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91.
Previous research suggests that potato cultivars offer little aphid resistance. However, few studies have measured the effects of host cultivar on aphid age dependent life table statistics or related these measures to field performance. In this study, laboratory and field studies assessed four commercial potato cultivars (Anya, Desiree, Pink Fir Apple, Santé) for resistance to Myzuspersicae. Cultivars were found to show considerable differences in resistance. In the laboratory, the intrinsic rate of increase (rm) and effective fecundity of M. persicae was lowest on cv. Anya and highest on cv. Desiree. Aphids also took longer to develop to adults and were smaller in size on Anya compared with Desiree. Field studies over two seasons found that M. Persicae infestations started earlier on Desiree than on Anya and that the greatest weekly counts were recorded on the former.  相似文献   
92.
新疆盐渍化区土壤养分的空间结构和分布特征   总被引:2,自引:2,他引:2  
结合地理信息系统(GIS),在面积约为2000km2的新疆典型盐渍化区渭干河流域布设了土壤取样点43个,测定了土壤表层(0~30cm)养分(全氮、全磷、全钾、碱解氮、速效磷、速效钾)的空间变异规律。结果表明:七种养分元素中除了碱解氮、速效磷的含量服从对数正态分布,其它养分元素均符合正态分布;半方差分析得出各项目都能很好的用模型来拟合,全氮、全磷、速效钾符合指数模型,碱解氮、速效磷、全磷符合球状模型。只有有机质是符合高斯模型;全氮和碱解氮的系统空间相关性很弱,而其余养分元素均表现出中等强度的空间相关性,变程在14.3km~67.0km之间,相差比较大;用Kriging插值法对未测点的养分元素进行最优估计,绘制含量分布图,从而可以更直观的反映研究区土壤养分的空间结构和分布特征。  相似文献   
93.
A green atmosphere and interaction with nature (plants and flowers) can considerably improve the human senses and sanity by decreasing the stress associated with anxiety, depression, neurotic impairment, and other psychologic symptoms. The current paper reports a therapeutic horticultural study’s findings regarding the effect of indoor foliage plants and flower arrangements on health prospects of surgical patients. Two surgical wards, ward A (with foliage plants and arranged flowers) and ward B (without foliage plants and flowers), were selected for the study. A total of 270 patients were randomly assigned to either ward to give 135 patients in each. Patients admitted to ward A had significantly more optimistic and promising health improvements than those in ward B. Provision of foliage plants and flower arrangements to the patients in ward A resulted in shorter postoperative stays, lower intake of analgesics, lower pain intensity, less stress fatigue, and improved vital signs (blood pressure, heart rate, respiration rate, body temperature) as compared to patients in ward B. Moreover, analyses showed that patients in ward A had a stronger psychologic frame of mind regarding their recovery from surgery and had more positive emotions and feelings regarding their stay in the hospital. They also felt that the ward atmosphere was more calming, pleasant, and satisfactory. Additionally, small group discussions and focal interviews with ward doctors and nurses confirmed the findings of the questionnaire that foliage plants & flower arrangements create a cherished environment in the ward, reduce patients’ stress, improve medical and psychologic status of patients, and also conveye positive messages of the hospital. These findings confirm the therapeutic value of horticultural activities, particularly in surgical patients in a stressed hospital setting.  相似文献   
94.
The objective of this study was to determine the effects of soybean meal (SBM) or spray-dried blood meal (BM) supplementation of diets based on untreated (UNT-WS) or alkaline hydrogen peroxide-treated wheat straw (AHP-WS). A 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments was used. Variables included nutrient digestion and flow to the duodenum. Four Simmental steers (average weight 477 kg) fitted with ruminal and duodenal cannulas were fed 65% UNT-WS or AHP-WS based diets in 12 equal portions daily. Diets were formulated to contain 10% CP. Chromic oxide was used as the digesta flow marker and purines were used as the microbial marker. There were no straw type x protein source interactions. Total tract and ruminal OM digestibility were approximately 25% greater (P < .04) when AHP-WS was fed than when UNT-WS was fed. Source of protein did not affect (P > .10) OM or fiber digestion in the rumen or total tract. Ruminal digestion of NDF and ADF was increased (P < .01) by 51 and 40%, respectively, when AHP-WS was fed than when UNT-WS was fed. Main effect means (P > .10) for N flow to the duodenum as a percentage of N intake were 128.2, 142.5, 133.4, and 137.6 for UNT-WS, AHP-WS, SBM, and BM treatments, respectively. Despite increased (P < .01) ruminal OM digestion for AHP-WS, microbial N flow to the duodenum was greater (P < .01) when UNT-WS was fed than when APH-WS was fed.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
95.
The aim of present study was to know about past cultivation of pseudocereals and millets in Kashmir province of Indian state of Jammu and Kashmir. These crops which were cultivated throughout Kashmir in plains as well as in hilly areas are buckwheat species, Fagopyrum esculentum and Fagopyrum tataricum; amaranth and minor millets, Setaria italica and Panicum miliaceum. In Kashmir these are now forgotten crops. Few plants of amaranth (Amaranthus caudatus) are still grown in almost every kitchen garden in Kashmir. The crop is however not cultivated commercially neither in Kashmir nor in Ladakh or Jammu provinces of the state. Our study has revealed that cultivation of all these crops has been abandoned some five or six decades back throughout Kashmir excepting in few farflung hilly areas in north Kashmir. Currently these crops are also cultivated in Ladakh, but here also their cultivation is dwindling rapidly. The reasons as to why farmers have abandoned these crops and are increasingly losing interest in these biological assets in the areas of their present cultivation have been discussed. There is a need to rescue these threatened crops which have many advantages besides, being nowadays categorized as quality health foods. During our survey in Ladakh province we have collected 30 germplasm accessions of these crops from various locations. These have been deposited in National Seed Gene Bank at NBPGR, New Delhi for conservation and evaluation. The improvement and revival of these lost crops has the potential to diversify agriculture, food system and income of the poor farmers and have the ability to ensure food security and livelihood of the people in this Himalayan state under future adverse climatic conditions.  相似文献   
96.
97.
In the conservation agricultural systems practised in Australia, cultivation is not commonly utilised for the purpose of weed control. However, occasional use of tillage (strategic tillage) is implemented every few years for soil amelioration, to address constraints such as acidity, water repellence or soil compaction. Depending on the tillage method, the soil amelioration process buries or disturbs the topsoil. The act of amelioration also changes the soil physical and chemical properties and affects crop growth. While these strategic tillage practices are not usually applied for weed control, they are likely to have an impact on weed seedbank burial, which will in turn affect seed dormancy and seedbank depletion. Strategic tillage impacts on seed burial and soil characteristics will also affect weed emergence, plant survival, competitive ability of weeds against the crop and efficiency of soil applied pre-emergent herbicides. If growers understand the impacts of soil amelioration on weed demography, they can more effectively plan management strategies to apply following the strategic tillage practice. Weed seed burial resulting from a full soil inversion is understood, but for many soil tillage implements, more data is needed on the extent of soil mixing, burial of topsoil and the weed seedbank, physical control of existing weeds and stimulation of emergence following the tillage event. Within the agronomic system, there is no research on optimal timing for a tillage event within the year. There are multiple studies to indicate that strategic tillage can reduce weed density, but in most studies, the weed density increases in subsequent years. This indicates that more research is required on the interaction of amelioration and weed ecology, and optimal weed management strategies following a strategic tillage event to maintain weeds at low densities. However, this review also highlights that, where the impacts of soil amelioration are understood, existing data on weed ecology can be applied to potentially determine impacts of amelioration on weed growth.  相似文献   
98.
Canola cultivars positively responded to sulphur fertilization in term of seed yield and oil quality. Oscar cultivar increased seed yield 53% as compared to control plots. Sulphur @ 45 kg ha–1 increased seed yield, biological yield, and quality of rapeseed. Number of days to flowering (76), number of pods plant–1 (372), number of seeds pod–1 (24), plant height (173 cm), biological yield (15547 kg ha–1), seed yield (2209 kg ha–1), harvest index (19%), glucosinolate (μmol g–1) content (31.03 μmol g–1) and oil content (45.81%) was enhanced significantly with sulphur treated @ 45 kg ha–1 applied plots as compared to delayed flowering (78 days), shortest plant (151 cm), pods formation (298 pods), seed pod–1 (21), biological yield (11090 kg ha–1), seed yield (1436 kg ha–1), and oil content (42.62%) in control plots. Among cultivars “Oscar” ranked first in different growth stages and attain more plant height (164 cm), and examined substantial number of pods plant–1 (359), seeds pod–1 (24), seed yield (2005 kg ha–1), biological yield (14298 kg ha–1), harvest index 17%, and oil content (46.29%) as compared to other sowed cultivars. On the basis of the result it is recommended that cultivar “Oscar” treated with sulphur @ 45 kg ha–1 should be applied for higher yield and quality of rapeseed under the agro-climatic condition of swat valley.  相似文献   
99.
Plant growth promoting rhizobacteria (PGPR) promote the plant growth by various direct and indirect mechanisms. The present study was undertaken to isolate and characterise the PGPRs of plum (Prunus domestica) rhizosphere in Pakistan. A total of 95 rhizobacteria were isolated, out of which 40 strains were selected on the basis of morphological, biochemical and Gram staining characteristics. The selected isolates were screened for in vitro plant growth promoting potential and were subsequently evaluated for host plant growth promotion. The selected isolates demonstrated strong lytic enzymatic activities and were able to produce ammonia, siderophore, Hydrogen cyanide along with capability of phosphate solubilisation. Moreover, the results showed a significant growth suppression of pathogenic Fusarium oxysporum and Rhizoctonia solani in an in vitro assay. The plant microbe interaction study was carried out using 11 most efficient rhizobacterial strains inoculated to roots of plum plants. The inoculated PGPRs significantly augmented the leaves number per shoot, shoot diameter, shoot length and plant height. The inoculation also significantly increased the chlorophyll contents of leaves, concentration of micro and macro nutrients compared with control. The current study shows the importance of these selected PGPRs as bio-fertilizer to improve the health and productivity of plum species in Pakistan.  相似文献   
100.
Mass vaccination with reduced dose 1/50 Rev 1 strain live vaccine (1–2 109 colony forming units), administered subcutaneously, over a four and a half year period reduced the prevalence of Brucella melitensis in Kuwait's small ruminant population from 5.8% in 1993 to 2.02% in 1997.Serological test results using the Rose Bengal Plate Test, Rivanol Agglutination Test and Complement Fixation showed no evidence of persistence of positive serology in animals nine or more months after vaccination. Questionnaires and post-vaccination flock inspections found that the effects on gestation (abortions) were minimal – and not proven to be due to the vaccine.The conclusion from these findings is that mass vaccination with reduced dose Rev 1 administered by the subcutaneous route is a practical field strategy for control of Brucella melitensis.  相似文献   
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