RESPONSE OF ‘GRANNY SMITH’ APPLE TREES TO FOLIAR TITANIUM SPRAYS UNDER CONDITIONS OF LOW SOIL AVAILABILITY OF IRON,MANGANESE, AND ZINC

The aim of the study was to examine impact of foliar titanium (Ti) sprays on vegetative and reproductive response of apple (Malus domestica Borkh.) trees under conditions of low soil availability of iron (Fe), manganese (Mn), and zinc (Zn). The experiment was conducted during 2005–2006 at a Experimental Station in Isparta region, Turkey, on mature ‘Granny Smith’ apple trees/M.9, planted at a spacing of 3.5 × 1.5 m, on fine-textured soil with neutral reaction, medium status of organic matter, high amounts of available phosphorus (P), potassium (K), and magnesium (Mg), and low availability of Fe, Mn, and Zn. The trees were sprayed with Ti-ascorbate at the green and pink bud stage, petal fall, and 3, 6, and 9 weeks after full bloom, at a rate of 3 g Ti ha^?1 per spray. The efficiency of Ti sprays was compared to combined sprays of Fe, Mn, and Zn [chelated with ethylenediaminetetraacetic acid (EDTA)], applied at the same terms as Ti sprays, at rate of 36 g, 36 g and 24 g per spray, respectively. Trees unsprayed with Ti, Fe, Mn, and Zn served as the control. It was shown that summer leaf Ti concentrations of the trees untreated with Ti were high, varying from 34 to 36 mg kg^?1 dry matter. Foliar Ti sprays increased leaf status of this nutrient but they had no effect on nutrition of essential macro- and microelements, tree vigor, and fruit yield. Mean apple weight, coloring, firmness, soluble solids concentration, and titratable acidity of fruit were not also influenced by Ti sprays. Foliar sprays of Fe, Mn, and Zn improved leaf status of nitrogen (N), Mg, Fe, Mn, and Zn; leaves of the trees sprayed with those micronutrients were also greener, and contained more Fe²⁺ than those of the control plants. Combined sprays of Fe, Mn, and Zn improved tree vigor and fruit yield.     

ROOT FERRIC CHELATE REDUCTASE IS REGULATED BY IRON AND COPPER IN STRAWBERRY PLANTS

In the present experiment, we studied the interaction between copper (Cu) and iron (Fe) in strawberry plants grown in nutrient solutions containing different concentrations of Fe. Plants grown in the absence of iron (Fe0) had the characteristic symptoms of Fe deficiency, with smaller chlorotic leaves, less biomass, acidification of the nutrient solution, and roots that were smaller and less ramified, while no symptoms of Fe deficiency were observed in plants grown with Fe. A greater amount of Cu was found in roots of chlorotic plants than in those grown with Fe, while plants grown with 20 μM of Fe (Fe20) in the nutrient solution had a greater amount of Fe compared with plants from the other treatments. Chlorotic plants (Fe0) and plants grown with the greatest level of Fe (Fe20) had a greater root ferric chelate reductase (FC-R; EC 1.16.1.17) activity compared with the other treatments with 5 or 10 μM Fe in the nutrient solution. The same pattern was obtained for relative FC-R mRNA concentration and for the sum of Fe and Cu contents in shoots (leaves plus crowns). The DNA obtained from amplification of the FC-R mRNA was cloned and several of the inserts analysed by single strand confirmation polymorphism (SSCP). Although there were different SSCP patterns in the Fe20 treatment, all the inserts that were sequenced were very similar, excluding the hypothesis of more than one FC-R mRNA species being present. The results suggest that Cu as well as Fe is involved in FC-R expression and activity, although the mechanism involved in this regulation is unknown so far. Both small contents of Fe and Cu in plants led to an over-expression of the FC-R gene and enhanced FC-R activity in strawberry roots.     

Effect of titanium on the activity of lipoxygenase

Lipoxygenase was extracted from untreated tomato fruits and those treated with titanium ascorbate (TITAVIT) at the last stage of ripening. It was found that titanium (Ti) had a activating effect on lipoxygenase so that the development of red pigments was inhibited to some extent. The addition of Titavit to the reaction mixture resulted in a lag period of about 1 minute to lipoxygenase‐catalyzed linoleic acid oxidation, whereas, incubation of this complex with enzyme extract for 10 minutes significantly increased enzyme activity. Activation of lipoxygenase by Ti was confirmed when addition of titanium chloride also increased the enzyme activity. Titanium also increased the stability of lipoxygenase preparations when kept under refrigeration.     

Interaction of Different Iron Chelates with an Alkaline and Calcareous Soil: A Complementary Methodology to Evaluate the Performance of Iron Compounds in the Correction of Iron Chlorosis

Abstract

A great number of studies have shown that the stability of iron chelates as a function of pH is not the unique parameter that must be considered in order to evaluate the potential effectiveness of Fe‐chelates to correct iron chlorosis in plants cultivated in alkaline and calcareous soils. In fact, other factors, such as soil sorption on soil components or the competition among Fe and other metallic cations for the chelating agent in soil solution, have a considerable influence on the capacity of iron chelates to maintain iron in soil solution available to plants. In this context, the aim of this work is to study the variation in concentration of the main iron chelates employed by farmers under field conditions—Fe‐EDDHA (HA), Fe‐EDDHMA (MA), Fe‐EDDHSA (SA), Fe‐EDDCHA (CA), Fe‐EDTA (EDTA), and Fe‐DTPA (DTPA)—in the soil solution of a calcareous soil over time. To this end, soil incubations were carried out using a soil:Fe solution ratio corresponding to soil field capacity, at a temperature of 23°C. The soil used in the experiments was a calcareous soil with a very low organic matter content. The variation in concentration of Fe and Fe‐chelates in soil solution over time were obtained by measuring the evolution in soil solution of both the concentration of total Fe (measured by AAS), and the concentration of the ortho‐ortho isomers for Fe‐EDDHA and analogs or chelated Fe for Fe‐EDTA and Fe‐DTPA (measured by HPLC). The following chelate samples were used: a HA standard prepared in the laboratory and samples of HA, MA, SA, CA, Fe‐EDTA, and Fe‐DTPA obtained from commercial formulations present in the market. The percentage of iron chelated as ortho‐ortho isomers for HAs was: HA standard (100%); HA (51.78%); MA (60.06%); SA (22.50%); and CA (27.28%). In the case of Fe‐EDTA and Fe‐DTPA the percentages of chelated iron were 96.09 and 99.12, respectively. Results show that it is possible to classify the potential effectiveness of the different types of iron chelates used in our experiments as a function of two practical approaches: (i) considering the variation of total iron in soil solution over time, MA is the best performing product, followed by HA, CA, SA, DTPA, EDTA, and ferrous sulfate in the order listed and (ii) considering the capacity of the different iron chelates to maintain the fraction of chelated iron (ortho‐ortho isomers for HA, MA, SA, and CA and total chelated iron for EDTA and DTPA) in soil solution, the order is: SA > CA > HA > MA > EDTA ≈ DTPA. This result, that is related to the nature of the chelate and does not depend on the degree of chelated Fe in the products, indicates that SA and CA might be very efficient products to correct iron chlorosis. Finally, our results also indicate the suitability of this soil incubation methodology to evaluate the potential efficiency of iron compounds to correct iron chlorosis.     

以二甲基-正丁基-磺化木质素基氯化铵为模板剂制备多孔钛材料

以碱木质素为原料合成二甲基-正丁基-磺化木质素基氯化铵两性表面活性剂,并以其为模板剂采用溶胶-凝胶法制备多孔钛材料。结果表明:二甲基-正丁基-磺化木质素基氯化铵含氮量为1.360%,含硫量1.860%;红外光谱和1H NMR证实产物中存在磺化和季胺的化学结构。溴酚蓝和亚甲基蓝实验表明二甲基-正丁基-磺化木质素基氯化铵具有两性化合物结构,溶于碱性、中性和稀酸溶液。随着模板剂与钛酸正丁酯的质量比增加,多孔钛材料的比表面积加大;继续增加模板剂的量,多孔钛材料的比表面积下降。多孔钛材料孔径分布范围较宽,为晶态,主要以锐钛矿形式存在。煅烧后的多孔材钛料中有TiO2特征吸收峰,也有少量残留的木质素。当二甲基-正丁基-磺化木质素基氯化铵与钛酸正丁酯的质量比为0.65∶1、煅烧温度为450 ℃时,可得到最大比表面积、锐钛矿晶态的多孔钛材料。      

Influence of soil pH and application of zinc on the yield and uptake of selected nutrient elements by rice

Abstract

Rice grown on a recently water‐leveled Crowley silt loam that contained less than 1.8 μg g^‐1 of 0.1 N HCl‐extractable Zn with pH levels ranging from 6.8 to 7.7, responded to Zn application. Each kg ha of applied Zn as Zn chelate, 14.2 % Zn, resulted in increases of +673, +477, and +2026 kg rice ha^‐1 at pH 6.8, 7.3, and 7.7, respectively. There was a critically low concentration of Zn in rice plants at the midtillering, first joint, and panicle differentiation stages of plant development when no Zn was applied. A yield response to applied Zn was obtained when the concentration of Zn in rice tissue was less than 15 μg g^‐1.

Application of Zn resulted in a significant increase in the uptake of N by rice plants at each of the three stages of plant development. Application of Zn also resulted in relatively large and significant increases in the uptake of Zn from the soil irrespective of soil pH. The uptake of Zn by rice plants at each of the growth stages showed a two‐ to three‐fold increase following Zn application when soil pH was 6.8 and 7.3. Also, the uptake of Zn by rice plants following Zn application showed a four‐fold increase at midtillering, a five‐fold increase at first joint, and a six‐fold increase at panicle differentiation, respectively, when soil pH was 7.7.     

TiO_2光催化剂改性形态及其在废水中降解作用的研究进展

综述了光催化剂二氧化钛(TiO_2)的各种改性形态,包括钛白粉、金属及金属离子掺杂TiO_2、纳米级TiO_2以及其它形态TiO_2对废水中污染物的降解作用。     

测定食品中二氧化钛时产生白色沉淀的原因分析

按照《食品安全国家标准食品中二氧化钛的测定》(GB 5009.246—2016)第二法二安替比林甲烷比色法测定食品中二氧化钛的含量时经常会产生白色沉淀的现象,从而导致测量数据产生较大偏差,并对测试结果准确度产生较大影响。本文分别从混合酸的不同比例、显色剂和助溶剂的用量以及不同消解温度等方面探究分析了白色沉淀产生的原因,提出了解决措施;并使用离子色谱仪和电感耦合等离子体质谱仪进行相应分析,确定了白色沉淀的主要成分为硫酸盐。     

Technical note: using an automated head chamber system to administer an external marker to estimate fecal output by grazing beef cattle

The objective of this experiment was to determine if titanium dioxide (TiO₂) dosed through an automated head chamber system (GreenFeed; C-Lock Inc., Rapid City, SD, USA) is an acceptable method to measure fecal output. The GreenFeed used on this experiment had a 2-hopper bait dispensing system, where hopper 1 contained alfalfa pellets marked with 1% titanium dioxide (TiO₂) and hopper 2 contained unmarked alfalfa pellets. Eleven heifers (BW = 394 ± 18.7 kg) grazing a common pasture were stratified by BW and then randomized to either 1) dosed with TiO₂-marked pellets by hand feeding (HFD; n = 6) or 2) dosed with TiO₂-marked pellets by the GreenFeed (GFFD; n = 5) for 19 d. During the morning (0800), all heifers were offered a pelleted, high-CP supplement at 0.25% of BW in individual feeding stanchions. The HFD heifers also received 32 g of TiO₂-marked pellets at morning feeding, whereas the GFFD heifers received 32 g of unmarked pellets. The GFFD heifers received a single aliquot (32 ± 1.6 g; mean ± SD) of marked pellets at their first visit to the GreenFeed each day with all subsequent 32-g aliquots providing unmarked pellets; HFD heifers received only unmarked pellets. Starting on d 15, fecal samples were collected via rectal grab at feeding and every 12 h for 5 d. A two-one sided t-test method was used to determine agreement and it was determined that the fecal output estimates by HFD and GFFD methods were similar (P = 0.04). There was a difference (P < 0.01; Bartlett’s test for homogenous variances) in variability between the dosing methods for HFD and GFFD (SD = 0.1 and 0.7, respectively). This difference in fecal output variability may have been due to variability of dosing times-of-day for the GFFD heifers (0615 ± 6.2 h) relative to the constant dosing time-of-day for HFD and constant 0800 and 2000 sampling times-of-day for all animals. This research has highlighted the potential for dosing cattle with an external marker through a GreenFeed configured with two (or more) feed hoppers because estimated fecal output means were similar; however, consideration of the increased variability of the fecal output estimates is needed for future experimental designs.     

掺镍TiO2的微波合成及催化降解有机废水

以氯化镍和硫酸钛为原料,以十二烷基硫酸钠为表面活性剂,通过直接投料微波合成了掺镍二氧化钛(Ni2+TiO2).以催化降解甲基橙为模型来考察其可见光光催化活性,研究了Ni的掺杂量、热处理温度、双氧水投加量、溶液酸度及掺Ni2+TiO2光催化剂用量等因素对光催化性能的影响.结果表明,当Ni2+/TiO2复合物的直接投料摩尔比为0.8％,在500℃的温度下热处理2h,催化剂用量为1.0 g/L,H2O2投加量为3 mL/L,溶液pH 5的条件下,可见光催化效果最好,此时2 mg/L的甲基橙溶液经光催化降解40min后,降解率达到94.5％.