首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The purpose of this study was to investigate the mechanisms underlying alleviation of salt stress by arbuscular mycorrhizal fungi Glomus mosseae. Tomato (Lycopersicon esculentum L. cv. Zhongzha105) plants were cultivated in soil with 0, 50 and 100 mM NaCl. Mycorrhization alleviated salt induced reduction of root colonization, growth, leaf area, chlorophyll content, fruit fresh weight and fruit yield. The concentrations of P and K were higher in AM compared with nonAM plants grown under nonsaline and saline conditions. Na concentration was lower in AM than nonAM plants grown under nonsaline and saline conditions. AMF colonization was accompanied by an enhancement of activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in leaves of both salt-affected and control plants. In addition, inoculation with AMF caused reduction in MDA content in comparison to salinized plants, indicating lower oxidative damage in the colonized plants.  相似文献   

2.
Water logging and salinity of the soil alter both the physical and biological environment of plant roots. In two experiments, we investigated the effects of imposed aeration on yield and the physiological response of tomato (Lycopersicon esculentum L.) variety Improved Apollo growing under protected conditions over a range of salinities (the salinity experiment), and under constant field capacity (FC) or drier soil conditions (the moisture experiment). Subsurface irrigation with aerated water (12% air in water) stimulated above-ground growth, and enhanced the reproductive performance through earliness for flowering and fruiting compared with the control. Fruit yield of tomato with aeration in the moisture experiment was increased by 21% compared with the control (4.2 kg versus 3.7 kg per plant), and the effect of aeration on fruit yield was greater in FC than in the drier treatment. Fruit yield was increased by 38% in saline soil due to aeration compared with the non-aerated control. Increasing salinity from 2 to 8.8 dS m−1, and 10 dS m−1 reduced fruit yield by 18% and 62%, respectively, but 4 dS m−1 did not suppress yield. Aeration in both the experiments increased plant water use and water use efficiency (WUE), expressed as weight per unit of applied water. Biomass WUE was greater by 16% and 32% in the moisture and salinity experiments, respectively. The increased yield with aeration was also accompanied by an increased harvest index (HI) defined as the proportion of dry fruit biomass to total dry biomass, greater mean fruit weight, high fruit DM, and increase in leaf chlorophyll content and shoot: root ratio, and a reduced water stress index (computed from the difference between air and leaf temperature). The benefit gained from aerating irrigation water was not only observed under conditions where air-filled porosity may be low (e.g., in poorly structure sodic soils, or at field capacity in clay soils), but also in drier soils.  相似文献   

3.
Salt tolerance of five cultivars of Capsicum annuum L. Early Jalapeno, Golden Treasure, NuMex Sweet, NuMex Joe E. Parker, and Santa Fe Grande, two cultivars of C. chinense Jacq. Habanero and Pimienta De Chiera, and one accession of C. annuum, NMCA 10652, were evaluated in a field study. Seedlings were transplanted in late May to field raised beds containing loamy sand soils in a semi-arid environment. Plants were well irrigated throughout the experiment. Three saline solution treatments, prepared by adding NaCl, MgSO4, and CaCl2 to tap water at different amounts to create three salinity levels of 0.82 dS m−1 (control, tap water), 2.5 dS m−1, and 4.1 dS m−1 electrical conductivity (EC), were initiated on 15th June and ended in late August. Among the eight varieties, NMCA 10652 had the highest survival percentage at 100% in the 4.1 dS m−1 treatment, followed by ‘Early Jalapeno’, ‘NuMex Sweet’, ‘Pimienta De Chiera’, ‘Santa Fe Grande’, ‘Golden Treasure’, and ‘NuMex Joe E. Parker’. ‘Habanero’ had the lowest survival at 28%. Compared to control, final shoot dry weight of the plants irrigated with saline solution at 4.1 dS m−1 was reduced by 92% in ‘Habanero’, followed by ‘Golden Treasure’ at 80%. For fruit fresh weight in 4.1 dS m−1 vs. control, ‘Habanero’ had the highest reduction at 86%, followed by ‘Golden Treasure’ at 74%, while NMCA 10652 and ‘Santa Fe Grande’ had the least at 26% and 19%, respectively. NMCA 10652, the most tolerant to salinity, had the lowest leaf Na+ accumulation, while ‘Habanero’, the most sensitive to salinity, had the highest Na+ in the leaves. For leaf Cl−, ‘Early Jalapeno’ had the highest, while ‘Habanero’ had the lowest Cl− accumulation in the leaves. Generally, sensitive varieties accumulated more Na+ and/or Cl− in leaves, except for ‘Early Jalapeno’, which was relatively tolerant to salinity but had high Na+ and Cl− accumulation in leaves.  相似文献   

4.
Plant production under salinity requires increased capacity for K+ homeostasis. For this purpose, supplementary K2SO4 in the nutrient solution and grafting on a tolerant rootstock were employed in two experiments to test whether grafting, potassium and their interactions can alleviate salinity stress in tomato (Solanum lycopersicum L.). In Exp-ion, plants were cultivated for 122 days to compare different ionic compositions: EC 9 dS m−1 in ECall (by macro-nutrients) and in ECNaCl (by 64.2 mM NaCl), EC 12 dS m−1 in ECK (ECNaCl + 25.8 mM K+). Exp-K+ was established to compare K+ concentrations of 6, 16 and 36 mM at 150 mM NaCl. In both Experiments, ‘ZS-5’, selected as a salt sensitive cultivar, was either self-grafted or grafted onto the cultivar ‘Edkawi’, reported as salt tolerant. Yield and growth, minerals, gas exchange, soluble sugars, and proline were analyzed. Different ionic treatments affected almost all characteristics considered while differences between rootstocks were rarely observed. No pronounced differences were found in shoot growth, yield and gas exchange between ECall and ECNaCl. ECK did not show any salinity alleviative effects but inhibited even growth compared with the other treatments. In Exp-K+, 16 mM K+ increased plant growth, leaf soluble sugars and proline concentrations. 36 mM K+ did not further reduce upper leaf Na+ although leaf K+ concentration increased significantly. The results indicated that the response of tomato plant to NaCl stress was principally attributed to the osmotic component in Exp-ion, excessive K+ showed no mitigating effect on fruit yield and shoot growth. However, 16 mM K+ in the root environment enhanced the salt adaptive capacity of plants stressed at 150 mM NaCl. The use of the tolerant rootstock resulted in no ameliorative effects, owing to its susceptibility to blossom-end rot, failure in enhancing photosynthesis, and ineffectiveness of restraining the long-distance transport of Na+.  相似文献   

5.
Closed cycle soilless techniques can be adopted to minimize water and fertilizer losses in greenhouse cultivation. There is a general lack of information regarding the soilless cultivation of vegetables with closed cycle subirrigation techniques, specifically when using saline water. In this study, a trough bench subirrigation system (SUB), with two fertilizer concentrations (“100%”, containing 9.8 mol m−3 N-NO3, 1.6 mol m−3 P-H2PO4, 8.7 mol m−3 K+, 2.8 mol m−3 Ca+, 1.8 mol m−3 Mg+, 4 mol m−3 S-SO4, and “70%”, containing 70% of the macronutrient concentration) in the nutrient solution (NS), was compared with open cycle drip-irrigation (DRIP with “100%” NS). For all the three treatments, NS was prepared using rain water (0.05 dS m−1) and adding NaCl (1 g L−1), in order to simulate moderate saline irrigation water. The effect of the treatments on tomato (Solanum lycopersicum L.) plant growth, yield, fruit quality, water use efficiency (WUE) and fertilizer consumption was evaluated. Substrate and recirculating NS composition were also studied. Subirrigation, regardless of NS concentration, reduced plant height (by 30 cm), leaf area (by 1411 cm2), total fresh and dry weight (by 429 and 48.5 g plant−1, respectively) but not dry matter percentage of the whole plant, with respect to DRIP. Yield was reduced when plants were subirrigated with the higher concentrated NS, but no differences with open cycle DRIP were recorded when the lower NS concentration was used in SUB. Fruit quality was not affected by irrigation system or NS concentration. The higher WUE was obtained with subirrigation. NaCl accumulated similarly over the crop cycle in recirculating NS of both SUB treatments and in growing substrates of all the three treatments. Higher salt concentration was found in subirrigated substrates, in particular in the upper part of the substrate profile. Fertilizers accumulated in the subirrigated substrates when the higher NS concentration was used, but not when the NS concentration was reduced by 30%. The results of this study indicate that tomato can be grown successfully in a closed cycle subirrigation system, using saline water, by reducing the fertilizer NS concentration normally used with traditional open cycle systems.  相似文献   

6.
Salicornia is a new vegetable crop that can be irrigated with highly saline water, even at salt concentrations equivalent to full-strength seawater. During leafy vegetable cultivation, the onset of the reproductive phase is an undesired phenomenon that reduces yield and quality and prevents year-round cultivation. Knowledge about the regulation of floral induction in the members of the tribe Salicornieae, however, is lacking. To establish year-round cultivation, we studied the flower induction of five Salicornia and two Sarcocornia varieties. Plants were grown under two day lengths, 13.5 h and 18 h, and harvested by a repetitive harvest regime. A 13.5-h day length prevented flower induction in the Israeli Salicornia varieties, but a longer day length was required to prevent flower induction in two species originating from more northern latitudes. The onset of the reproductive phase under suboptimal short day length conditions severely reduced vegetative growth and yields in Salicornia. In Sarcocornia, the repetitive harvest regime prevented flowering, making it a promising candidate for year-round cultivation. Irrigating the plants with full-strength seawater (electrical conductivity 48 dS m−1) vs. water with moderate salinity (electrical conductivity 10 dS m−1) did not change the general flowering pattern of the studied Salicornieae members.  相似文献   

7.
We investigated the hypothesis that split root fertigation (SRF) approach could provide complementary benefits over traditional fertigation (TF) in terms of water use, vegetative growth and yield formation in the high radiation season and under two atmospheric conditions in a greenhouse. Plants of cucumber (Cucumis sativus L. cv. Cumuli) were grown in a traditional high-wire cultivation system in a peat growing medium. In the SRF method the root system of a plant was separated into two compartments over the crop cycle. One compartment received fertigation solution with low EC (1.2 dS m−1) and the other compartment solution with high EC (3.5 dS m−1) value. In the TF method the EC value of fertigation solution was 2.4 dS m−1. The atmospheric conditions included an open (ventilated) and a semi-closed (cooled) greenhouse. The employment of cooling resulted in an enhancement of the average CO2 in a semi-closed (810 ppm) over an open (530 ppm) greenhouse resulting in a yield improvement (37%). SRF improved water uptake in both atmospheric conditions and water use efficiency (WUE) in an open greenhouse. The water uptake in SRF was highest in the root part with the low EC values, namely 61% in the open and 66% in the semi-closed greenhouse. In both atmospheric conditions, SRF decreased flower abortion, leading to an improved fruit set with a small effect on vegetative growth. SRF increased yield by 21% in the open and 17% in the semi-closed greenhouse compared to TF in corresponding greenhouses.  相似文献   

8.
In closed-loop soilless culture, one of the most relevant problems may be the accumulation in the recirculating nutrient solution of ions contained in irrigation water that are not or scarcely absorbed by the plants (e.g. Na, Cl) In order to verify the possibility to reduce the rate of recirculating water salinisation by means of subirrigation, an experiment was carried out in the spring of 2002 and 2004, with tomato plants (cv. Jama) grown in glasshouse and watered by conventional drip irrigation (D) or by subirrigation (trough bench system; S). The plants were cultivated in pots filled with a peat-perlite substrate for approximately 3 months and fed with complete nutrient solution, which was prepared with fresh water containing 10 mol m−3 NaCl; the nutrient solution in the collecting tank was replaced when the value of electrical conductivity (EC) exceeded 6.0 dS m−1. Water and nutrient crop use, salt accumulation in the substrate, and fruit yield were monitored. In S culture, the composition and EC of the recirculating nutrient solution changed slightly, while in D treatment there was a fast water salinisation that made it necessary to flushed out the nutrient solution in six different occasions, with consequent loss of water and fertilisers. In S culture, the upward water movement in the substrate, coupled with selective mineral uptake by the roots, caused salinity build-up in the upper region of the substrate, which was associated with Na+ accumulation. No significant influence of irrigation methods on fruit yield and quality was observed. These findings suggest that subirrigation can be a tool to reduce the water consumption and nutrient runoff in closed-loop substrate culture of tomato conducted with saline water.  相似文献   

9.
NaCl was applied to nutrient solution (5 dS m−1 versus 1.4 dS m−1 in the control) of hydroponically-grown tomato and its effects on taste grading and chemical composition of fruit were investigated. Taste panels indicated NaCl treatment increased sweetness, acidity, umami (i.e. the taste of deliciousness) and overall preference. Hexose concentration of the fruit grown on NaCl treated plants significantly increased; and at the same time, chloric ion, organic and amino acids in general had higher concentrations in NaCl treated plants than the control. Our results showed that (1) consumer grading of the tomato fruit was influenced not only by sugar content but also by the organic and amino acids; (2) increased concentration of soluble solids in the fruit of NaCl treated plants was not the result of simple overall condensation due to the reduction of water transport. The relation of diversified consumer preference, fruit chemical composition, and appropriate evaluation of tomato fruit are also discussed.  相似文献   

10.
In arid regions, such as Tunisia, the reuse of treated wastewater (TWW) in agriculture can be a sustainable solution for water scarcity. A two-year field experiment was conducted in order to investigate the short-term effects of TWW on olive growth, yield and concentration of total nitrogen (Nt), potassium (K), phosphorous (P), and heavy metals (i.e. Zn, Mn, Pb and Cd) in olive leaves. Olive trees were subjected to the following irrigation treatments: (i) trees irrigated with well water (WW) and (ii) trees irrigated with treated wastewater (TWW). For both treatments, the TWW and WW were applied at a rate of 4.5 m3 day−1 tree−1 (5000 m3 ha−1 year−1). After two years, non-significant injuries caused by salts and/or heavy metals were observed on shoot growth of trees irrigated with TWW. The application of TWW significantly increased concentration of Nt, P and K in the leaves, whereas heavy metals (Zn and Mn) showed a significant increase only after the second year of irrigation.  相似文献   

11.
This study examines the feasibility of using saline irrigation water for commercial pot cultivation of three ornamentals: Calceolaria hybrida, Calendula officinalis and Petunia hybrida. Two saline treatments were assayed: irrigation with low saline tap water (electrical conductivity = 1.16 dS m−1), and irrigation with a high saline solution of NaCl 100 mM + CaSO4 10 mM + MgSO4 2.5 mM (electrical conductivity = 12.5 dS m−1). When the control plants reached marketable size the watering was stopped and the plant response to drought was studied. Petunia and Calceolaria were tolerant to salinity. Petunia saline-treated plants reduced their growth slightly and increased N and chlorophyll contents in the leaves. Calceolaria experienced a strong reduction in growth and a delay in flowering but no toxicity symptoms or mortality was recorded. These species were moderate NaCl accumulators. Calendula was sensitive to salinity: 16% of the plants died and the surviving ones experienced a heavy reduction of growth, a decrease in chlorophyll and a large accumulation of NaCl in the leaves. Saline pre-conditioned plants of Calceolaria and Petunia were tolerant to drought. In these plants, leaf water content and, specifically, leaf relative water content were sustained longer than in non-pre-conditioned plants throughout the drought period. In Calendula, leaf relative water content decreased at the same rate in pre-conditioned and non-pre-conditioned plants. Consequently, salinization did not confer drought resistance upon this species. Possible factors determining the tolerance to drought in saline pre-conditioned plants are discussed.  相似文献   

12.
Flower heads of Calendula officinalis L. are used for medicinal or culinary purposes. Since Egyptian agricultural lands contain salt, this study investigated the effects of saline irrigation water on yield (fresh and dry weights of flower heads), essential oil (EO) yield, chemical constituents of the EO and total flavonoids and carotenoids of flower heads at three flowering stages, i.e. initial (21 days after bud formation (DABF)), full flowering (81 DABF) and final (111 DABF). After plants were treated with different levels of saline irrigation water (0.39, 1.56, 3.13, 4.69, 6.25, 7.81 and 9.38 dS m−1) consisting of NaCl, CaCl2 and MgCl2 salts, the flower head yield and pigment (total flavonoids and carotenoids) content were significantly reduced. Irrigation with saline water increased the EO content and its main components (α-cadinol, γ- and Δ-cadinene). Fresh and dry weights of flower heads and EO increased near 81 DABF while the content of pigments increased by 111 DABF.  相似文献   

13.
设施果类蔬菜土壤EC 值动态及盐害敏感性分析   总被引：1，自引：0，他引：1  
在建立饱和及土水比1∶5（m∶v）条件下ECe 与EC1:5 相关关系的基础上,建立EC1:5 的土壤盐分分级指标,评价了传统管理条件下设施越冬长茬和春茬的土壤盐分动态。结果表明：设施菜田土壤ECe 与EC1:5 呈极显著正相关,在京郊土壤条件下换算公式为EC1:5 =0.105 ECe;果类蔬菜中茄子和辣椒属敏感蔬菜作物,苗期和全生育期耐盐性根层土壤EC1∶5 临界值分别为0.10 dS·m -1 和0.30 dS·m -1,当季根层土壤EC1∶5 可接受调控范围为0.30～0.50 dS·m -1;番茄和黄瓜属非敏感蔬菜作物,苗期和全生育期耐盐性根层土壤EC1:5 临界值分别为0.30 dS·m -1 和0.60 dS·m -1,当季根层土壤EC1∶5 可接受调控范围为0.60～0.90 dS·m -1;日光温室越冬长茬土壤EC1:5 均值从定植至翌年3 月一直稳定在0.30～0.34 dS·m -1 之间,之后逐渐下降,7 月降至0.15 dS·m -1;塑料大棚春茬定植后根层土壤EC1:5 逐渐下降,4 月之前为0.29～0.30 dS·m -1,7 月降至0.20 dS·m -1;结合蔬菜作物耐盐指标发现,传统管理条件下日光温室越冬长茬和塑料大棚春茬蔬菜作物在苗期易出现盐害问题;越冬长茬敏感蔬菜作物从定植至翌年3 月期间,土壤盐度易超过其耐盐临界值,需要合理水肥调控以防盐害。  相似文献   

14.
Data on the growth-promoting effects of Azospirillum on lettuce exposed to either normal or saline conditions, is scarce. Lactuca sativa L., cv Mantecosa seeds were colonized with A. brasilense Sp245 cells during imbibition. Germination percentages were determined after 7 d treatments with 0, 30, 50 or 80 mol m−3 NaCl. In another experiment, seeds germinated in Hoagland were irrigated for 30 d with 0, 30, 50 or 80 mol m−3 NaCl supplemented media. Vegetative growth proceeded in a growth chamber with a 13–11 h day–night cycle. Buffer-imbibed seeds were considered non-inoculated controls. Plant samples were taken at 0, 14, 20, and 30 d after the onset of NaCl treatments and dissected in aerial and root portions. The weights of both tissues were measured. Azospirillum-inoculated seeds had significantly higher germination percentages than controls in all treatments. Inoculated dried seeds stored up to 30 d maintained such characteristic in most of the treatments, particularly at 80 mol m−3 NaCl. Plants grown from inoculated seeds and irrigated with saline media displayed higher total fresh and dry weights and biomass partition to the aerial portion, than non-inoculated controls. Azospirillum-inoculated lettuce seeds had better germination and vegetative growth than non-inoculated controls after being exposed to NaCl.  相似文献   

15.
This study was conducted in order to determine if inoculation with arbuscular mycorrhizal fungi (AMF) would enhance the tolerance of vinca plants to high levels of alkalinity, induced by KHCO3, in irrigation water. AMF-inoculated and non-inoculated plants were irrigated with water containing varying HCO3− concentrations: 0, 2.5, 5, 7.5, 10, and 15 mM. Increased HCO3− concentration inhibited plant growth, specifically at concentrations ≥7.5 mM. Leaves were more affected by high HCO3− concentration than other plant parts. In non-inoculated plants, a visual evaluation of quality demonstrated that acceptable quality was produced when irrigation water contained ≤2.5 mM HCO3−, but AMF-inoculated plants of good quality were produced when irrigation water contained ≤7.5 mM HCO3−. In general, AMF alleviated HCO3− stress, as indicated by greater plant growth and ranking of quality. However, AMF-inoculated plants irrigated with 0 mM HCO3− exhibited reduced growth when compared to non-inoculated plants. Bicarbonate did not affect leaf Fe concentration, indicating that vinca may be a Fe efficient plant. Plants inoculated with AMF exhibited an enhanced leaf P concentration and content, which was related to an increase in the activity of the soluble alkaline phosphatase. Plants inoculated with AMF exhibited increased leaf concentration and content of Mn, Zn, Cu, B, and Mo, and increased antioxidant activity under high concentrations of HCO3−. In conclusion, the tolerance of vinca to alkalinity in irrigation water can be enhanced by AMF inoculation, thus, allowing for irrigation with water of high alkalinity.  相似文献   

16.
Reliable and affordable moisture sensors for measuring the water content in soilless substrates are limited. In this study, we examined the efficacy of two moisture sensors (ECH2O-10 and Theta probe ML2X) for measuring water content in soilless substrates. We developed calibration equations and analyzed the effect of increasing electrical conductivity (EC) and substrate temperature on the voltage output of probes. We found that a single equation (one for each probe) could be used to adequately measure water content in different custom-made substrates maintained at low EC and a substrate temperature of ∼23 °C. The calibration equation developed for the Theta probe from substrates maintained at low EC could also be used in two commercial substrates with high EC (2.0–5.0 dS m−1). Further measurements in substrates maintained at different water contents and EC levels indicated that the output of the ECH2O-10 probe, but not the Theta probe, was significantly affected by substrate EC. The lack of a substrate EC effect on the Theta probe readings was surprising, because the probe was sensitive to EC when fertilizer solutions with different ECs were measured. Increasing the temperature of the substrate from 10 to 40 °C increased the voltage output of ECH2O-10 probes by 1.88 mV °C−1, or on average 0.0022 m3 m−3 water content per °C. There was no effect of increasing substrate temperature on the Theta probe. It was concluded that ECH2O-10 probes can be used in greenhouse operations requiring less measurement precision (like irrigation), however for accurate measurements of water content, the Theta probe is preferred.  相似文献   

17.
High-pressure sodium (HPS) light supplementation during the low-light months has become quite common for high-light requiring crops at latitudes above 45°. Most common systems have fixed installations, while movable systems have been tried with various results in greenhouses. The concept is that fewer lamps are used on a track system, and that light intensity varies over time. In two trials, we determined whether the speed of the HPS lamp movement had any effect on leaf CO2 exchange rate, growth and developments of various plants species. Plants (chrysanthemum, petunia, rose and tomato) were grown in a greenhouse supplemented with HPS lamps which moved at various speeds (0, 2, 8 and 20 mm s−1) between 06:00 and 24:00 h daily for about 6–7 weeks. One trial started at the end of November and one started at the end of January. The light sum from the lamps were 0.212 ± 0.004 mol m−2 h−1 at bench level, and the supplemental lighting represented 55 and 35% of the total light received by the plants for the two trial dates, respectively. The growth (dry matter) was reduced for tomato only when grown under moving lights compared to those grown under the stationary system, while plant height was not affected. Light saturated CO2 exchange rate on the youngest fully developed leaves increased with lamp speed for petunia and tomato, but not for chrysanthemums, while apparent quantum yield was not affected by lamp speed for any species. In situ measurements of net CO2 exchange rate (NCER) with supplemental lighting only, showed that NCER decreased exponentially when lamp speed increased from 0 to 20 mm s−1.  相似文献   

18.
Tomato (cv. Durinta) plants were grown hydroponically under two electrical conductivities (EC, 2.3 and 4.5 dS m−1) of nutrient solution inside a greenhouse. The high EC treatment was initiated either immediately after anthesis (high EC treatment) or 4 weeks after anthesis (delayed high EC treatment). Fruits were harvested weekly beginning 2 weeks after anthesis, until all fruits reached the red stage (8 weeks after anthesis). Lycopene, chlorophyll, sugar and total soluble solid (TSS) concentrations of fruits were measured every week for all harvested tomatoes from the different ripeness stages. The results showed that lycopene concentration, fructose and glucose concentrations and TSS of red ripe tomato fruits were enhanced by both high EC and delayed high EC treatments compared to those in the low EC treatment. The lycopene concentration of red ripe tomato fruits in the high EC and the delayed high EC treatments showed an increase of 30–40% (1.29–1.39 mg g−1 dry matter) compared to those in the low EC treatment (0.99 mg g−1); however, there was no significant difference in the lycopene concentration between the high EC and delayed high EC treatments. TSS of red ripe tomato fruits grown in the high EC treatment was 6.1%, significantly greater than those grown in the delayed high EC treatment (5.7%). Weekly change in lycopene concentration indicated that lycopene synthesis was enhanced by the high EC treatment, regardless of the application timing. Regardless of EC treatment, chlorophyll concentration in fruit declined linearly during fruit development and ripening and reached non-detectable levels 7 weeks after anthesis. Our results indicated that: (1) accumulation of sugars and TSS in fruit was due to reduced water flux to the fruit under high EC as previously reported, and (2) lycopene synthesis was promoted by, but chlorophyll degradation was independent from, the osmotic and/or salt stress caused by the high EC.  相似文献   

19.
Effects of the commercial product TrichoFlow WP™ (Agrimm Technologies Ltd., New Zealand), based on the fungus Trichoderma harzianum, on quality characteristics and yield of bulb onion was investigated. Bulb sets of the local cultivar Kantartopu was planted in soil with in and between row distances of 0.15 m and 0.40 m, respectively. The product, at considerably high dosages of 5 g m−2, 10 g m−2 and 15 g m−2, was mixed with water and sprinkled once to the plots at planting. Analyses of data at harvest did not show statistical significance for Trichoderma effect on total bulb yield, bulb diameter, leaf length, number of shoot apex, %titratable acidity, number of internal (fleshy) leaves, number of external (papery) leaves, %soluble solids and %bulbs with diameters of 20–39 mm, 40–69 mm and ≥70 mm. The yields obtained from the plots treated with the dosages of 5 g m−2, 10 g m−2 and 15 g m−2 and the control plots were 1063.7 kg da−1, 1051.0 kg da−1, 1066.5 kg da−1 and 985.0 kg da−1, respectively. Our results showed that high dosages of the Trichoderma product were not effective in enhancing onion bulb and yield characteristics under the given conditions.  相似文献   

20.
Two plant stress factors, salinity and high levels of boron, often co-occur in natural and agricultural environments. Many investigations have been conducted to document the influence of the combined stresses on crop growth and yield. Only limited information, however, is available concerning the combined effects of the two stresses on mineral ion uptake and partitioning to shoot organs and tissues. Data for this study were obtained from an experiment conducted in greenhouse sand cultures with two water types: (1) a chloride-dominated system, and (2) sulfate-dominated waters characteristic of those present in the San Joaquin Valley of California. Each saline composition treatment was tested at three salinity levels (2, 12, 18 dS m−1) and three B concentrations (0.046, 1.11, 2.22 mM; 0.5, 12, 24 mg L−1). The gradient in B distribution in individual leaves sampled midseason was steep, with less boron accumulating in petioles than in the blades. The highest B concentrations (>100 mmol B kg−1 dry weight) were found in leaf margins of plants grown in the low salinity-high boron treatments. These leaves were cupped upward, an unusual visual symptom characteristic of B toxicity. At final harvest, concentrations of B, Ca, Mg, Na, K, and Cl were highest in the oldest leaves on the broccoli shoots, decreasing acropetally to the heads. Total-P, however, was highest in broccoli heads, decreasing in the older tissues. Leaf-B accumulation was more closely related to salinity rather than to the concentration of Cl in the irrigation waters. Analysis of variance indicated that substrate B had little effect on Cl accumulation in salt-stressed broccoli leaves regardless of water type. No clear cut relationships were evident that would explain the reciprocal effects of B and Cl on crop yields.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号