Foliar application of micronutrients enhances crop stand, yield and the biofortification essential for human health of different wheat cultivars

Globally about half of the world’s population is under micronutrient malnutrition due to poor quality food intake.To overcome this problem,fortification and biofortification techniques are often used.Biofortification is considered a better option than fortification due to the easy control of nutrient deficiencies present in daily food.This field experiment was conducted to evaluate the effects of foliar application of a micronutrient mixture(MNM)consisting of zinc(Zn),iron(Fe),copper(Cu),manganese(Mn)and boron(B)on yield and flour quality of wheat.The results show the effectiveness of foliar feeding for growth and yield parameters,in addition to the enriching of wheat grains with Zn,Cu,Fe,Mn and B.Compared to the control without foliar feeding,foliar application on wheat crop increased tillering ability,spike length,grain yield and the contents of Zn,Cu,Mn,Fe and B by 21,47,22,22 and 25%in wheat flour,respectively.Therefore,foliar feeding of micronutrients could be an effective approach to enrich wheat grains with essential nutrients for correcting malnutrition.

Role of micronutrients in staging of nonalcoholic fatty liver disease:A retrospective cross-sectional study

BACKGROUND Nonalcoholic fatty liver disease(NAFLD) presents high incidence throughout the world and has been progressively increasing in prevalence. This disease has a heterogeneous natural history, including simple steatosis, nonalcoholic steatohepatitis(NASH), and cirrhosis. The factors that determine its evolution to more severe forms of the disease are still poorly understood, and micronutrients with antioxidant potential may be involved in the pathophysiology of the disease.AIM To evaluate the relationship between serum levels of micronutrients and the severity of NAFLD.METHODS A retrospective, observational and cross-sectional study was conducted. This study included all patients undergoing bariatric surgery who experienced liver biopsy during the procedure, and had serum levels of micronutrients(vitamin D,vitamin B12, zinc, iron, and magnesium), which was assessed in a preoperative evaluation conducted at a reference center in southern Brazil.RESULTS A total of 614 patients were analyzed, of which 93% had steatosis, 70.7% had NASH, and 49.3% had some degree of fibrosis. Serum levels of vitamin D were negatively correlated with the severity of steatosis and NASH, and serum levels of vitamin B12 were positively correlated with the severity of steatosis and fibrosis. The other micronutrients showed no association with NAFLD staging.CONCLUSION Serum levels of vitamin D are inversely related to the severity of steatosis and NASH, and serum levels of vitamin B12 are higher in more advanced stages of simple steatosis and liver fibrosis. Serum levels of zinc, iron, and magnesium were not associated with NAFLD severity.

Embracing cancer immunotherapy with vital micronutrients

Immunotherapy is now commonly prescribed to cancer patients,but autoimmune-related adverse events are considerable.For severe,life-threatening side effects,cessation of therapy seems unavoidable,let alone intensive medical care required for patching up the adverse events.Even without serious adverse events,the response rates are too low and various combinatory regimens have been tried.However,toxicities are also added on,unless the adjuvant agents have remarkably few side effects.Actually,micronutrients are usually taken by a majority of cancer patients as nutritional support or to boost the immune function,let alone hoping to counteract treatment side effects.Recent studies have shown that combinations of micronutrients exert pleiotropic effects in controlling tumor growth and metastasis by modulating the tumor microenvironment,enhancing gut microbiota immune functions,and providing adjunct nutritional support to micronutrient deficient cancer patients.A higher than recommended dietary allowance micronutrient dose is proposed to reduce the toxic free radicals generated as a result of immunotherapy and tumor metabolism.This is not only helpful for managing treatment side effects but also enhancing treatment efficacy.As micronutrient supplementation is also useful to improve patients’quality of life,prolong survival,and sustain compliance to immunotherapy,further investigations are mandatory.

Effect of Foliar Application of Micronutrients on Fruit Quality of Peach

This experiment was conducted to study the effect of foliar spray of micronutrients on quality of peach fruits at Horticulture Farm, University of Agriculture Peshawar during 2010. The experiment was conducted in randomized complete design with six treatments and four replications on peach orchards (early grand). Our pre-treatment soil analysis showed silt loam soil class, alkaline and calcareous in nature and adequate in organic matter. The soil was deficient in P, Zn, Fe and B, whereas adequate in Mn and Cu. The fruit quality was evaluated and maximum fruit length, diameter and yield were noted in T6 (Zn + Cu + Fe + Mn + B). The juice pH decreased and the juice acidity increased in a linear fashion after foliar spray of micronutrients. The total soluble solids of fresh fruit juice ranged 7.01%-8.88% and vitamin C ranged from 4.80%-7.90% after foliar spray. So the foliar spray of micronutrients significantly (P ≤ 0.05) affected the quality of peach fruit.

Foliar Application of Micronutrients Enhances Wheat Growth, Yield and Related Attributes

Wheat is one of the most essential foods in the world. To increase its productivity, nutrient management is one of the most important factors. To assess the possible role of micronutrients in improving wheat yield, an experiment was conducted to evaluate the wheat performance by foliar application of micronutrients. Treatments consist of T1 = No spray, T2 = Spraying plants with tube well water (control), T3 = Spraying plants with 1.6 kg FeSO4/100 L water/acre, T4 = Spraying plants with 3 kg ZnSO4 (21%)/100 L water/acre, T5 = Spraying plants with 1 kg MnSO4/100 L water/acre, T6 = Spraying plants with (FeSO4 + MnSO4), T7 = Spraying plants with (FeSO4 + ZnSO4), T8 = Spraying plants with (ZnSO4 + MnSO4), and T9 = Spraying plants with (FeSO4 + ZnSO4 + MnSO4). Results showed that foliar application of micronutrients substantially improved plant height, spike length cm, spikelets/spike, grains/spike, test weight, Tillers m-2, grain and biological as well as harvest index of wheat. Among treatments, foliar application of FeSO4 + ZnSO4 + MnSO4 remained comparatively better regarding yield related attributes of

Effects of Sulfur and Manganese Micronutrients on the Yield of Soybean Varieties

In this article, it is given about lengthening of praxis period, stem and leaf growth, leaf surface, number of stems and weight than the control variant soybean varieties, and the yield and grain quality of soybean varieties are significantly higher when the three types of sulfur and manganese on background of mineral fertilizers are applied in suspension in the condition of meadow-swamp soil. In the soybean varieties, mineral fertilizers were used in the variant with an additional yield of around 5 - 12 c/ha compared to the control. According to the norms of the manganese element, around 7 - 20 c/ha;when using sulfur, the yield in soybean varieties is around 8.0 - 18.0 c/ha. On the background of mineral fertilizers, grain quality has changed due to micronutrients. Protein content in the “Orzu” variety increased by 3.1% - 8.4% when manganese and sulfur elements were used;in the “Nafis” variety, the protein content was found to increase by 6.1% - 8.5%.

Effects of Micronutrients on Oxidative Stress and Islet Function in Type 1 Diabetes Mellitus Rats:Relationships to Th2 Type Cytokines,Interleukin-4,and Interluekin-10

To observe the effects of the micronutrients on oxidative and autoimmune destruction of islets so as to prevent a person from the onset and development of type 1 Diabetes Mellitus （T1DM）, the interleukin-4 and interleukin-10 expressions of lymphocytes in peripheral blood and spleen of T1DM rats were determined by flow cytometry. GSH-Px activity and MDA level in the rats＇ pancreas were measured using biochemical methods. The insulin contents in serum and β cell insulin secret storage were tested by RIA and IHC, respectively. There was an increase in the percentages of IL-4 and IL-10 positive lymphocytes in the peripheral blood and spleen of the groups of rats supplemented with various combinations of micronutrients（p 〈0.01 and p 〈0.05, respectively） ; the blood glucose concentration decreased （p 〈 0. 05 ） ; both the functional β cell in islets and the insulin content in pancreatic tissue increased （p 〈 0. 05 and p 〈0. 01 ） ; the GSH-Px activity and MDA level of pancreas in the rats enhanced and decreased respectively（p 〈0. 01 and p 〈 0. 05）. The results suggest that micronutrients may alleviate the islet lesions by upregulating the expressions of IL-4 and IL-10 and lowering oxidative stress in diabetic rats .

Double Burden of Malnutrition: Toxic Metals in Breast Milk May Limit the Amounts of Micronutrients Available to Infants through Breast Milk

Background: The amounts of micronutrients in the diets of infants, and the factors that influence them needs to be monitored at the population level in order to avert detrimental developmental defects that impose lifetime-limitations on an infant’s regulatory and defense systems. This study therefore, sought to evaluate if increasing levels of the toxic metals, Hg, Pb and Cd in breast milk will result in reducing amounts of the micronutrients Zn, Se and Cu in breast milk. Methods: Breast milk samples of 114 women living in two mining areas (57 women each) in Ghana, whose babies’ amounts of breast milk intake at three months postpartum, and amounts of toxic metals had previously been determined in a prospective study, were analyzed for micronutrients by a combination of acid and microwave digestion, and quantifications were by two different modes (hydrogen and helium) of Octapole Reaction System Inductively Coupled Plasma Mass Spectrometer (7500 ce. Agilent), equipped with an ASX-510 Auto-sampler (Cetac). Results: All the breast milk specimen collected contained detectable amounts of Cu, Zn, both at levels less than have been previously reported, and Se. For specimen that did not contain Pb the amount of Se ranged from about 110 to 245 ng/g of milk, however, as the amount of Pb increased, the corresponding highest detected amount of Se reduced steeply, resulting in a right-angle triangle-shaped scatter plot. Similar relationships were observed between other toxic metals and micronutrients studied. A curve fitting regression analysis showed significant quadratic and cubic relationships between the amounts of Hg and Se, as well as between Pb, As and Cu. Conclusion: The results clearly suggest a double burden of malnutrition in these mining areas, where high loads of maternal toxic metals in breast milk, related significantly with a progressive reduction in the amounts of the micronutrients Cu and Se in breast milk, potentially reducing in infants’ intake of these micronutrients.

Content of Genome-Protective Micronutrients in Selected Fresh and Processed Foods in the Australian State of Victoria

Maintenance of genome stability by preventing DNA damage is crucially important for counteracting carcinogenesis and age-associated diseases. The levels of niacin, vitamin E, vitamin B12, folate, β-carotene, retinol, magnesium, calcium, selenium and zinc, which are key micronutrients considered to be important in the prevention of genome damage, were measured in a range of fresh and processed foods available to consumers in the state of Victoria, Australia. Some of the richest dietary sources of the micronutrients, expressed as a percentage of the (Australian) recommended dietary (daily) intake for adults per 100 g of food, were: wheat germ oil (vitamin E, 1400%);oyster (vitamin B12, 2666%);rice bran (niacin, 296% and magnesium, 212%);chicken liver (folate, 354%);beef liver (retinol, 1777%);golden sweet potato (β-carotene);brazil nuts (selenium, 404%);wheat bran (zinc, 575%);skim milk powder (calcium, 116%). The data will be useful for formulating dietary guidelines for micronutrient intake as well as for formulating functional foods enriched in key micronutrients.

Effect of Phosphorus Level on the Availability of Some Micronutrients in a Vertic Argiudoll Soil under No-Tillage System in Argentina

There are interactions between phosphorus （P） and some micronutrients which can affect their availability if P is applied as a fertilizer in high concentrations. There are many mechanisms of interactions between P and micronutrients and changes in pH values caused by phosphate fertilization is one of them. These interactions between nutrients might be more pronounced under a no-tillage system which produces stratification and accumulation of few mobile nutrients as P in the surface horizons due to the lack of soil removement. The objectives of this study were： （1） to evaluate the effect of P concentration on the availability ofCu, Zn, Fe and Mn in soil under no-tillage system; （2） to produce maps of nutrients availability and to analyze whether an interaction between nutrients spatial distribution exists. The study was carried out in Parana, province of Entre Rios, in a soil classified as Vertic Argiudol in two consecutive growing seasons （2006 and 2007）. A plot of 1 （one） hectare under no-tillage system with a double-cropped wheat-soybean rotation in sequence （soybean sowing after wheat harvest） was sampled by the grid methods. The results of this study suggest which tillage regime and phosphate fertilization increased P levels in superficial horizons and this produced a negative relationship between micronutrients and P. Regarding the nutrients map distributions, the negative interaction between P and micronutrients was clearly seen in the case ofFe_ Mn and Zn.

Influence of Whitefly, Bemisia tabaci （Gennadius）, Infestation on Micronutrients Content in Some Vegetable Plants in a Greenhouse

The whitefly is well-known as a serious pest on many economic vegetable crops. It feeds by absorbing plant sap which includes many important nutrients for plant,＇;. An experiment was carried out to investigate the effect of whitefly, B. tabaci （Gennadius）, infestation on the micronutrients; Manganese, Zinc, Copper and Molybdenum, in three plant varieties; cantaloupe （Cucumis melo L.）, cucumber （Cucumis sativus L.） and zucchini （Cucurbita pepo L.） that were planted in a greenhouse at the Agricultural Research Station in Hada AI Sham, north east of Jeddah in Saudi Arabia. Results of this investigation showed that, in general whitefly infestation reduced micronutrients content in plants. Mean content of total micronutrients in each of infested cucumber and zucchini were less than control plants significantly, but the infestation did not vary total micronutrients content in cantaloupe significantly. Feeding of the whitefly reduced mean content of each Zinc and Molybdenum in infested plants significantly, but did not vary Manganese and Copper content significantly.

The Effects of Essential Minerals in Different Cations and Anion Forms on Assimilation of Macro and Micronutrients in Soybean Leaves

In our present study, we have investigated the acquisition of minerals into soybean leaves as affected by application of various minerals in different forms of positive and negative ions. A greenhouse experiment was conducted including the following 11 treatments applied to the soil: potassium nitrate (KNO3), potassium iodide (KI), potassium chloride (KCl), sodium chloride (NaCl), calcium, magnesium and ammonium nitrates [Ca(NO3)2, Mg(NO3)2 and NH4NO3] and ammonium dihydrogen phosphate NH4(H2PO4), Na2SO4, ammonium sulfate (NH4)2SO4, and disodium phosphate Na2(HPO4). Besides essential minerals, KI was also included as part of this comprehensive study, since according to some reports, molecular iodine (I2) and KI may have positive effect on growth and increased stress tolerance in some species of plants. Soybean seeds were sown in pots arranged in twelve groups/3 replicates in each group including control. At V3 stage the plants were treated with 30 mmol/pot of the proper chemicals. Ten days after the treatments, leaves were sampled and were dried, analyzed for 5 macro (K, P, S, Ca & Mg) and micronutrients (B, Cu, Fe, Mn, Zn and Na). The results showed that of all the 11 treatments, KI (T4) application increased the maximum number of mineral nutrients in leaves, which increased K by 31.9, Mg by 8, P by 60.8, S by 38.7 respectively. KI treatment also reported increased micro minerals by B, Cu, and Zn were 53.6%, 36.3% and 10.8% respectively. Similarly, KNO3 (T1) application increased several macro and micronutrients in leaves. We made an attempt to investigate the effects of various other cations like K1+ vs Na1+, and NH+ 4, Ca2+ vs Mg2+;and Anion comparisons I1- vs NO1-3, Cl1-, H2PO14;?SO2-4? ?vs (HPO4)2- in the present investigation. After reviewing our results, of all the 11 (eleven), treatments studied in our present study, T1 (KNO3), T4 (KI) and T10 Ca(NO3)2 applications proved to be the most efficient treatments by affecting the uptake of several minerals in soybean leaves.

Response of different corn populations to fertigated nitrogen and certain micronutrients in sandy soil

A field study was conducted during 2008 and 2009 at El-Khattara farm station, Zagazig Uni-versity, Sharkyia, Egypt (30°36' N, 32°15' E) to determine the effect of three N rates (214, 273, and 333 kg N ha-1), four micronutrients spray treatments (Check, Zn, Mn, and Zn + Mn), and three planting density levels ( 4.76, 5.71, and 6.66 plant m-2) on growth and grain yield of corn (Zea mays, L). The soil was sandy (Entisols) and groundwater was used for irrigation. Response to N was maximized to 214 kg ha-1 without a significant effect on most growth traits and grain yield. Agronomic efficiency of N use for grain yield was negatively related to N rate (r2 = 0.49). Application of micronutrients had no ef-fect on most growth and yield characters except a significant increase by 9.5, 8.7, and 9 % in plant weight (g plant-1), biomass yield (kg m-2), and N agronomic efficiency for biomass yield, respectively. Growth was decreased by in-creasing plant density without affecting harvest index, agronomic efficiency, biomass yield, and grain yield. The application of Zn to the highest maize plant density increased grain yield by 16 % as compared to the check. It is recommended, as predicated by the linear model, that N ferti-gation rate should be around 220 kg ha-1 with plant density of 6.66 plant m-2 accompanied by Zn application for maximum irrigated corn grain yield in sandy soil. Abbreviations: DAS, days after sowing;LA, leaf area;LAI, leaf area index;RPP, relative photosynthetic potential;HI, har-vest index;BW, plant weight g plant-1, GYP, grain yield g plant-1, BYM, biomass yield kg m-2, GYM, grain yield kg m-2, NAE, nitrogen agro-nomic efficiency.

Evaluation and Comparison of DTPA Extractanting Methods for Available Cationic Micronutrients in Non-acidic Soils of Andhra Pradesh,India

The research work was carried out to compare and evaluate the extractability of cationic micronutrients(Zn,Cu,Fe and Mn)using widely employed diethylene triamine pentaacetic acid(DTPA)-triethanolamine(TEA)-CaCl2 method with that of multinutrient extractant(ammonium bicarbonate(AB)-DTPA)in Inceptisols,Alfisols and Entisols in the erstwhile united Andhra Pradesh.The percent variation of extraction of Zn was higher in soils with DTPA-TEA-CaCl2 over AB-DTPA method in all the soil orders(types)in the range of 35.3% to 46.2%.AB-DTPA extracted high amounts of Cu to an extent of 10%-21% in Entisols and Alfisls,respectively.In Inceptisols both extracatants extracted equal amounts of Cu.AB-DTPA extracted high amounts of Fe 13% and 18% in Alfisols and Entisols compared to that of DTPA-TEA-CaCl2 method and DTPA-TEA-CaCl2 method was good extract for Fe in Inceptisols and even for Mn in Alfisols.The amounts of micronutrient contents extracted were found to be highly and significantly correlated with soil properties like electrical conductivity(EC)and organic carbon(OC).The individual micronutrient contents of Zn,Cu and Fe extracted by DTPA-TEA-CaCl2 methods were found to be highly correlated with that of AB-DTPA extractant.However,such correlation was not observed for Mn extraction when all soils were grouped.

Evaluation of Combined Effect of Micronutrients (ZnSO4 + Borax) and Fungicides to Control the Purple Blotch Complex of Onion (Allium cepa)

Ten different treatments viz. T0 = Control, T1 = Micronutrients (ZnSO4 + Borax), T2 = Rovral 50 WP + Micronutrients, T3 = Dithane M-45 + Micronutrients, T4 = Ridomil Gold + Micronutrients, T5 = Cupravit + Micronutrients, T6 = Rovral 50 WP, T7 = Dithane M-45, T8 = Ridomil Gold and T9 = Cupravit were evaluated against the purple blotch complex disease of onion caused by Alternaria porri and Stemphylium vesicarium in field condition for bulb yield. In lab condition, all the tested chemical fungicides (Rovral 50 WP, Dithane M-45, Ridomil Gold MZ-72 and Cupravit 50 WP) significantly reduced mycelial growth of both pathogens. Among the fungicides, Rovral 50 WP @ 0.2% reduced the highest radial mycelial growth followed by Dithane M-45 @ 0.45% and Ridomil Gold MZ-72 @ 0.2% compared to control. In field experiment, application of Rovral 50 WP @ 0.2% along with micronutrients showed significant effect in reducing disease incidence and severity which significantly increased bulb yield and yield contributing characters.

Distribution of Micronutrients in Selected Pedons of Sugarcane Growing Vertisols in Northern Karnataka State of India

Micronutrients deficiency is a major limiting factor for increasing yield and productivity of major crops in India. Recent findings of multiple micronutrients interactions have evidenced the indispensable role played by micronutrients in plant nutrition. Though they are needed in smaller quantities, however, their availability in the Right amount, at the Right time, and for the Right crop has been a major limiting factor for improving the productivity and yield of Sugarcane in northern Karnataka state of India. This study was conducted to assess the level of Boron (B), Copper (Cu), Iron (Fe), Manganese (Mn) and Zinc (Zn) deficiencies in Sugarcane growing Vertisols of six micro-watersheds in northern Karnataka. The six selected micro-watersheds were intensively traversed and six representative pedons of standard dimensions were dug and horizon-wise soil samples collected and analyzed for various micronutrients using standard analytical procedures. Based on the optimum critical levels of micronutrients, B, Fe and Zn were deficient, ranging from 0.15 - 0.64, 1.23 - 5.92 and 0.11 - 0.64 mg⋅kg−1 respectively while Cu and Mn were in excess, ranging from 1.54 - 7.62 and 1.22 - 7.03 mg⋅kg−1 respectively. The distribution of B, Fe and Zn were inversely proportional to soil depth whereas that of Cu and Mn were irregular, which is an indication of the influence of pedoturbation in these soils. With the current rate of agricultural intensification, unbalanced fertilizer application, depletion of nutrients and no replenishment by smallholders, the results reveal that the current deficiency levels may increase further if appropriate and timely actions are not taken. We therefore recommend the use of site-specific nutrient management, balanced fertilizer application and good agronomic practices. These can enhance nutrient use efficiency in the study area.

Breast Milk Micronutrients in Lactating Mothers from Ribeirao Preto(SP),Brazil

Breast milk is the ideal food for infants and should be consumed as the exclusive food for the first six months and then be complemented up to two years of age. The aim of this study is to determine breast milk’s content of macro and micronutrient in lactating mothers from the Ribeir?o Preto (SP) region, in Brazil. A cross-sectional study was conducted with breast milk samples of 70 mothers from the city of Ribeir?o Preto (SP). The samples were analyzed in order to determine iron, copper, zinc, calcium and magnesium concentrations. They were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The study was approved by the Research Ethics Committee of the University Hospital, Faculty of Medicine of Ribeir?o Preto, University of S?o Paulo, and all subjects gave written informed consent to participate. The current study revealed that all 70 lactating mothers were healthy and delivered babies more than 38 weeks gestation;71.4% of them were younger than 30 years and 47.1% were primiparae. The iron, copper, zinc, calcium and magnesium concentrations detected in milk were 2.7 ± 0.4, 0.4 ± 0.02, 3.6 ± 0.2, 142 ± 21.6 and 39.8 ± 4.2 mg/L, respectively. Therefore, it can be concluded that in the present sample, except for calcium, all other mineral concentrations were adequate for the infant’s requirements according to the Dietary Reference Intake (DRI).

Application of Micronutrients in Rice-Wheat Cropping System of South Asia

Rice-wheat cropping system (RWCS) is one of the most important cropping systems in South Asia. However, sustainability of this system is under threat owing to several factors, of which deficiency of micronutrients particularly zinc (Zn), boron (B) and manganese (Mn) is one of the major problems. Continuous rotation of rice and wheat, imbalanced fertilizer use and little/no use of micronutrient-enriched fertilizers induce deficiencies of Zn, B and Mn in the RWCS of South Asia. Here we review that (i) imbalanced fertilizer use and organic matter depletion deteriorate soil structure resulting in low efficiency of applied macro- and micro-nutrients in RWCS.(ii) The micronutrients (Zn, B and Mn) are essentially involved in metabolism of rice and wheat plants, including chlorophyll synthesis, photosynthesis, enzyme activation and membrane integrity.(iii) Availability and uptake of Zn, B and Mn from rhizosphere depend on the physico-chemical soil properties (which differ under aerobic and anaerobic conditions) including soil pH, soil organic matter, soil moisture and interaction of these micronutrients with other nutrients.(iv) Plant ability to uptake and utilize the nutrients is affected by several plant factors such as root architecture, root hairs, transport kinetics parameter and root exudates.(v) Crop management and application of these microelements can help correct the micronutrients deficiency and enhance their grain concentration.

Effects of Nitrogen Fertilization and Genotype on Rice Grain Macronutrients and Micronutrients

High nitrogen （N） input features China＇s intensive rice production system. To elucidate N and genotype effects on accumulation of macronutrients and micronutrients in grains of japonica rice, and to discuss its significance in rice production, a three-year field experiment involving six japonica rice varieties and seven N treatments were performed. Macronutrients （Ca, Mg, K, and Na） and micronutrients （Cu, Fe, Mn, and Zn） concentrations in brown and milled rice were measured using an atomic absorption spectrophotometer. For macronutrients, no consistently significant effect of N was detected in both brown and milled rice. For micronutrients, N showed significant effect, especially in lowering Zn accumulation in brown and milled rice. In addition, N tended to increase Fe concentration in milled rice. Genotype showed larger effect on distribution of minerals in milled rice than N. The high-yielding variety, Wuyunjing 7, accumulated larger proportion of Mg, K, and Zn in the milled rice as compared with the other five varieties and could be of value for rice breeding programs aiming at high nutritional quality. The results demonstrated differences in response to N between macronutrients and micronutrients, and are of significance for coping with ＇hidden hunger＇ both in humans and crops through agronomical practices.

Growth Responses of Trees to Micronutrients and Their Feedback Effect in Various Soil-Forest Ecosystems of Taihu Lake Region

Vector analysis technique and ecological sequential comparison methods were adopted to study tree growth response to the micronutrients, B, Mo, Cu, Zn, Fe, and Mn, in soils derived from various parent materials in the forest area of Taihu Lake region in southeast China. The results showed that the dry weight of individual current-year needle of Chinese fir (Cunninghamia lanceolata) grown on the soi1 derived from granite parent rock was increased by 8% and 13% in comparison with that grown on the soils derived from sandstone and ash-tuff parent rock, respectively. And such dry weight of loblolly pine (Pinus taeda) grown on the soil derived from sandstone parent rock was increased by 21% in comparison with that on the soil derived from ash-tuff parent rock. One of the reasons for those results was that micronutrients content in the soil derived from ash-tuff parent rock were not sufficient to meet the requirement of the growth of Chinese fir and loblolly pine, i.e., micronutrients in soil were deficient and/or induced deficient. The amounts of Cu, Zn, Fe, and Mn uptake by Chinese fir and loblolly pine were in agreement with the contents of available micronutrients in soil respectively, except for B and Mo. Meanwhile, there might exist an "antagonism" between the uptake of B versus Mo by trees, although more studies are needed to confirm it. Regression analysis indicated that amount of a soil available micronutrient was correlated to the type of parent material and its total amount in the forest floor, except for B. The F test identified that the correlation of each equation reached the significant level to different extents, respectively. The t test confirmed that amount of available forms was mainly depended on the type of parent material for Mo, Cu, Zn and Mn but on the forest floor for Fe. There was a feedback effect of forest stand on the amount of soil available micronutrients. The ability of accumulating available micronutrients in soil was better by the sawtooth oak (Quercus acutissima) stand than by the Chinese fir stand (except for B). The ability of accumulating available Zn, Fe, Mn and Mo in soil was better by the Chinese fir stand than by the loblolly pine stand, while as for available B and Cu, by the latter was better than by the former. When discussing the effect of forest stand on the amount of soil available micronutrients, not only the amount of micronutrient in the forest floor and the parent materials but also the amount of micronutrient taken up by current-year needles have to be considered.