Effect Of Potassium Nutrition Research Articles

Effects of potassium nutrition and water availability on iron toxicity of rice seedlings

The aim of the study was to investigate the influence of potassium (K) nutrition and/or aeration of flooded soil through drainage on iron (Fe) toxicity of rice during the period of establishment. A hydroponic experiment with three Fe (0.1, optimal; 1, high; 2.5 mM, very high) and K levels (0.3, low; 2, optimal; 5 mM, high), and a soil experiment with two moisture levels [continuously flooded; alternate-wetting and drying (AWD)] and three Fe levels (16, low; 163, optimal; 490 mg Fe(II) kg−1 soil, high) was conducted. In the hydroponic experiment, high Fe supply increased tissue concentrations of Fe, phosphorus (P) and magnesium (Mg), and reduced manganese (Mn) concentrations. Particularly Fe, K and P were maintained at root surfaces in larger amounts than taken up by the roots. Growth of rice, photosynthesis, maximum quantum yield, effective quantum yield and electron transport rate were decreased at high and very high Fe concentrations while K application had no positive effect. In the soil experiment, growth and nutrient relations under increased Fe supply were similar to those observed in the hydroponic experiment. However, comparing both moisture levels showed that soil solution Fe concentration and plant growth were reduced and tissue P, Mg and Mn concentrations were increased in the AWD system compared to flooding. Therefore, the application of K or aeration of flooded soil cannot be generalized as promising strategies to alleviate Fe toxicity in rice at the initial crop establishment stage.

EFFECT OF POTASSIUM FERTILIZATION ON YIELD, GROWTH AND CHEMICAL COMPOSITION OF BASIL HERB

In the cultivation of herbal plants, besides the size of the crop, the quality of obtained raw material is extremely important, which is proven not only by the appearance and taste, but also biological value. Factors that affect these parameters include plant nutrition. The main nutrient affecting the correct course of metabolic processes in a plant is potassium. To obtain high yield in terms of quantity and quality, the nutritional requirements of plants must be met. The aim of the study was to determine the effect of potassium nutrition on the quality of basil herb. The experiment was established in a two-factor scheme, in which the factors were: potassium dose (0.5, 1.0, 1.5 g K·dm–3) and the type of potassium fertilizer (KCl, K2SO4, KCl + K2SO4). The yield of basil plants was influenced by the dose and type of potassium fertilizers used (0.5 g K·dm–3 – 92.5; 1.0 g K – 67.3; 1.5 g K – 69.75 g·plant–1). The highest content of L-ascorbic acid was found in basil plants fed with the average potassium dose (65.9 mg·100 g–1 FW). The least nitrates (V) were contained in basil fertilized with KCl in the highest dose of K (63 mg·100 g–1 FW). No effect of the dose and type of potassium fertilizer on the content of phosphorus and sulfur in the plant material, was recorded. The content of Ca and Mg was influenced by both the potassium dose and the type of potassium fertilizer. The most of these components was revealed by plants fed with KCl, and with the increase of the dose, the content of both these mineral components decreased. Chlorine content in the herb increased with the applied potassium dose, the effect on the concentration of chlorine in the plant material was exerted by the type of potassium fertilizer applied – the highest concentration of this element was recorded. The content of macroelements in the substrate from basil cultivation was influenced by the dose and type of potassium fertilizers used. The best quality parameters of basil were obtained after application of 1.0 g K·dm–3 substrate in the form of KCl + K2SO4.

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The effects of potassium nutrition on water use in field-grown maize (Zea mays L.)

Water is about to become increasingly limited for crop production, which jeopardizes the whole maize sector. Potassium (K) nutrition has been proposed to mitigate water deficit in plants, but field-scale studies involving grain yield components are scarce. In this study, we aimed at analyzing the effect of K nutrition on grain yield, vegetative growth and physiological parameters of maize subjected to water deficit. The effect of K nutrition on water use efficiency was also calculated at the whole-crop level (WUE) and through leaf gas exchange measurements (WUEi). A large-scale field experiment was designed, combining three levels of K fertilization (low, normal and high K) and two water supply scenarios (normal and 30% deficit based on a water balance model). Water deficit induced a strong decrease in leaf area, which was essentially due to a lower leaf elongation rate. The grain yield of the water-stressed plants was 25% lower than that of the well-irrigated ones. Grain yield was even worse when K deficiency was superimposed on water deficit, with a specific effect of K on grain filling. The optimal K fertilization helped the plants mitigate the effect of water deficit, through a better WUE (+30%), which was related to lower leaf evapotranspiration (ET). Moreover, under water deficit, leaf rolling was more pronounced when K was added, which also prevented water losses. Leaf water potential measurements suggested that the isohydric behaviour (maintenance of close stomata during water stress) of the maize was made possible thanks to K fertilization. When calculated at field scale, ET was higher with K fertilization, due to its positive effect on leaf area, in spite of a better stomata control and better WUE. We concluded that K addition, in K deficient soils, can help maize to cope with droughts and could be used as a new management option.

The effect of potassium nutrition on growth and on plant hormones content in Scots pine (Pinus silvestris L.) seedlings

Pine seedlings were cultivated in Ingestad nutrient solution containing potassium as KCl on a 16-hr day, under light intensity of about 4000 lx and temperature of about 23° C. K+ used in a concentration of 50 ppm exerted a most pronounced positive effect on the growth of seedlings. After 4 months it was found that potassium used in this concentration increased elongation of hypocotyls, shoots, roots, primary and secondary needles as well as fresh weight and dry matter of tissues. In leafy shoots K+ increased the level of free gibberelirns (GAs) and auxins and decreased the amount of bound GAs and an ABA-like inhibitor. In the roots K+ nutrition increased the amount of free GAs and of the growth inhibitor and decreased the level of bound GAs and auxins. No evident influence of K+ on the level of cytokinins in plant tissues was stated.

Effect of potassium nutrition on essential oil of Calendula officinalis L. flowers

Effect of potassium nutrition on essential oil of Calendula officinalis L. flowers

The effect of potassium nutrition on pest and disease resistance in plants

Providing a fast growing world population with sufficient food while preserving ecological and energy resources of our planet is one of the biggest challenges in this century. Optimized management of chemical fertilizers and pesticides will be essential for achieving sustainability of intensive farming and requires both empirical data from field trials and advanced fundamental understanding of the molecular processes controlling plant growth. Genes involved in plant responses to nutrient deficiency and pathogen/herbivore attack have been identified, but we are lacking information about the cross-talk between signalling pathways when plants are exposed to a combination of abiotic and biotic stress factors. The focus of this review is on the relationship between the potassium status of plants and their susceptibility to pathogens and herbivorous insects. We combine field evidence on potassium-disease interaction with existing knowledge on metabolic and physiological factors that could explain such interaction, and present new data on metabolite profiles and hormonal pathways from the model plant Arabidopsis thaliana. The latter provides evidence that facilitated entry and development of pathogens or insects in(to) potassium-deficient plants as a result of physical and metabolic changes is counteracted by an increased defence. A genetic approach should now be applied to establish a causal relationship between disease susceptibility on the one hand and individual enzymatic and signal components on the other. Once identified, these can be used to design agricultural strategies that support the nutritional status of the crops while exploiting their inherent potential for defence.

Quality of yellow passionfruit (Passiflora edulisSims f.flavicarpaDeg.) as affected by potassium nutrition

Introduction . The yellow passionfruit is consumed mainly as juice and is well accepted around the world. The nutritional state of the plant influences yield and fruit quality. We studied the particular effect of potassium nutrition on the quality of yellow passionfruit. Materials and methods . The experiments were conducted in a greenhouse at the Federal University of Vicosa, in Brazil, outlined in a randomized block design. The treatments were five concentrations of K [(1, 2, 4, 6 and 8) mmol·L–1] in a modified nutritive solution of Hoagland and Arnon. The experimental unit consisted of one plant in a 20-L pot containing washed sand. The plants were irrigated by a circulating hydroponic system. The nutrients were re-added to the solution based on its electric conductivity and on the K content in each solution. Results and discussion . The K supply increased yield and average fruit weight up to the concentration of (6.43 and 6.24) mmol·L–1, respectively, and linearly increased the number of seeds per fruit, thickness and relative water content of the pericarp and vitamin C content. The total titratable acid content increased according to a square equation, with the maximum point at 5.27 mmol K ·L–1. The pulp percentage, pH and total soluble solids content were not influenced by K doses. Conclusions . The increase in K supply promoted yield and fruit quality. At 90% of the maximum yield, the fruits had adequate quality traits.

Influence of Potassium Nutrition on Gas Exchange Characteristics and Water Relations in Cotton (Gossypium hirsutum L.)

The effects of potassium nutrition [0, 6.25, 12.50, 25.00 g(K) m−2 of K2SO4 or KCl] on gas exchange characteristics and water relations in four cultivars (CIM-448, CIM-1100, Karishma, S-12) of cotton were assessed under an arid environment. Net photosynthetic rate (PN) and transpiration rate (E) increased with increased K supply. The leaf pressure potential (Ψp) increased significantly by the addition of 25.00 g(K) m−2 compared to zero K level. The water use efficiency (PN/E) was improved by 24.6 % under the highest K dose compared to zero K. There were positive correlations (0.99**, 0.98**, 0.95**, 0.97**) between K-doses and PN, E, Ψp, and PN/E, respectively.

Effect of Potassium Nutrition during Bell Pepper Seed Development on Vivipary and Endogenous Levels of Abscisic Acid (ABA)

Seeds in fruit of bell pepper (Capsicum annuum `California Wonder') plants grown in nutrient solutions deficient in potassium (<3 mmol·L-1) showed a higher incidence of sprouting (i.e., vivipary) than seeds in fruit from plants grown at adequate potassium levels (6 mmol·L-1). Tissue analysis showed a progressive drop in the leaf content of potassium with increasing plant maturation for all levels of potassium nutrition. However, potassium in fruit and seeds increased at later stages of maturity. ABA was extracted, isolated and identified from bell pepper seeds obtained from fruit grown under the potassium treatments (0.0, 0.6, 1.5, 3.0, and 6.0 mmol·L-1) at five fruit maturity stages (mature-green to overripe). At early fruit maturity stages, there were no significant differences in seed ABA content in the fruit from the different potassium treatments. However, differences in ABA content and vivipary among the potassium treatments became highly significant as the fruit matured. The concentration of ABA in seeds of potassium-deficient treatments was ≈14% of the control (0.4 versus 2.8 μg·g-1 dry mass). High concentrations of ABA in bell pepper seeds were associated with low incidence of vivipary and high potassium content in the leaves, fruit and nutrient solution.

Effect of potassium nutrition of rice on rhizosphere redox status

With four soils differing in K supplying power and with four rice cultivars (Oryza sativa L.) differing in K uptake kinetic parameters, the relationship between K fertilizer application and soil redox status in rhizosphere and; the distribution of ferrous iron and other toxic substances on the root surface and in the rhizosphere; and the effect of K supply on uptake of reduced iron by rice plants have been studied. The results show that K application on K-deficient soils reduced the content of active reducing substances and ferrous iron in the soil, raised the soil redox potential in the rhizosphere, increased the Eh value of rice roots and lowered the content of iron in the rice plants. These effects of K varied with different rice cultivars. When no K fertilizer was applied, active reducing substances and ferrous iron in rhizosphere soils were decreased more by the rice cultivars absorbing K strongly (e.g. Shanyou 64) than by cultivars absorbing K weakly (e.g. Zhongguo 91). Therefore, the diminution of the toxic substances by K application in the weakly K-absorbing cultivars was more significant. The observation of a rhizobox separated by a nylon screen showed that appreciably more iron oxides, compared with the control, were deposited at or adjacent to the root surfaces of the rice plant supplied with K fertilizer, fully demonstrating the relationship between K nutrition and the total oxidizing power of rice plants. According to the distribution of active reducing substances and ferrous iron, the oxidizing range of the rice root extended in K application treatment a few centimeters away from the root plane. K application to rice affected the soil redox status in rhizosphere in many ways. The main effect was an increase of the oxidizing power of the rice root. As a result, the value of soil Eh was increased, the contents of active reducing substances and ferrous iron were lowered, as well as the number of oxygen consuming microorganisms.

The effect of potassium nutrition on 137Cs uptake in two upland species

Agrostis capillaris (Agrostis) and Calluna vulgaris (Calluna), two species with differing phenologies and widespread presence in upland areas of Britain where high Chernobyl fallout occurred, were grown in pot culture with varying concentrations of potassium in the rooting medium. Tissue content of potassium increased with increasing supply in both species. Roots, excised from these plants, were placed in a solution of 137-Cs-labelled caesium chloride for 15 min to determine uptake potential. There were clear negative relationships between the rate of uptake of 137Cs by both species and (a) the concentration of potassium supplied and (b) plant tissue potassium concentrations. With Agrostis, there was an approximately ten-fold difference in 137Cs uptake between potassium-deficient and optimum plants; with Calluna, it was approximately eight-fold. These results demonstrate the suppression of 137Cs uptake into plants by potassium supply.

Effect of potassium nutrition on frost damage and yield of potato plants on alluvial soils of the Punjab (India)

Field experiments were conducted during 1974 and 1975 on 14 alluvial soils, varying in available K from 56 to 158 ppm, at Jullundur-Punjab (India) to study the effect of K nutrition on frost damage to potato crops. Frost damage was inversely related to the available K content of the soils and the K concentration of the potato leaves. K fertilization significantly reduced the frost damage and increased tuber yields in soils containing less than 114 ppm available K. Frost damage was significantly related to potato response to K application and negatively correlated to tuber yield.

Effect of Potassium Nutrition on Some Enzymes of the Tomato Plant

Effect of Potassium Nutrition on Some Enzymes of the Tomato Plant

Effect of Potassium Nutrition on Some Enzymes of the Tomato Plant

Effect of Potassium Nutrition on Some Enzymes of the Tomato Plant

Effect of potassium nutrition on leaf protein concentrations and growth of young tomato plants

The effect of potassium nutrition on the protein, total nitrogen and phosphorus concentrations in tomato leaves was studied in relation to plant growth. The concentration of protein in shoot apices significantly increased as a result of decreasing the supply of potassium to the plants. Compared to the potassium-sufficient plants, the expanding leaves of potassium-deficient plants exhibited up to 130 per cent increase in protein concentration while the amount of protein per leaf was much reduced (up to 25-fold reduction). In conditions of both potassium deficiency and excess, the concentration of total nitrogen in the laminae of expanding leaves increased. The phosphorus concentration and also the activity of a phosphatase increased in expanding leaf tissue with potassium deficiency.

Effect of potassium nutrition on tomato plant growth and fruit development

The effect of K nutrition on the growth in sand culture of young tomato plants, cv. Amberley Cross, was examined and the concentrations of K in the nutrient feed and in the leaves associated with maximum flower number, fruit set and yield were determined. The distribution of K between and with-in fruit trusses of normal and K-deficient plants, cv. Amberley Cross and Moneymaker grown in peat/loam was also studied. Total dry weights of 6-wk-old plants grown in sand were maximal when the nutrient feed contained 0.53–5.03 me K+/l, although plants receiving 10.23 me K+/l retained more water in the foliage and therefore had the greatest foliage fresh weight. Both peduncle length and height of the basal truss were increased by K in the feed up to 10.23 me/l, the highest concentration used. Flower development was retarded below 0.53 me K+/l, and fruit setting efficiency was reduced below 2.03 me K+/l. Fruit ripened faster on plants receiving low concentrations of K. Maximum fruit yields were produced on plants grown in sand receiving 5.03 or 10.23 me K+/l.

Effect of potassium nutrition on some enzymes from ripening Lycopersicon esculentum fruit

The maximum respiration rate of tomato fruit during the climacteric period was markedly increased when the plants were grown under potassium-deficient conditions. Whereas potassium deficiency had no effect on cytoplasmic glutamate-oxoloacetate transaminase, there was a significant increase in the activity of this enzyme from mitochondria once the fruit began to change colour. Malate dehydrogenase was reduced in activity by potassium deficiency. It is suggested that the augmented mitochondrial transiminase levels, coupled with reduced malate dehydrogenase activity in low potassium fruit, result in reduced levels of oxaloacetic acid which is a potent inhibitor of Krebs cycle oxidations, thus leading to higher respiration rates for the intact fruit.

Effect of potassium nutrition on fruit splitting in Valencia oranget

SummaryThe effect of K supply on fruit splitting and other quality features was studied in outdoor soil culture of Valencia orange trees on sour orange rootstock. K application reduced splitting, and increased fruit size, peel thickness and fruit acidity. Addition of P to the NK treatment moderated the K effect on acidity.In the K treatments, the leaf K was raised, on an average, from 0.69 to 1.36% and K in the peel from 0.42 to 1.0%. The putrescine content in the fruit peel of trees not receiving K, and split fruits, was significantly higher than in the K-treated trees.

Effects of potassium nutrition on the absorption of sodium, calcium, and magnesium by intact tomato plants

Abstract Tomato plants (cv. VF145 B 7879) were grown in a greenhouse by the water culture technique with six levels of K nutrition. The absorptions of Na, Ca, and Mg were not affected greatly by the K nutritional status of the intact tomato plants, except when the plants were extremely K deficient. The rates of absorption by the intact plants were slow initially when the plants were small, and then increased rapidly as the growth rates increased. At the onset of K deficiency, the rate of growth and water use by the tomato plant decreased. A linear function of water use and plant size was obtained, indicating that water use was a function of plant size and hence a function of the plant's nutritional status. Waterlogging, simulated by aeration cut‐off of the culture solution for two days, had only a small effect on water use, but concurrently interrupted the absorption of K, Ca, and Mg.