Effect of zinc application methods on apparent utilization efficiency of zinc and potassium fertilizers under rice-wheat rotation

Apparent utilization of zinc (Zn) and potassium (K) fertilizers was examined in rice (Oryza sativa L.)-wheat (Triticum aestivum L.) using combinations of no K; soil applied K levels and no Zn; soil and foliar applied Zn. Application of 33.2 kg K ha^?1 in rice and 24.9 kg K ha^?1 in wheat along with foliar spray of 2 kg Zn ha^?1 at 30 and 60 days gave the highest mean grain yields. Foliar application of zinc increased Zn concentration in flag leaves, grain, and straw of rice and wheat and K concentration in flag leaves of rice and straw of wheat significantly. Potassium application increased Zn concentration in rice grain and straw and K concentration in wheat straw significantly. Zinc and K increased the uptake of each other in grain; straw and total uptake by both crops significantly. Zinc fertilizer enhanced the utilization of soil K. Potassium fertilizer enhanced the utilization of applied Zn.     

Iron nutrition in low chill peach for improving yield and fruit quality

Foliar fertilization and microbe supplemented iron (Fe) bioavailability can fulfill iron demand of plants. An experiment was performed to examine the effect of Psuedomonas fluorescens along with foliar spray ferrous sulfate on low-chill peach plants suffering from iron deficiency. Number of leaves per shoot, leaf area, chlorophyl content, Fe: Mn ratio of leaves, fruit yield and fruit physico-chemical parameters were recorded. The results showed a significant increase in leaves chlorophyl content, iron: manganese ratio of leaves, fruit yield, fruit length, fruit breadth, total soluble solids (T.S.S) and T.S.S and acid ratio with the inoculation of Pseudomonas fluorescens as well as foliar spray of ferrous sulfate, whereas, acidity of fruit pulp was decreased. Significantly higher number of leaves per shoot was also noted with foliar spray of ferrous sulfate. Pseudomonas fluorescens inoculation along with foliar spray of ferrous sulfate significantly increased leaves chlorophyl content, fruit length, T.S.S and T.S.S : acid ratio of fruit pulp.     

Response of Gemlik Olive Trees to Soil and Foliar Treatments of Iron in Combination with Zinc and Boron

This research was conducted to determine the effectiveness of various treatments in correction of single deficiency of iron (Fe) and multiple deficiencies of Fe, zinc (Zn), and boron (B) in an olive cultivar (Gemlik) in the southeastern Marmara region of Turkey. This study was consisted of four field experiments, which included control, soil and foliar applications of Fe alone, and combinations with Zn and B. Soil applications of the compounds were only performed in the first year of the experiments to estimate residual effect of soil applications in the following year. Foliar applications were sprayed onto leaves two and four times at two doses in consecutive years. Soil application of iron sulfate did not increase Fe concentrations in the both leaves and fruits. Foliar applications of iron sulfate considerably elevated leaf total and active Fe concentrations, but the effect of the foliar applications on fruit Fe concentrations was small. Two foliar applications of iron in each season seemed to be appropriate treatment in the all experiments, as well. To maintain sufficient Fe concentrations, especially in the newly developing tissues of olive trees, foliar application of Fe should be conducted at least four times at the lowest dose as performed in the experiments. Foliar applications of double and triple combinations of iron sulfate with zinc sulfate and borax increased significantly B and Zn concentrations in the trees, as well.     

EFFECT OF FOLIAR SPRAY OF SOLUBLE SILICIC ACID ON GROWTH AND YIELD PARAMETERS OF WETLAND RICE IN HILLY AND COASTAL ZONE SOILS OF KARNATAKA,SOUTH INDIA

Field experiments were conducted to evaluate the effect of foliar spray of soluble silicic acid on growth and yield parameters of wetland rice. The results revealed a significant effect on achieving higher grain and straw yield with foliar silicic acid over control. Foliar spray of silicic acid at 2 and 4 ml L^?1 increased the grain and straw yield and application of 8 ml L^?1 decreased the yield. Foliar spray of silicic acid at 4 ml L^?1 along with half dose of recommended pesticide effectively increased the yields over all other treatments. The content and uptake of silicon in grain and straw was recorded higher with the foliar spray of silicic acid over control. This investigation concludes that application of silicic acid at 4 ml L^?1 along with half dose of recommended pesticide as foliar spray increased the grain and straw yield, besides Si content and its uptake over control.     

Barley responses to copper foliar spray concentrations when grown in a calcareous soil

This study was designed to determine the adequate copper (Cu) foliar spray concentration to correct Cu deficiency on barley (Hordeum vulgare L.) when grown in a calcareous soil. Five Cu foliar spray solution levels were tested (0% or control; 0.03%, 0.06%, 0.13%, and 0.33%). Copper was applied in the sulfate form at the early boot stage. The results showed that Cu flag leaf concentration was increased with the highest Cu application (0.33%), while Cu concentration in the grain was increased with a spray of 0.03%. An antagonism between Cu, Zn, and Fe leaf concentration was observed. Grain yield and harvest index showed a linear positive response to Cu foliar spray concentrations. A significant increase of 19.6% on grain yield was recorded with a foliar spray 0.33% of Cu.     

IMPROVING SEED YIELD OF BLACK GRAM (VIGNA MUNGO L. VAR. DPU-88-31) THROUGH FOLIAR FERTILIZATION OF ZINC DURING THE REPRODUCTIVE PHASE

The response of zinc (Zn) deficiency on reproductive yield and recovery through foliar application of Zn was determined in black gram, an important edible legume in India. Results revealed that foliar spray of Zn [0.01 and 0.5% zinc sulfate (ZnSO₄)] improved not only the flowering, pollen producing capacity, pollen viability, stigma-receptivity and pollen-stigma interaction but also the yield parameters like number, size and weight of pods and seeds. Zinc deficiency induced changes in pollen grain structure, activity of esterase and poor stigmatic exudation leading to improper pollen-stigma interaction, which seem to be the main cause of poor fertility and decreased seed yield. Foliar application of 0.5% ZnSO₄ after bud formation was most beneficial not only for reproductive yield but also seed Zn content.     

叶面喷施锌硒肥对谷子抗氧化酶活性及籽粒锌硒含量的影响

  【目的】   研究叶面喷施锌、硒肥对谷子叶片抗氧化酶活性以及锌、硒在籽粒积累的影响,为谷子生产中合理施用锌、硒肥以及开发富锌富硒谷子提供参考。   【方法】   在2016—2017年,以冀谷21为试材进行田间小区试验。分别设3个锌水平 (0、2.25、4.50 kg/hm2) 和3个硒水平 (0、30、60 g/hm2),共组成7个处理分别为对照 (Zn0Se0)、单施低硒 (Zn0Se1)、单施低锌 (Zn1Se0)、低锌低硒 (Zn1Se1)、低锌高硒 (Zn1Se2)、高锌低硒 (Zn2Se1)、高锌高硒 (Zn2Se2),随机区组排列。分析了谷子叶片中超氧化物歧化酶 (SOD)、过氧化物酶 (POD)、谷胱甘肽过氧化物酶 (GSH-Px) 的活性,籽粒锌硒含量以及谷子产量。   【结果】   喷施锌、硒对叶片SOD、POD和GSH-Px活性影响达到显著或极显著水平。在低锌 (2.25 kg/hm2) 水平下,随着硒肥施用量的提高,SOD与GSH-Px活性均呈现出先升后降的趋势,且在低锌低硒配合处理下酶活性均达到最高。在低硒 (30 g/hm2) 水平下,随着锌肥施用量增加,SOD与GSH-Px活性先升后降。高锌高硒配合不利于叶片抗氧化酶活性的提高。喷施锌、硒对籽粒锌、硒的吸收影响极显著。单施锌、单施硒可显著提高籽粒Zn、Se含量。低Zn水平下,配施低Se提高了籽粒Zn含量,配施高Se则降低Zn含量。低Se水平下,配施Zn可提高籽粒的Se含量,而高Se水平下,提高Zn水平对籽粒Se含量没有显著影响。低锌低硒 (Zn 2.25 kg/hm2、Se 30 g/hm2) 对产量提高效果最好。   【结论】   叶面喷施Zn和Se可以显著提高叶片中的抗氧化酶活性,但是同时喷施Zn和Se,需注意喷施浓度。喷施低锌低硒 (Zn 2.25 kg/hm2、Se 30 g/hm2) 有利于提高谷子叶片抗氧化酶活性、籽粒锌硒含量与产量,Se和Zn有一定的协同效应。喷施高量Zn对Se的吸收没有显著的副作用,但是高锌时再喷施高Se则抑制籽粒Zn的吸收。     

Effects of foliar Fe and Zn fertilizers on storage root Fe,Zn, and beta-carotene content of sweet potato (Ipomoea batatas L.)

Foliar sprays of iron (Fe) and zinc (Zn) fertilizers are effective in improving Fe and Zn concentrations in sweet potato. The objective of this experiment was to examine the effects of foliar fertilization with Fe and Zn in association with amino acids (AA) on Fe and Zn biofortification and the nutritional quality of sweet potato under both greenhouse and field conditions. Compared with treatment CK, foliar Fe, Zn, and Fe-Zn fertilizer applications could biofortify Fe and Zn concentrations and other nutrients in sweet potato to different extents. However, when 0.4% (wt/vol) AA was added to Fe-Zn fertilizer, the average Fe and Zn concentrations were increased by 70.2% and 59.8% under greenhouse conditions, and 52.9% and 43.7% under field conditions, respectively. The Fe-Zn-AA fertilizer application also resulted in incremental increases in root yield and beta-carotene content. This research identified some useful foliar fertilizers for accelerating Fe and Zn accumulation in selected sweet potato cultivars.     

Enhancing nutrient translocation,yields and water productivity of wheat under rice–wheat cropping system through zinc nutrition and residual effect of green manuring

Abstract

Efficient nutrient and water use are two important considerations to obtain good harvests of wheat. This necessitates the development of an effective nutrient management technique that not only increases yield, but simultaneously can save nutrient and water use. In this context, a field experiment was conducted at Indian Agricultural Research Institute, New Delhi, India to evaluate the residual effect of sesbania and rice bean (in-situ), subabul (ex-situ) green manuring and Zinc (Zn) fertilization, using chelated Zn-ethylenediaminetetraacetic acid (Zn-EDTA) on nutrient use, yields and water productivity of wheat under rice–wheat cropping system. Among residual effects of green manure crops and Zn fertilization, sesbania and foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 days after sowing (DAS) recorded significantly higher nutrient content and uptake and yields than other green manure crops and Zn treatments. Residual effect of sesbania saved about 46.5?×?10³ and 30.5?×?10³ L irrigation water per tonne of wheat over subabul and rice bean, respectively. Foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 DAS saved about 55.5?×?10³, 47?×?10³ and 13?×?10³ L irrigation water per tonne wheat over residual effect of 5?kg Zn ha^?1 through chelated Zn-EDTA as soil application, 2.5?kg Zn ha^?1 through chelated Zn-EDTA as soil application + 1 foliar spray of 0.5% chelated Zn-EDTA at flowering and foliar spray of 0.5% chelated Zn-EDTA at active tillering?+?flowering?+?grain filling, respectively. Correlation analysis showed positive correlation between Zn uptake and grain yield.     

锌肥品种与施用方法对水稻产量和锌含量的影响

【目的】 鉴于在缺锌土壤上施用锌肥不仅可提高水稻产量,而且也能显著提高水稻籽粒锌含量,本研究旨在揭示不同品种锌肥和施用方法在提高水稻产量和籽粒锌含量方面的差异。 【方法】 以水稻品种‘镇稻 11 号’为供试材料,于 2011 年 5 月至 2012 年 11 月在大田条件下设置 4 组试验:试验 1,富锌稻种的生产制备与籽粒锌含量的染色鉴定试验,设水稻常规种植(CK)和生育期连续喷施 5 次硫酸锌(ZnSO₄·7H₂O,Zn) 2 个处理;试验 2,不同品种锌肥土壤施用试验,设不施锌肥对照(S1)、土施 ZnSO₄·7H₂O (S2)、土施氮锌复合肥(Urea-Zn,S3)、土施磷锌复合肥(Mosaic-Zn,S4)、土施钾锌复合肥(Kali-Zn,S5)、富锌种苗移栽(S6)和 ZnSO₄·7H₂O 蘸秧根移栽(S7) 7 个处理;试验 3,不同品种锌肥叶面喷施试验,设不施锌肥对照(F1)、孕穗期喷施 ZnSO₄·7H₂O (F2)、开花期喷施 ZnSO₄·7H₂O (F3)、孕穗期和开花期各喷施 ZnSO₄·7H₂O (F4)、开花期与农药一起喷施 ZnSO₄·7H₂O (F5)、开花期喷施 Kali-EPSO-Zn(F6)和开花期喷施 ADOB-IDHA-Zn(F7) 7 个处理;试验 4,富锌稻种育苗种植比较试验,设常规稻种(CK-grain)和富锌稻种(Zn-grain)育苗种植 2 个处理,研究其对水稻产量及构成、各器官(叶片、茎秆和籽粒)锌含量和累积分配的影响。 【结果】 1) 在水稻生育期进行叶面高浓度和高强度的喷锌方式可制备富锌稻种,且可采用双硫腙(DTZ)染色直观鉴定籽粒锌含量。2) 施用锌肥显著提高水稻产量和锌含量,且不同锌肥品种和施用方法间差异显著。3) 土壤施锌各处理平均增产效果显著高于叶面喷锌 5.2%;与土壤施锌处理相比,叶面喷锌各处理的叶片、茎秆和籽粒锌含量的平均值则分别显著提高 224.6%、78.5% 和 12.1%。4) 在土壤施锌条件下,不同锌肥品种中氮锌复合肥 (S3) 和钾锌复合肥 (S5) 的增产效果显著高于磷锌复合肥 (S4),而在叶面喷锌条件下,以 Kali-EPSO-Zn 处理 (F6) 提高水稻各器官锌含量的能力显著高于 ADOB-IDHA-Zn 处理 (F7) 和 ZnSO₄·7H₂O 处理 (F3)。5) 较常规稻种 (CK-grain),应用富锌稻种 (Zn-grain) 育苗种植的水稻产量和籽粒锌含量分别提高 4.6% 和 3.9%。 【结论】 结合锌肥土施增加水稻产量和喷施增加籽粒锌含量的田间应用效果,因地制宜地综合采用土施氮锌复合肥和喷施钾锌复合肥的配合施肥方法以及选用富锌稻种育苗种植,可协同实现最佳的锌肥利用效率、最大程度地稳产增产和提高稻米的锌营养品质。      

Foliar Symptomology and Tissue Concentrations of Nutrient‐Deficient Vegetative Strawflower Plants

Abstract

Elemental deficiencies of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper, zinc, or boron (N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, or B) were induced in plants of Florabella Pink strawflower [Bracteantha bracteata (Vent.) A. A. Anderberg]. Rooted stem cuttings were planted in 4.87‐L plastic containers and fertilized with a complete modified Hoagland's solution or this solution minus the element that was to be investigated. Plants were harvested for tissue analyses as well as dry weights when initial foliar symptoms were expressed and later under advanced deficiency symptoms. Deficiency symptoms for all treatments were observed within 7 weeks. The most dramatic expression of foliar symptoms occurred with N (chlorotic lower foliage leading to necrotic margins on the mature leaves), Ca (black necrotic spots on the tips of the young leaves), S (uniform chlorosis of young leaves and recently mature leaves), B (thick, leathery, and deformed young leaves), Fe (uniform yellowish‐green chlorosis on the young leaves), and Zn (brownish‐gray necrosis on the tips of the mature leaves). At the initial stage, only Fe‐deficient plants weighed less than the control, whereas K‐, Ca‐, and Mg‐deficient plants had greater dry weights than plants receiving the complete modified Hoagland's solution (control plants). Dry weights of plants treated with solutions not containing N, P, Ca, S, Cu, or Mn were significantly lower when compared with the control plants under an advanced deficiency. Foliar‐tissue concentration data will assist plant‐tissue analysis laboratories in establishing foliar symptom standards for growers.     

Interaction of Iron with Copper,Zinc, and Manganese in Wheat as Affected by Iron and Manganese in a Calcareous Soil

Iron (Fe) availability is low in calcareous soils of southern Iran. The chelate Fe-ethylenediamine di (o-hydroxy-phenylacetic acid) (Fe-EDDHA), has been used as an effective source of Fe in correcting Fe deficiency in such soils. In some cases, however, its application might cause nutritional disorder due to the antagonistic effect of Fe with other cationic micronutrients, in particular with manganese (Mn). A greenhouse experiment was conducted to evaluate the influence of soil and foliar applications of Fe and soil application of manganese (Mn) on dry matter yield (DMY) and the uptake of cationic micronutrients in wheat (Triticum aestivum L. var. Ghods) in a calcareous soil. Results showed that neither soil application of Fe-EDDHA nor foliar application of Fe sulfate had a significant effect on wheat DMY. In general, Fe application increased Fe uptake but decreased that of Mn, zinc (Zn), and copper (Cu). Application of Mn increased only Mn uptake and had no significant effect on the uptake of the other cationic micronutrients. Iron treatments considerably increased the ratio of Fe to Mn, Zn, Cu, and (Mn + Zn + Cu). Failure to observe an increase in wheat DMY following Fe application is attributed to the antagonistic effect of Fe with Mn, Zn, and Cu and hence, imbalance in Fe to (Mn + Zn + Cu) ratio. Due to the nutritional disorder and imbalance, it appears that neither soil application of Fe-EDDHA nor foliar application of Fe-sulfate is appropriate in correcting Fe deficiency in wheat grown on calcareous soils. Hence, growing Fe-efficient wheat cultivars should be considered as an appropriate practice for Fe chlorosis-prone calcareous soils of southern Iran.     

Effect of single and combined applications of zinc with iron and boron on the contents of “Deveci” pear trees

This research was conducted to correct the ion of zinc (Zn) deficiencies and to examine the efficiency of foliar Zn application on pear groves along with iron and boron. The treatments consisted of control, soil and foliar applications. Every foliar applied Zn elevated considerably Zn contents of the leaves. But, increases in fruit Zn contents were rather limited as compared to Zn contents of the leaves. It is thought that accumulation of Zn in the fruits was due to movement of Zn from the leaves well-supplied with Zn to the fruits. Therefore, foliar application of Zn should be conducted at least four times at the rate of 0.1% to increase Zn contents in the fruits in terms of human's daily Zn intake. Foliar applications of Zn alone and combined Zn + Fe, Zn + B and Zn + Fe + B applications significantly increased Zn, Fe and B concentrations, respectively, in the pear trees, as well.     

硫酸锌和EDTA-Zn不同施用方法对第二季小麦籽粒锌和土壤锌有效性的影响

【目的】在潜在缺锌石灰性土壤上,特别是种植小麦并以此为主粮的地区,缺锌问题日益受到人们的关注。提高小麦籽粒锌含量以满足人体锌需求,对于改善人体锌营养不良的现状具有重要意义。【方法】以ZnSO₄和Zn-EDTA为锌源,布置了2个为期两年的田间定位试验。试验均采用裂区设计,即主因子为喷施锌肥,设喷施与不喷2个主处理;副因子为土施方法,设不施锌、均施、条施3个副处理。在第1季试验基础上,第2季不再土施锌肥,调查了小麦籽粒锌含量、土壤有效锌含量及锌组分含量,分析了第1季锌肥的后效。【结果】第2季单独喷施ZnSO₄小麦籽粒Zn含量提高了11.13 mg/kg,提高幅度为33%,而喷Zn-EDTA无明显效果。不喷Zn时,第1季均施和条施的ZnSO₄在第2季均表现出一定后效,小麦籽粒锌含量比对照分别提高了6.05、3.51 mg/kg,提高幅度为20%和11%;喷Zn时,第2季均施和条施ZnSO₄处理的小麦籽粒锌含量增加了28.59和21.59 mg/kg,增幅100%和76%,表现出显著富锌作用,但增加幅度比单独喷施要小很多。第1季土施的两种锌肥在第2季小麦收获后DTPA-Zn仍维持在1 mg/kg以上,即不喷Zn时,均施和条施ZnSO₄处理的土壤有效锌含量分别为1.99和1.65 mg/kg,均施和条施Zn-EDTA的有效锌含量分别为1.23和1.01 mg/kg;喷Zn时,均施和条施ZnSO₄处理的土壤有效锌含量分别为1.44和2.22 mg/kg,均施和条施Zn-EDTA处理的有效锌含量分别为1.16和1.10 mg/kg。土壤各锌组分含量均表现为:松结有机态Zn > 碳酸盐结合态Zn > 氧化锰结合态Zn > 紧结有机态Zn > 交换态Zn。具体而言,第1季均施和条施ZnSO₄,第2季结束后交换态Zn（Ex-Zn）、松结有机态Zn（Wbo-Zn）、碳酸盐结合态Zn（Car-Zn）含量均显著提高,其提高幅度分别为184%和116%;75%和85%;53%和43%。而均施和条施Zn-EDTA仅Ex-Zn、Wbo-Zn含量显著提高,其提高幅度分别为232%和132%;18%和10%。均施Zn-EDTA处理的锌肥利用率为0.27%,条施为0.70%,后者约为前者的3倍;而条施与均施ZnSO₄无差异。【结论】在潜在缺锌石灰性土壤上,单独喷施ZnSO₄显著提高了小麦籽粒锌含量,而喷施Zn-EDTA效果不显著;土施ZnSO₄和Zn-EDTA,不论条施或均施,虽然会使有效锌（DTPA-Zn）及较高活性锌形态（Ex-Zn、Wbo-Zn）长时间维持较高含量,但对第2季小麦籽粒富锌的后效有限;土施基础上配合喷施ZnSO₄对小麦籽粒锌的含量效果最令人满意。     

Zinc bioavailability and nitrogen concentration in grains of wheat crop sprayed with zinc sulfate,ammonium sulfate,ammonium chloride,and urea

Abstract

It is still unclear if different sources of nitrogen (N) can variably influence grain accumulation of zinc (Zn), N, and phytate. We tested foliar treatments of 0 or 0.25% Zn as zinc sulfate in combination with 0 or 1% N as ammonium chloride, ammonium sulfate or urea sprayed on field-grown-wheat (Triticum aestivum L.) foliage at anthesis and 10 days later. Leaf burning caused by ammonium chloride significantly decreased grain yield. Grain N concentration was the highest in the urea +0.25% Zn treatment. Foliar N application influenced grain Zn concentration only if Zn was included in the spray. Grain phytate concentration was significantly decreased by both N and Zn sprays. Estimated Zn bioavailability in grains was the highest at 0.25% Zn and was not influenced by the N sources. Based on grain yield, grain N concentration, and Zn bioavailability in grains, foliar application of Zn?+?urea is an optimal strategy.     

Alleviation of drought stress in winter wheat by late foliar application of zinc,boron, and manganese

In many regions, drought during flowering and grain‐filling inhibits micronutrient acquisition by roots resulting in yield losses and low micronutrient concentrations in cereal grains. A field and a greenhouse experiment were conducted to study the effect of foliar applications of zinc (Zn), boron (B), and manganese (Mn) at late growth stages of winter wheat (Triticum aestivum L.) grown with or without drought stress from booting to maturity. Foliar applications of Zn, B, and Mn did not affect grain yield in the absence of drought. However, under drought, foliar application of Zn and B in the field increased grain yield (15% and 19%, respectively) as well as raising grain Zn and B concentration, while Zn and Mn sprays in the greenhouse increased grain yield (13% and 10%, respectively), and also increased grain Zn and Mn concentrations. Furthermore, under drought stress both in the field and greenhouse experiment the rate of photosynthesis, pollen viability, number of fertile spikes, number of grains per spike, and particularly water‐use efficiency (WUE) were increased by late foliar application of micronutrients. These results indicate that by increasing WUE foliar application of Zn, B, and Mn at booting to anthesis can reduce the harmful effects of drought stress that often occur during the late stages of winter wheat production. These findings therefore are of high relevance for farmers' practice, the extension service, and fertilizer industry.     

低锌旱地施锌方式对小麦产量和锌利用的影响

西北地区是我国典型的旱地低锌区。本文选择黄土高原中部两个典型地点,通过田间试验,在两个施氮水平下,研究了不施锌、 土施锌、 叶喷锌和土施+叶喷锌4种方式对冬小麦产量、 锌的吸收和累积以及锌肥利用效率的影响。结果表明,不同施锌方式对小麦产量均无显著影响,但均提高了小麦子粒锌含量,提高幅度因施锌方式而异。与不施锌相比,叶喷和土施+叶喷锌肥可使小麦子粒锌含量提高40%左右,平均达到 40 mg/kg;单独土施锌肥虽使土壤有效锌提高3倍左右,但子粒锌含量无显著变化。叶喷锌肥的锌利用效率远高于土施和土施+叶喷处理,每公顷喷施1 kg锌可使小麦子粒锌含量提高6.70~13.04 mg/kg;子粒锌利用率为6.02%~9.40%, 达到土施锌肥的80倍左右;总锌利用率为19.78%~30.91%,是土施锌肥的132~221倍。施氮水平对小麦产量及锌肥利用效率均无显著影响。可见,在旱地低锌区,与土施锌相比,叶喷是更加经济有效、 环境友好的锌肥施用方式,是提高小麦锌营养品质切实可行的措施。     

Increasing root and leaf growth and yield in Mg‐deficient faba beans (Vicia faba) by MgSO4 foliar fertilization

Magnesium (Mg) deficiency reduces yield and quality of crops as Mg is involved in carbohydrate and protein anabolism. Foliar application of MgSO₄ represents a means of ameliorating the nutritional status of crops growing under conditions of deficiency. Foliar Mg application has been demonstrated to increase the chlorophyll concentration and vegetative yield of plants. However, in crop plants used for seed production, the limited number of available studies provides only conflicting results in terms of the efficiency of Mg leaf application on yield and quality. We have examined the effect of increasing Mg foliar application rates on differentially developed leaves and leaf stages with regards to Mg concentration, chlorophyll concentration and biomass formation. Our data reveal that in order to obtain significant effects MgSO₄ concentrations in the spraying solution should be higher than 50 mM, as lower concentrations did not lead to significant changes in the vegetative or generative material. Positive effects of the foliar application on chlorophyll concentration and leaf area were only measured in leaves treated with 200 mM foliar MgSO₄. The application of Mg did not affect the parameters chlorophyll, ion concentration and leaf area in the newly developing leaves, but it had an important influence with regard to yield traits, especially on the formation of pods. The quality of the seeds with regard to the protein concentration was reduced in response to the magnesium deficiency treatment, but the application of foliar magnesium prevented a significant loss of protein.     

Foliar Application of Iron (Fe) Improved the Antioxidant Defense and Cd Accumulation Potential of <Emphasis Type="Italic">Ricinus communis</Emphasis> Under Hydroponic Condition

Heavy metal-polluted water has become a problem for sustainable environment, agriculture, and human health. Phyto-accumulation is an eco-friendly technique for decontamination of metal-polluted water and soil. The efficiency of phyto-accumulation and rhizo-filtration can be enhanced by the application of certain nutrients to accumulator plants. In this study, we focused on the role of iron (Fe) in rhizo-filtration and phyto-accumulation of cadmium (Cd) from polluted water/media, using Ricinus communis plant. Medium was contaminated with 10 ppm Cd while Fe (2.50, 5.00, and 7.50 ppm) was applied both as foliar spray and medium addition separately. Accumulation of Cd and concentrations of soluble proline, phenolic compounds, and chlorophylls were measured in plant tissues. Addition of Fe into media significantly increased biomass in the plants but decreased Cd absorption by roots and its accumulation in other tissues of the plants. Foliar application of Fe, especially 7.5 ppm, significantly increased biomass as well as accumulation of Cd in tissues of the plants. Contents of soluble proline (41.88?±?3.56 ppm) and phenolics (171.00?±?4.98 ppm) in leaves were highly increased by foliar spray of 7.5 ppm Fe on the plants. On the other hand, highest concentrations of free proline (67.00?±?2.00 ppm) and total phenolics (82.67?±?2.52 ppm) in plant roots were observed in 7.5 ppm Fe added to media and as foliar spray, respectively. Strong correlations were observed between phenolics content in roots and leaves with Cd accumulation after foliar application of 7.5 ppm Fe.     

Effect of zinc application methods on apparent utilization efficiency of zinc and phosphorus fertilizers under basmati rice–wheat rotation

To examine the effect of zinc (Zn) application method on the utilization of phosphorus (P) from applied P fertilizer, a field experiment was conducted on basmati rice–wheat rotation with combinations of Zn levels (0, soil application of 2.5 kg Zn ha ^{– 1} and two foliar applications of 2.0 kg Zn ha ^–1) and P levels (0, soil application of 8.7, 17.5 and 26.2 kg P ha ^–1). The highest pooled grain yields of basmati rice and wheat were obtained with soil application of 17.5 kg P ha ^–1 and foliar applications of 2 kg Zn ha ^–1. Foliar applications of Zn increased the P concentration in grain and straw and the total P uptake by basmati rice and the P concentration in flag leaves of wheat significantly, while soil or foliar application of Zn increased the total P uptake of wheat. Phosphorus application increased the Zn concentration in flag leaves, grain and straw of basmati rice and in grain and straw of wheat and the total Zn uptake of both crops. Phosphorus levels up to 17.5 kg P ha ^–1 increased utilization efficiency of soil or foliar application of Zn. Zinc application increased the P utilization efficiency of basmati rice and wheat up to 17.5 kg P ha ^–1 level; foliar Zn application was more effective in a wheat crop than a rice crop.