摘要:

Marigold (Tagetes erectaL. cv. ‘Discovery Yellow’, “Perfection Yellow’, ‘Inca Yellow’, and ‘Merrymum Yellow') were grown in aluminum (Al) solution culture concentrations of 0, 1, or 4 mg/L. Aluminum increased root length and weight, but had no effect on stem and leaf weight. Uptake and stem and leaf tissue nutrient concentration of phosphorus (P), calcium (Ca), and magnesium (Mg) were reduced by the Al treatments. The Al treatments increased stem and leaf concentrations of potassium (K) and decreased the concentrations of manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn). No typical Al‐toxicity symptoms were observed in the roots. Root stunting caused by Fe toxicity was alleviated by the Al treatments.

ISSN:0190-4167    

DOI:10.1080/01904169309364620

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Plant screening assays were used to determine whether significant levels of growth inhibitory and phytotoxic contaminants were present in a new industrial source of potassium dihydrogen phosphate fertilizer intended for foliar and root application. Maize(Zea maysL.) plants hydroponically cultured in a controlled environment chamber, were used for the assays. The threshold concentration of industrial potassium phosphate which just caused burn damage symptoms, when applied as standard droplets to the leaf surface with Tween 80 wetting agent was 0.5M. The comparative threshold concentration for damage by an ultrapure analytical grade of potassium phosphate was >0.6M. Thus, the industrial grade had slightly higher toxicity for leaf application. Effects on plants of supplying industrial and analytical grade phosphates via the roots were also compared. Root and leaf elongation kinetics, mature leaf cell lengths, apparent capacity for leaf cell production, shoot ontogeny, and shoot fresh weight yields were determined at low and high potassium phosphate concentrations. The effects of analytical and industrial grade fertilizer salts were equivalent. We suggest that these rapid and relatively simple plant screening assays can provide a useful safety check, prior to large scale field trails, for fertilizer nutrients produced by new industrial processes.

ISSN:0190-4167    

DOI:10.1080/01904169309364621

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A field experiment was conducted to evaluate the effect of iron (Fe) chlorosis on the mineral composition of lemon tree leaves cultivated in calcareous soil in the region of Murcia, Spain. A Fe‐polyflavonoid was employed as fertilizer to control Fe deficiency. The evolution of the leaf content in Fe, potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), phosphorus (P), manganese (Mn), and zinc (Zn) was monitored during all the sampling cycle. A high correspondence between total Fe and chlorophyll content could be appreciated. A multivariance analysis was performed with the data obtained, showing that Fe was correlated with P, Mn, and K.

ISSN:0190-4167    

DOI:10.1080/01904169309364622

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The Diagnosis and Recommendation Integrated System (DRIS) has been proposed to determine nutrient balance in plants at different stages of growth. The DRIS index for each nutrient allows ranking of nutrients in order of their deficiency. Preliminary DRIS norms for potato(Solanwn tuberosumL.) were developed during the 1991 growing season in Damavand area located 70 km. northeast of Tehran. The soil and leaf samples at flowering stage (early tuber development stage) were collected from 50 different farms. Average concentrations of nutrients in both high‐ and low‐yielding populations were calculated. The following average foliar nutrient concentration were obtained from the high‐yielding populations: N = 5.22, P = 0.38, K = 4.20, Ca = 1.50, and Mg = 0.65 percent; and Fe = 150, Mn = 50, Zn = 40, Cu = 11, and B = 38 ppm. The average nutrient concentrations for the low‐yielding population were close to those in high‐yielding ones except for K which was 3.23 in contrast to 4.20‐percent. There was no significant relationship between different soil nutrient availability indices and yield except for K. The DRIS indices ranked K as the most limiting nutrient in the low yielding farms with only one exception. It seems high rates of N and P fertilization have created a lack of balance between these nutrients and K.

ISSN:0190-4167    

DOI:10.1080/01904169309364623

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The objective of this work is to analyse the sodium (Na+) and calcium (Ca++) importance in thein vitromorphogenesis of a halophile species theAtriplex halimus.The experiments have been made on plantlets coming from a seed population collected in a natural area (Algeria). Twenty medium, all different by their sodium chloride (NaCl) and calcium chloride (CaCl2) content, have been tested. For five Na+concentrations, four [Na+]/[Ca++] ratios have been tested. The [Na+]/[Ca++] ratio has a significant effect on the studied criteria (stem length, longest root length and leaf number). The ratio equal to two is the one which gives the lowest values and the ratio equal to one (for the same [Na+] quantity and a double quantity of [Ca++]) gives the strongest ones. A new doubling of the [Ca++] (ratio equal to 0.5) induces a decrease of the values. These results are remarkable if we take into account the low cation concentrations used in the experiments. The morphogenetical events observed here will be explained when results about cation ratios inside the plant and the enzyme activity will have been obtained.

ISSN:0190-4167    

DOI:10.1080/01904169309364624

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Previous research has shown that the Diagnosis and Recommendation Integrated System (DRIS) is useful to identify the nutrient most likely to limit yield of soybean(Glycine max). However, recent work with other crops has shown that DRIS diagnoses are sometimes unsatisfactory due to large numbers of false positve (F+) diagnoses, which would lead to recommendation of unnecessary fertilizer application. This paper reports a reconsideration using the prescient diagnostic analysis approach of data previously used to establish the diagnostic utility of DRIS for soybean. In addition to previously‐published evaluation criteria, the approach is extended by defining an efficiency rating which accounts for differences in the incidence of sufficient and deficient cases. Using this evaluation approach, DRIS phosphorus (P) and potassium (K) diagnoses of soybean using numerous sources of norms and methods to calculate function values and nutrient indices led to unacceptable efficiency ratings (<67%), even though accuracies often exceeded 90%. In one test, diagnoses of nitrogen (N), P, and K by both DRIS and sufficiency ranges were low in accuracy and efficiency ratings. In several other tests, poor ratings for P diagnoses often followed from low accuracy among deficient cases;i.e.false negative (F‐) diagnoses were excessive. In contrast, K diagnoses were often poor due to low accuracy among cases of sufficiency: false positive (F+) diagnoses were excessive. Despite much modification, DRIS diagnoses of soybean N, P, and K status among data sets of known response to fertilizer application are not sufficiently reliable to support routine adoption of DRIS for diagnosis.

ISSN:0190-4167    

DOI:10.1080/01904169309364625

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Copper (Cu) contamination in the lower reaches of the Sado River in the Alcacer do Sal region of Portugal (a major rice producing area) has became a major pollution problem. In an attempt to study the changes in rice growth(Oryza sativaL.), the effect of excess Cu on the plasma membrane activity (as measured throughout proton extrusion) and membrane permeability as well as on the zinc (Zn), nitrogen (N), phosphorus (P), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), boron (B), molybdenum (Mo), and aluminum (Al) net uptake and translocation was studied. Long‐term studies (30 days) were conducted with rice subjected to increasing Cu concentrations (ranging from 0.002 to 6.25 mg/L) showed a concentration increase of Cu in root and shoot tissues. Root proton extrusion increased 7.4‐fold between the 0.01 and the 1.25 mg/L Cu treatments, whereas its membrane permeability (as measured throughout the electrolytic conductance) revealed a marked increase after the 1.25 mg/L Cu treatment. Zinc concentrations decreased with increasing Cu levels in the nutrient solution (excepting the 6.25 mg/L Cu treatment in shoots), while N, P, K, Na, Ca, Mg, B, Mo, and Al concentrations, although showing different patterns, did not reveal any correlation with increasing Cu level. The absolute content of all these metals as well as their net uptake exhibited (excepting Al) its highest values in the 0.25 mg/L Cu treatment. It is suggested that these variations, triggered by excess Cu on root growth, might be explained based on the interaction among Cu‐uptake mechanism(s), plasma membrane‐H+ATPase and root membrane permeability. It is also suggested that Cu affects the N, P, K, Na, Ca, Mg, B, Mo, and Zn concentrations in rice shoots mainly by changing their net uptake rate.

ISSN:0190-4167    

DOI:10.1080/01904169309364626

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A greenhouse experiment to study the effect of humic acid (HA) on the growth and nutrient uptake of Teak(Tectona grandisL.f.), a tropical hardwood, was conducted in Ibadan, Nigeria. The plants were grown for four months in top soils (0–30 cm) collected from an Alfisol (high organic matter) and an Oxisol (low organic matter) in Southern Nigeria. Three levels of HA,viz:, 50, 500, and 1000 mg/kg were added to the two soils. The results indicated that HA was beneficial to the growth and nutrient uptake of teak seedlings. Plant monthly growth rates, and height and total dry matter yield increased significantly (p = 0.05) over the controls in the two soils at the three HA application levels. Effects of adding 500 mg/kg and more of HA to the Alfisol were less beneficial while plant parameters and nutrient uptake tended to increase with increasing amounts of HA in the Oxisol. A significant positive correlation was established between rate of HA application and plant height (r = 0.57), stem diameter (r = 0.77) and total dry matter yield (r = 0.67) in the Oxisol, whereas the HA application rate was significantly correlated only with height (r = 0.57) and root/shoot ratio (r = 0.56) in the Alfisol. The addition of HA to the two soils increased the uptake by seedlings of N, P, K, Mg, Ca, Zn, Fe, and Cu, while Mn was decreased.

ISSN:0190-4167    

DOI:10.1080/01904169309364627

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Intensive land use and concomitant land degradation are strongly undermining the sustainability of current crop production systems in the tropics. Thus, finding alternative cropping strategies to overcome soil and environmental stresses is an integral part of the ongoing process of maintaining and improving crop productivity. In this paper, major features of crops and crop production systems were reviewed. Production systems such as pastures, perennial crops, and agroforestry were found to be highly effective in promoting high and stable crop productivity, restoring and/or enhancing soil fertility, and minimizing erosion risk.

ISSN:0190-4167    

DOI:10.1080/01904169309364628

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The response of carob(Ceratonia siliquaL.) seedlings grown at different root zone temperatures affected by nitrate and ammonium nutrition was studied. When root temperatures ranged from 10 to 35°C, ammonium‐fed plants were significantly larger than nitrate‐fed plants. Ammonium‐fed plants displayed toxicity symptoms and were much smaller at 40°C root temperature in comparison with the nitrate‐fed plants grown at the same root temperature. Root/shoot ratio slightly increase with root temperature in ammonium‐ and nitrate‐fed plants in a similar way, and shoot demand per root unit decreased with root temperature between 15 and 25°C. There was a general increase in net photosynthesis with root temperature, though nitrate‐fed plants were more sensitive to low and ammonium‐fed plants to high temperatures. Increasing the root temperature of ammonium fed plants from 10 to 40°C leads to a 30% increase in the amount of photosynthates sent to the roots. The presence of ammonium resulted in the distribution of newly fixed carbon away from carbohydrates and into nitrogen compounds. Potassium, calcium, and nitrogen content of the plants also increased with increasing root temperature.

ISSN:0190-4167    

DOI:10.1080/01904169309364629

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor