Influence of Plant Phosphorus and Iron Concentrations on Growth of Soybean

Growth responses to phosphorus (P) and iron (Fe) are commonly assessed based on element concentrations to which plants are exposed. Such data offer little insight about responses to the concentration of P and Fe actually accumulated in plants. In this study, soybean (Glycine max Merr., cv. ‘Biloxi’) was grown on nutrient solutions to induce varying P and Fe concentrations in plant tissues. Leaf P and Fe concentrations were correlated at lower concentrations. However, under high P treatments there was an apparent excess of accumulated P based on plant response. These results were interpreted to indicate that these plants could accumulate P in excess of the amount required for normal physiological activity. There appeared to be no excess accumulation of Fe so that correlations between leaf Fe concentration and leaf area and plant mass were significant for all data. Root mass did not correlate significantly with either leaf P or Fe concentration.     

The response of okra to molybdenum in sandculture

Abstract

The role of molybdenum in plant growth was examined by growing ‘Emerald’ okra (Abelmoschus esculentus L. Moench) to fruiting in sand‐culture.

Molybdenum treatment lower than 1 ppm, resulted in leaves that were generally pale yellow and curled upwards. At 1 ppm and 4 ppm Mo, plants were generally healthy with deep green leaves, while Mo application at 6 and 16 ppm resulted in stunted plant growth, deep green leaves, and dark brownish coating on the roots. Shoot/root ratio decreased with increasing rates of Mo. Total chlorophyll was unaffected by Mo application, whereas plant dry matter production and fruit yield were depressed at the 16 ppm Mo treatment.

Leaves of plants receiving less than 1 ppm Mo had higher concentrations of NO₃‐N, P, K, Ca and Mg than plants receiving above 1 ppm Mo treatments. The reverse was the case with the micronutrient levels. Specifically, Mo treatments higher than 1 ppm increased leaf‐Mo, ‐Fe, Mn and Zn and root‐Mo and Mn. The highest percentage of Fe and Mn, accumulated in the leaves, followed by the root and least in the wood, whereas the roots had the highest percentage of accumulated Mo, Cu and Zn. Leaf‐Mo was positively correlated with leaf‐Fe and Mn and root‐Mo and Mn. Molybdenum deficiency symptoms appeared in plants with leaf‐Mo of 5 ppm and treated with less than 1 ppm Mo. The 2 ppm Mo treatment with leaf‐Mo of 18 ppm produced normal and healthy plants, whereas. Mo application from 8 to 16 ppm with corresponding leaf‐Mo of 42 and 90 ppm Ho respectively produced plants that were severely stunted and had generally poor growth. The relatively high Ho concentration observed suggests that the okra plant is a Mo accumulator.     

Interactive effect of boron and zinc on growth and metabolism of mustard

Abstract

Mustard (Brassica campestris L.) cv. T9 was grown in refined sand at three levels of boron (B), deficient (0.0033 ppm), normal (0.33 ppm), and excess (3.3 ppm), each at three levels of zinc (Zn), low (0.00065 ppm) adequate (0.065 ppm), and high (6.5 ppm). The B deficiency effects were accentuated by low zinc viz., the decreased biomass, B and Zn concentrations in leaves and seeds and the activity of carbonic anhydrase and accumulation of reducing sugars and stimulated activities of peroxidase, ribonuclease, and acid phosphatase in B deficient leaves were aggravated further. Synergism was also observed between the two nutrients when both B and Zn were in excess together as excess B accelerated the effects of high Zn by lowering further the reduced biomass, economic yield, and carbonic anhydrase activity and raised further the increased concentration of B and Zn in leaves and seeds, reducing sugars and activity of peroxidase obtained in excess Zn. In mustard, additive effects of high Zn and low B was reflected when high Zn increased the reduced biomass, seed yield, leaf B, and decreased the stimulated activities of peroxidase, ribonuclease, acid phosphatase, and high concentration of non‐reducing sugars to some extent in low B.     

Relationships of Spectral Reflectance with Plant Tissue Mineral Elements of Common Bean (Phaseolus Vulgaris L.) Under Drought and Salinity Stresses

ABSTRACT

Salinity and drought stresses are critical for Phaseolus vulgaris L. growth and development. They affect plants in various ways, including tissue mineral element content. Micro- and macro-elements in leaves of Phaseolus vulgaris L. (cv. ‘Blue lake’ and cv. ‘Terli’) subjected to deficit irrigation and salinity treatments were investigated, both analytically and with regards to their effect on the leaves’ spectral reflectance. B (boron), K (potassium), Mn (manganese), Na (sodium), Si (silicon) and Zn (zinc) appeared to be influenced by stress factors, mainly responding to salinity increase. The leaf spectral reflectance of the plants appeared to be significantly correlated with most of the elements under investigation. Multivariate regression identified a relationship of the reflectance at particular regions of the spectrum with phosphorus and NDVI (normalized difference vegetation index) and indicated a significant correlation with B, Fe (iron), K, Mn, P (phosphorus) and Zn. Moreover, customized spectral indices, exhibiting significantly high correlation with B, Fe, K, Mg (magnesium), Mn, Na, P, Zn and N (nitrogen), were developed.     

Effect of aluminum on growth and chemical composition of marigolds

Marigold (Tagetes erecta L. 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.     

C-Pro (grapefruit seed extract) as supplement or replacement against rose- and cucumber powdery mildew

Abstract

Numerous fungicide applications are often needed to control powdery mildews in greenhouse-grown crops, and consequently there is an increasing demand for alternative means to control them. In commercial greenhouses, attack of powdery mildew caused by Podosphaera xanthii in cucumbers and P. pannosa in cut roses was controlled by weekly sprays of C-Pro CE601, a dilution of grapefruit seed extract (GSE). The raw material of GSE, delivered by Citricidal®, is a glycerolic extract from seed and juiceless pulp of grapefruits (Citrus paradise). In both cultures C-Pro at 2000 ppm achieved as good control as treatments with penconazole or triforine. The mean level of attack by powdery mildew on leaves of cut roses one week after the last of three weekly treatments, was 9.8, 12.9 and 40.5% for penconazole, C-Pro (2000 ppm), and untreated, respectively. In cucumbers, there was less difference between the untreated control and the different treatments, but for all times of assessments, C-Pro and triforine were better than untreated (p=0.001). There was no significant difference in cucumber between C-Pro and triforine. Phytotoxicity symptoms such as leaf twisting and rolling in roses (cv. Jade and Cezann) and dark green leaves and indications of growth retardation in cucumbers (cv. Ventura) were observed at the higher concentrations used (3000–4000 ppm). Thin layer chromatography of C-Pro CE601 has previously shown presence of benzethonium chloride, a synthetic antiseptic agent. Further research is necessary to determine if the observed effects of the product tested are due to natural compounds or are merely due to a synthetic preservative agent added. Our results revealed that C-Pro might be a supplement or even a replacement to some of the current fungicides used against powdery mildew.     

Growth and Localized Energy Status in Phosphorus-Stressed Soybean

Abstract

In plants experiencing phosphorus (P) stress, ATP concentrations can be reduced significantly and shoot growth is strongly restricted, raising the possibility that energy availability is responsible for the growth inhibition. Experiments were conducted to investigate the relationship between P deprivation and energy availability in tissues involved in the growth response. Young soybean (Glycine max [L.] Merr. cv. Ransom) plants were deprived of P for 32 days. Leaf initiation and individual leaf expansion were followed along with localized P and ATP concentrations. Tissue analyses revealed preferential distribution of P to the root, which accompanied a decline in the shoot to root dry weight ratio. Even though P concentrations in all shoot tissues dropped sharply, ATP concentrations and energy charge in the shoot meristem region were maintained similar to controls for an extended period when leaf initiation slowed. In the first trifoliolate leaf, ATP and energy charge remained at control levels during the expansion phase, but expansion was inhibited by 50%. Furthermore, ATP levels in root tips were decreased almost 30%, yet growth of the root system was equal to or greater than the control. The absence of a positive correlation between ATP levels and growth responses in the different tissues suggests that energy availability is not a primary factor limiting growth under P stress conditions. The results, along with others from previous experiments, support the notion that a signaling mechanism, as yet unidentified, controls down regulation of cell division in shoot growth regions.     

Evaluation of catalase and peroxidase activity as indicators of Fe and Mn nutrition for soybean

The influence of Fe and Mn supply on plant growth, Fe and Mn uptake and catalase and peroxidase activities of soybean (Glycine max L. Merr.) cv. Williams was studied. Plants were grown in nutrient solutions until the second trifoliate stage under growth chamber conditions. Growth was depressed by the lowest Mn (0.0 ppm) and Fe (0.25 ppm) levels, and also by Mn in excess (5.0 ppm). The levels of Fe and Mn, and the interaction FexMn affected Mn and Fe uptake. Peroxidase activity was greatest at the highest Mn concentration at each Fe treatment level. On the other hand, catalase activity increased with Fe supply but no relation was observed with leaf Fe concentration. The interferences observed on both indicators make the use of these metalloenzymes difficult to appraise Fe nutritional status.     

Microdistribution of aluminum and manganese in the tea leaf tissues as revealed by X‐ray microanalyzer

Abstract

Tea plants (Thea sinensis L.) were found to accumulate large amount of Al (4457 ppm, D.W.) in their old leaves. The results showed that Mn stimulated the Al uptake and increased the Al content in the leaves. High concentrations of Ca and Mg in the soils decreased the Al and Mn and increased the Ca and Mg contents in the leaves. No phosphorus and aluminum interaction was found in the leaves of tea plants.

Microdistribution patterns of Al and Mn in the tea leaf tissues were also studied by means of a wavelength dispersive type X‐ray microanalyzer in conjunction with cryostage. The results of X‐ray micrographs showed that Al was densely deposited on the cell walls of the adaxial epidermis and palisade parenchyma cells of the old leaf tissues, and this distribution pattern of Al was different than that of Mn which was found mostly concentrated in the epidermal cells.     

Effect of zinc application on the dry matter yield uptake and distribution of zinc and other micronutrients in cocoa (Theobroma cacao. L.)

Abstract

The effects of application of zinc fertilizer on dry matter yield, uptake and distribution of zinc and other nutrients by Amazon and Amelonado cocoa cultivars grown in a soil of low zinc content in the greenhouse were investigated.

There was a differential response to zinc fertilization by the two cocoa cultivars. Maximum dry matter yields of Amazon and Amelonado were attained with 10 ppm Zn and 50 ppm Zn, respectively. Under similar experimental conditions Amelonado seedlings expressed zinc deficiency symptoms whereas Amazon did not.

Zinc concentrations in the leaves, stem and roots of both cuitivars did not give a good index of the zinc status of the crops. This was because of the existence of the “Piper‐Steenbjerg”; effect in that nil zinc rates often gave higher leaf concentration of the zinc than next higher rate. In general, the relative content of zinc followed the pattern; leaves > roots > stem with the Amazon cultivar containing more zinc than the Amelonado.

The distribution of absorbed Cu in the leaves, stem and roots did not differ in both varieties. Whereas Fe uptake was mostly concentrated in the roots, Mn absorbed was largely concentrated in the leaves of both varieties and only Mn uptake in the leaves of Amazon consistently increased with Zn application.

The differences in the uptake and distribution of nutrients between the two cocoa cultivars was attributed to differences in their ability to extract nutrients from the soil and in their requirements for metabolic processes.     

Plant Growth-Promoting Rhizobacteria (Pgpr) Increase Yield,Growth And Nutrition Of Strawberry Under High-Calcareous Soil Conditions

Plant growth promoting effects of Alcaligenes 637Ca, Staphylococcus MFDCa-1, MFDCa-2, Agrobacterium A18, Pantoea FF1 and Bacillus M3 were tested on strawberry cv. ‘Aromas’ based on yield, number, and weight of fruit, leaf area, vitamin C, total soluble solids (TSS), acidity and ionic composition of leaves under calcareous soil conditions. The results demonstrated that all of bacterial treatments significantly affected all parameters tested. The best result was obtained from 637Ca treatment, which significantly increased fruit yield, number and weight about 47.5, 34.7, and 9.4%, respectively, compared to control. Except for magnesium (Mg) and zinc (Zn) in the leaf, the concentrations of all plant tissue nutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), iron (Fe), copper (Cu), manganese (Mn), boron (B)] were significantly increased by bacterial treatments tested. The data in the present study showed that all bacterial treatments including Alcaligenes 637Ca, Staphylococcus MFDCa-1, MFDCa-2, Agrobacterium A18, Pantoea FF1, and Bacillus M3 to strawberry plants can ameliorative the deleterious effect of high lime on fruit yield, growth and nutrition. These results suggested that plant growth-promoting Rhizobacteria (PGPR) treatments could be offer an economic and simple means to increased plant resistance for high calcareous soil conditions.     

Manganese toxicity alleviated by mycorrhizae in soybean

Abstract

Soybean (Glycine max (L.) Merr.) plants nodulated with Bradyrhizobium japonicum. Nitragin strain 61A118, were grown with or without the vesicular‐arbuscular mycorrhizal (VAM) fungus Glomus mosseae (Nicol. Gerd.) Gerd. and Trappe in pot cultures in soil high (40.4 μg/g) in available Mn. Leaves of the nonVAM plants showed severe symptoms of Mn toxicity and had toxic (314 μg/g) concentrations of Mn in the foliage. NonVAM plants had significantly lower dry weights and nodule mass than VAM plants. Concentrations of Mn in the VAM plants were significantly (P<0.05) lower than in the nonVAM plants, and there were no symptoms of Mn toxicity. Both VAM and nonVAM plants had a significant negative correlation between shoot dry mass and leaf Mn concentration. Since levels of Mn increased with increasing VAM‐fungal colonization, we conclude that it was not the VAM condition per se which alleviated Mn toxicity. We suggest that the significantly higher levels of Mn in the leaves (P<0.05) and the roots (P<0.001) of nonVAM plants was due to increased uptake of Mn by the nonVAM plants. This exudation, which are generally observed in nonVAM plants, and to the role of such exudates in solubilizing MnO₂ and chelating the resulting Mn²? for facilitated absorption.     

Effect of nitrogen and phosphorus on ‘delicious’ apple trees grown in caliche soil in the greenhouse

Abstract

In a greenhouse study, mono‐ammonium phosphate applications to ‘Delicious’ (Oregon spur cv) apple trees, Malus domestica Borkh., improved a low‐vigor condition associated with a caliche soil. The moderate rate of mono‐ammonium phosphate (6 grams per tree) resulted in trees with greater shoot extension, leaf numbers, a higher percent leaf phosphorus, and less purple leaf margins or spots than other soil treatments or the control. By September, trees treated with the highest rate of mono‐ammonia phosphate (12 grams per tree) had the highest level of leaf phosphorus and significantly higher levels of leaf phosphorus than all forms of nitrogen‐only fertilizer (ammonium nitrate, ammonium sulfate, calcium nitrate, and urea). In most cases, applications of the nitrogen‐only fertilizers, reduced leaf phosphorus levels throughout the experiment.     

Effect of cadmium on autoxidation rate of tissue and inducing accumulation of free proline in seedlings of mung bean

Solution cultures were conducted to investigate the effects of cadmium (Cd) toxicity on the growth of mung bean (Phaseolus aures Roxb. cv VC‐3762), autoxidation rate of tissue and accumulation of proline. Results showed that leaf proline concentrations increased significantly in response to increasing Cd concentrations from 0 to 20 umol L^‐1 Cd in the solution. Compared to the control, Cd treatments increased lipid peroxidation (malondialdehyde concentration) and autoxidation rate of leaves and roots. In all treatments, leaves of mung bean had greater proline concentration and had lower the autoxidation rate of tissue than the roots. There was a close positive relationship between accumulation of free proline and the rate of tissue autoxidation.     

Effect of foliar and soil applications of zinc sulphate on zinc uptake,tree size,yield, and fruit quality of mango

To compare the effect of methods (foliar and soil) and rate of application of zinc sulphate on zinc and phosphorus uptake, tree size, yield and fruit quality of mango (Mangifera indica L.) cv. Dusheri, zinc sulphate was applied as a foliar spray application (0.25, 0.50, 1.0%) and soil (0.5, 1.0, 2.0 kg tree^‐1) treatments during the second week of October (during flower bud differentiation period). All the zinc sulphate treatments of soil and foliar spray were effective in increasing the leaf zinc concentrations above recommended adequate level of (>20 mg kg^‐1) whereas control trees maintained low leaf zinc concentrations (13.8 to 13.3 mg kg^‐1). The uptake of foliar‐applied zinc was more rapid than that of soil applied zinc. All the treatments of zinc sulphate except the foliar spray treatment of zinc sulphate (0.25%) significantly increased zinc concentrations in the fruit pulp as compared with those in the control trees. The percent increase in the stem girth of trees was highest with the soil application of zinc sulphate (0.5 kg tree¹) followed by foliar application of zinc sulphate (1.0%) as compared with all other treatments. The percent increase in the tree canopy volume was highest with the foliar application of zinc sulphate (1.0%) followed by soil application of zinc sulphate (1.0 kg tree¹) as compared with control and all other treatments. There was no significant (P<0.05) increase in yield, fruit size and weight, pulp or stone weight with any treatment of zinc sulphate. Total soluble solid (TSS) in the fruit was significantly higher (18.6%) with the treatment of soil application of zinc sulphate (0.5 kg tree¹) as compared with all other treatments of zinc sulphate and the control. Acid and sugar content of the fruit was not significantly affected by the foliar or soil application of zinc sulphate.     

Tomato response to long‐term potassium and lime application on a sandy ultisol high in non‐exchangeable potassium

In a ten‐year study of potassium (K) and lime application to a Kalmia sandy loam (fine‐loamy, siliceous, thermic Typic Hapludult), a soil high in nonexchangeable K, corn (Zea mays L.) and soybean [Glycine max (L.) Herr.] have not responded to applied K. The objectives of this study were to determine if a high K‐requiring crop such as tomato (Lycocersicon esculentum Mill. cv. Redpak) would respond to KCl fertilizer rate or lime type (dolomitic, calcitic, and mixed) and rate on such a soil. Potassium was applied at 0, 56, and 112 kg K/ha every year for ten years. Lime was applied at 0, 2, and 9 Mg/ha in calcitic, mixed, and dolomitic forms twice in ten years (1970 and 1973). In 1980, the tenth year of the study, tomato fruit was harvested by hand once‐over to simulate machine harvest and divided into four maturity groups by color. Soil pH was higher with dolomitic than calcitic lime. Soil K saturation was not influenced by lime rate or type. Fruit yield and leaf phosphorus (P), calcium (Ca), and magnesium (Mg) concentrations increased with increasing lime rates. Leaf K, manganese (Mn), iron (Fe), boron (B), copper (Cu), zinc (Zn), barium (Ba), strontium (Sr), and aluminum (Al) concentrations decreased with increasing lime rate. Leaf Mn, Ba, and Sr concentrations were lower with dolomitic than with calcitic lime. Lime type had no effect on tomato yield. Wide ranges in basic cation saturation ratios had little effect on yield. Soil K saturation and leaf K, Zn, and Ba concentrations increased with increasing K rate. Soil Ca and leaf Ca, Mg, and Al concentrations decreased with increasing K rate. Applied K had no effect on total yield but onceover marketable yield increased linearly with increasing K rate. Marketable yield increased 14% with an increase in K rate from 0 to 56 kg/ha. Thus, fruit maturity was apparently hastened by K fertilization.     

Content of boron and other elements in main stem and branch leaves and seed of soybean

Tissue testing is commonly used to determine nutrient status of crops, however, there may be differences in macro‐ and micronutrient content of main stem and branch leaves of plants. Macro‐ and micronutrient analyses of main stem and branch soybean (Glycine max [L] Merr.) leaves were performed separately to ascertain where foliar‐applied boron (B) was accumulating and to determine if other nutrients were partitioned differently between main stem and branch leaves in control plants and plants treated with foliar B. Foliar applications of 2.24 kg B/ha increased main stem leaf B content from 47 to 248 μg/g and caused leaf manganese (Mn) and aluminum (Al) content to decline. In a separate experiment, foliar applications of 1.12 kg B/ha onto soybean growing on a soil high in available Al increased B leaf content by over 50 μg/g and decreased leaf Al content by 100 μg/g. In other field experiments, foliar B applications of 0.90 kg/ha or more increased leaf B content in both main stem and branch leaves. Boron content was consistently higher in branch leaves than in main stem leaves. Branch leaves and seeds of soybean were higher in the phloem‐mobile elements potassium (K), magnesium (Mg), phosphorus (P), zinc (Zn), iron (Fe), and copper (Cu) than main stem leaves. With the exception of B, the relatively phloem‐immobile elements, calcium (Ca) and Mn were lower in branch leaves than in main stem leaves. The higher B content in branch leaves and seeds may indicate that B is more mobile in soybean than previously thought. The difference in macro‐ and micronutrient content of branch and main stem leaves and seeds should be noted when soybean leaves are being harvested for determination of macro‐ and micronutrient sufficiency, or when seeds are harvested for nutrient quality determinations.     

Effects of Root Plant Growth Promoting Rhizobacteria Inoculations on the Growth and Nutrient Content of Grapevine

The objective of this study was to evaluate the effects of seven nitrogen (N₂)-fixing and/or phosphorus (P)-solubilizing and siderophore-producing microorganism based bio-fertilizers in single and triple strain combinations isolated from the acidic rhizospheric soil of native tea, grapevine, and wild red raspberries. As a result of this study, bacterial efficiency was found to be variable and depended on the bacterial strains and evaluated growth parameters. Plant growth-promoting rhizobacteria (PGPR) has improved macro- and micro-nutrient concentrations in grapevine leaves, and stimulated plant growth. Triple inoculation and single inoculation based bio fertilizers were found to stimulate overall plant growth, including shoot and leaf weight, main shoot length, leaf ground index, chlorophyll, nitrogen, zinc and iron content of grapevine cv ‘Italy’. Bio-fertilizers increased the nutrients such as nitrogen, zinc and iron concentrations and consequently increased the chlorophyll content of the leaves.     

Influence of irrigation and growth stage on element concentrations of soybean plant parts

Abstract

A three‐year field study was conducted to determine the influence of irrigation on the nutrition of the “Lee 74” cultivar, a determinate soybean (Glycine max (L.) Merr.). The objectives were to measure seasonal concentrations of N, K, Ca, and Mg in steins, leaves, and pods for soybeans grown on a Crowley silt loam (Typic Albaqualf) and a Kobel clay (Vertic Fluvaquent) under irrigated and nonirrigated moisture regimes. Fluctuations in element concentrations in relation to plant growth stage for irrigated and nonirrigated leaves and stems were modeled using multivariate regression. Elements in the pods as effected by irrigation and growth stage were also compared.

During 1974, a wet year, element concentrations of the leaves, stems, and pods were unaffected by irrigation. In the dry years of 1975 and 1976, significant differences in the concentration of N, K, Ca, and Mg in the plant component parts were found due to irrigation. Generally, element concentrations of stems, leaves, and pods of irrigated plants were greater than those of water‐stressed stems, leaves, and pods at several growth stages. Element concentrations in stems and leaves that were significantly affected by irrigation also were reflected in the pods, Regression models generally accounted for the majority of the seasonal element variation. Irrigation improved the predictability of the K and Ca regression models.     

Salinity and Irrigation Method Affect Mineral Ion Relations of Soybean

Abstract

Soybean [Glycine max(L.) Merrill] is moderately salt tolerant, but the method of irrigation used for crop production under saline conditions may influence the uptake and distribution of potentially toxic salts. This field study was conducted to determine the effects of application of saline waters by different methods, namely, drip and above‐canopy sprinkler irrigation, on the ion relations of soybean cultivar “Manokin”. Salinity was imposed by adding NaCl and CaCl₂ (1:1 by weight) to nonsaline irrigation waters. Saline treatments with electrical conductivity (EC _i ) of 4 dS m^?1 were compared with nonsaline controls (EC _i  = 0.5 dS m^?1). Ion concentrations in leaves, stems, roots, and when present, pods were determined at four stages of growth: vegetative, flowering, podding, and grain filling. Both Na⁺ and Cl^? were excluded from the Manokin leaves and stems when plants were drip‐irrigated and the uptake of these ions occurred solely via the root pathway. However, when saline water was applied by sprinkling, the ions entered leaves by both foliar absorption and root uptake and their concentrations in the leaves were about 9‐fold higher than in those under saline drip irrigation. Regardless of treatment, leaf‐K was highest during the vegetative stage, then decreased with plant age as K⁺ was mobilized to meet nutrient demands of the developing reproductive structures.