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1.
Effects of chlormequat chloride (CCC), ethephon and mixtures of CCC and ethephon, applied at Zadoks growth stage (ZGS) 30 (the beginning of stem elongation) on the number of spike-bearing shoots and their contribution to grain yields of four spring barley ( Hordeum vulgare L.) cultivars were studied in 1987 and 1988 at McGill University, Quebec, Canada. The results varied between years and among cultivars. The mixtures of CCC and ethephon or ethephon alone, produced significant increases in the number of spikes m−2 in cultivars Joly and Laurier , in both years, and in Leger only in 1988. Ethephon and ethephon containing mixtures reduced the yields of Joly and Leger in 1988. In both years CCC had no effect on spikes m−2 for all cultivars. Increases in spikes m−2 were accompanied by decreases in 1000-grain weight, and/or grains per spike, which offset or more than offset potential benefits from increased spikes m−2. These results indicate that under continental climatic conditions such as those prevalent in Quebec, Canada, application of PGRs to spring barley at ZGS 30 does not increase grain yield through an increased number of spikes m−2.  相似文献   

2.
The effect of fungicides and their combination on yield of barley under different nitrogen, slurry and tillage treatments was investigated at Hohenschulen Experimental Station near Kiel, Germany in 1991–97. Various fungicide treatments (no fungicide, and treatment with stem, leaf and ear fungicides and combinations of these), two nitrogen levels (120 and 240 kg N ha−1), two tillage systems (minimum and conventional tillage) and four slurry applications (no application, and autumn, spring and autumn plus spring applications) were used. On average, fungicide application increased barley yield by 1.1 t ha−1. The fungicide treatments could be classified into four types: (1) fungicides against stem diseases, which slightly increased yield by 0.25 t ha−1, very similar to the results for the untreated control; (2) leaf fungicides and ear fungicides applied separately, and fungicides against a combination of stem and leaf diseases, which increased yield by 1.0 t ha−1 on average; (3) fungicides against a combination of ear and stem diseases, which increased the yield by 1.22 t ha−1, and (4) fungicides against a combination of leaf and ear diseases and a combination of stem, leaf and ear diseases, which increased yield by 1.59 t ha−1 on average. The effects of fungicide on the yield were modified by crop husbandry. It can be concluded that application of fungicides against a combination of leaf and ear diseases could increase barley yield and reduce yield variation.  相似文献   

3.
Plant growth regulators (PGR) have potential to increase grain yield and may also alter grain protein levels of cereal crops. A 3-yr field experiment with spring barley ( Hordeum vulgare L.) and wheat ( Triticum aestivum L.) cultivars was conducted to determine whether ethephon treatment increased protein concentration, protein yield, and grain yield. A greenhouse experiment was also conducted to evaluate the response of barley grain protein concentration to gradual addition of ethephon (2.2 × 10-3 mM) or chlormequat (5.8 × 10-3 mM) solution after an thesis. Under field conditions, ethephon treatment increased barley and wheat grain protein concentrations by as much as 16 % but decreased grain yield so that protein yield increases were small or did not occur. For Laurier barley, total gram N content was increased by up to 20 % in one year of this study. However, over the 3 years, an inverse relation existed between grain protein and yield. Greenhouse data showed that i) the gradient in grain size and protein concentration among spikelets of a spike, which is established before anthesis, was not affected by either chlormequat or ethephon; and ii) chlormequat increased grain protein by 7 to 11 % whereas ethephon increased protein concentration by up to 13 % in one of the two experiments. Our data indicate that PGR can alter protein accumulation in the grain, and thus, the quality of bread wheat and feed barley crops can be increased m regions with a short crop-growing season. However, a portion of the increase in gram protein concentration is due to decreased starch deposition, which is associated with yield reductions. The greenhouse data confirmed that a portion of the increase in grain protein concentration due to PGR application is caused by increased protein accumulation in the barley grain.  相似文献   

4.
When one of the crops is a legume, intercropping has potential to reduce fertilizer nitrogen (N) needs and increase food quality. Total dry matter (DM) and grain yields of different plant populations of intercropped maize ( Zea mays L.) and climbing beans ( Phaseolus vulgaris L.), cowpeas ( Vigna unguiculata [L.] Walp.), or velvet beans ( Mucuna pruriens [L.] DC. var utilis [Wight] Bruck.) were compared in two experiments. Maize populations were 40,400 and 50,500 plants ha−1 in combination with climbing bean populations of 0, 20,200, 40,400 and 80,800 plants ha−1 in Experiment 1. In the second experiment, climbing beans, cowpeas and velvet beans at 215,200 plants ha−1 were intercropped with maize at 64,600 plants ha−1. Climbing beans contributed up to 5% to total DM yields in the first experiment. In the second experiment legume contributions to total DM were 20% for climbing beans, 12% for cowpeas and 8% for velvet beans. Increasing populations of maize and climbing beans increased grain and DM yields. Dry matter yield of maize was lowered by intercropping. However, DM yields of the intercrop were not different to maize sole cropped. Maize/cowpeas produced more total DM than maize/climbing beans. Cowpeas increased the total yield of crude protein by over 15% without lowering total DM yield of the intercrop compared to maize alone and are promising as a legume for intercropping with maize. Climbing beans show little promise as a possible legume for intercropping with maize.  相似文献   

5.
Most farmers in the rainfed parts of Jordan who use fertilizers use less than optimum rates of N and P because of the uncertainties associated with rainfall. Research results obtained by the national program indicated that the use of improved barley cultivars and fertilizers would result in substantial yield increases. The objective of the present investigation was to determine the optimum combination level of N and P for newly promising cultivars. The effect of 0–0, 5–10, 10–20 and 15–30 kg.ha−1 of nitrogen (N) and phosphorus (P) levels on barley cultivas Rum, Giza, Fun, Harmel and Arta under rainfed conditions in the Mediterranean climate was studied during two cropping seasons, 1994-95 and 1995–96. Increased grain and straw yields, total N and P uptake and RUE were recorded with increasing N and P levels for almost all cultivars. Rum was significantly (P = 0.05) the highest grain and straw producer and highest RUE at the 10 N- and 20 P kg.ha−1 level. The cultivar × fertility level (N–P) interactions were not significant for both grain and straw yields and for total N and P uptake.  相似文献   

6.
Crop losses caused by environmental stresses might be reduced by applying osmoprotectans to crop canopies. Glycinebetaine is endogenously accumulated by some halophytes under stress conditions and represents such a compound. Glycinebetaine was applied exogenously to barley ( Hordeum vulgare L.), oat ( Avena sativa L.), spring wheat ( Triticum aestwum L.), and summer turnip rape ( Brassica rapa ssp. oleifera DC.) canopies and its optimal concentration was monitored in the greenhouse. In field experiments the response of crop plants to betaine applications was assessed by measuring accumulation of above ground biomass, leaf area index (LAI), leaf chlorophyll, and yield. The optimum betaine concentration producing advantageous effects on growth and crop physiology in turnip rape was close to 0.1 M and for wheat 0.3 M. Such concentrations promoted accumulation of betaine similar to that of halophytes under stress conditions [ca. 200 μmol (g DM)−1]. In the 1993 field experiment peak LAIs were recorded in irrigated wheat and barley treated with 17.5 kg ha−1 betaine applied at 300 1 ha−1. Green leaf area was slightly more persistent in wheat treated twice with 1 kg ha−1 betaine applied at 200 1 ha−1 in 1994, although it was not associated with increased grain yield. Our results indicated that betaine has no actual potential in Finland for the principal grain crops but further studies are needed in stress prone environments to assess the potential of betaine treatments for preventing crop failures.  相似文献   

7.
Determination of optimal N-fertilization rates, NOR , for crop production that minimize risk of environmental degradation require accurate application of a response model. Several models are available to describe crop yield response to N fertilization. The objective of this work was to compare the relative accuracy of a quadratic, f(N Q), a modified Mitscherlich, and tanh( N ) models on 48 data sets. Data were collected from a Tara silt loam (fine-silty, mixed, frigid Pachic Udic Haploboroll) over a 6-year period using two maize ( Zea mays L.) hybrids and four tillage treatments, mouldboard plough, chisel plough, ridge tillage and no-tillage. In about one-third of the cases, all models performed about equally well. Generally, the tanh( N ) and modified Mitscherlich models gave better fit between N rate and grain yield data. The NOR, ranged from about 140 to 170 kg ha−1 for the modified Mitscherlich model, 136 to 184 kg ha−1 for the tanh( N) function, and 124 to 173 kg ha−1 using the f(N Q) model. Estimated grain yields at these rates ranged between 6.58 ± 1.30 to 7.59 ± 1.69 Mg ha−1 for the 90-day Minnesota maturity rated (MR) hybrid and between 7.52 ± 2.40 to 8.72 ± 1.70 Mg ha−1 for the 95-day MR hybrid.  相似文献   

8.
The effects of nitrogen and sulphur on the yield and fatty acid composition of mustard ( Brassica juncea L.) oil were studied in a field experiment. Significantly higher grain and oil yields were obtained with N and S application. Applications of nitrogen up to 60 kg ha−1 and sulphur up to 40 kg ha−1 favourably influenced the grain yield. Increasing levels of N decreased the oil content while application of sulphur improved the oil content. The contents of linoleic and linolenic acid were maximum (16.82 and 8.73%, respectively) with 60 kg N along with 40 kg S ha−1. No use of fertilizers led to higher contents of undesirable fatty acids such as palmitic (hypercholesterimic) and erucic (do not have food value) acids.  相似文献   

9.
A field experiment was conducted during 1994 and 1995 at Lucknow (26.5°N, 80.5°E, 120 m above mean sea level) to optimize planting density and fertilizer-N application for high essential oil yield of late transplanted mint ( Mentha arvensis ). The treatments studied were 2.5, 2.0 and 1.66 × 105 mint seedlings ha−1 and 0, 80, 160 and 240 kg N ha−1. Under 3 months delayed planting conditions using 2-month-old seedlings, the high planting density of 2.5 × 105 plants ha−1combined with 160 kg N ha−1 gave significantly higher herb and essential oil yields compared with those of lower planting densities (2 and 1.66 × 105 plants ha−1) and all other rates of N application. It is demonstrated that a transplanted mini crop, yielding essential oil at a level of 164 kg ha−1, is feasible after the harvest of rabi cereal, oil seed or legume crops in the north Indian plains.  相似文献   

10.
The effect of varying seed rates (100–1000 seeds m−2) and nitrogen fertilizer (0–60 kg N ha-1) applied either in a single basal dose or in splits was investigated on a tall elongating, photosensitive rice variety, Nalini, under semi-deepwater conditions (0–100cm) during 1993 and 1994 at Cuttack, India. Seedling emergence was higher in 1993 (53.9 %) than in 1994 (44.1 %) and it increased proportionately with increasing seed rate, Increase in the number of tillers and panicles m−2 at higher seed rates was associated with a corresponding decrease in panicle weight. Regression analysis indicated a decrease of 0.91–1.28g in panicle weight for an increase of 100 panicles m−2. The grain yield of rice was significantly higher at 400 seeds m−2 in 1993 and at 600 seeds m−2 in 1994 than at low seed rates but further increase in seed rate did not increase the yield. Application of N fertilizer increased the panicle number and thereby grain yield significantly. The effect of basal and split applied N at active or maximum tillering stages as well as between 30 and 60 kg N ha−1 was not significant on the grain yield. The results suggest that a basal dose of 30kg N ha−1 and seeding density of 400–600 seeds m−2, resulting in 40–50 % seedling emergence and 150–200 panicles m−2, each with 2.0–2.5 g weight, may be adequate for optimum productivity of rice under semideepwater conditions.  相似文献   

11.
A field expenment was conducted during 1992–94 at CIMAP, Field Station, Bangalore, India to study the effect of depth (25, 37.5 and 50 mm) and methods (Ridge and furrow and Broad Bed and furrow method) of irrigation and nitrogen levels (0, 200 and 400 kg N ha−1 year−1) on herb and oil yields of Java citronella. At the highest level of N application (400 kg N ha−1 year−1) ridge and furrow method was better suited for irrigating citronella. However, under lower N levels (0 and 200 kgN ha−1 year−1), as much as 30 % water can be saved by the broad bed and furrow method. The results have shown that highest herb and oil yields of citronella were achieved with the application of 400 kg N and maintaining 25 mm depth of irrigation. Content and quality of oil were not affected either by irrigation or nitrogen.  相似文献   

12.
A field experiment was conducted at the Division of Agronomy, Indian Agricultural Research Institute, New Delhi during 1983-84 and 1984-85 to study the effect of lentil residues on the yield and response of succeeding rice to nitrogen. Lentil residues benefitted the succeeding rice and gave longer and heavier panicles, more grains per panicle, higher 1000-grain weight and higher grain and straw yield of rice as compared to fallow. Rice responded well to applied nitrogen both in the absence and presence of lentil residues. The effect of lentil root residues and root residues plus incorporation of lentil straw was equivalent to 11 and 33 kg N ha−1 when 60 kg N ha−1 was applied to rice; the corresponding values being 54 and 60 kg N ha−1 when 120 kg N ha−1 was applied to rice.  相似文献   

13.
A 1-year study was conducted in 1983/84 at 2 experimental sites in Brazil to determine the effect of Azolla green-manure (AO), A. intercrop (OA) and their combination (AA) on rice yield in comparison to mineral fertilization with urea. Nitrogen sources were combined with 4 rice sowing/planting systems.
On terraced terra-roxa soil (Paleudalf) in subtropical northern Paraná State, transplanted rice (T) yielded 8.66 t · ha−1 compared to pregerminated (P), direct-sown (D) and conventionally sown (C) rice with 7.92; 7.73 and 7.48 t · ha−1, respectively. N-source treatments yielded 9.33; 8.54 and 7.34 t · ha−1 for AA, OA and AO compared to 8.46; 7.98 and 6.05 for 100, 50 and 0 kg N · ha−1, respectively. Fertilizer-nitrogen equivalence (FNE) of Azolla treatments compared to urea broadcast in 3 applications ranged between 0 and more than 100 kg N · ha−1.
On hydromorphic latosol (Ustic Dystropept) in tropical Goiás State, rice yields were 4.07; 2.52; 1.46 and. 1.33 t · ha−1 for systems T, P, C and D, respectively. N-source treatments yielded 2.79; 1.98 and 1.78 t · ha−1 for AA, AO and OA compared to 3.43; 2.63 and 1.46 t · ha−1 for 60; 30 and 0 kg N · ha−1 as urea broadcast in 2 applications, respectively. FNE of Azolla was between 0 and 56 kg N · ha−1.  相似文献   

14.
In a field experiment conducted during 1992–95 at Lucknow, India, sugarcane was planted in rows 60 and 90 cm apart in three crop rotations (rice-sugarcane-ratoon, Sesbania aculeata for green manure-sugarcane-ratoon, and cowpea-sugarcane-ratoon) with 0, 150 and 300 kg N ha−1 as urea either with or without farmyard manure (FYM) at 10 t ha−1. Sugarcane yields were significantly greater in the Sesbania rotation than in the other because of a larger N uptake. N uptake of the crop was significantly affected by soil organic carbon, and available N and K contents. Ratoon yields, however, were largest in the cowpea sequence followed by the rice rotation, probably due to a prolonged residual effect of cowpea and rice root residues. The residual effect of a Sesbania green manure was negligible as demonstrated by the low NO3-N content of the soil profile after sugarcane harvest compared to the other two crop sequences. The total cane productivity (main sugarcane plus ratoon) was greater (156 t ha−1) in the cowpea rotation than the Sesbania (152 t ha−1) and rice (140 t ha−1) rotations.  相似文献   

15.
In a soil lacking indigenous Bradyrhizobium japonicum , soybean ( Glycine max [L.] Merr.) nodulation depends upon the number of rhizobia applied with the inoculum. This field study reports the effect of different rates of applied rhizobia on nodulation, dry matter and nitrogen content in soybean in a Mediterranean soil lacking B. japonicum.
Treatments included six rates of B. japonicum , ranging from 2.5 × 104 to 6.075 × 106 rhizobia cells per seed applied to the seed as peat inoculant at planting, 100 kg N ha−1 and an uninoculated control. The experiment was conducted in an Entisol soil. Regression analysis showed linear relationship between the rate of applied rhizobia and the number of the nodules per plant or the dry weight per nodule. In early stages of development (32 and 68 days after planting) plant dry weight was not affected by inoculation rate. At harvest a rate of 7.5 × 104 rhizobia cells per seed was necessary for maximum total and stover dry weight. A higher rate, 6.75 × 105 rhizobia cells per seed, was required to obtain maximum grain yield, total N content in plant tops and grain N content. Grain percentage N was increased up to 2.025 × 106 rhizobia cells per seed. Nitrogen application increased grain yield, total N content and grain N content at the same level as the lower inoculation rate.  相似文献   

16.
Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha−1) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha−1 (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha−1 and of single fertilizer N at 200 kg N ha−1 recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha−1 full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha−1 applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.  相似文献   

17.
In a 3-year field experiment conducted on a Gleyic Luvisol in Stuttgart-Hohenheim, ten maize cultivars (nine commercial and one experimental hybrid) were compared in their ability to utilize a high soil nitrogen (N) supply. Total N content of the shoots at about silage maturity ranged from 213 to 328 kg N ha−1 (1986), from 177 to 223 kg N ha−1 (1987) and from 185 to 226 kg N ha−1 (1988). In all three experimental years, total shoot N uptake was significantly positively correlated to stover yield, and also to N concentrations in the ears and in the total plant dry matter. In contrast, a negative correlation between ear yields of the cultivars and total N uptake was indicated. Differences between the cultivars in N uptake were reflected in a corresponding soil nitrate depletion. At harvest, residual nitrate-N in the 0–90 cm soil layer ranged from 34–63 kg N ha−1 m 1987 and 32–71 kg N ha−1 in 1988. The results indicate, that growing of cultivars selected for high N uptake-capactiy of the shoots may contribute to an increased utilization of a high soil N supply and thus to a reduction of nitrate leaching.  相似文献   

18.
Field experiments were conducted to determine the effects of tillage (ploughing followed by one rotary hoeing (CT), rotary hoeing (MT) and no-tillage (NT)) and type of fertilization (NP 154/75 kg ha−1, digested farmyard manure 30 t ha−1) on growth (biomass and roots), N-accumulation and nodulation of vetch plants (Vicia sativa cv. Alexander) at different stages. The highest dry matter yields and root weight were determined for the NT and the lowest for the CT systems. The NT system promoted nodulation of vetch plants to a higher degree than the MT and CT systems. At the time just before harvesting, the N-accumulation in the above ground plants, was 54.3 for CT, 76.7 for MT, and 109.0 kg ha−1 for NT, and the corresponding values at roots were 73.3, 112.0 and 173.3 kg ha−1. Growth and nodulation of vetch plants was in general much better on farmyard manure plots than it was with the NP fertilization. The closest correlation coefficients between dry matter of biomass and roots on the one hand, and number of nodules and percentage N in roots on the other, were found with NT. The highest correlation between nodulation and percentage N in roots (r = 0.91***) was observed at the 128-days-old vetch plants. The highest correlation between the number of nodules and percentage N in biomass (r = 0.82**) was found at the beginning of the plants' flowering period. *, **, *** indicate significance at P = 0.05, 0.01 and 0.001 respectively.  相似文献   

19.
Nitrogen (N) fertilization with foliar urea and fungicide treatment at flag leaf emergence (GS 47) are common strategies to improve both grain yield and quality in wheat ( Triticum aestivum L.). Mixing of urea and a fungicide, together, would save time in farm operations. In some cases, the effect of foliar sprayings of urea either alone or in combination with a fungicide may, however, give unexpected low response to grain yield and quality when compared to separate application of foliar urea and fungicide. This study was designated to provide more detailed information about the effects of late-season spraying of urea (15 kg N ha−1 as an aqueous solution of 110 g l−1) alone or mixed with fungicide (propiconazole, 125 g ha−1) on the grain yield and grain protein content of spring wheat. To avoid foliar injury or phytotoxic effect of foliar spray of urea, mixing of urea with propiconazole in warm growing conditions should be avoided. In turn, during cool and rainy growing season, a mixture of these two chemicals is recommended in order to improve rapid absorbtion of both propiconazole and foliar urea. However, the genotypic differences were recorded in response to propiconazole and urea sprayings. The positive effects on cultivars of these chemicals were attributed to high leaf photosynthesis rate after propiconazole and foliar urea treatment and high leaf urease enzyme activity after foliar urea application.  相似文献   

20.
Three sulphydryl compounds, viz., 2-mercaptoethanol, 2-mercaptoethylamine and thiourea, were tested for improving dry matter partitioning and grain production of maize in field culture. The chemicals were applied ca. 0.1 % concentration as foliar spray at grain formation stage. Mercaptoethanol, mercaptoethylamine and thiourea increased grain yield ha−1 by 18.1, 29.2 and 34.1 %, respectively compared with water control Significant improvement in harvest index, a measure of dry matter partitioning for grain production, was also noted with the spray chemicals but stover and biological yields ha−1 remained uninfluenced. Foliar spray of 0.1 % urea did not have any effects on the above parameter and thus the effects of thiourea were largely a function of sulphydryl group. It is suggested that sulphydryl compounds have a considerable potential for increasing grain production of maize and perhaps of similar other cereals.  相似文献   

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