Physiological changes associated with potassium deficiency in cotton

Potassium (K) fertility recommendations based on cotton petiole diagnostic analysis results have been inconsistent in the past, partly because the lowest acceptable petiole K concentration is unknown. Therefore, cotton was grown in sand filled 8‐L pots under two K treatments in a growth chamber at the Altheimer Laboratory in Fayetteville, AR to determine the petiole K concentration that will impact leaf physiology. Chamber‐grown plants were watered every second day with nutrient solution and with deionized water on alternate days. At 14 days after planting two treatments were established consisting of (1) continued complete nutrient solution, and (2) nutrient solution containing no K. Measurements were taken 13, 19, and 26 days after treatment establishment (DATE). Organ K concentrations, leaf chlorophyll, photosynthesis, adenosine triphosphate (ATP), and nonstructural carbohydrate concentrations were monitored as plant K deficiencies developed. All organ K concentrations were much lower in the no‐K treatment on each analysis date. Visual K deficiencies were first observed at 19 DATE along with reductions reductions in leaf chlorophyll concentration. Leaf photosynthesis was greatly reduced in the no‐K treatment beginning at 19 DATE. However, leaf ATP and nonstructural carbohydrate concentrations were higher at 19 and 26 DATE in the no‐K treatment, which may have been the result of reduced utilization and translocation of these metabolites. Our studies show that reductions in leaf physiological processes and plant growth did not occur until the petiole K concentration fell below 0.88% on a dry weight basis. Therefore, reductions in lint yield and quality should not develop until this critical petiole level is attained.     

Calibration of the mehlich 3 soil test for potassium using leaf analyses and potassium deficiency symptoms in cotton plants

Abstract

A new calibration of the Mehlich 3 soil test for potassium (K) is proposed for the Mississippi Delta area, based on leaf analyses and K deficiency symptoms in cotton plants. The calibration reflects the need to supply adequate K concentrations to plants during the fruiting period of greatest K demand. The lowest levels and highest percent of sites exhibiting K‐deficiency symptoms were associated with the fifth week of flowering; or at the peak bloom stage of plant growth. The fifth week of flowering was selected to base soil and plant evaluations for K needs. A 1.5% leaf K level was selected as the critical leaf K level (the level that plants experience a nutrient deficiency and yield reductions), based on visual leaf K‐deficiency symptoms observed in plants 95% of the time. Leaf K concentrations below 1.51% identifies K‐deficiency symptoms in the upper leaves through eight weeks of flowering. A simplified equation [Topsoil K (lb/A) = 480 + 5 x CEC (Milliequivalents/100g soil)] defines critical soil test K concentrations with respect to the cation exchange capacity (CEC) in soils. This equation can be used to determine present topsoil K needs for cotton in the Mississippi Delta area based on a 1.5% critical leaf K level during the fifth week of flowering.     

Potassium absorption and partitioning in cotton as affected by periods of potassium deficiency

Cotton (Gossypium hirsutum var. Latifolium) was grown in nutrient media, at two K levels: 58.5 mg/K and 11.7 mg/K. Potassium deficiency (11.7 mg K/g of K) was imposed upon cotton plants at different stages of plant development. A sequence of increasing sensitivity to K deficiency among cotton plant parts was observed: leaves<bolls<roots<stems. When K deficiency symptoms are clearly visible in the leaves, all the other plant parts are already affected. Bolls are a very important component in K partitioning within the cotton plant, but K is required most by the bur itself and is not translocated to seeds or fibers. Cotton could overcome a 30 day deficiency late in the season without significant losses in lint and seed cotton yields.     

How potassium deficiency alters flower bud retention on cotton (Gossypium hirsutum L.)

Potassium (K) is fundamental for plant growth and development but despite the increased quantities of fertilizers applied, incidents of K deficiency are commonly observed. The objective of this study was to record the effects of K deficiency during cotton’s (Gossypium hirsutum L.) early reproductive stage on carbohydrate content and metabolism, total antioxidant capacity and oxidative damage of cotton flower buds as well as the physiology of the leaf, subtending to the flower buds. Growth chamber experiments were conducted using cotton cultivar DP0912 and treatments consisted of normal K and deficient K fertilization for the duration of the experiment. Potassium deficiency resulted in significant oxidative damage in the cotton flower buds, despite the substantial increase in their total antioxidant capacity. Sucrose metabolism of the flower buds was markedly affected resulting in significant reductions in all non-structural carbohydrate concentrations. Furthermore, K deficiency disturbed leaf physiology leading to increased membrane damage, decreases in chlorophyll and carotenoid content and ultimately leaf photosynthetic rates. Concomitant increases in specific leaf weight under K deficient conditions indicated reductions in photoassimilate translocation, which in conjunction with the disruptions observed in flower bud sucrose metabolism, due to the insufficient antioxidant response, resulted in significant decreases in flower bud retention.     

Diagnosis of zinc deficiency in cotton

The diagnosis of Zn deficiency in cotton by means of total analysis or the appearance of deficiency symptoms is unsatisfactory. In order to obtain a better understanding of the development of Zn deficiency symptoms in relation to Zn content cotton plants were cultivated in waterculture under reproducible environmental conditions and Zn deficiency induced by different means. It was observed that deficiency symptoms developed equally, regardless of the inducing factors such as low Zn in the nutrient solution, high nutrient solution pH, high Ca and high Fe supply. High amounts of P in the nutrient solution did not induce Zn deficiency symptoms. Zn deficiency symptoms appeared first as interveinal chlorosis in the medium-aged leaves. The internodes remained short. Later red spots appeared on the leaf blades. The leaves suffering from deficiency were thicker because of enlarged palisade cells. The total Zn content of the leaves did not correlate with the symptoms. Different fractions of the Zn in the leaf (extractable with water, NaCl solution, hydrochloric acid) gave no better results. The analytically determined and calculated Zn fractions are discussed in relation to Zn deficiency inducing conditions.     

Assessing the plant minimal exchangeable potassium of a soil

The plant minimal exchangeable K (E_Pl,min) defines the lower accessible limit of the most available pool of soil K to plants. It is also an index of long‐term K reserve in soils. However, its estimation by the classical method of exhaustion cropping is laborious. This study aimed at comparing E_Pl,min values obtained by the exhaustion cropping method with E_Pl,min values estimated by an alternative approach based on the cationic exchange capacity (CEC) of the infinitely high selective sites for K (i.e., always saturated with K) in the K‐Ca exchange (E_K‐Ca,min). A set of 45 soil samples, corresponding to the various fertilization K treatments of 15 long‐term K fertilization trials, was used in this study. The selected soil samples presented a wide range of texture, CEC, and exchangeable K. The plant minimal exchangeable K was found more or less independent of the K treatment, whereas E_K‐Ca,min increased when the soil exchangeable K content increased. The plant minimal exchangeable K was systematically lower than E_K‐Ca,min, showing that E_K‐Ca,min is at least partially available to the plant. Hence, E_K‐Ca,min is not a surrogate of E_Pl,min. Conversely, the plant minimal exchangeable K was strongly, positively correlated to soil CEC (measured at soil pH; r² = 0.90^***). This soil property can consequently be used as a proxy of E_Pl,min.     

Some observations of potassium deficiency in chrysanthemum

Pot chrysanthemums (Chrysanthemum morifolium ‘Bright Golden Anne') were grown at 10 rates of K supply, symptoms of K deficiency were recorded, and the K concentrations in the leaves at harvest were measured. The initial K deficiency symptoms, consisting of glazing and bronzing of the leaf underside, were nearly identical to the injury attributed to the air pollutant, peroxyacetyl nitrate (PAN). Leaves with these symptoms contained 0.5 to 0.6% K. During vegetative growth K deficiency symptoms developed first on the most recently mature leaf; during rapid flower development the symptoms appeared first on the uppermost leaf of the stem. In K‐deficient plants, there was a gradient in K concentration from upper leaves (0.2% K) to lower leaves (1.7% K).     

Sodium‐induced calcium deficiency in sugar beet during substitution of potassium by sodium

Functions of sodium (Na⁺) and potassium (K⁺) are closely associated. In some crops, Na⁺ is able to prevent or reduce considerably the occurrence of K⁺ deficiency. Sugar beet (Beta vulgaris L.) is a natrophilic crop, and positive effects of Na⁺ applications on yield were observed when K⁺ was sufficiently supplied. However, it is not known which specific function of K⁺ can limit the growth of sugar beet when K⁺ is substituted by an equivalent amount of Na⁺. Therefore, K⁺ substitution by Na⁺ was investigated for sugar beet in hydroponics. Surprisingly, no K⁺‐deficiency symptoms were observed. However, calcium (Ca²⁺) concentrations in the leaves were significantly decreased. Moreover, Ca²⁺ uptake and translocation through xylem sap were reduced in Na⁺‐treated plants. It is concluded that Ca²⁺ uptake by roots and its translocation via xylem sap primarily limit the possibility of K⁺ substitution by Na⁺ in sugar beet nutrition.     

中国三大棉花种植区域土壤速效钾丰缺指标及推荐施钾量研究

为给西北内陆棉区、长江流域棉区和黄河流域棉区棉花的钾肥施用提供科学依据,采用“零散实验数据整合法”“反正弦-对数矫正模型”以及“养分平衡-地力差减法”,开展了上述三大棉区棉花土壤速效钾丰缺指标和推荐施钾量研究。结果表明,中国三大棉区土壤速效钾丰缺指标均可划分出5级,西北内陆棉区第1～5级丰缺指标为≥418、166～418、111～166、80～111和<80 mg/kg;长江流域棉区第1～5级丰缺指标为≥357、128～357、81～128、56～81和<56 mg/kg;黄河流域棉区第1～5级丰缺指标为≥213、129～213、102～129、85～102和<85 mg/kg。三大棉区土壤速效钾临界值分别为166.0、127.2和128.4 mg/kg。当钾肥当季利用率为50%,籽棉(皮棉)目标产量为2.5～9.0(1.0～3.6)t/hm²时,第1～5级土壤的推荐施钾量依次为0、30～108、60～216、90～324和120～432 kg/hm²。     

棉花施钾的增产效果及其技术研究

根据近年来衡水7个县市的试验表明:在土壤速效钾含量为100～150mg/kg情况下,棉花钾肥施用量以每公顷施112.5kg为宜;在土壤不同钾素含量的情况下,土壤速效钾含量与施钾肥的增产效果呈负相关;在施用方法上建议底施为主,底追结合。     

The respiration in the roots of broad bean and barley under a moderate potassium deficiency

The previous work on the respiration in taro plants (1) suggests that superior activities of the glycolysis and the Krebs cycle in these plant tissues under a moderate K-deficiency may be reduced a) with advancing plant maturation, b) with extended K-deficiency, or c) with increasing damage in the metabolism itself, due to unfavourable treatments. Thus the question arises where a critical point of potassium deficiency resulting in a higher respiration rate compared with its normal status should be set up in each plant species, giving careful consideration to the physiological and environmental conditions of the plant concerned. This work was undertaken in an attempt to compare the effects of potassium nutrition on the respiration in the roots of broad bean and barley with those in a longer term culture of taro plants (1).     

钠钾替代对不同基因型棉花钾利用效率的影响

【目的】钾是植物生长发育所必需的营养元素之一,缺钾影响棉花的生长。钠与钾有一些相同的生理功能,钠钾替代和协同作用是提高作物钾效率有效途径之一。研究钠钾替代对不同基因型棉花钾效率的影响,旨在为生产中科学高效利用钾肥提供依据。【方法】于2013~2014年在华中农业大学利用盆栽试验,筛选并获得了钾高效高增产潜力棉花基因型103和钾低效低增产潜力棉花基因型122为试验材料,采用营养液培养对不同K+、Na+浓度处理条件下棉花苗期农艺性状(株高、根长和叶片数)、干物质积累与分配、各部位(根、茎、叶和柄)钾钠含量和钾钠积累量等进行了研究,探讨了钠钾替代作用对其钾素利用效率的影响。【结果】缺钾的条件下,施钠增加了两个基因型的根长,且103增加的幅度大于122;增加了103和122各部位干重和根冠比,而减少了根和茎的钾含量,对各部位钾积累量影响不明显,施钠还能显著提高基因型棉花103的钾利用效率,其为不施钠时的1.37倍。另外,适钾的条件下施钠,两个基因型的根长都有所增加,且103增加的幅度大于122;103和122各部位干重和总干重都显著增加,但二者根和叶钾含量显著降低,除了叶和柄其他各个部位的钾积累量都不同程度的提高;同时,103和122的钾利用效率均增加,103增加了28%,大于122的19%。此外,钾钠交互作用对根长和株高的相对生长速率,各部位干物重和根、叶中钾、钠含量和积累量以及全株钾利用效率都有显著影响。【结论】无论是否施钾、施钠均能增加两个基因型棉花的根长,通过促进根系的伸长来提高棉花对钾的吸收和生物量的积累。缺钾时施钠显著增加了103的钾效率,且适钾时施钠高效基因型103的钾效率增加幅度大于低效基因型122,表明钠钾替代和协同效应对钾高效基因型103比低效基因型122更显著。     

Nitrogen fertilization and plant development of cotton as determined by nodes above white flower 1

Early maturation is very beneficial in successfully harvesting a high‐quality, high‐yielding cotton (Gossypium hirstum L.) crop. If harvest is delayed until inclement weather patterns are established, both yield and fiber quality may be lost. The objective of these studies was to determine the maturity differences that occur in cotton differentially fertilized with nitrogen (N). Field experiments with irrigated cotton were conducted in 1990 and 1991 in three locations to study the effects of soil applied N rates on cotton maturity as estimated by nodes above white flower (NAWF) measurements. The test sites and soils were a production field near Manila, AR, on a Dundee sandy loam (fine‐silty, mixed, thermic Aeric Ochraqualfs), the Southeast Branch Experiment Station (SEBES) near Rohwer, AR, on an Hebert silt loam (fine‐silty, mixed, thermic Aeric Ochraqualfs), and the Northeast Research and Extension Center (NEREC) near Keiser, AR, on a Sharkey silty clay (very fine, montmorillonitic, nonacid, thermic Vertic Haplaquepts). Criteria used as indicators of crop maturity and earliness in these studies were the time in days after planting (DAP) and the accumulated heat units (HU) for the crop to reach NAWF=5. Increasing N rates delayed maturity at SEBES both years and at Manila in 1991 but not at NEREC either year. Differences in maturity between N treatments of 168 and 224 kg N/ha were minimal at all locations both years. Smaller differences in time for the plants to achieve NAWF=5 were observed in the cotton grown at Manila in 1990 and at NEREC both years. The smaller differences at Manila are assumed to be due to high levels of residual N from previous crops. Early‐season vegetative growth was indicated by NAWF extrapolated to first flower (60 DAP or 945 HU). A trend of higher NAWF at the extrapolated first flower stage with increasing N rate was observed, but generally differences were minimal. The NAWF values at DAP=60 were lower in 1991 than in 1990 for all locations.     

Efficiency of mannose-binding plant lectins in controlling a homopteran insect,the red cotton bug

Yield losses of different crops due to the attack of various classes of insects are a worldwide problem. Sucking type homopteran pests causing damage to many crop species are not controlled by commonly known insecticidal proteins, namely, Bacillus thuringiensis delta-endotoxin (Bt). This study describes the purification of mannose-binding lectins from three different monocotyledonous plants (Allium sativum, Colocasia esculenta, and Diffenbachia sequina) and their effects on a homopteran insect, the red cotton bug. All of them had a detrimental effect on the growth and development of the insect, where A. sativum bulb lectin showed the highest mortality of all, in particular. The same bulb lectin not only affected the growth and fecundity of the insect but also imparted drastic changes in the color, weight, and size, even on the second generation of the insects which have been reared on artificial diet supplemented with a sublethal dose of the lectin. Thus, this finding opens up a possibility of using this lectin as an important component in crop management.     

The growth and the respiration in roots of sweet potato plants under a moderate potassium deficiency

A seven days' culture of sweet potato plants under a deficient potassium application induced various metabolic disturbances in the roots (1,2) and the leaves (3). Prolonged cultures of taro (4), broad bean plants (5), and barley (5) suggested that a half level of the normal potassium content in roots might be a critical point of K -deficiency resulting in a higher respiration rate than its normal status. Such a temporary enhancement of respiration accompanied by accumulation of amino-N and reducing sugars may not necessarily contribute to the accumulation and the assimilation of salts, but accelerate the disturbance of plant metabolism to cause early death of the tissues. This work deals with supplemental data on the effects of K -deficiency on the plant growth and the respiration in roots, comparing these effects in a 15 days' culture of sweet potato plants with those in a longer term culture of other plant species (4,5).     

Selecting cotton yield response function to estimate profit-maximizing potassium fertilization rates for cotton production in Tennessee

Recent research has shown that stochastic yield response functions fit data better than deterministic yield response functions; however, little research exists comparing profit-maximizing fertilizer rates for upland cotton (Gossypium hirsutum L.) using stochastic and deterministic yield response functions. The objective of this research was to determine the most appropriate yield response functional form from which to determine the profit-maximizing potassium (K) rate for cotton in Tennessee. Data were used from a nine-year K fertilizer experiment in Jackson, Tennessee. Quadratic, quadratic-plus-plateau, linear response plateau, and linear response stochastic plateau response functions were estimated to determine the yield response function that best fit the data. The linear response stochastic plateau function was the most suitable yield response function for the data. The profit-maximizing K rate ranged from 65.2 to 74.3 kg K ha^?1. Misspecification of the yield response function recommended over-application of K fertilizer and decreased the producer's short-term profits.     

Growth promotion and increased potassium uptake of cotton and rape by a potassium releasing strain of Bacillus edaphicus

A potassium-releasing bacterial strain Bacillus edaphicus NBT was examined for plant-growth-promoting effects and nutrient uptake on cotton and rape in K-deficient soil in pot experiments. Inoculation with bacterial strain B. edaphicus NBT was found to increase root and shoot growth of cotton and rape. Strain NBT was able to mobilize potassium efficiently in both plants when illite was added to the soil. In cotton and rape growing in soils treated with insoluble potassium and inoculated with strain NBT, the potassium content was increased by 30 and 26%, respectively. Bacterial inoculation also resulted in higher N and P contents of above ground plant components. The bacterial isolate was also able to colonize and develop in the rhizosphere soil of cotton and rape after root inoculation.     

Influence of surfactants on potassium uptake and yield response of cotton to foliar potassium nitrate

Foliar potassium (K) applications are intended to supplement soil K uptake, and thereby, increase cotton (Gossypium hirsutum L.) yields. Considerable research has been conducted to evaluate yield response to foliar K, but research evaluating surfactant effects on foliar uptake has been limited. Research was initiated in West Tennessee in 1991 to evaluate effects of foliar applied potassium nitrate (KNO₃) with and without surfactants on leaf and petiole K concentrations and on lint yield. Field research was conducted on three sites over a four year period using upland cotton ‘DPL 50’. Treatments included a check (no foliar treatment), 4.1 kg K/ha in water, 4.1 kg K/ha with Penetrator Plus, 4.1 kg K/ha with X‐77, 2.0 kg K/ha with Penetrator Plus, and 2.0 kg K/ha with X‐77. Surfactants were added to KNO₃ solutions at 1.25% v/v for Penetrator Plus and 0.5% v/v for X‐77. Kinetic was substituted for X‐77 after 1991 and was applied at 0.12% v/v. Cotton leaves and petioles were collected one, three, and seven days after each foliar application for K concentration determinations. Applying 4.1 kg K/ha (high‐K rate) as KNO₃ in water increased four‐year average leaf K but not petiole K concentrations in tissue collected 24 h after treatment relative to the check. Applying the high‐K rate with a surfactant increased the four‐year average concentration of leaves and petioles collected one, three, and seven days after application relative to the check or to the high‐K rate applied with water. Increases in both leaf and petiole K concentrations varied with year, with significant increases in two of the four years of the study. Yearly K concentrations of the day‐one and day‐three petioles were higher after applying the high‐K rate with Penetrator Plus relative to the check. Petiole K was not increased by applying low‐K rates with surfactants or the high‐K rate in water. First harvest lint yields were generally unaffected by foliar treatments. Second harvest and total yields were increased by applying the high‐K rate with Penetrator Plus relative to the other treatments. Yield responses may have been due in part to the nitrate anion (NO₃‐) being applied with the K+ cation, but higher K concentrations generally accompanied higher yields. These results suggest that surfactants may enhance K uptake and yield, but that more research is needed to determine why responses vary from year to year.     

The effect of potassium fertilization on iron deficiency

Abstract

Preliminary experiments indicate that potassium fertilization at a rate of 270 mg K/kg soil amel.iorates Iron deficiencies in peanuts grown in an extremely calcareous soil (63% CaCO₃). Amelioration was greater with the application of KCl than with that of KNO₃ or K₂HPO₄, indicating that the cation:anion balance of roct uptake is involved. Potassium chloride application caused a 73% increase in the chlorophyll content; this value is 90% of that of the FeEDDHA treatment. Manipulation of the cation: anion balance of macronutrients may prove to be an effective means of controlling lime‐induced chlorosis.