Diagnosis of zinc deficiency in canola by plant analysis

Abstract

Canola plants (Brassica napus cv. Eureka) were grown in soil culture with seven levels of zinc (Zn) supply (0, 67, 133, 200, 267, 533, and 1,067 μg Zn/kg soil) for 39 days. Critical Zn concentrations in young leaf blades and petioles were established for the diagnosis of Zn deficiency in canola plants during vegetative growth by assessing the relationship between the Zn concentration in the leaves and shoot dry matter on 22 and 39 days after sowing (DAS). Zinc concentrations in leaf blades and petioles increased with increasing Zn supply, but Zn concentrations were always 50% higher in the youngest open leaf (YOL) than in the youngest mature leaf (YML). The relationship between shoot dry matter and Zn concentrations in leaf petioles exhibited Piper‐Steenbjerg curvature, indicating their unsuitability for Zn‐deficiency diagnosis either alone or by inclusion with leaf blades. By contrast, inclusion of leaf mid‐ribs with leaf blades did not alter the relationship between shoot dry matter and Zn concentrations, nor the critical Zn concentration. Critical Zn concentrations in the YOL, YOL+1, and YOL+2 blade on 39 DAS, corresponding with the stem elongation stage, were 15–17, 9–10, and 7–8 mg Zn/kg dry matter, respectvely. In comparison, the critical Zn concentration in the YOL+2 leaf blades with mid‐ribs was 7–8 mg Zn/kg dry matter. In conclusion, during the vegetative stage up to stem elongation, YOL+2 leaf blades which are also the YML are recommended for the diagnosis of Zn deficiency in canola plants with the critical Zn concentration being 7–8 mg Zn/kg dry matter.     

Diagnosis of zinc deficiency in peanut (Arachis hypogaea L.) by plant analysis

Abstract

Critical values of zinc (Zn) concentration in young leaves Here established for the diagnosis of Zn deficiency in peanut by examining the relationship of Zn concentration in leaves to shoot dry matter (DM) at two growth stages of plants grown in pots of Zn deficient sand at seven levels of Zn supply (0, 67, 133, 200 267, 533, and 1067 μg Zn/kg soil). Zinc deficient peanut accumulated reddish pigments in stems, petioles and leaf veins in addition to the more common symptoms of Zn deficiency in plants. Zinc concentrations increased with increasing Zn supply in the blades of the youngest fully expanded leaf (YFEL) and in the blades of the leaves immediately older (YFEL+1) and younger (YFEL‐1) than it: they also increased with increasing Zn supply in the petioles of the YFEL+1 and YFEL and in the basal stem internode but their Zn concentrations Here always much lower than those in the blades. Critical Zn concentrations in the blades of the YFEL and YFEL+1 Here 8–10 mg Zn/kg DM at early pegging and mid pod filling: values for YFEL‐1 were similar but more variable. The blade of the YFEL is recommended for diagnosis of Zn deficiency in peanut and 8–10 mg Zn/kg DM as its critical value.     

锌对不同基因型玉米缺锌后的恢复效果及胚乳在缺锌中的作用

用溶液培养法研究不同Zn浓度对玉米缺Zn后恢复效果及胚乳在缺Zn中作用结果表明,不同基因型玉米缺Zn后恢复所需的适宜Zn浓度不同,敏感品种比非敏感品种要求更高的Zn浓度。缺Zn后恢复所需适宜Zn浓度高于正常培养所需适宜Zn浓度,低浓度Zn(0.1μmol/L)无恢复作用(生物量)。带上胚乳使敏感品种在缺Zn、低Zn下受抑程度(缺Zn与供Zn生物量差值)提高,而非敏感品种受抑程度反而减小。缺Zn与低Zn培养时体内P含量提高,胚乳可缓解这种影响。缺Zn后再供Zn可使体内Zn含量提高,而P含量降低,玉米对Zn产生奢侈吸收,使体内Zn含量超过正常供Zn水平,表明缺Zn后植物对Zn的要求提高。0.1μmol/L Zn恢复对“吉单120”玉米Zn含量无明显影响,但“辽单22”玉米Zn含量显著提高,这表明非敏感品种比敏感品种利用低Zn的能力更强。     

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.     

Diagnostic indices of zinc deficiency in tropical legumes

The effect of 0.005 ppm, 0.01 ppm, 0.05 ppm and 0.10 ppm zinc on the growth and chemical composition of Desmodium uncinatum Jacq. cv. Silverleaf; Macroptilium lathyroides L.; Lablab purpureus; and Glycine max. L. cv. Wills were studied in solution culture in a controlled environment room.

Dry matter production of tops of all species was reduced at the lower zinc treatments while that of roots was unaffected by zinc supply.

Zinc concentrations of leaves from three plant positions did not provide a reliable index of zinc nutrition. The lowest zinc treatments often produced greater leaf concentrations of zinc than did higher zinc treatments. The cytoplasmic fractions of the leaf tissue contained the highest zinc concentrations. Cell walls, nuclei, chloroplasts and mitochondria contained extremely low concentrations, and the data were generally variable, reflecting the poor reproducibility of the techniques used.

Phosphorus concentrations in leaves were generally increased at the low zinc treatments, an effect not entirely attributable to the reduction in dry matter production. The proportion of inorganic phosphorus increased and that of organic phosphorus decreased at the lower zinc treatments. Lipoid and residual phosphorus fractions were not affected consistently by zinc treatments.

Leaves of plants receiving the lowest zinc treatment generally had significantly lower nitrogen concentrations than those receiving the higher zinc treatments.

In another experiment, in which Glycine wightii was substituted for G. max., RN‐ase activity increased as the zinc supply was reduced and this was accompanied by a decrease in protein concentration. The data show that RN‐ase activity could be a useful diagnostic index of incipient zinc deficiency.     

Iron deficiency causes zinc excess in Zea mays

Iron deficiency stress causes a severe reduction in plant growth. Although Fe deficiency causes an imbalance in divalent heavy metal nutrients, the mechanisms underlying the growth reduction caused by this imbalance remain unclear. We investigated Zn uptake and accumulation in maize under Fe-deficient conditions. Under Fe-deficient conditions, Zn uptake was 15-fold higher and Zn accumulation was 16-fold higher than that under normal nutrient conditions. The Zn content of maize leaves under Fe-deficient conditions was >0.4 mg g⁻¹ dry weight, which was higher than the content of plants grown in a nutrient solution containing 50 µM ZnCl₂. Plant growth under conditions of both Fe and Zn deficiency was significantly higher than that under only Fe-deficient conditions. Moreover, Fe deficiency increased the thiol content of the plant. These results indicate that Fe deficiency causes excess uptake and accumulation of Zn, and that the stress resulting from the Zn overload accelerates growth reduction in maize.     

Effect of shading on zinc deficiency symptoms in rice plant

Under Zn deficiency, some major deficiency symptoms were observed on rice plants, i.e., reduction of young leaf elongation and development of necrosis on the expanded leaves. To clarify the former phenomena, the physiological role of Zn was studied from the standpoint of protein synthesis (Kitagishi and Obata 1986; Obata et al. 1994, 1996) and metabolism of auxin (Takaki and Arita 1986; Domingo et al. 1992). In contrast, the direct cause of the latter phenomenon has not yet been studied.     

玉米幼苗对短暂供锌的反应及缺锌后再供锌的恢复

用溶液培养的方法研究了玉米幼苗对短暂供锌的反应及缺锌后再供锌的恢复效果.结果表明:10～12小时的正常供锌后再缺锌培养,对玉米幼苗的危害比一直缺锌的还大;缺锌培养使玉米幼苗出现缺锌症状后再正常供锌,可使之恢复,低锌使玉米出现的缺锌症状比缺锌培养的更难以恢复,证明低锌比缺锌对玉米造成的危害更大,缺锌使玉米的有机酸分泌增加,低锌增加的更多.     

Effect of zinc deficiency in wheat on the release of zinc and iron mobilizing root exudates

The effect of Zn deficiency in wheat (Triticum aestivum L. cv. Ares) on the release of Zn mobilizing root exudates was studied in nutrient solution. Compared to Zn sufficient plants, Zn deficient plants had higher root and lower shoot dry weights. After visual Zn deficiency symptoms in leaves appeared (15–17 day old plants) there was a severalfold increase in the release of root exudates efficient at mobilizing Zn from either a selective cation exchanger (Zn-chelite) or a calcareous soil. The release of these root exudates by Zn deficient plants followed a distinct diurnal rhythm with a maximum between 2 and 8 h after the onset of light. Re-supply of Zn to deficient plants depressed the release of Zn mobilizing root exudates within 12 h to about 50%-, and after 72 h to the level of the control plants (Zn sufficient plants). The root exudates of Zn deficient wheat plants were equally effective at mobilizing Fe from freshly precipitated Fe^III hydroxide as Zn from Zn-chelite. Furthermore, root exudates from Fe deficient wheat plants mobilized Zn from Zn-chelite, as well as Fe from Fe^III hydroxide. Purification of the root exudates and identification by HPLC indicated that under Zn as well as under Fe deficiency, wheat roots of the cv. Ares released the phytosiderophore 2′-deoxymugineic acid. Additional experiments with barley (Hordeum vulgare L. cv. Europa) showed that in this species another phytosiderophore (epi-3-hydroxymugineic acid) was released under both Zn and Fe deficiencies. These results demonstrate that the enhanced release of phytosiderophores by roots of grasses is not a response mechanism specific for Fe deficiency, but also occurs under Zn deficiency. The ecological relevance of enhanced release of phytosiderophore also under Zn deficiency is discussed.     

Diagnosis and correction of manganese deficiency in corn

Abstract

Although manganese (Mn) deficiency in soybeans (Glycine max) has been recognized on the Atlantic Coastal Plain, it has not been well recognized in corn (Zea mays) until recent years. Hence, there is a lack of information relating to the diagnosis and correction of Mn deficiency in corn. Field experiments were conducted to determine if the Mn soil test interpretation for soybeans would work for corn. The leaf Mn critical level also was evaluated, as were soil and foliar application methods of correcting a deficiency. Corn yield response to Mn fertilization was best explained by both soil pH and Mehlich‐3 extractable Mn concentration. The influence of these two soil properties for predicting yield response was similar for corn and soybeans, but it appears that the soil Mn critical level is lower for corn than for soybeans. The critical Mn concentration in the ear leaf at early silking was found to be 11 mg kg^‐1. Manganese banded with diammonium phosphate (DAP) was three times as effective as Mn broadcast with DAP in increasing the leaf Mn concentration of corn. Banding DAP also tends to increase the availability of native soil Mn. A foliar Mn rate of 0.6 kg ha^‐1 applied once partially corrected a Mn deficiency, but multiple applications were required for optimum yield.     

Diagnosing zinc deficiency in rapeseed and mustard by seed analysis

Abstract

Zinc (Zn) deficiency in crops, including rapeseed and mustard, is a widespread nutritional disorder especially in alkaline soils. However, plant analysis diagnostic criteria for interpreting Zn analysis in rapeseed and mustard are scarcely reported in the literature. Use of seeds for diagnosing Zn fertility status of soils has certain advantages over foliar analysis—ease of sampling, processing, and chemical analysis. Despite this, mature seeds of these species were hardly evaluated as an index tissue for this purpose. Our study determined Zn requirement in foliar tissues and also evaluated Zn composition of mature seeds as an index of Zn status of soils and plants. Zinc concentration in mature seeds of the test crops reflected the Zn status of the soil where plants were grown. In fact, the range of Zn concentration in grains was almost comparable with the ranges in foliar plant parts. Critical Zn concentration (mg/kg) in diagnostic plant parts of rapeseed was: whole shoots, 29; leaves, 33; and seeds, 29; while the Zn requirement of mustard was a little higher: whole shoots, 35; leaves, 41; and seeds, 33.     

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.     

Silicon mitigates boron deficiency and toxicity in cotton cultivated in nutrient solution

Silicon (Si) application, both via foliar application and via roots, may be promising to improve plant growth under different biotic or abiotic stresses. In the present study, we investigated whether application of Si can also mitigate the harmful effects of boron (B)‐related nutritional disorders, such as B deficiency, when the application of B is inefficient or insufficient, and B toxicity, when the soil presents high levels of B. This may enable producers to apply Si preventively, if there is a low availability of B in the environment or if B deficiency is induced during the growth season due to a water deficit reducing the plant's B absorption. The objective of this study was to investigate the influence of leaf and root Si application on alleviating the harmful effects of B deficiency and toxicity in cotton. Three experiments were carried out with cotton plants (Gossypium hirsutum cv. Bayer FM910®), using a soilless system. In a first experiment, we determined that highest plant Si concentrations were obtained with application of stabilized sodium and potassium silicate at concentrations of 0.8 g L^?1 (foliar) and 0.056 g L^?1 (roots). Experiment 2 indicated that the B concentrations in the nutrient solution associated with moderate B deficiency, sufficiency and moderate toxicity were 33.7, 83.6, and 130.5 µM B L^?1, respectively. In Experiment 3 we evaluated the effect of optimum Si applications on the physiology and dry weight production of cotton plants subjected to B deficiency, sufficiency, and toxicity. Silicon mitigated the harmful effects of both B deficiency and toxicity by increasing whole‐plant biomass production and levels of chlorophyll a, chlorophyll b, and total chlorophyll, and reduced initial and maximum fluorescence, thereby improving the quantum efficiency of photosystem II. Collectively, these results indicate that the greatest benefit of Si in mitigating B deficiency occurred with foliar B application, while Si supplied via the nutrient solution was more effective against B toxicity.     

应用数字图像分析技术进行棉花氮素营养诊断的研究

本文利用图像分析技术并结合常规观测手段,研究应用图像分析技术诊断棉花氮素营养状况的可行性及获取的光谱参数与表征棉花氮素营养状况的生物学参数之间的关系.结果表明:棉花在不同时期特征光谱参数与棉花含氮量及叶片含氮量呈显著相关,其中盛蕾期棉花全氮含量与光谱参数的相关性最好,在盛花期棉花叶片含氮量与光谱参数的相关系数最高,G/(G R B)可作为氮素营养诊断的指标.在棉花全生育期内,地面覆盖度与棉花叶面积指数、生物量及吸氮量呈显著相关,在出苗至盛花期之间达极显著相关.经检验,地面覆盖度可很好地预测棉花的叶面积指数、生物量及吸氮量,相对误差分别为26.2%、3.46%和3.37%.     

Critical limits of deficiency and toxicity of zinc in paddy in a typic Ustipsamment

Abstract

A pot culture experiment was conducted to establish the critical limits of deficiency and toxicity of Zn in a Typic Ustipsamment from tropical India. Critical limits of Zn deficiency and toxicity were 0.39, and 12 μg/g with DTPA‐TEA‐CaCl₂, 2.2 and 26 μg/g with EDTA‐(NH₄)₂Co₃ and 0.78 and 12 μg/g with HC1 (0.05 N), respectively. Critical concentrations in the rice plants associated with deficiency and toxicity were 16 and 190 μg/g.     

Differential responses of soybean and dry bean to zinc deficiency 1

Whether a legume obtains its nitrogen (N) from the air, through dinitrogen fixation, or from the soil, as nitrate (NO₃), may influence its susceptibility to zinc (Zn) deficiency. The influence of N source [potassium nitrate (KNO₃)+ native soil N versus rhizobium‐inoculated seed + native soil N] and phosphorus (P) (0 and 200 mg P/kg), and Zn fertilizers (0, 1, and 8 mg Zn/kg) on growth and nutrient composition of soybean (Glycine max L. cv. McCall) and navy bean (Phaseolus vulgaris L. cv. Seafarer) grown on a calcareous soil were studied under greenhouse conditions. Inoculated plants, but not their KNO₃‐treated counterparts, had root nodules. However, due to N deficiency resulting from suboptimal N fixation, growth of these inoculated plants, especially of navy bean, was poorer than that of similarly treated KNO₃‐fed plants. As a consequence of this restricted growth, responses to P and Zn fertilizers were generally greater in KNO₃‐treated plants. Added P decreased the yield of KNO₃‐treated navy bean in the absence of added Zn, but P‐induced Zn deficiency had little effect on the growth of similarly treated inoculated plants. Plant excess bases (EB)/total plant N ratios [EB = 1/2 Ca + l/2Mg + Na + K ‐ Cl ‐ total S (S = divalent) ‐ total P (P = monovalent)] were less in KNO₃‐treated soybean than in correspondingly treated navy bean. Therefore, rhizosphere pH values around navy bean roots were probably less than those around soybean roots. Despite the hypothesized lower rhizosphere pH values, KNO₃‐treated navy bean was more susceptible to Zn deficiency than soybean. This greater susceptibility of navy bean to Zn deficiency was apparently at least partly due to poor translocation of Zn from the roots to the tops.     

Response of carboxylate metabolism to zinc deficiency in Lactuca sativa and Brassica oleracea plants

Species or genotypes differ in their zinc use efficiency (ZnUE) under low Zn availability in the soil. Organic acids (OAs) synthetized by plant carboxylate metabolism may play a role in Zn‐deficiency tolerance. The main objective of the present work was to assess the response of two species of great agronomic interest such as Lactuca sativa and Brassica oleracea to Zn deficiency focusing on OAs and carboxylate metabolism. For this, L. sativa and B. oleracea plants were grown in hydroponic culture with two different Zn‐application rates: 10 µM Zn as control and 0.1 µM Zn as deficiency treatment. ZnUE parameters, concentrations of OAs and enzymes of carboxylate metabolism were analyzed. L. sativa showed better Zn uptake efficiency (ZnUpE), while B. oleracea demonstrated better Zn utilization efficiency (ZnUtE). In L. sativa, citrate and oxaloacetate concentrations and phosphoenolpyruvate carboxylase and citrate synthase activities increased, while fumarase and malate dehydrogenase activities declined. In B. oleracea no significant response was found in concentrations of carboxylate metabolism or enzyme activity except for a decrease in fumarase activity. These results suggest that a possible factor that induces the tricarboxylic acid cycle could be the low ZnUtE rather than the low Zn concentration under Zn‐deficiency conditions. In L. sativa citrate, oxaloacetate, phosphoenolpyruvate carboxylase, and citrate synthase may play a key role to face Zn deficiency, while in B. oleracea the higher ZnUtE cannot be explained in terms of a rise in OAs synthesis.     

Phosphorus-induced zinc deficiency in wheat pot-grown on noncalcareous and calcareous soils of different properties

High levels of phosphorus (P) often induce zinc (Zn) deficiency in plants grown on Zn-poor soils. We investigated P-induced Zn deficiency in durum wheat (Triticum durum L. ‘Carpio’) grown on 16 noncalcareous and 31 calcareous soils differing in levels of available (Olsen) P and available (diethylenetriaminepentaacetic acid (DTPA)-extractable) Zn using micropots. A completely randomized factorial design with two levels of P (0 and 40 mg P kg^?1 soil) and Zn (0 and 3 mg Zn kg^?1 soil), i.e. four treatments (‘control’, + P, + Zn, and + PZn), were used. Grain yield of control plants depended mainly on the Olsen P level. Phosphorus had a negative effect on yield in 6 soils with Olsen P/Zn_DTPA > 25, and Zn a positive one in 5 soils with Olsen P/Zn_DTPA > 50; and the + PZn treatment generally resulted in the highest yield. Grain Zn concentration of control plants was negatively correlated with growth and Olsen P. Calcareous soils were less sensitive to P-induced Zn deficiency than noncalcareous soils because phosphate is sorbed by calcite rather than being co-adsorbed with Zn on the Fe oxides. Co-application of P and Zn to soil at low and application of Zn at high Olsen P ensured both maximum yield and grain Zn bioavailability.     

Biofortification of common bean as a complementary approach to addressing zinc deficiency in South Africans

Deficiencies of vitamin A, iodine, iron and zinc (Zn) in humans are caused partly by the consumption of food that has insufficient quantities of these. Their deficiency has a negative impact on the health, wellbeing, social and economic status of human beings. A national survey conducted in 2012 identified deficiencies of vitamin A, Fe, and Zn among other nutrients in South Africans and regarded the deficiencies of vitamin A and Fe as a moderate but not Zn. This review discusses causes of Zn prevalence in low-income South Africans and that it is largely caused by the low content of Zn in their diets. Initiatives to reduce Zn deficiency include fortification of wheat products and maize meal which has failed to address it successfully. Weaknesses of fortification include high cost of fortified food products to low-income populations, poor regulation in ensuring compliance in fortification, non-fortification of sorghum meal, and leaching of fortified nutrients during processing. This review suggests Zn-biofortification of locally-preferred common bean cultivars as an alternative strategy to compliment fortification. The review also discusses advantages of adopting biofortified Nutritional Andean common beans. Furthermore, the review suggests initiatives including evaluation of the common bean genotypes’ adaptation to different agro-ecologies.