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1.
The effects of salinity on the growth and production of `nopalitos' (young cladode sprouts) of Opuntia ficus-indica (L.) Mill. cv. Copena V-1 were investigated. Salinity (NaCl) irrigation levels with electrical conductivities of 2, 5, 10, 13, 18 and 21 dS m–1 were used. In general, all cladode variables (stem area, number of young cladodes, length and width of cladodes, and fresh and dry weights) decreased with increasing salinity. The root-to-stem ratio and young cladode water content decreased significantly as salinity increased. Other variables that decreased with increasing salinity included harvest index, relative growth rate, stem area ratio, dry mass accumulation, and Na+ and Cl concentrations. For rooted cladodes, increased salinity decreased fresh weight, succulence, and root fresh weight, dry weight and length. Our conclusions suggest that this species is salt sensitive; however, there is some indication that it could be effectively managed in saline environments. Further studies and evaluation of different cultivars are needed to identify the mechanism of adaptation of salt tolerance in this species.  相似文献   

2.
Differential salt sensitivity during growth stages and reproductive compensation of plants after salt stress relief are important factors for adopting appropriate irrigation strategies with saline waters. Consequently, recovery of cotton after exposure to different levels of salt stress was evaluated. An outdoor, sand culture experiment was conducted with cotton. Water salinities were 2, 10 and 20 dS m−1, and the growth phases were vegetative (G1), reproductive (G2) and boll development (G3). G1 and G3 were the least and the most salt tolerant phases, respectively. The significant yield reduction in all of the saline water treatments as compared to control was mainly due to the reduction in number of bolls per plants. In general, cotton plants were capable of producing seed cotton under salt stress, as well as, after salt stress relief. However, as the salt stress severity increased the ability of cotton to compensate yield loss decreased. Irrigation of cotton at G1 stage with either moderate (10 dS m−1) or high (20 dS m−1) salinity waters should be avoided. Moderate saline water could be applied either at G2 or G3 stage. High salinity water can be used for irrigation only at G3 stage to produce acceptable cotton seed yield.  相似文献   

3.
Pulses such as chickpea, faba bean and lentil have hypogeal emergence and their cotyledons remain where the seed is sown, while only the shoot emerges from the soil surface. The effect of three sowing depths (2.5, 5 and 10 cm) on the growth and yield of these pulses was studied at three locations across three seasons in the cropping regions of south-western Australia, with a Mediterranean-type environment. There was no effect of sowing depth on crop phenology, nodulation or dry matter production for any species. Mean seed yields across sites ranged from 810 to 2073 kg ha−1 for chickpea, 817–3381 kg ha−1 for faba bean, and 1173–2024 kg ha−1 for lentil. In general, deep sowing did not reduce seed yields, and in some instances, seed yield was greater at the deeper sowings for chickpea and faba bean. We conclude that the optimum sowing depth for chickpea and faba bean is 5–8 cm, and for lentil 4–6 cm. Sowing at depth may also improve crop establishment where moisture from summer and autumn rainfall is stored in the subsoil below 5 cm, by reducing damage from herbicides applied immediately before or after sowing, and by improving the survival of Rhizobium inoculated on the seed due to more favourable soil conditions at depth.  相似文献   

4.
The effect of salinity on the nodulation, N-fixation and plant growth of selected chickpea- Rhizobium symbionts was studied- Eighteen chickpea rhizobial strains were evaluated for their growth in a broth culture at salinity levels of 0 to 20 dS m−1 of NaCl + Na2SO4. Variability in response was high. Salinity generally reduced the lag phase and/or slowed the log phase of multiplication of Rhizobium. Nine chickpea genotypes were also evaluated for salt tolerance during germination and early seedling growth in Petri dishes at five salinity levels (0–32 dS m−1). Chickpea genotypes ILC-205 and ILC-1919 were the most salt-tolerant genotypes. The selected rhizobial strains and chickpea cultivars were combined in a pot experiment aimed at investigating the interactive effect of salinity (3, 6 and 9 dS m−1) and N source (symbiosis vs. inorganic N) on plant growth. Symbiotic plants were more sensitive to salinity than plants fed mineral N. Significant reductions in nodule dry weight (59.8 %) and N fixation (63.5 %) were evident even at the lowest salinity level of 3 dS m-1. Although nodules were observed in inoculated plants grown at 6 dS m-1, N-fixation was completely inhibited. The findings indicate that symbiosis is more salt-sensitive than both Rhizobium and the host plant, probably due to a breakdown in one of the processes involved in symbiotic-N fixation. Improvement of salinity tolerance in field grown chickpea may be achieved by application of sufficient amounts of mineral nitrogen.  相似文献   

5.
【目的】本研究旨在科学合理地利用浅层咸水资源。【方法】依托短期定位试验开展了在第3年和第4年不同咸水利用方式下(CK:造墒和蕾期灌淡水;T1:造墒和蕾期灌咸淡混配矿化度3 g·L^-1的微咸水;T2:淡水造墒蕾期灌矿化度5 g·L^-1咸水;T3:造墒和蕾期灌矿化度5 g·L^-1咸水;T4:淡水造墒蕾期不灌水)棉花长势、叶绿素荧光参数、土壤盐分累积及其运移的变化。【结果】T1和T2处理的齐苗率、株高、干物质质量、叶面积指数、叶绿素荧光参数、产量及霜前花率与CK无显著差异,土壤盐分含量较CK有所增加,但未对棉花生长产生明显抑制。T3处理的棉花长势指标、叶绿素荧光参数较CK显著降低,0~100 cm土壤盐分含量较CK明显增加。【结论】从土壤质量安全和咸水高效利用的角度考虑,连续4年用3 g·L^-1的咸淡混合水灌溉或用淡水与5 g·L^-1的咸水轮灌不仅能节约淡水,且不影响棉花产量。本研究结果为当地在棉花生产中安全利用咸水提供技术参考。  相似文献   

6.
Growth and yield responses to plant density (6.75 × 104, 9.75 × 104 and 12.75 × 104 plants ha–1) and stage of transplanting (30, 35 and 40 days after sowing) of winter oilseed rape cultivar HO 605 were investigated in two field trials in the 1996/97 and 1997/98 growing seasons at Zhejiang University Farm, Huajiachi Campus, China. Results revealed a progressive decrease in leaf area per plant in response to increasing plant density and delayed transplanting, though leaf area m–2 and leaf area index were higher in high-density plants. Number of effective branches and pod per branch decreased with increasing plant density and delayed transplanting. There were no significant differences in the mean seed weight among treatments. Although the average number of seeds per pod was significantly lower for high-density plants and delayed transplanting, the economically highest seed yields were realized in relatively high-density plants. Seed oil content was negatively affected by increasing plant density, but no significant differences were observed with delayed transplanting. The highest seed yields of 1730.7 and 1748.1 kg ha–1 with no significant differences were observed for plant densities of 9.75 × 104 and 12.75 × 104 plants ha–1, respectively, transplanted at 35 and 30 days after sowing.  相似文献   

7.
The identification of genotypes having potential salt tolerance is an effective approach to solve the problems of saline soils.
Seed germination and seedling establishment are limiting factors in crop production. Seven wheat ( Triticum aestivum L.) and one Triticale (X Triticosecale Wittmak) genotypes were evaluated for salt tolerance at emergence and early seedling growth in solution culture with NaCl salinities up to 300 mM L−1 (electrical conductivity equals 27.6 dS m−1).
Seedling emergence was delayed by increasing NaCl in nutrient media. At 200 mM L−1 NaCl, the emergence percentages of wheat genotypes ranged between 68.7 % and 91.3 % after 7 days and 79.3 % and 98.7 % after 15 days. While at 300 mM L−1, the emergence percentages of the wheat genotypes were 0.0 % after 7 days. After 15 days the emergence percent ranged between 24 % and 72 %. The emergence percent of the Triticale line was 88.7 after 7 days and 89.3 after 15 days at 200 mM L−1, while it was 25.3 % and 84 % after 7 and 15 days, at 300 mM L−1, respectively. Root and shoot dry weight were greatly reduced by increasing NaCl, however, the Triticale line showed less reduction in growth compared to the wheat genotypes. K+, Ca2+ and Mg2+ were decreased with increasing salinity levels while Na+ content was decreased in the shoot tissues of wheat and Triticale genotypes.  相似文献   

8.
The effect of very high sowing rates on establishment year dry matter (DM) yield and stand persistence of irrigated lucerne ( Medicago sativa L.) was studied. Two cultivars ('Peace' and 'Apollo II') were sown in 1986 at two row spacings and six sowing rates from 5.6 to 50.4 kg ha−1. Established seedling density (Sd) increased linearly with sowing rate (R):Sd= 24.1R. Establishment year DM yield increased at sowing rates from 5.6 to 16.8 kg ha−1, levelled off as sowing rate increased to 33.6 ka ha−1, and then decreased as sowing rate increased further. Thus, there was a broad optimum sowing rate that gave a maximum sowing year DM yield. Percent plant survival to the third year (1988) decreased with increasing sowing rate so that plant densities became similar for sowing rates greater than 16.8 kg ha−1. Within the range 5.6 to 16.8 kg ha−1, increasing sowing rate increased stand persistence measured as 1988 plant density; however, a corresponding increase in DM yield was not obtained. For all full-production years, DM yield was independent of sowing rate. Sowing rate did not affect three chemical measures of forage quality.  相似文献   

9.
Understanding the influence of growth temperature and carbon dioxide (CO2) on seed quality in terms of seed composition, subsequent seedling emergence and early seedling vigour is important under present and future climates. The objective of this study was to determine the combined effects of elevated temperature and CO2 during seed-filling of parent plants on seed composition, subsequent seedling emergence and seedling vigour of red kidney bean ( Phaseolus vulgaris ). Plants of cultivar 'Montcalm', were grown at daytime maximum/nighttime minimum sinusoidal temperature regimes of 28/18 and 34/24 °C at ambient CO2 (350 μmol mol−1) and at elevated CO2 (700 μmol mol−1) from emergence to maturity. Seed size and seed composition at maturity and subsequent per cent emergence, early seedling vigour (rate of development) and seedling dry matter production were measured. Elevated CO2 did not influence seed composition, emergence, or seedling vigour of seeds produced either at 28/18 or 34/24 °C. Seed produced at 34/24 °C had smaller seed size, decreased glucose concentration, but significantly increased concentrations of sucrose and raffinose compared to 28/18 °C. Elevated growth temperatures during seed production decreased the subsequent per cent emergence and seedling vigour of the seeds and seedling dry matter production of seed produced either at ambient or elevated CO2.  相似文献   

10.
Soil and climatic conditions in Newfoundland are on the margins of agricultural capability, and almost all feed grain is imported. The overall objective of this work was to develop guidelines for the production of barley in Newfoundland, with the goal of establishing modern cropping recommendations. We conducted a 4-year study near St. John's to examine the effect of seeding rate and topdress ammonium nitrate (N) fertilization rate on Chapais six-row barley ( Hordeum vulgare L.) yield components and grain yield. Increasing seeding rate from 200 to 380 seeds m–2 did not alter grain yield in any year. Increasing topdress fertilization from 0 to 60 kg N ha–1 increased spike density m–2 at harvest, resulting in linear increases in grain yield in all years. Highest N rates had greatest lodging in two years. Based on our results, agronomic recommendations for eastern Newfoundland now include barley seeding rates of 250 ± 50 seeds m–2, with topdress applications up to at least 30 kg N ha–1.  相似文献   

11.
Seedling growth and ion content of Pakistani bread wheat cultivars was assessed in solution culture in the absence and presence of NaCl (100 and 200 mol m−3) to determine whether seedling traits could be used in breeding programs for salt-tolerance. Growth was recorded as seedling fresh weight, and the shoot and leaves analysed for major inorganic ions. Plants subjected to salt stress excluded Na+ and Cl ions from the shoot to varying extents. Exclusion preferentially maintained lower Na+ and Cl levels in the apical tissue, as the leaf to leaf gradient in Na+ and Cl became steeper as the external salinity increased, although there were significant differences between cultivars. Correlation analysis on individual plants indicated that excluding Na+ at low salinity, and Na+ and Cl at high salinity, were correlated significantly with growth performance, although it was clear that other factors were also involved. The relationship of tolerance to ion exclusion was stronger when the data were examined on an individual plant basis than when related to pooled cultivar data or to the cultivar rank order derived from field trials, probably due to large variations in Na+, and to a lesser extent, Cl transport in supposedly homozygous cultivars.  相似文献   

12.
The treated seeds (control, KNO3 and hydropriming) of sunflower (Helianthus annuus L.) cultivar Sanbro were evaluated at germination and seedling growth for tolerance to salt (NaCl) and drought conditions induced by PEG-6000 at the same water potentials of 0.0, −0.3, −0.6, −0.9 and −1.2 MPa. Electrical conductivity (EC) values of the NaCl solutions were 0.0, 6.5, 12.7, 18.4 and 23.5 dS m−1, respectively. The objective of the study was to determine factors responsible for germination and early seedling growth due to salt toxicity or osmotic effect and to optimize the best priming treatment for these stress conditions.

Results revealed that germination delayed in both solutions, having variable germination with different priming treatments. Germination, root and shoot length were higher but mean germination time and abnormal germination percentage were lower in NaCl than PEG at the same water potential. Seeds were able to germinate at all concentrations of NaCl but no seed germination was observed at −1.2 MPa of PEG treatments. NaCl had less inhibitor effect on seedling growth than the germination. It was concluded that inhibition of germination at the same water potential of NaCl and PEG resulted from osmotic effect rather than salt toxicity. Hydropriming increased germination and seedling growth under salt and drought stresses.  相似文献   


13.
Sowing of chickpea in the heavy‐textured soils of north‐west Bangladesh with minimum tillage technology aims to increase the timely planting of large areas during a relatively short sowing window before soil water deficit limits germination and emergence. However, the seedbed conditions into which chickpea is sown need to be better quantified, so that limiting factors which affect germination and emergence can be identified. Two of the soil physical characteristics of importance are soil water and aeration. Growth cabinet studies have identified the fastest germination and emergence of chickpea on representative soils for this area at gravimetric water contents of 17–18 %, whilst soil water contents above and below this delayed germination and emergence. Emergence was recorded at soil water potentials between field capacity (?10 kPa) and wilting point (?1500 kPa). Emergence was possible at lower soil water potentials in the finer textured soil, whilst in coarser textured soil, emergence was still possible at higher soil water potentials.  相似文献   

14.
In the dry Mediterranean environments of the West Asia and North Africa region, irrigation is frequently used to supplement rainfall to increase crop productivity and yield stability. Chickpea (Cicer arietinum L.), an important pulse crop of the region, often suffers from drought and can benefit from such a practice. To investigate the response of chickpea to irrigation, experiments were conducted in the field at Tel Hadya, Syria, from 1985 to 1988 using 24 improved chickpea genotypes sown in winter. Irrigation scheduling was done using the daily water balance computed from rainfall and pan evaporation data. Yearly rainfall was 316, 358, and 504 mm and supplemental irrigation amount was 130, 120, and 80 mm in 1985–86, 1986–87, and 1987–88, respectively. Irrigation increased seed yield by 916 kg ha?1 (44.0%) over the 3-year period. Irrigation requirement for chickpea coincided with flowering and seed development period. The top 10 highest-yielding genotypes under irrigated conditions were ILC 464, ILC 1272, ILC 237, ILC 613, ILC 95, ILC 4291, ILC 142, ILC 147, ILC 295, and ILC 3256. Their mean seed yields ranged from 3877 to 3208 kg ha?1. Among these four genotypes, ILC 464, ILC 1272, ILC 3256, and ILC 4291 with mean seed yields of 3877, 3726, 3208, and 3266 kg ha?1, respectively, were with predictable response to favourable conditions. Aboveground biomass contributed 49% of the total increase in seed yield from irrigation followed by plant height (26%) and early maturity (16%). These results indicate that it may be possible to breed chickpea for improved response to irrigation, and irrigation can enhance the yields of winter-sown chickpea grown in the lowland Mediterranean drylands.  相似文献   

15.
通过室内盆栽试验研究不同基肥施用方式对小麦出苗及苗期生长的影响。设置种肥混播条播、条播侧方施肥、条播下方施肥、种肥混播宽幅撒播4种播种施肥方式,同时每个播种施肥方式下设置225、375、600 kg/hm2 3个肥料用量水平。结果表明,种肥混播条播方式对小麦的出苗影响极为明显,且随着施肥量的增加小麦出苗率明显降低,条播侧方施肥、下方施肥以及种肥混播宽幅撒播方式对于小麦的出苗率影响不大。在种肥混播方式下,无论条播还是宽幅撒播方式均表现出了随着施肥量增加小麦株高和根系增加的趋势,其中种肥混播宽幅撒播方式下小麦株高和根长数值相对较高。同一播种施肥方式下,小麦地上部生物量随着施肥量的增加而增加,而在等量肥料投入的情况下,地上部生物量均表现为种肥混播宽幅撒播>条播侧方施肥>条播下方施肥>种肥混播条播。本试验条件下,建议小麦基肥采用种肥混播宽幅撒播的方式,以降低化肥用量、保证出苗安全和培育壮苗。  相似文献   

16.
[Objective] This study explores the effect of mulching film residue on the spatial and temporal distribution of soil water and salt in a cotton field under drip irrigation. [Method] Three treatments of 0 kg·hm-2, 225 kg·hm-2 and 450 kg·hm-2 residual mulching film were applied. Soil salt content was measured and the difference between the mulching treatments was analyzed using a soil drilling method to delaminate 0–40 cm soil before cotton sowing, after harvesting and on days 1, 3 and 5 after watering during the blooming period. [Result] The results showed that residual mulching film reduced soil moisture uniformity in the drip irrigated cotton field. An uneven distribution of salt in different soil layers was also observed after irrigation. The soil salinity of the 0 kg·hm-2 residual film treatment decreased in each soil layer over time, while the soil salinity of the 225 kg·hm-2 and 450 kg·hm-2 treatments decreased 1 and 3 days after irrigation, but then increased 5 days after irrigation (non-significant difference). With respect to distribution of soil salinity following irrigation, uniformity in the 0 kg·hm-2 residual film treatment was best, followed by the 450 kg·hm-2 treatment and the 225 kg·hm-2 treatment. The effect of residual mulching film on soil salinity balance before and after sowing of cotton was as follows: 250 kg·hm-2 > 450 kg·hm-2 > 0 kg·hm-2. As the depth of the residual film increased, the enrichment of soil salts in the topsoil was more likely to occur. [Conclusion] It can be concluded that residual mulching film hinders the downward migration of soil salinity. Under conditions of elevated residual mulching film, the soil salinity migration is disrupted to the degree that soil salt enrichment occurs at the soil surface.  相似文献   

17.
A 3-year study was conducted in the Central Valley of California to evaluate 125 prospective winter-growing cover crops for growth and nitrogen productivity in saline soils. Soil saturation paste electrical conductivities (ECes) in the surface 15 cm averaged 7 dS  m−1 at fall planting and 5.3 dS m−1 at spring harvest dates of each experiment. Species evaluated varied substantially in plant height. In general, the tallest plants were the Brassica species, which consistently grew to over 1.4 m. Annual grasses (barley, rye, triticale and wheat) averaged about 1.0–1.3 m in each year. Of the legume species screened, heights were greatest for Hedysarum coronarium , Trifolium alexandrium , Vicia spp., and Medicago polymorpha and truncatula , averaging 59, 47, 39, 38 and 37 cm, respectively, over all experiments. About one third of the species screened produced crop cover in excess of 90 % in each year. Groups of plants with consistently high crop cover percentages included various species/accessions of Brassica , Hedysarum , annual grasses, cool-season annual medics, Medicago polymorpha and Medicago truncatula , and two annual clovers, Trifolium alexandrium cv 'Multicut' and rose clover, Trifolium hirtum cv 'Hykon.' Total above-ground plant dry weights were highest for Brassica spp., which produced twice as much biomass as the annual grass species, and roughly four times as much dry matter as any of the legume species. Hedysarum , Lana and Namoi woolypod vetch, purple vetch, berseem clover, and several of the annual medic species consistently had the highest biomass among the legumes.  相似文献   

18.
Irrigation is a management option available to farmers in the subhumid zones of Sri Lanka to increase mung bean yields during the dry Yala season. The objective of this study was to quantify the yield gain in response to irrigation at different stages of the crop and thereby determine the most suitable stage/s of irrigation. Four field experiments were conducted during Yala in 1995 and 1996 at two sites, Maha-Illuppallama (MI) and Kundasale (KS). Eight irrigation regimes consisting of all possible combinations of irrigation at three growth stages of the crop were defined. The respective growth stages were vegetative (from germination to appearance of first flower), flowering (from appearance of first flower to 75 % pod initiation) and pod-filling (from 75 % pod initiation to maturity). The treatments which received irrigation during two or more stages had significantly higher yields (793–1396 kg ha−1) than those which received irrigation during only one stage (401–756 kg ha−1) with the lowest yield being shown by the rain-fed treatment (227–396 kg ha−1). When at least two stages can be irrigated, irrigation during the flowering and pod-filling stages was most effective. Irrigation during flowering produced the highest yield gain when only one stage could be irrigated. Seed yield showed a strong positive correlation with number of pods m−2. Fifity per cent de-podding caused yield reductions at both sites, indicating sink limitation. In contrast, 50 % defoliation reduced the yields only at MI where the number of pods m−2 was greater than at KS. Hence, source limitation was present only when the number of pods was higher.  相似文献   

19.
The effects of increasing soil-salt levels on emergence, shoot and root growth and yield composition of rapeseed were investigated. A range of electrical conductivity (EC) values in the soil solution from 2.3 dS m-1 to 10.3 dS m-1 was obtained by adding NaCl to the substrate. The emergence was significantly (P < 0.05) decreased at EC values higher than 6 dS m-1 Above this value, a delay in the appearance of leaves and of the first visible internode was observed. The further increase of salinity level extended the period for siliqua formation and grain filling, and plant height, pod number and grain number per plant were lowered. However, the cultivar used showed the ability of counterbalancing for this lower grain number by increasing the seed weight, thus there were no variations on seed yield. The seed oil and protein content were also not affected by the changes in salinity. Root growth was adversely affected when salinity levels exceeded 6 dS m-1. Beyond this value, short tuber-like roots became remarkably frequent. This may be an adaptation mechanism of this species to saline stress; a similar reaction in rapeseed is known in adaptation to drought stress.  相似文献   

20.
Salinity is one of the major factors limiting agricultural productivity in arid and semi‐arid regions. Saline areas around the world are increasing and sources of fresh water are decreasing. The increasing importance of the use of brackish water to supplement regular irrigation has demonstrated a need for finding new potential plants with tolerance to irrigation with saline water which can be used in industrial agriculture. The aim of this study was to determine whether irrigation with brackish water of Crambe Abyssinica, a plant commonly used for industrial oil production and for ornamental purposes and with high economical value, especially in Central Asia and the Aral Sea region, is feasible. One more goal was to study how it influences growth and development, seed and oil yield and some physiological parameters such as photosynthesis, transpiration, chlorophyll content, osmotic potential and accumulation of fresh and dry weight. The effects of three salinity levels, 3, 6 and 9 dS m?1, were investigated in a greenhouse experiment during two consecutive years. Results of this study showed that growth of Crambe abyssinica in arid zones and irrigation with mild saline water up to EC 6 dS m?1, mostly common in these areas is feasible, suggesting tolerance to moderate salinity levels and feasibility of its culture in areas of the Aral Sea with adequate salinity levels. Consequently, in spite of the fact that biomass and seed yield were significantly decreased in plants irrigated with brackish water, Crambe abyssinica might be cultivated as an alternate source of green biomass and for industrial vegetable oil under conditions not suitable for conventional plant production.  相似文献   

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