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1.
Eggplant is one of the most common vegetable crops grown in India and other parts of the world. Leucinodes orbonalis is the key pest infesting eggplant, with international importance as it causes heavy damage in all eggplant growing areas. It is very difficult to control this pest since it feeds inside the shoot and fruit, and there is every possibility of toxic residues remaining in the fruits as they are harvested at frequent intervals and are consumed after little cooking. In the sub-himalayan region of West Bengal, India the pest was found to be most active during summer and the rainy season, particularly during May–August, and caused 49.5–81.0% damage to fruits. Peak infestation (81.0% fruit damage) was noticed in the first week of June (22nd standard week), when the mean temperature, mean relative humidity and weekly rainfall were 27.8°C, 79.2% and 81.2 mm respectively. The pest became less active during winter months particularly in December–January. Borer infestation showed a significant positive correlation (P = 0.05) with maximum and mean temperature, minimum and mean relative humidity and rainfall, whereas with maximum relative humidity the correlation was negative but non-significant. The insecticides evaluated in the field for L. orbonalis control on eggplant revealed that avermectin (Vertimec 1.9 EC; 0.5 ml/l) was the most effective in suppressing dead heart caused by the pest, closely followed by Beauveria bassiana (Biorin 107 conidia/ml; 1 ml/l) and Bacillus thuringiensis Berliner (Biolep 5 × 107 spores/ml; 1 g/l). Significantly lower levels of fruit damage were recorded after avermectin treatment, closely followed by DDVP (0.05%) (Nuvan 76 SL; 2 ml/3 l) when compared with the untreated control. The other insecticides tested, including a neem formulation (Neemactin 0.15 EC; 2.5 ml/l) and malathion (0.05%) (Malathion 50 EC; 1.0 ml/l), were less effective. None of the insecticides evaluated produced satisfactory results against L. orbonalis. However, avermectin, besides being environmentally safe, was effective for a longer duration and could thus be recommended for Integrated Pest Management programmes on eggplant.  相似文献   
2.
One of the major challenges in Asian countries is the effective management of rice straw. To ensure food security for their ever-growing population, Asian countries grow more rice, leading to increasing rice straw generation. Burning of rice straw, a common practice, is detrimental to both environmental and human health. However, if managed effectively, rice straw has the potential to safeguard the sustainability of agricultural ecosystems and to uplift the economic security of the population de...  相似文献   
3.
Abstract

Different solvent extracts of neem seed kernels were evaluated against Spodoptera litura F. on cauliflower, Brassica oleracea var. botrytis leaves. Based on this evaluation, aqueous extract was dissolved in ethanol, and methanol extract in ethanol, and dissolved parts were designated as fraction I and fraction II, respectively. The extracts having more antifeedant activity were encapsulated to achieve stability against the sunlight. Among the solvent extracts tested at 1.0% concentration, methanol extract provided maximum protection (100%) of the leaves followed by ethanol (98.39%) and aqueous (93.01%) extracts. Fraction I and fraction 11 were equally effective at 0.1 % concentration against S. litura larvae and checked more than 70% of leaf damage. However, such extracts were found to be unstable when exposed to sunlight. The pre‐gelatinized starch‐encapsulated products, viz. ρre‐gel I and pre‐gel II were quite stable and afforded more than 68.0% protection to the cauliflower leaves even after 6 days of exposure to sunlight.  相似文献   
4.
Induced systemic resistance (ISR) is a mechanism by which certain plant beneficial rhizobacteria and fungi produce immunity, which can stimulate crop growth and resilience against various phytopathogens, insects, and parasites. These beneficial rhizobacteria and fungi improve plant performance by regulating hormone signaling, including salicylic acid (SA), jasmonic acid (JA), prosystemin, pathogenesis-related gene 1, and ethylene (ET) pathways,which activate the gene expression of ISR, the synth...  相似文献   
5.
Fractionation of soil is undertaken to isolate organic carbon with distinct functional properties, such as stability and turnover times. Soil organic carbon (SOC) fractionation helps us to understand better the response of SOC to changes in land use, management or climate. However, fractionation procedures are often poorly defined and there is little information available on their reproducibility in different laboratories. In a ring trial, we assessed the reproducibility of a SOC fractionation method introduced by Zimmermann et al. (2007). The isolated fractions were linked to the model pool sizes of the Rothamsted carbon model (RothC). We found significant differences between six laboratories for all five defined fractions in three different soils with coefficients of variation ranging from 14 to 138%. During ultrasonic dispersion, the output power (energy per unit time) was identified as an important factor controlling the distribution of SOC within these five fractions, while commonly only the output energy is standardized. The amount of water used to wet‐sieve dispersed soil slurry significantly influenced the amount of extracted dissolved organic carbon (DOC). We therefore suggest using a fixed amount of power for ultrasonic dispersion (20 W) and a minimum amount of water for wet sieving (2000 ml). RothC pool sizes were predicted from the measured fractions and compared with RothC equilibrium pool size distributions. This model initialization using measured SOC fractions, however, led to an over‐estimation of stable RothC SOC pools when compared with pool size distributions derived from RothC equilibrium runs under a bare fallow soil model simulation. To improve the isolation of particulate organic matter from stable mineral‐bound organic matter, we suggest that the density should be increased from 1.8 to 2.0 g cm?3 in the density fractionation step. We formulated a modified fractionation procedure, which aims specifically to enhance reproducibility across laboratories and to improve the match of the isolated SOC fractions with RothC's SOC pools.  相似文献   
6.
Forty five micromutant lines of blackgram variety PU-30, developed by single and combination treatments with Gamma-rays, ethyl methane sulphonate (EMS), N-methyl-N-nitroso guanidine (NG) and maleic hydrazide (MH) were evaluated for yield and component traits. The mutant lines showed significant differences in all 9 traits indicating that the different mutagenic treatments were effective in inducing changes in all the quantitative characters, though magnitude, direction and frequency of changes varied with treatments. Genetic divergence among the mutants and the parent was estimated by D2 analysis.100-seed weight, plant height and pod length had high contribution to genetic divergence indicating induction of more micromutations in these traits. The genetic diversity D2 estimates among the 45 mutant lines and the parent were significant indicating the effectiveness of mutagenic treatments in isolation of mutant lines with diverse changes in multivariate traits from the parent. Using Tocher’s method the mutants grouped in to 11 diverse genetic clusters. 31 of the 45 mutant lines grouped into 10 different clusters away from the parent. These lines not only exhibited genetic diversity from the parent but also among themselves. The mutant lines derived from the same mutagenic treatment often grouped into different clusters indicating that there was no mutagen specific trend in clustering. On the basis of D2 values and character complementation, hybridization of mutant line PM 3-3 with PN 3-2 or PGN 2-2 is expected to produce promising and desirable segregants in subsequent generations. The use of index selection on multiple traits including yield proved to be an effective and efficient method for selection of high yielding productive mutant lines such as PE2-3, PGN 2-3, PGN 2-2, PGM 2-2, PG2-1 and PG 3-2. These productive mutants showed changes in some growth and productivity traits from the parent variety and had 38.5 to 28.7 % yield superiority over parent. Three of these six mutants were derived from combined treatments and other three from single treatment with Gamma-rays or EMS.  相似文献   
7.
8.
ABSTRACT

Phosphate-solubilizing microbes (PSM) are widely distributed in the rhizosphere and helps plant to acquire phosphates from soil. The availability of phosphates in soil are governed by several factors among which the proton exchange capacity has been regarded to be the most important factor involved in cation complex formations with soluble phosphates making them unavailable to plants, thereby disturbing the phosphorus cycling events found in arable soils. PSM solubilizes the cation complexes and thereby improves the functioning of phosphorus cycle in soil. In addition to involvement in biogeochemical cycling events, PSM have been also found to have antagonistic potential against several plant phytopathogens. These biocontrol microbes represent the most abundant groups of soil microflora. Among which some nutrient solubilizers have been used for effective biocontrol of important plant diseases. This review article shows contributions of different plant growth promoters used in nutrient and disease management practices in agriculture.

Abbreviations: P (phosphorus), PSM (phosphate-solubilizing microbes), PSB (phosphate-solubilizing bacteria), PSF (phosphate-solubilizing fungi), PGPM (plant growth-promoting microbes), PGPB (plant growth-promoting bacteria), SAR (systemic acquired resistance), ISR (induced systemic resistance), TCP (tri-calcium phosphate), HCN (hydrogen cyanide), IAA (indole-3-acetic acid), aPhosphorus [(SSP) single super phosphate, RP (rock phosphate), PM (poultry manure) and FYM (farm yard manure)], PAL (phenylalanine ammonia lyase), ESI-MS (electrospray ionization mass spectrometry), DAPG (2,4-diacetylphloroglucinol) and NMR (1H nuclear magnetic resonance).  相似文献   
9.
Model initialization in soil organic carbon (SOC) turnover models has often been described as a crucial step in making future projections. Model initialization by the spin‐up of pools of SOC (model equilibrium run) has been questioned, because equilibrium has to be assumed. Measured SOC pools are independent of model assumptions and are thought to reflect better real site conditions. It has been suggested that model initialization with measured SOC fractions could provide an advantage over model spin‐up of SOC pools. In this study we tested this suggestion in relatively undisturbed native grasslands in Australia. We tested the Rothamsted SOC turnover model (RothC) under climate change at 12 sites with three different initialization methods, viz. model initialization with (i) spin‐up of model pools with inert organic matter (IOM) pool size calculated from a regression equation, (ii) spin‐up of model pools with measured IOM and (iii) all pools estimated from measured fractions. Averaged over the sites and initialization methods, maximum absolute variations (absolute differences in projected SOC stocks expressed as a percentage of initial 2008 SOC stocks) as well as averaged absolute variations throughout the projection period were very small (2.2 and 1.6%, respectively). Averaged across the sites, there were no significant differences in projected grassland SOC stocks under climate change after 93 years of simulation with model initialization by different methods and averaged absolute variation was only 1.6% across initialization methods. These findings suggest that in a relatively undisturbed land‐use system such as native grassland, projections of SOC under climate change are relatively insensitive to the model initialization method.  相似文献   
10.
The effect of restricted medication with lasalocid sodium on the development of acquired immunity against Eimeria tenella was evaluated. The medication was allowed for all or part of 6-day test period (one day before until 4 days after infection). The parameters used for such evaluations were lesion score, caecal, bursal and splenic weights. The optimum treatment time for the drug was clearly indicated by lesion score which was very low when the medication was initiated 1 day before until 1 day after inoculation, but only partly effective if given on Day 2 post-inoculation. The challenge with higher doses on 14th day of immunizing infection revealed a reverse picture where the higher lesions were recorded by the groups where medication was started earlier than the delayed treatment groups. This indicates partial interference with the development of immunity in the earlier treatment groups. Birds treated on Day 4 p.i. were not significantly different (P less than 0.05) from the infected unmedicated control group, suggesting no interference in acquired immunity. A correlation was noticed between day of treatment, the lesion score and weight gain of the caecum as well as the spleen. After both immunizing and challenge infections, the bursa did not show any significant variation in weight, whereas the weight of the spleen did vary. The infected unmedicated group and the delayed-treatment groups had a comparatively higher splenic weight than the uninfected unmedicated group of birds.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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