Critical nutrient concentrations and antagonistic and synergistic relationships among the nutrients of NFT‐grown young tomato plants

Critical concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), and manganese (Mn) with respect to dry matter yield end antagonistic and synergistic relationships among these nutrients were studied in which tomato (Lycopersicon esculentum L.) was grown in recirculating nutrient solution (NFT). Increments of nutrient elements in the nutrient solution increased the proportional rate of the corresponding nutrient elements. Increasing levels of N negatively correlated with plant P and positively correlated with Ca, Fe, and Zn. Iron and Mn contents of the plants were increased and N, K, Ca, and Mg were decreased as a function of P applied. Increases in K in the nutrient solution caused increases in the concentrations of K, N, P, and Zn, and decreases in the concentration of Ca and Fe. Applied Ca increased the concentrations of Ca and N, and decreased the concentrations of P, Mg, Fe, Zn, and Mn. Potassium, Ca, and Fe contents of the plants were decreased and Zn increased, while N, P, and Mn were not affected by the increasing levels of external Mg. Iron suppressed the plant Mg, Zn, and Mn contents. Synergism between Zn and Fe was seen, while P, K, Ca, Mg, and Mn contents were not affected by Zn levels. Potassium, Ca, Mg, and Fe were not responsive to applied Mn, however, N and P contents of the plants were decreased at the highest levels of Mn.     

Application of Excess Nitrogen,Phosphorus, and Potassium Fertilizers Leads to Lowering of Grain Iron Content in High-Yielding Tropical Rice

Influences of nitrogen (N), phosphorus (P), and potassium (K) fertilizer doses were assessed on iron (Fe) accumulation in leaves and grains of three high-yielding rice cultivars differing in grain Fe concentration. Effects of these treatments were also measured on grain yield, leaf area, and plant biomass of the cultivars. Nitrogen, P, and K applications improved plant biomass and grain yield of all cultivars. Among the nutrients, N was most effective in increasing leaf Fe concentration, followed by P and K in all three rice cultivars. Sharbati accumulated the greatest concentration of leaf Fe followed by IR-64 and Lalat. However, greater doses of these nutrients adversely affected grain yield and Fe content of leaf and grain. Application of excess N, P, and K fertilizers may, thus, sometimes results in lowering of grain Fe content in rice. Judicious application of the elements is recommended for prevention of Fe-induced malnutrition.     

Embryo Abortion in Relation to Fruit Size,Quality, and Concentrations of Nutrients in Skin and Pulp of Mango

To investigate the effects of embryo abortion on fruit size and weight, stone weight, and fruit quality, including total soluble solids (TSS), acidity, TSS/acid ratio, sugars, and concentrations of macro and micronutrients in skin and pulp, nubbins (seedless fruit) and seeded fruit of mango (Mangifera indica L.) cultivars ‘Glenn,’ ‘Irwin,’ ‘Haden,’ ‘Kent,’ and ‘Kensington Pride’ were compared at the ripe stage. Nubbins had significantly smaller fruit size and lower fruit weight than in seeded fruit in all the cultivars. Mean stone weight was also significantly lower in nubbins (9.04 g) than in seeded fruit (30.27 g) and the trend was similar in all the cultivars. Percent dry pulp weight was significantly higher in nubbins than in seeded fruit in all five cultivars. Nubbins exhibited significantly lower acidity and higher TSS and TSS/acid ratio than did seeded fruit in all of the cultivars. The concentrations of nitrogen (N), potassium (K), magnesium (Mg), iron (Fe), and copper (Cu) in the skin and N, phosphorus (P), K, calcium (Ca), Mg, sulfur (S), Fe, zinc (Zn), and Cu in the pulp of nubbins did not differ significantly from those in the skin and pulp of seeded fruit in all of the cultivars. However, mean concentrations of P, Ca, and S were significantly higher in the skin of nubbins than in the skin of seeded fruit. Mean concentrations of manganese (Mn) and boron (B) in both skin and pulp of nubbins were significantly higher than in the skin and pulp of seeded fruit. The experimental results suggest that embryo abortion at early stages of fruit development, although it reduces fruit size and weight, does not affect the concentrations of these elements in the pulp and skin of mature fruit. In conclusion, embryo abortion in mango fruit substantially reduced fruit size, weight, and stone weight and improved TSS, TSS/acid ratio, total sugars, and non-reducing sugars compared with seeded fruit in all the cultivars and led to minor changes in the concentrations of most of macro and micronutrients in skin and pulp of the fruit.     

Seasonal dynamics of mineral nutrients by walnut tree fruits

Walnut (Juglans regia L.) tree fruit showed after the endocarp lignification a fast growing stage during which fresh and dry weights increased abruptly. From the beginning of fruit ripening and during the fast sperm growing stage, fresh weight started to decrease while dry weight continued to increase with a reduced growth rate. Dry weights increased in sperm and decreased in exocarp‐mesocarp tissues during the fast sperm growing stage. The material exit from pericarp tissues was completed in the ripe fruit. By contrast, fresh weight continued to decrease in the tissue. Patterns of nutrient accumulation per fruit increased continuously during the fruit growth period. The observed reductions of nutrient accumulations for total nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in the fruit individuals during the very late fruit stage after fruit ripening, and in conjunction with the pericarp tissues senescence, are supposed to represent mineral nutrient returns from the ripe fruit. Patterns of total N, P, Mg, Fe, and Zn accumulations increased in the exocarp‐mesocarp tissue during the slow sperm growing stage and decreased during the fast sperm growing stage. Potassium accumulation in the tissue increased continuously up to the fruit ripening time. Calcium, Mn, and Cu increased continuously. Patterns of all nutrients in endocarp tissue increased during the slow sperm growing stage and decreased at the fast sperm growing stage. In the sperm tissues, total N, P, Mg, and Ca accumulations increased during the sperm development and slightly decreased in a late stage. The increasing trend of Ca accumulation was temporarily interrupted during the fast sperm growing stage. Iron, Mn, Cu, and Zn accumulations showed no reductions at all. Potassium accumulation was drastically restricted in the tissue with the approach of fruit ripening. Sperm tissues are extraordinary rich in mineral nutrients. Sperm total N, P, Mg, Mn, Zn, Cu, and Fe accumulations represented the 98.1%, 88.2%, 59.2%, 81.5%, 72.3%, 65.6%, and 52.5% of the total nutrients accumulation in the fruit, respectively. Sperm K and Ca accumulations represented only the 13% and 11.6%, respectively. Exocarp‐mesocarp K, Ca, and Mg accumulations represented the 76%, 72% and 37.1% of the total nutrients accumulation in the fruit individual, respectively. Total N and P accumulation in the tissue were detected in very low levels 1.3% and 7%, respectively. Iron, Cu, Zn, and Mn accumulations were detected in the same tissue in ratio values of 27.5%, 22%, 5.4%, and 11%, respectively. Macro‐ and micro‐nutrient accumulations of the endocarp tissues were detected in the lower levels as compared to the other fruit tissues. The estimated values of mineral nutrient returns from the mature fruit individuals were 2.8% for total N, 13% for P, 16.5% for K, 23% for Ca, 12% for Mg, 28.5% for Fe, and 21% for Zn. Manganese and Cu showed no returns at all. The estimated nutrient returns from the sperm tissues were 60% for total N, 67% for P, 22% for K, and 50% for Mg of the total returned nutrient from the fruit individual. The estimated nutrient returns from exocarp‐mesocarp were 100% for Zn, Fe, and Ca, 50% for Mg, 78% for K, 33% for P, and 40% for total N. Calcium, Fe, Mn, Cu, and Zn in the sperm and Mn and Cu accumulations in pericarp tissues showed no returns at all. A restricted nutrient diffusion from exocarp‐mesocarp and sperm tissues to the endocarp tissues is supposed to be possible. These results suggested a pericarp tissue behaviour similar to the old senescing leaves.     

施用氮、磷、钾对密植梨枣生长与叶片养分季节动态的影响

以山地梨枣(Zizyphus jujuba Mill. cv. Lizao)为试验材料,采用野外试验与室内分析,研究了黄土丘陵区山地滴灌下施用氮磷钾对矮化密植梨枣叶片8种营养元素（N、P、K、Ca、Mg、Fe、Mn、Zn）季节动态变化规律以及施肥对梨枣生长,产量及品质的影响。结果表明:不同生育期梨枣叶片养分含量变化具有一定的规律性。开花坐果期（5月上旬至7月上旬）,叶片N、P、K含量处较高水平,Mg、Fe、Mn、Zn含量处于较低水平。果实膨大期（7月中下旬到8月下旬）,叶片N、P有一个相对稳定的含量,K快速下降,而Fe、Mn、Zn含量上升。果实成熟期（9月初到10月初）,叶片N、P、K含量下降,Mg、Fe、Mn、Zn则是缓慢上升并趋于稳定。叶片N、P、K、Mn含量之间呈正相关,Ca、Mg、Fe、Zn含量之间也呈正相关关系,叶片N、P、K之间达极显著正相关关系,而N、P、K与Ca、Mg、Fe、Zn含量之间呈负相关关系。施氮肥可促进前期枣树新枝生长和枣果膨大;施磷肥可提高产量,达到33210 kg/hm2;施钾肥可明显提高枣果品质。     

SILICON NUTRITION AND PHYTOPHTHORA DRECHSLERI INFECTION EFFECTS ON GROWTH AND MINERAL NUTRIENTS CONCENTRATION,UPTAKE, AND RELATIVE TRANSLOCATION IN HYDROPONIC-GROWN CUCUMBER

A hydroponic experiment was performed to investigate silicon (Si) and Phytophthora drechsleri root rot effects on growth and tissue partitioning of Si, zinc (Zn), iron (Fe), and manganese (Mn) in two cucumber cultivars (Cucumis sativus L. cvs. ‘Dominus’ and ‘Super Dominus’). Root length, plant height, and root fresh weight were significantly decreased by P. drechsleri, which were all significantly alleviated by 1.0 mM Si. Increasing Si level in the nutrient solution was accompanied with its enhanced uptake by cucumbers. Plants infected with P. drechsleri transported lower Mn to shoot than non-infected plants. Influence of P. drechsleri infection on root Fe concentration was dependent on cucumber cultivar while a decrease in root Zn concentration was found in infected cucumbers. Silicon nutrition increased Zn and Fe uptake in both cucumber cultivars. It is suggested that Si nutrition improved the crop growth, particularly under biotic stress, and hereby, increased micronutrients uptake by cucumber.     

Seasonal changes in durian leaf and soil mineral nutrient element content

The 3–4 year monitoring study showed that fluctuations in durian (Durio zibethintts Murray) leaf and soil nutrient element levels were closely related to seasonal changes in the crop phenology. The leaf sampling method was standardized taking the 5th and 6th mature green leaf from the shoot tip. The best sampling time was determined to be in November where the coefficient of variability for most nutrient elements were the lowest at or lower than 20%. Tentative standards for durian leaf nutrient elements were set up taking the 95% confidence interval of the means at this sampling stage. All the leaf macro elements, nitrogen (N), phosphorus (P), potassium (K), sulfur (S), and the micro elements, zinc (Zn), manganese (Mn), copper (Cu), and iron (Fe) declined or were lower during fruit set and development from September to end of fruit harvest in January. Leaf N was also the lowest in July and leaf P at the tail end of harvest. Soil N, P, and the bases K, Ca, and Mg also exhibited similar trends, lower during fruit development especially in October‐November and were lower during active leaf flushing from March to May.     

Pecan leaf analysis: I. Varietal,fertilizer, and seasonal effects

Abstract

Differences in elemental content of pecan [Carya illinoensis (Wang.) K. Koch] leaves among cultivars were found for N, P, K, Ca, Mg, Mn and Zn. Of the 7 elements studied, only leaf K indicated a date by cultivar interaction. Differences in leaf K among cultivars became greater as the season progressed. Increasing rate of application of N‐P‐K fertilizer increased leaf N, Ca, Mn, and Al, but had very little or erratic effect on leaf P, K, Fe, B, Cu, Zn, and Sr. There were very few consistent significant fertilizer rate by date interactions for the 13 elements tested. Seasonal trends for element leaf contents from mid‐May through October were generally downward for N, upward for Ca, Mn, Fe, B, Cu, Al, and Ba and changed very little for Mg, Zn, and Sr. Leaf P and K responses to sampling date varied with year. Large year to year variations in leaf trends over dates suggests difficulty in selecting a period for leaf sampling where little change in leaf levels consistently occurs.     

不同早实核桃品种叶片矿质元素含量变化及其与产量的关系

试验于2010~2011年连续2年以济源市4个早实核桃品种香玲、鲁光、中林1号、薄丰为试材进行了对比试验,研究了不同采样时期叶片中N、 P、 K、 Ca、 Mg、 Fe、 Cu、 Mn、 Zn 9种矿质营养元素的含量变化及其与产量的关系。结果表明,早实核桃叶片中9种元素的含量在年周期内呈规律性变化,含量高低依次为 Ca＞N＞Mg＞P＞K,Fe＞Mn＞Zn＞Cu。不同品种各元素的含量变幅最大为127.69~169.53 mg/kg（Mn）,最小为2.1~92.26 g/kg（K）。不同早实核桃品种叶片内矿质元素含量的年变化趋势表现为N、 P、 K总体上呈下降趋势,最高含量为展叶期（4月20日）分别为36.79、 5.54、 2.93 g/kg,最低在落叶前期（9月28日）,分别为17.45、 2.66、 1.86 g/kg;Ca、 Mg、 Fe、 Mn 4元素含量的变化总体上表现为前期低后期高;Cu、Zn含量的变化有差异但差异不明显。总的来看, 5~7月份,即新梢速长期（5月20日）至硬核期（7月20日）是核桃树养分稳定的时期, 叶片中N、 P、 K含量之间呈极显著的正相关, N、 P与Ca、 Mg、 Mn、 Cu间呈极显著的负相关,可以认为N、 P、 K之间存在增效作用,Ca、 Mg、 Mn、 Cu 对N、 P 和 K 均存在一定的拮抗作用。元素含量与产量的相关分析表明,N、 P、 K在新梢速长期均与产量达（极）显著正相关,相关系数分别为0.819、 0.843和0.895。因此, 利用叶片进行营养诊断最佳,采样时间以新梢速长期（5月20日前后）为宜。     

Relationships between leaf and fruit minerals and fruit quality attributes of apples grown under northern conditions

Field experiments were conducted during 1994–1995 in seven apple (Malus spp.) orchards located in the southwest of Finland (the mainland and the Åland Islands). The cultivars were ‘Transparente Blanche’, ‘Samo’, ‘Melba’, ‘Raike’, ‘Red Atlas’, ‘Åkerö’, ‘Aroma’, and ‘Lobo’. Leaf samples from branches bearing fruits (BF) and not‐bearing fruits (BNF) were collected two times during the growing seasons. Fruit samples were picked about one week before commercial maturity. Macronutrient concentrations in fruits and leaves, fruit diameter and juice pH, titratable acidity (TA) and soluble solids concentrations (SSC) were determined. Leaf nitrogen (N), phosphorus (P), and potassium (K) were higher, but calcium (Ca) and magnesium (Mg) were lower in BNF. Branch types (BF and BNF) were closely related in leaf N, P, and Ca, but not in leaf K and Mg at the first sampling time. Fruit N, P, K, and Mg were closely related to each other but not to fruit Ca. Mean fruit N and Ca and leaf P and Mg were low compared with the recommended levels. Relationships between fruit and leaf nutrient concentrations were found only in P and Mg. Fruit diameter increased and juice SSC decreased with increasing leaf N concentration. Fruit P declined with increasing fruit diameter and juice TA increased and SSC/TA decreased with increasing leaf P and Ca concentrations.     

Nitrogen and potassium effects on the macronutrient and micronutrient content of zoysiagrasses 1

Zoysiagrass has more potential for utilization in the Gulf Coast states. There has been minimal research on the nitrogen (N) and potassium (K) fertility response of zoysiagrass and the resulting effect they have on the macronutrient and micronutrient content. The objective of this study was to evaluate the effects of N and K fertility on the nutrient content of zoysiagrass. A study was conducted on four zoysiagrasses: Zoysiajaponica x Z. tenuifolia Willd. ex Trin. ('Emerald'); Z. japonica Steud. ('El Toro’ and ‘Meyer'); and Z. matrella. The study was a completely randomized design with 3 replications. It was a 2x2 factorial with the factors being N and K at two levels that were imposed on the four zoysiagrass cultivars. The N and K treatment combinations consisted of high (H) and low (L) rates of N and K at the following levels: N levels of 454 and 227 g N 93 m^‐2 month^‐1 and K levels of 454 and 227 g K 93 m^‐2month^‐1. The treatment combinations were (N and K): HH, HL, LH, and LL and were applied in 2 split applications monthly from July through November. All plots received two applications of a micronutrient fertilizer (June and August), were irrigated as needed, and maintained at a height of 3.8 cm weekly. Plant tissue samples were collected in September and analyzed for nitrogen (N), phosphorus (P), K, calcium (Ca), magnesium (Mg), sulfur (S), boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) concentrations. There were significant differences for the concentrations of N, K, P, Ca, Mg, B, Cu, Fe, Mn, and Zn. The concentrations of K, Ca, and Mg were below the sufficiency range for these nutrients for all cultivars and treatments.     

Influence of nitrogen and potassium on micronutrient content of fifteen cultivars of bermudagrass

Abstract

There is limited information concerning the micronutrient composition of different turfgrass species and cultivars. Bermudagrass [Cynodon dactylon (L.) Pers.] is an important turfgrass utilized throughout the Southeastern and Southwestern states and the transition zone of the United States. A study was conducted to determine the effects of different rates of nitrogen (N) and potassium (K) on the micronutrient content of fifteen bermudagrass cultivars. The cultivars utilized were: ‘Ormond’, ‘Texturf 10’, ‘Tiflawn’, ‘Tufcote’, and ‘U‐3’ [Cynodon dactylon (L.) Pers.]; ‘Everglades’, ‘Midiron’, ‘Midway’, ‘Pee Dee’, ‘Santa Ana’, ‘Tifdwarf, ‘Tifgreen’, ‘Tifway’, and ‘Tifway II’ [Cynodon dactylon (L.) Pers. x Cynodon transvaalensis Burtt‐Davey]; and ‘Sunturf [Cynodon magennisii Hurcombe]. The study was a 2x2 factorial with the factors being two levels each of N and K imposed on the fifteen cultivars. It was a completely randomized design with three replications. The N and K rates were 227 g N and 227 g K 93 m^‐2 month^‐1 (low rates) and 454 g N and 454 g K 93 m^‐2 month^‐1 (high rates) that resulted in four N:K treatment combinations as follows: 1) high N:high K; 2) high N:low K; 3) low N:high K; and 4) low N:low K. Plant tissue samples were collected in late August and analyzed for boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn). There were differences for the Cu, Fe, Mn, and Zn concentrations for several cultivare under certain treatment combinations. Zinc concentrations exceeded the sufficiency range in all but one instance, while there were several cases in which Fe and Mn concentrations were above the sufficiency range. The levels of B and Cu were within the sufficiency range and there were no differences for B.     

Seasonal Variation in Nutrient Status of Foxglove Leaves

The seasonal variation of mineral elements and the relationships among them were studied in natural populations of foxglove (Digitalis obscura). Young and mature leaves were collected in 10 different populations and on four sample dates (May, July, October, and February). Leaf mineral elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu)] were determined. The highest concentrations of N, P, and K in young leaf were recorded in May, followed by a decrease in the other months, while in contrast Ca and Fe showed the lowest concentration in May. Mature leaves showed differential seasonal behavior. Besides seasonal variations, significant fluctuations of N/P and Ca/Mg ratios were observed in young leaves. Strong positive correlations existed among N, P and K, while negative correlations were found between Ca and N, P, or K.     

Seasonal dynamics of mineral nutrients and carbohydrates by walnut tree leaves

The dry weight accumulation per leaf as well as the concentration per gram of dry weight and the accumulation of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were determined in walnut tree leaves (Juglans regia L.) during a complete life cycle. Additionally, the dynamics of plant nutrient concentration in leaf petiole sap and carbohydrate accumulation in leaves were studied in relation to the main life cycle events of the walnut tree. Total N, P, K, Cu, and Zn concentrations decreased, whereas that of Ca, Mg, and Mn increased during the season. Iron concentration fluctuated around a mean value. Total N, P, K, Mg, and Cu concentrations detected in younger mature leaves were at the sufficient level, whereas Ca, Fe, Mn, and Zn concentrations were at higher levels as compared to those previously reported. All the detected nutrient accumulations increased abruptly during leaf ontogeny and leaf maturation until a maximum level was attained in the younger mature leaves. Similarly, sucrose, glucose, and fructose accumulation were observed at the same period. The rates of total N, P, Cu, and Zn accumulation were lower than the rates of the observed dry matter accumulation and nutrient concentration dilution. Potassium and Mn accumulation rates were almost equal, whereas those for Ca and Mg were higher as compared to the dry matter accumulation rate. The fast embryo growing phase resulted in a considerable decrease in dry weight, total N, P, K, Cu, Zn, and carbohydrate accumulation, and to a lesser degree in Ca, Mg, and Mn accumulation. Nutrient accumulation reduction in leaves by the influence of the growing fruits were estimated to be: total N 52%, K 48%, P 29.5%, Mg 16.3%, Ca 15%, Fe 51.2%, Cu 55.2%, Zn 37.3%, and Mn 5.4% of the maximum nutrient value of the younger mature leaves. Old leaves preserved nutrients before leaf fall as follows: total N 25.4%, P 45%, K 31%, Ca 74.8%, Mg 76.5%, Mn 89.2%, Fe and Zn 50%, and Cu 37%. Nutrient remobilization from the senescing old leaves before leaf fall were: total N 22.6%, P 25.5%, K 21%, Ca 10.2%, Mg 7%, Fe 3.2%, Mn 5.4%, Cu 8%, and Zn 13.3% of the maximum value in the younger mature leaves. In early spring, the absorption rates of N, P, and Ca were low while those of Mg, Fe, Mn, Cu, and Zn were high. During the fast growing pollen phase, the N, P, Fe, Mn, Cu, and Zn concentrations were reduced. Calcium concentration is supposed to be more affected by the rate of transpiration rather than during the growing of embryo. Calcium and Mg concentrations in the sap were negatively correlated. The detected K concentration level in the sap was as high as 33 to 50 times that of soluble N, 12 to 21 times to that of P, 5 times to that of Ca, and 10 to 20 times to that of Mg. The first maximum of starch accumulation in mature leaves was observed during the slow growing embryo phase and a second one after fruit ripening. Old senescing leaves showed an extensive carbohydrate depletion before leaf fall.     

Differential response of citrus rootstocks to aluminum levels in nutrient solutions: II. Plant mineral concentrations 2

The objective of this study was to determine relations between Al effects and mineral concentrations in citrus seedlings. Six‐month‐old seedlings of five citrus rootstocks were grown for 60 days in supernatant nutrient solutions of Al, P, and other nutrients. The solutions contained seven levels of Al ranging from 4 to 1655 μM. Al and similar P concentrations of 28 μM P. Aluminum concentrations in roots and shoots increased with increasing Al concentration in the nutrient solution. Aluminum concentrations in roots of Al‐tolerant rootstocks were higher than those of Al‐sensitive rootstocks. When Al concentrations in nutrient solution increased from 4 to 178 μM, the K, Mg, and P concentrations in roots and the K and P levels in shoots increased. Conversely, Ca, Zn, Cu, Mn, and Fe in the roots and Ca, Mg, Cu, and Fe in the shoots decreased. The more tolerant rootstocks contained higher Fe concentrations in their roots than did the less tolerant ones when Al concentrations in solution were lower than 308 μM. Concentrations of other elements (Ca, K, P, Mg, Zn, and Mn) in roots or shoots exhibited no apparent relationship to the Al tolerance for root or shoot growth of the rootstocks. Calcium, K, Zn, Mn, and Fe concentrations in roots and Mg and K concentrations in shoots of all five rootstocks seedlings had significant negative correlations with Al concentrations in corresponding roots or shoots.     

Jerusalem artichoke growth,development, and field storage. II. Carbon and nutrient element allocation and redistribution

Jerusalem artichokes store carbon (C) predominately in the form of inulin, a functional food of increasing interest due to its dietary health benefits for humans and calorie replacement potential in processed foods. To better understand the developmental and agronomic requirements of this crop, the allocation of C and nutrient elements into individual plant parts (stems, leaves, stolons, tubers, ‘seed’ tuber, and roots) was monitored at 2‐week intervals throughout the entire growth cycle of the cultivar ‘Sunchoke’ grown on a Cecil sandy clay loam. Accumulation patterns of C and nutrient elements in individual plant parts were generally in accordance to the pattern of dry matter accumulation, though concentration patterns differed. Overall, nutrient element levels in vegetative structures decreased with the onset of rapid tuber development. Leaves had the highest nutrient levels, except iron (Fe) and sodium (Na). The concentrations of nitrogen (N), phosphorus (P), potassium (K), sulfur (S), and copper (Cu) in tubers were greater than in stems. Total N, P, and K concentrations in the stolons were at lower levels and the total calcium (Ca), Fe, and manganese (Mn) at higher levels compared to the tubers. During rapid tuber growth, the concentration of individual phloem‐mobile nutrient elements (e.g., N, P, and K) in the leaves and stems decreased progressively due in part to reallocation. In contrast, the concentration of less mobile nutrient elements (e.g., Ca and Mn) in the leaves and stems generally increased due to losses of C and other mobile materials. In the tubers, the concentration of C and most nutrient elements remained fairly constant through the final harvest, indicating carbohydrates and nutrient elements were accumulating at the same rate. Knowledge of C and nutrient element allocation/ reallocation in the Jerusalem artichoke is of value for improving fertilization strategies and in identifying critical traits for the selection of new, high yielding cultivars.     

李营养累积、分布及叶片养分动态研究

基于保障生态和果品安全以及合理实施果园养分管理的前提,对大石早生李树体各部位营养元素积累、分布以及各营养元素的周年变化规律进行了分析.结果表明:①营养元素在各个器官的相对含量,除K、Zn在果实中含量最高外,N、P、Ca、Mg均以叶片中含量为最高,以叶片做营养诊断是适宜的.②大石早生李树体营养元素N、P、K、Ca、Mg、Fe、Zn的元素比值为10.00:1.26:6.42:12.57:2.46:1.87:0.14.⑧100 kg鲜果的养分吸收量分别为:N 772.47g,P74.25 g,K 730.33g,Ca874.16 g,Mg 169.82 g,Fe 66.05 g,Zn 7.53 g,N:P:K的比例为1.00:0.10:0.95.④N、P、K、Ca、Mg、Fe、Zn、Mn、Cu的含量随物侯期呈规律性变化.生长季初期,N、P、K、Zn、Cu的含量迅速下降,Fe、Mn、Ca、Mg呈逐渐上升的趋势;中期这9种元素总体变化幅度较小;后期Fe,Cu.N、P、K的含量呈下降趋势,Mn、Zn、Ca,Mg依然上升.本结果既丰富了国内李营养理论,同时又为制定合理的施肥措施及建立绿色优质果品科技示范基地提供了理论依据.     

Floral Analysis and Seasonal Dynamics of Mineral Levels in Carob Tree Leaves

The mineral concentration of flowers and the seasonal fluctuation of macro- [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] and micronutrients [iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu)] in leaves of male, female, and hermaphroditic carob trees (Ceratonia siliqua L.) were studied. The nutrient dynamics were linked not only to phenological events, but also to the gender of the trees. The females were able to allocate more nutrients to leaves than male trees, even though male flowers were richer in particular elements such as N and Zn. The hermaphrodites supported the development of both inflorescences and fruits with a lower seasonal variation and a lower leaf nutrient concentration, as compared to the other genders, which may indicate a more efficient use of resources. Flowers had, in general, a higher concentration of N, P, and K, and a lower Mn concentration than in leaves. Flowers of the females had a lower nutrient concentration compared to males or hermaphrodites.     

EFFECT OF CITRUS ROOTSTOCKS ON LEAF MINERAL COMPOSITION OF ‘OKITSU’, ‘CLAUSELLINA’, AND ‘SILVERHILL’ MANDARIN CULTIVARS

Citrus performance is strongly related with rootstock. This study was conducted to investigate leaf nutrient contents of ‘Okitsu’, ‘Clausellina’ and ‘Silverhill’ mandarin cultivars budded onto sour orange, ‘Carrizo’ and ‘Troyer’ citrange rootstocks in Dörtyol, Turkey in 2004 and 2005. The maximum nitrogen (N), potassium (K), and copper (Cu) contents were determined for ‘Clausellina’; phosphorus (P) for ‘Okitsu’; and sodium (Na) for ‘Silverhill’. Calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), and zinc (Zn) uptake were similar for the mandarin cultivars. ‘Carrizo’ citrange at N, K, Mg, Mn, and Cu uptake; ‘Troyer’ citrange at N, P, K, and Fe uptake; and common sour orange at Ca, Zn, and Na uptake was superior on the other rootstocks. It was observed that ‘Carrizo’ and ‘Troyer’ citrange rootstocks had advantages over sour orange in nutrient uptake. Thus, growth performance, yield, and quality parameters considered, ‘Carrizo’ and/or ‘Troyer’ citranges could be suggested as rootstocks for the studied mandarin cultivars under similar ecological conditions.     

High soil Mn and Al,as well as low leaf P concentration,may explain for low natural rubber productivity on a tropical acid soil in Vietnam

The aim of the current study was to identify major soil and leaf factors accounting for low natural rubber (NR, Hevea brasiliensis) productivity on tropical acid Acrisols in Vietnam. Twenty NR plots were measured with NR productivity, leaf factors (N, P, K, Ca, Mg, Mn, Cu, Fe, and Zn), soil factors (pH, particle size distribution, total C, N, P, K, exchangeable K, Ca, Mg, Al, Mn, Fe, Zn, available P). Cluster analysis showed that NR productivity could be separated into three clusters with low (23.2), medium (38.2), and high (61.3 g tree^?1 harvest^?1) yield. High-yield cluster had higher leaf P concentration and soil pH, while low-yield cluster had higher leaf Mn, soil exchangeable Al, and Mn concentration. Simple and multiple linear regression analysis applied with backward elimination procedure suggested that leaf and soil toxic concentration may be responsible for low NR productivity in the study soil.