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21.
A predictive model for daughter pregnancy rate (DPR) in Indian Murrah buffaloes has been developed. The data pertaining to first lactation reproduction traits, viz., age at first calving (AFC), first service period (FSP), and number of services per first conception (NS/FCON) of 719 Murrah buffaloes calved from 1985 to 2010 at the National Dairy Research Institute (NDRI), Karnal (Haryana), India were adjusted against significant environmental influence. First lactation reproduction records of 474 Murrah buffaloes were used for determining voluntary waiting period (VWP) and estimating DPR. Seven simple and multiple regression models in each case were developed where the buffaloes had their first insemination after 63 days (DPR 63), 84 days (DPR 84), and 105 days (DPR 105) of first calving. Among the seven models (I to VII) for DPR 63, DPR 84, and DPR 105, model II, having only FSP as an independent reproduction variable, was found to be the best prediction model, based on the four statistical criterions (high coefficient of determination (R 2), low mean sum of squares due to error (MSSe), conceptual predictive (CP) value, and Bayesian information criterion (BIC)). Three linear equations were developed using model II, viz., DPR 63?=?0.0033 (274???FSP), DPR 84?=?0.0027 (332???FSP), and DPR 105?=?0.0027 (310???FSP). The average errors for the prediction of DPR 63, DPR 84, and DPR 105 were 1, 13, and 8 %, respectively. Therefore, 63 days of VWP is the optimum period for getting the best DPR in Indian Murrah buffaloes.  相似文献   
22.
In tests under aseptic conditions, the herbicides hexazinone (PrononeTM5G® and Velpar L.R.®), glyphosate, and triclopyr reduced seedling growth and mycorrhizal development of Pinus contorta var. Litifolia and Picea glanca. Triclopyr was most toxic of the tour herbicide formulations. Under greenhouse condition, only 2 formulations of hexazinone (Pronone TM5G® and Velpar L.®) were tested. At high concentrations (2 and 4 kg/ha) it reduced growth and mycorrhizal infections significantly but showed recovery with time. No adverse effects were observed at low concentration (1 kg/ha). In general, seedlings inoculated with mycorrhizal fungus (Suillus tomentosus), were more sensitive to herbicide than the ones without mycorrhizal inoculation. Under field conditions overall effects of herbicide application were less intense. Only 4 kg/ha rates of hexazinone resulted in reductions in seedling growth and mycorrhizal infections. The nonmycorrhizal seedings planted in the field developed mycorrhizae in over 40% of short roots within 2 months after planting in all herbicide treatments.  相似文献   
23.
The effect of pre-inoculation with VA mycorrhizae on Fusarium wilt of Albizia procera and Dalbergia sissoo was done in a green house trial. Inoculation with Fusarium spp. decreased plant growth compared to noninoculated controls. Mycorrhizal plants were significantly higher than nonmycorrhizal ones. In addition to plant growth, the disease severity caused by Fusarium spp. reduced significantly when inoculated with VA mycorrhizae. The lowest percentage of Fusarium spp. were found on plants when treated with VA mycorrhizae. The population of Fusarium spp. were higher in the rhizosphere of nonmycorrhizal roots. The P concentration in the leaves of mycorrhizal and nonmycorrhizal plants were higher in the absence of Fusarium spp.  相似文献   
24.
We documented the status of fern diversity,biomass and carbon accumulation at Chilapatta Reserve Forest in Cooch Behar Wildlife Division,West Bengal.Stratified random nested quadrat sampling was adopted for analyzing the qualitative and quantitative characters.Nineteen fern species were recorded,of which two are yet to be identified.Identified species were of eight families and nine genera.Highest and lowest frequency recorded were 25.44 and 0.19 while relative frequency varied from 3.16 to 12.25.Fern density ranged from 93 to 13,403 individuals·ha-1.Most of the species were widely distributed.IVI values ranged from 7.54 to 37.45.The above ground portion of ferns accumulated the major portion of biomass and carbon.  相似文献   
25.
在孟加拉西部的Pundibari地区,研究在4个采集(豆荚)时间,3个采集豆荚长度(〈10cm,10-20cm和〉20cm),以及进行的13种预处理对大叶合欢种苗生长和萌发率的影响。豆荚采集时间为2月19日,且没有任何预处理,大叶合欢种子萌发率为92.5%。这明确表明,在2月19日采集的种子具有非休眠,有活力和生理成熟的特性。从长度为10-20 cm豆荚剥离出的种子,2月19日播种,种苗生长良好。利用硫脲预处理种子后,种子的萌发率并没有表现出明显提高,但是当利用低浓度硫脲(100 μL·L-1)预处理种子后,有利于种苗生长。  相似文献   
26.
Phellinus tremulae is the most important decay fungus on Populus tremuloides. In forest industries using aspen wood chips, two blue-stain fungi Ophiostoma crassivaginatum and Ophiostoma piliferum cause considerable reduction in the value of the end product. Thirty-eight homologues and analogues of 4-phenyl-3-butenoic acid were studied against P. tremulae, O. crassivaginatum, and O. piliferum. Varied inhibition of the in vitro growth of these fungi was observed at 1–1000 μg/ml. The wood-chip colonization by P. tremulae was not affected by the six most active compounds at 1 μg/ml, however, at 10 and 100 μg/ml the growth of P. tremulae on wood chips was totally arrested. 4-Phenyl-3-butenoic acid and 4-phenyl-3-butynoic acid prevented blue-stain development on wood chips at 1 μg/ml.  相似文献   
27.
The effects of the herbicide glyphosate [N-(phosphonomethyl)glycine]on seedling growth of Pinus resinosa and on the ectomycorrhizal development of the symbiotic fungus Paxillus involutus were investigated under greenhouse and field conditions. Glyphosate at 0–54 and 3–23 kg ha?1 did not reduce seedling growth or ectomycorrhizal development under greenhouse conditions. There was no seedling mortality due to glyphosate treatment at either rate. Under field conditions, seedling growth of P. resinosa and ectomycorrhizal development of P. involutus were not affected by the above rates. Seedlings (46–48%) failed to survive in non-glyphosate-treated plots, presumably because of weed competition, whereas all survived in glyphosate-treated plots. All the non-mycorrhizal seedlings were colonized bv indigenous mvcorrhizal fungi within 2 months after planting in both control and glyphosate-treated plots. The injection rates varied from 74–86 %.  相似文献   
28.
From March 2007 to March 2009 we quantified plant diversity at Chilapatta Reserve Forest in Terai Duars in the Indian eastern Himala-yas. We sampled stratified random nested quadrats. Species richness was 311, representing 167 genera and 81 families. The species diversity index and concentration of dominance of the forest were 2.20 and 0.0072, respectively. Shannon-Wiener index and evenness indices were 4.77 and 1.44, respectively. The Importance Value Index (IVI) of species ranged from 0.13 to 37.94. The estimated diversity indices indicated heterogene-ity of the forest in its composition, structure, function and dynamics. Rich forest plant diversity supports the need for continued conservation of tropical forests.  相似文献   
29.
The study was conducted to assess early-expressed reproductive traits of Boran cattle and their crosses with Jersey and Holstein Friesian (HF). The traits studied were age at first services (AFS), number of services for first conception, age at first calving (AFC), first dry period (FDP), first calving interval (FCI), and first service period (FSP). Genetic group and period of birth/calving had a significant (p?<?0.05) effect on reproductive traits. The Boran cattle were inferior to HF or Jersey crosses. First crosses (F 1) for Jersey and Boran (50 % Jersey: 50 % Boran) showed a significantly (p?<?0.05) younger AFS (by 7.25 months) and AFC (by 10.75 months), had shorter FCI (by 63.27 days), FDP (by 61.13 days), and FSP (by 60.3 days), and needed less (by 0.35) numbers of services per first conception as compared to the Boran cattle. The F 1 for Jersey and Boran (50 % Jersey: 50 % Boran) crosses showed better performance than the F 1 for HF and Boran (50 % HF: 50 % Boran). Heritability values for AFS and AFC were the highest and were estimated at 0.51?±?0.10 and 0.49?±?0.13, respectively, and lowest heritability was recorded for FDP (0.02?±?020) and FSP (0.10?±?0.29). The genetic correlation was highest (0.10?±?0.20) between AFS and AFC and was lowest (?0.01?±?0.66) between FCI and FSP. The breed additive for Jersey was only significant (p?<?0.01) for AFS and AFC. The crossing of HF with Boran cattle has desirably reduced 9.16?±?2.88 months in AFS; the corresponding reduction in AFS was 3.49?±?3.59 months by crossing with Jersey. The performance comparisons and genetic and crossbreeding parameters indicated that crossbreeding of Boran with HF or Jersey can improve reproductive performance.  相似文献   
30.
We examined the changes in body weight (BW), back-fat thickness (BFT) and blood metabolites in relation to postpartum (PP) ovarian activity status in twenty female yaks raised under semi-intensive system. BFT and ovarian activities, like follicle development, ovulation (OV) and corpus luteum (CL) development, were monitored from 4 to 15 weeks (wk) PP using ultrasonography. Resumption of ovarian activity was confirmed with ovulation of dominant follicle (DF) and subsequent CL development, and >1 ng/ml progesterone concentration in blood plasma sample after 1week of ovulation. Yaks were further classified as cyclic (with CL), acyclic (without CL), and cystic (with >25 mm follicular cyst; FC). Within 20 weeks PP, 60% yaks resumed cyclic ovarian activity, while 25% failed to initiate cycling activity, and 15% developed follicular cysts. In all categories of yak, BW gradually decreased (p < .05) till nadir; however, nadir reached earlier (p < .05) in acyclic yaks. BFT differed (p < .05) among the yak groups, but it tended to be higher in cyclic yaks as compared to acyclic and cystic. No difference (p > .05) in non-esterified fatty acids (NEFA) values was found among the different categories of yaks, whereas, beta-hydroxy butyrate (BHB) levels were higher in cystic animals as compared to acyclic and cyclic. Blood glucose levels decreased in all yaks during initial 2 weeks after calving. Our findings suggest that yaks with low BW, BFT and glucose levels, and higher BHB values were at risk of delayed resumption of ovarian activity and concomitant development of follicular cysts.  相似文献   
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