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51.
The synthesis of novel, fluorinated non-ester pyrethroids by electrophilic fluorination of a stabilised anion with N-fluorobenzenesulfonimide is reported. © 1999 Society of Chemical Industry  相似文献   
52.
Abstract

In field experiments conducted at the Punjab Agricultural University, Ludhiana during 1973–74 and 1974–75, pre-emergence application (one day after sowing) of methabenzthiazuron (1.05 kg a.i./ha), metoxuron (1.6 kg a.i./ha) and chlortoluron (0.75 kg a.i./ha) gave effective control of Phalaris minor and Avena ludoviciana in wheat without any phytotoxic effect on the crop. Methabenzthiazuron, metoxuron and chlortoluron gave 1410, 1420 and 1090 kg/ha, respectively, more grain than the unweeded crop and 590, 600 and 270 kg/ha more than the crop hand-weeded twice. Nitrofen (1.25 kg a.i./ha) applied pre-emergence was effective against P. minor only and gave substantial increase in grain yield. Terbutryne, dichlormate and linuron, while effective against P. minor, also had a phytotoxic effect on the crop.  相似文献   
53.
54.
ABSTRACT

Chromium (Cr) is an environmental pollutant and its accumulation up to toxic levels in the soil and plants by applying irrigation with untreated industrial effluents has become a major problem throughout the world, especially in developing countries like India. Various inorganic as well as organic compounds are known for their ability to reduce mobilization of heavy metals in soils for plant uptake and leaching to ground water. The present study was undertaken under controlled glasshouse conditions to assess the effectiveness of farm yard manure (FYM) applications (equivalent to 0, 1, and 2% organic matter on w/w basis) to ameliorate Cr toxicity in spinach grown in two texturally different soils (silty loam and sandy) contaminated artificially with five levels of Cr (0, 1.25, 2.5, 5.0, and 10.0 mg Cr kg? 1 soil as K2Cr2O7). The diethylene triamine pentaacetic acid (DTPA)-extractable Cr in soil (before seeding and after harvest), Cr concentration, and its uptake by shoots and roots of spinach increased with increasing level of applied Cr. Roots accumulated more Cr than shoots, which depicts limited translocation of Cr from roots to shoots. A significant decrease was observed in dry matter yield (DMY) of shoots as well as roots by raising levels of applied Cr (0 to 10 mg Cr kg? 1 soil) in both soils, but the extent of the DMY decrease was higher in the sandy loam soil. Application of FYM showed mitigating effects on Cr toxicity. The DMY was higher in the presence of FYM, than its absence, at all rates of applied Cr in both soils. The FYM application caused decline in the DTPA-extractable Cr in soil, and concentration of Cr and its uptake by shoots and roots of spinach at a given level of applied Cr. The magnitude of Cr toxicity and its amelioration by FYM application was higher in sandy soil compared to silty loam soil. The results of this study indicated that FYM application to the soil could be used as an effective measure for reducing Cr toxicity to crop plants in Cr-contaminated soils irrigated by untreated industrial effluents.  相似文献   
55.
Summary Most of the commercial hybrids of indica rice are based on wild abortive (WA) source of cytoplasmic-genetic male sterility (CMS). Such cytoplasmic uniformity may lead to genetic vulnerability to disease and insect pests. To overcome this problem, diversification of CMS sources is essential. Crosses of 46 accessions of O. perennis and two accessions of O. rufipogon as female parents were made with two restorers (IR54, IR64) of WA cytosterility. Sterile hybrids were backcrossed with the respective recurrent parents. Of all the backcross derivatives, one line having the cytoplasm of O. perennis Acc 104823 and the nuclear background of IR64 was found to be stable for male sterility. The newly developed CMS line has been designated as IR66707A. This line is completely sterile (0% seed set) under selfed conditions. Crosses of IR66707A with 10 restorers of WA cytoplasm showed almost complete (93–100%) pollen sterility, indicating that the male sterility source of IR66707A is different from WA sterility. Southern hybridization of IR66707A, O. perennis (cytoplasmic donor), IR66707B (maintainer) and V20A (WA cytoplasm) using mitochondrial DNA specific probes (5 endonucleases × 8 probes) showed identical banding patterns between IR66707A and O. perennis. However, in more than half of the combinations, different banding patterns were observed between IR66707A and IR66707B and between IR66707A and V20A. The results suggest that IR66707A has the same cytoplasm as the donor (O. perennis), and CMS may not be caused by any major rearrangement or modification of mtDNA. The new CMS source identified will be useful in cytoplasmic diversification in hybrid rice breeding.  相似文献   
56.
Blood flow of the preovulatory follicle (POF) wall can be used as a predictor of the quality of POF. Our aim was to determine the correlation of blood flow of POF with the POF diameter, and intra‐follicular and plasma concentrations of Insulin‐like Growth Factor‐I (IGF‐1) and oestradiol in dairy buffalo. Nine Murrah buffalo subjected to an ovulation synchronization protocol (Ovsynch) were assessed on day 10 of the protocol for diameter and blood flow of POF, followed by the aspiration of follicle fluid. Prior to follicular aspiration, blood samples were obtained from jugular vein for estimation of IGF‐1 and oestradiol. The vascularity of POF was determined (Range: 250–967 pixel2) along with intra‐follicular and plasma concentration of IGF‐1 (Range: 9.3–31.8 ng/ml and 14.7–29.7 ng/ml respectively) and oestradiol (Range: 124.2–447.9 ng/ml and 0.25–1.05 ng/ml respectively). Diameter of the POF was weakly correlated (r = 0.21, p < 0.01) with blood flow to it. As compared to POF diameter, the blood flow of POF had greater positive correlation with intra‐follicular and plasma concentrations of hormones (IGF‐1 and oestradiol). A strong positive correlation was recorded between intra‐follicular IGF‐1 and oestradiol. Also, plasma concentrations of oestradiol and progesterone were negatively correlated In brief, assessment of the blood flow of the POF is a non‐invasive and reliable indicator of its functional competence as compared to the POF diameter.  相似文献   
57.
The effect of different levels of nitrogen N0 (0), N1 (60), N2 (80) and N3 (100) kg/ha and phosphorus P0 (0), P1 (32), P2 (48) and P3 (64) kg/ha on the nutrient composition of sweet pepper fruits was investigated. Dry matter content was found to increase at N0 level at highest concentration of phosphorus and as well as at P0 level at highest concentration of nitrogen. At P2 concentration, at different levels of nitrogen, the ascorbic acid content was more as compared to that at other levels of phosphorus. Protein content was found to increase with increasing nitrogen doses and was also found to increase at maximum dose of nitrogen with increasing concentration of phosphorus. Capsaicin content was found to be more at P2 level at different doses of nitrogen. The uptake of phosphorus by the pepper fruit was found to increase at N0 and N2 levels. Maximum uptake of phosphorus and dry matter content was observed at N0P3 levels. Maximum protein, ascorbic acid and capsaicin contents were found at N3P2 level.  相似文献   
58.
The cultivated rice (Oryza sativa L.) is known to contain two major subspecies, indica (O. sativa L. ssp. indica) and japonica (O. sativa L. ssp. japonica). The indica and japonica differentiation resulted in significance of hybrid sterility and hybrid breakdown, which are barriers of gene flow between the two major subgene pools within O. sativa. Traditional classification of indica and japonica germplasm based on isozymes. Here, we report the identification of several random amplified polymorphic DNA (RAPD) markers that have alleles specific in indica or japonica varieties and thus provide a quick and accurate tool to distinguish japonica lines from indica ones.  相似文献   
59.
60.
The contact and feeding toxicity of NeemAzal T/S (EID Parry, Chennai, India) to the parasitoid Encarsia sophia (Girault & Dodd) was compared with three synthetic insecticides (chlorpyriphos, endosulfan and triazophos) against immatures and adult emergence. NeemAzal T/S (1.0%) at lower dose (200 mg/l) did not cause any effect on the emergence of E. sophia adults, but there was a significant reduction in emergence at higher doses (800 mg/l). Also, it did not show contact toxicity to adults of E. sophia, but there was a significantly high feeding mortality in a dosage dependant manner, whereas chlorpyriphos, endosulfan and triazophos showed high toxicity both by contact and feeding method. Three neem preparations registered in India, NeemAzal T/S, Nimbecidine (T. Stains, Coimbatore) and Godrej Achook (Godrej Agrovet, Mumbai) were tested against egg and larval stages of Chrysoperla carnea (Stephens) at three dosages, using a synthetic insecticide, triazophos 40 EC (200 mg/l), for comparison under laboratory conditions. The three biorationals did not induce any adverse effect on the hatchability of C. carnea eggs. The mortality of the first instars of C. carnea was not affected by any of the azadirachtin enriched formulations; however, at higher dosage of 800 mg/l these neem based products resulted in increased mortality of the first and second instar larvae of C. carnea relative to the untreated controls. Whereas, triazophos induced very high mortality rates (85.0, 89.0 and 81.5%) of all the three larval instars. The neem based insecticides showed a dosage-dependant effect on the larval instars of C. carnea. Thus, these biorationals show that there is a potential to use them in an IPM system, being safe for natural enemies of B. tabaci in cotton.  相似文献   
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