸡生长发育有显著的促进效果。     

Effects of Latent Infection of Stock Plants and Abundance of Thrips on the Occurrence of <Emphasis Type="Italic">Tomato spotted wilt virus </Emphasis>in Chrysanthemum Fields

DAS-ELISA proved to be reliable enough to detect a latent infection by Tomato spotted wilt virus (TSWV) in asymptomatic stock plants of chrysanthemum. A high density of Frankliniella occidentalis, the predominant vector, in the presence of latently infected stock plants resulted in a high incidence of disease in the chrysanthemum production field. The incidence of disease was low when the vector thrips were not abundant in spite of the presence of latently infected stock plants. These results suggest that an infestation of the vector thrips causes severe secondary spread of TSWV originating from latently infected stock plants in chrysanthemum production fields. Received 27 July 2001/ Accepted in revised form 27 November 2001