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61.
Land development, improved systems of irrigation and drainage, and proper irrigation scheduling are becoming more and more important for the success of command area development of the various major and minor irrigation schemes. For realistic planning and execution of such programmes or for improving existing ones, a systematic evaluation of the various components of the existing systems would be necessary but is invariably lacking. This paper presents an attempt made in this direction at C.S.S.R.I. farm, Karnal (India) to evaluate the integrated effect of water management technology on the efficiency of the irrigation system. The parameters selected for evaluation were the efficiencies of pumping, conveyance and field application. Besides these three parameters, water use efficiency, an index of crop production per unit of water applied, was also evaluated.Investigations revealed that pumping efficiency for electrically driven centrifugal pumps was about 52% and the corresponding value for diesel engine run pumps sets was 30%. The conveyance efficiency in the study area was as high as 93% because the seepage loss in the field channels laid in the alkali soils of the study area was only 7%. The field layout for water application in the study area consisted of long, narrow borders. The water application efficiency for this system was 58% for a wheat crop and 42% for rice. The overall system efficiency for wheat crops was observed to be 54% as against a value of 39% for rice.The observed average total water requirements and water use efficiencies for wheat were 46 cm and 70 kg/ha cm?1 and for rice 150 cm and 46 kg/ha cm?1, respectively. At these efficiencies, it was also noted that a cavity tubewell would command an area of 4.5 ha, with rice and wheat as the principal crop rotation.From this study, it can be inferred that reasonably high irrigation system efficiencies (54% as against the national average of about 30%) are possible with good water management at farm level.  相似文献   
62.
Summary Dry seeds of palmarosa (Cymbopogon martinii Stapf) var. motia were subjected to 12 doses of gamma rays ranging from 5 kr to 100 kr to find out the effects of gamma irradiation on growth parameters, herbage yield and yield and quality of essential oil. Several biological parameters such as seedling growth, pollen fertility, mitotic chromosome behaviour, productive tillers/plant, leaf area index, leaf/stem ratio (by fresh weight) and total herbage yield/ /plant together with yield and quality of oil have been studied in the first (M1) generation. Marked stimulatory effects of gamma radiation in 10 kr and 15 kr doses have been compared with the control for herbage yield, oil percentage and total alcohols (free geranyl and geranyl acetate).The two yield contributing traits, herbage yield/plant and leaf area index were remarkably increased in 15 kr, which indicates that in palmarosa the 15 kr dose is more effective than the higher doses in producing microlevel mutations. The yield and quality of oil at 10 kr and 15 kr doses were enhanced significantly. The results on high yield and quality of oil as induced by gamma-irradiation were discussed from the point of view that a gene may have been altered by mutagen treatment to produce a metabolic block between geraniol and geranyl acetate on the biosynthetic pathway or that modifier genes controlling the expression of a key precursor molecule may have been further modified to give rise to a geraniol rich chemotype in palmarosa.  相似文献   
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64.
Resistance to stem rust and leaf rust in five D genome species of wheat viz., 267 accessions of Aegilops tauschii Coss., 39 of Ae. cylindrica Host, 17 of Ae. ventricosa Tausch, 4 of Ae. crassa Boiss. and 8 of Ae. juvenalis (Thell.) Eig were evaluated at adult plant stage. Two hundred and thirty nine (90 %) accessions of Ae. tauschii, 30 (77 %) of Ae. cylindrica, 16 (94 %) of Ae. ventricosa, 3 (75 %) of Ae. crassa Boiss. and 5 (62.5 %) of Ae. juvenalis were resistant to stem rust pathotypes prevalent in South India at Wellington under field condition. Invariably, all the accessions of the five species were resistant to leaf rust pathotypes. Quantitative measurement of disease using area under the disease progress curve revealed the slow progress of disease in the resistant accessions compared to susceptible check (Agra Local). Since all the five species have D genome, it could be concluded that the genes present in D genome might play a vital role in leaf rust resistance, but in case of stem rust resistance wide range of differential response was noticed. Among the species evaluated, Ae. tauschii was exploited to a larger extent, followed by Ae. ventricosa and Ae. cylindrica for leaf and stem rust resistance because of the homology of D genome with hexaploid bread wheat. While, Ae. crassa and Ae. juvenalis could not be utilized so far, possibly due to partial homology which makes the transfer of traits difficult. So, these species have considerable potential as a source of rust resistance and may enhance the existing gene pool of resistance to stem and leaf rusts.  相似文献   
65.
Investigations were made to study the effect of unequal distribution of canal water in land and water productivity of the rice—wheat cropping system in terms of head—tail relationship in Bhakra Canal command, Haryana. Information on water supply, agronomic practices, crop yield, etc.,were collected from 216 farmers comprising 36 farmers each from the head, middle, and tail watercourses of two minors during year 2000–01. The unequal supply of canal water and presence of marginal quality groundwater creates large variations in the cropping pattern, irrigation application, and land and water productivity of the irrigation system. The groundwater of tail reaches, being saline in nature, was about 25% less productive as compared to head reaches. The unavailability of canal water in the tail reaches creates more dependency on groundwater. Due to its poor quality the crop production in the tail reaches was less by 10 to 20% in case of wheat, and 20 to 40% in case of rice, as compared to head reaches. Groundwater transfer from head to tail reaches and cultivation of low water requiring salt tolerant crops/varieties would be helpful in reducing the productivity gap and increasing the profitability of the farms in the region.  相似文献   
66.
J. S. Chauhan    M. K. Tyagi    A. Kumar    N. I. Nashaat    M. Singh    N. B. Singh    M. L. Jakhar    S. J. Welham 《Plant Breeding》2007,126(4):399-402
Effects of drought on yield and yield components were investigated during the spring season 2000–2001 by growing 14 Indian mustard genotypes under irrigated and rain-fed conditions at Bharatpur and Jobner. A disease and pest management schedule was followed when required. The drought susceptibility index (DSI) for seed yield and component characteristics was calculated to characterize the relative tolerance of genotypes. Plant height, primary branches, secondary branches per plant, 1000-seed weight and seed yield were reduced under rain-fed conditions. The top five genotypes at Bharatpur that showed tolerance to moisture stress for seed yield, as indicated by their lowest DSI, were, in descending order PSR-20, PRO-97024, JMMWR-941, IS-1787 and PCR-7, whereas at Jobner these were JMMWR-941, RC-1446, PSR-20, RH-819 and 'Varuna'. Of these, PSR-20 and JMMWR-941 were among the top six at both locations. These genotypes also showed relatively low DSI for one or more characteristics, such as primary branches per plant, secondary branches per plant, harvest index and seed : husk ratio. Genotypes with the lowest DSI, particularly for seed yield at both locations, would serve as useful donors in the breeding programme for improving the drought tolerance of existing Indian mustard cultivars.  相似文献   
67.
Journal of Crop Science and Biotechnology - Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is vital grain legume having nutritional and socio-economic importance, especially in the...  相似文献   
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69.
Ipomea carnea Jacq, a common weed known as ‘Beshram’ was introduced in India, as an ornamental plant. Surprisingly, except fiber length, other morphological characteristics like, cell wall thickness, lumen diameter, flexibility coefficient and wall fraction of I. carnea resemble with softwoods like, Pinus kesiya, and Picca abies. Cannabis sativa L., a common weed known as soft hemp consists of both bast fiber as well as core fiber. The unique morphological characteristics of I. carnea like, cell wall thickness and flexibility coefficient, which resembles with softwoods along with long fibers of C. sativa, in which I. carnea deficits in a proper blend ratio, can be used in a better way for the development of high quality value added paper. The optimum kraft cooking conditions for I. carnea and C. sativa were: active alkali 16%, sulfidity 20%, temperature 165 °C, time (at temperature) 120 min and wood to liquor ratio of 1:4 for I. carnea and 1:3.5 for C. sativa. The screened pulp yield of I. carnea and C. sativa were found to be 49.3 and 54.3% at Kappa number of 29, respectively. An anthraquinone (AQ) dose of 0.1% increases the pulp yield to the tune of around 0.6% as well reduce the Kappa number to the tune of 22%. CEHH bleaching of C. sativa produces pulp brightness of 82% (Elrepho) at total chlorine demand of 5.07%. On contrary to this the I. carnea kraft pulp at same chlorine demand produce a pulp with improved brightness of 85.4% (Elrepho).  相似文献   
70.
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