Effect of Selenium on Mineral Content and Nutritive Value of Melilotus officinalis L.

Plants of Melilotus officinalis L. were subjected to two different treatments: a) no selenium (Se), and b) addition of 3 mg Se L^?1 irrigation water for 45 days and samples of leaves, stems and roots were analyzed for Se, potassium (K), sodium (Na), magnesium (Mg), iron (Fe), copper (Cu), calcium (Ca), manganese (Mn) and zinc (Zn). Crude protein (CP) content, neutral detergent fiber (NDF), acid detergent fiber (ADF) and in vitro organic matter digestibility (IVOMD) were also estimated for the aerial plant tissues. In Se-treated plants Se mainly accumulated in leaf tissues, various changes in macronutrient concentrations were detected, while the micronutrient content decreased significantly. In addition, leaf CP, NDF and ADF content decreased, while IVOMD increased, possibly indicating ameliorated nutritive value. According to our findings, M. officinalis could be used either as a dietary supplement, in mixture with non-accumulator species, for livestock feed deficient in Se or for restoration of grasslands in seleniferous soils.     

Effects of organic solid cattle manure application on nutritive value of winter cereal forages

Nutritive value of winter cereal forages is one of interested subjects of farmers for animal feeding. Field experiments were established in 2007–2008 and 2008–2009 growing seasons in northeast Turkey to investigate the effect of organic solid cattle manure application (0, 10 and 20 Mg ha^?1 yr^?1) on nutritive value of three annual cereals for forage. The winter cereal forages were: wheat (Triticum aestivum L.), oat (Avena sativa L.) and rye (Secela cereale L.). ADF (acid detergent fiber), NDF (neutral detergent fiber) CP (crude protein), nitrogen, phosphorus, potassium, sulfur, calcium, copper, iron, magnesium, manganese, sodium, zinc and boron (N, P, K, S, Ca, Cu, Fe, Mg, Mn, Na, Zn and B) concentrations were researched in this study. Wheat had the highest CP, N, Ca, Cu, Na and Zn concentration, whereas oat had the lowest ADF and NDF and the highest K, Fe and Mn concentrations. The greatest Mg and P concentrations were determined in rye. Organic solid cattle manure applications had no effect on N and CP contents, but it decreased ADF and NDF contents. However, in most cases it positively affected the P, B, Cu, Fe, Mg and Na concentrations, whereas it decreased K, Ca, Mn and Zn concentrations. The results showed that wheat and oat are more nutritive species than rye in terms of animal feeding and the organic solid cattle manure, in some cases increased the nutritive values of wheat, oat and rye under organic agriculture conditions.     

Variation of forage and extractable soil minerals over two grazing seasons in North Florida

Abstract

A two‐year experiment was conducted at a north Florida farm to evaluate the mineral status of bahiagrass forages and soils. Forage samples were collected every 28 d throughout the grazing season, and soils evaluated twice yearly. The minerals calcium (Ca), sodium (Na), copper (Cu), cobalt (Co), selenium (Se), and zinc (Zn) were uniformly below the dietary requirements for growing beef cattle in both years. Forage magnesium (Mg), phosphorus (P), potassium (K), crude protein (CP), and manganese (Mn) were generally adequate throughout the grazing season, with the exception of low P concentration at the end of the growing season for both years. Extractable soil concentrations of Ca, P, K, Mg and Zn were adequate but low in Cu. Although CP was adequate (>7.0%) throughout the grazing season, IVOMD values were relatively low. There was a general trend for forage P, K, and IVOMD to decrease (P<0.05) with time.     

Interelemental relationships in the soil and plant tissue and photosynthesis of field‐cultivated wheat growing in naturally enriched copper soils

Several interelemental relationships have been examined in field‐cultivated wheat (Triticum aestivum L. cv Vergina) growing on naturally enriched copper (Cu) soils. Mean soil Cu concentration per site ranged from 103–394 μg.g^‐1 dry weight (DW). Interrelationships between Cu, iron (Fe), calcium (Ca), potassium (K), zinc (Zn), lead (Pb), and magnesium (Mg) concentrations in the soil and plant tissue (roots, stems, and leaves) were examined using Principle Components Analysis. Soil samples were clustered according to collection site and were primarily differentiated according to their Cu concentrations. Soil Cu concentrations were positively correlated with Zn, Ca, Fe, and K in the soil, with Cu, K, and Ca in the roots, and Cu and Fe in the leaves and negatively correlated with Fe in the roots. The increase in Cu in the roots and leaves was positively correlated with increases in K and Ca in the roots and Fe and Ca in the leaves, but negatively with Fe in the roots. Increases in leaf Ca concentrations were correlated with increases in Mg and decreases in Zn concentrations in the leaf. Plants growing in soil with high Cu concentration exhibited toxicity symptoms with reduced height, decreased total leaf area and lower chlorophyll concentrations. Photosynthesis expressed per unit leaf area was not affected by increasing Cu concentrations in the soil or plant tissue.     

Effects of pasture‐applied biosolids on forage and soil concentrations over a grazing season in north Florida. I. macrominerals,crude protein,and in vitro digestibility

Abstract

The rationale for this experiment was to determine forage nutrient concentrations as affected by biosolids fertilization. We studied the effects of single applications of two exceptional quality biosolids to bahiagrass (Paspalum notatum) pasture with regard to satisfying beef cattle nutrient requirements. Twenty‐five 0.8‐ha pastures were divided into five blocks. Two biosolids were applied as normal and double agronomic rates. The control plot received NH₄NO₃. Forages were analyzed for calcium (Ca), phosphorus (P), magnesium (Mg), potassium (K), sodium (Na), crude protein (CP), and in vitro organic matter digestibility (IVOMD), and soils were analyzed for Mehlich I extractable Ca, P, Mg, and K. Single (agronomic or twice this) applications of biosolids to pastures had little effect on Ca, P, Na, and K forage concentrations, but forage Mg was elevated in several treatments late in the season. Crude protein concentrations were elevated above the control for all biosolids treatments late in the season, whereas only small differences were observed at early sampling times. Trends were similar for IVOMD. In general, all treatments were associated with soils with adequate Ca, P, and Mg concentrations, while soil K was uniformly low. In relation to grazing beef cattle requirements, all treatments resulted in generally adequate forage levels of Ca, P, Mg, K, CP, and IVOMD, however, Na (<0.06%) was deficient.     

Effect of nitrogen and phosphorus fertilizers on some components of nutritive value of dwarf elephantgrass

Abstract

Crude protein (CP), calcium (Ca), and phosphorus (P) concentrations and in vitro dry matter digestibility (IVDMD) of leaves, stems, and whole plants of sprinkler‐irrigated dwarf elephantgrass (Pennisetum purpureum) cv. Mott as affected by the factorial combinations of nitrogen (N) (0, 150, 300, and 450 kg N ha^‐1 year^‐1) and P (0, 50, and 100 kg P₂O₅ ha^‐1 year^‐1) fertilization rates were evaluated in a tropical dry forest in the State of Zulia, western region of Venezuela. A randomized complete block design with three replications was used. Soil was a low‐fertility sandy‐loam Alfísol (Udic Paleustalf) with pH of 6.1. Data from eight cuttings carried out at 45‐day intervals were used. Only Ca and P concentrations in stems were affected by N fertilization. Phosphorus fertilization influenced (P>0.05) PC and P contents in leaves, IVDMD in stems, and Ca and P concentrations in both stems and whole plants. Overall mean IVDMD and CP, Ca, and P contents were: leaves, 62.9, 8.75, 0.39, and 0.30%; stems, 64.1, 7.38, 0.20, and 0.38%; and whole plants, 61.3, 8.13, 0.26, and 0.33%, respectively. Even though CP values were not very high, moderate production levels can be expected from ruminants fed this species since other components of its nutritive value can be regarded as adequate.     

Mineral Concentrations of Cool Season Pasture Forages in North Florida During Winter-Spring Grazing Season. I. Macrominerals and Forage Organic Constituents

Two experimental late fall-winter-spring grazing studies, each lasting two years, were conducted at the North Florida Research and Education Center (NFREC), Marianna, Florida to evaluate the organic constituents and macromineral concentrations of annual cool season pasture forages grazed by growing beef cattle. Eight 1.32 ha fenced pastures or paddocks were divided into two pasture land preparation/planting methods, four pastures for the sod seeding treatments and four for the prepared seedbed treatments. These pastures were planted with two different forage combinations: rye/oats mix with or without ryegrass for the first two years (Study 1), and oats with ryegrass or ryegrass only for the last two years (Study 2). Each of the four forage/land preparation combination treatments was assigned to two pastures each year, thereby giving two replicates per year. Forage samples were collected at the start of grazing and twice monthly thereafter until the end of grazing season for each year, pooled by month, and were analyzed for calcium (Ca), phosphorus (P), sodium (Na), potassium (K), magnesium (Mg), dry matter (DM) yield, crude protein (CP), and in vitro organic matter digestibility (IVOMD). Blood plasma samples were also collected from the tester cattle during the spring season of year 2 of Study 2 and were analyzed for Ca, P, and Mg. Month differences were observed in forage concentrations of P and K (P < 0.0001), and Mg (P < 0.05) in both studies, Ca (P < 0.01) in Study 1 only, and Na (P < 0.05) only in Study 2. Year affected P, K, and Mg concentrations in Study 1 and Ca, P, and Na concentrations in Study 2. In Study 2, forage type by month interactions on Ca, K, and Mg concentrations were noticed (P < 0.01). Forage Ca was lower (P < 0.05) than the critical level for all months from the oat plus ryegrass pastures, and for early winter months and late spring months from ryegrass only pasture. Forage Na concentrations were consistently low throughout the grazing season and unaffected by forage type or land cultivation methods used in both studies. Low Mg concentrations of both forage types in Study 2 (also with high K concentrations) were indicative of a potential risk of grass tetany (hypomagnesemia) for grazing ruminants. Forage DM yields were highly variable with fluctuations among the experimental months and were found to be highest in the spring months, with decreasing yields towards the end of the grazing season in both studies (P < 0.0001). The CP concentrations were greater than the required levels and both CP and IVOMD decreased gradually by month in both studies (P < 0.0001). Normal blood plasma concentrations of Ca and P obtained were indicative of a good overall status of these minerals in the animal's body. Plasma Mg concentrations were slightly above the critical level for cattle from both forage types. In summary, the macrominerals most likely to be deficient in North Florida during the cool season would be Ca, Na, and Mg. Special attention should be given to supplementation of Mg since forages reflected a marginal deficiency of this mineral and high K concentrations were found.     

Use of Mefluidide to Alter Growth and Nutritive Value of Pearl Millet

Abstract

Pearl millet (Pennisetum americanum L. Leeke) has an inherent rapid growth rate that often presents management problems to achieve optimum utilization by livestock throughout the growing season. Both the rapid spring–summer growth rate and photoperiodism that diminishes growth in late summer—early fall creates the need to use both grazing and mechanical defoliation to have efficient use of forage production. The objectives of this 2‐year field study were to evaluate the effects of a growth regulator, mefluidide (N‐[2, 4‐dimethyl‐5‐([(trifluoromethyl) sulfonyl] amino) phenyl] acetamide), on growth characteristics and nutritive parameters of “Millex 24” pearl millet. Mefluidide was broadcast applied at different rates to determine the effect on dry matter (DM) yield and nutritive value of leaves and stems of pearl millet. Mefluidide reduced DM biomass at each weekly harvest, and at three weeks post‐treatment DM was reduced 3‐fold in Year 1 and 2‐fold in Year 2. Percent leaf, however, was nearly doubled by mefluidide application. Crude protein (CP) of leaves was not affected by mefluidide, however, CP of treated stems was significantly higher (P < 0.05) than untreated pearl millet. Fiber components were lowered (P < 0.05) in treated leaves and stems compared to untreated pearl millet. The 2‐year study showed that mefluidide enhanced nutritive value of pearl millet, but at the expense of DM.     

Calcium,magnesium, and potassium uptake by crested wheatgrass grown on calcareous soils

Abstract

Forage intake with potassium/(calcium + magnesium) [K/(Mg + Ca)] values in excess of 2.2 are associated with grass tetany and Mg deficiencies in ruminants. This study was conducted to determine the degree to which forage K and Mg concentrations and K/(Ca + Mg) ratios could be predicted from soil bicarbonate (HCO₃) extractable phosphate‐phosphorus (PO₄‐P), and saturation extract Ca, Mg, K, sodium (Na), and nitrate‐nitrogen (NO₃‐N) concentrations. Crested wheatgrass (Agropyron spp) strains and cultivars representing four ploidy levels were grown in the greenhouse on eight calcareous soils with different saturation extract Ca, Mg, K and K/Mg ratios. The plants were harvested three times. Soil solution K/(Ca + Mg) and K/Mg ratios were the only measured soil parameters that showed a consistent correlation with plant K/(Ca + Mg) ratios. Bicarbonate extractable soil P was positively related to plant P and K uptake in the first harvest, but was not related in the second and third harvests nor was soil P related to plant Ca or Mg content. There was a tendency for the higher ploidy level entries to have higher plant K/(Ca + Mg) ratios. It was concluded that soil K/(Ca + Mg) ratios can be used to predict relative forage K/(Ca + Mg) ratios for grasses grown under similar conditions.     

Effects of K-Mg ratio on growth and cation nutrition of Vitis vinifera L. cv. “Dattier de Beiruth” grafted on SO4 rootstock

The area of planting of Vitis vinifera L. cv. “Dattier de Beiruth” (DB) grafted on the SO4 (Selection OPPENHEIM 4) rootstock is significant and constantly growing in Northern Algeria. A hydroponic culture was carried out with DB to investigate the effects of potassium-magnesium (K-Mg) ratio on plant growth and mineral nutrition. Four nutrient solutions were tested on which the K-Mg ratio is variable (nutritive solution (NS)1 = 0.3 K: 3.8 Mg, NS2 = 2.1 K: 2 Mg, NS3 = 2.6 K: 1.5 Mg and NS4 = 3.8 K: 0.3 Mg). The results showed that DB was characterized by a high capacity for K uptake. No significant differences among the treatments were detected in the leaf concentrations of calcium (Ca), however Mg uptake was inhibited by increase of K: Mg in the nutrient solution. Results showed that DB is sensitive to the variation of the cation composition in the nutrient solution. Antagonism between K-Mg was apparent.     

Bragg soybeans grown on a southern coastal plain soil

Determinate soybean (Glycine max) has been characterized by very few detailed nutrient partitioning studies. Knowledge of the variation in nutrient concentrations with plant part, nodal position, and plant age is needed for a better understanding of plant function. The information will benefit soybean nutrient modeling and diagnostic interpretation of plant analysis. In this study, ‘Bragg’ soybean were grown on an Aquic Paleudult soil (Series Goldsboro loamy sand). Plants were sampled at 10 to 14‐day intervals beginning 44 days after planting (July 7) until harvest. Maximum observed K concentrations were 5.27, 5.05, 2.88, and 2.99% for stem internodes, petioles (+ branches), leaf blades, and pods, respectively. Maximum observed Ca concentrations were 1.05, 1.98, 2.48, and 1.47% for the same respective plant parts. Maximum observed Mg concentrations were 0.63, 0.81, 0.65, and 0.58% for the same respective plant parts. Nodal and temporal mean concentrations of K and Ca generally varied considerably due to plant age and nodal position, respectively, in all plant parts. Mean concentrations of Mg were largely unaffected by either plant age or nodal position. Peak concentrations of Ca and Mg are generally associated with upper nodal positions. As new nodes are initiated, the expanding tissue represents an identifiable sink for K. Of importance in plant analysis is the observation that mean concentrations of elements in all four plant parts can vary by two fold or more depending upon plant age and nodal composition of the sample.     

Influence of cucurbitacin-containing phytonematicides on selected nutrient elements in leaf tissues of green bean under greenhouse conditions

Cucurbitacin-containing phytonematicides consistently reduce nematode population densities in various crops. However, there is no information on how these products affect the accumulation of essential nutrient elements in crops. The objective of this study was to determine the influence of Nemafric-BL and Nemarioc-AL phytonematicides on accumulation of essential nutrient elements in leaf tissues of green bean (Phaseolus vulgaris L.) under greenhouse conditions. Weekly application of phytonematicides each at 0%, 2%, 4%, 8%, 16% and 32%, were assessed on plant growth variables, nematode suppression and nutrient elements (Ca, K, Na, Fe, Zn) in leaf tissues of green bean at 56 days after initiating the treatments. Phytonematicide concentrations significantly (P?≤?0.05) affected nematode numbers and nutrient elements, without affecting plant growth. Calcium (R²?=?0.97), K (R²?=?0.93), Na (R²?=?0.94) and Fe (R²?=?0.91) each with increasing Nemafric-BL phytonematicide concentration exhibited positive quadratic relations. In contrast, K (R²?=?0.97) and Fe (R²?=?0.98) each with increasing Nemarioc-AL phytonematicide concentration exhibited positive quadratic relations, whereas Na (R²?=?0.92) and Zn (R²?=?0.72) each with increasing phytonematicide concentration exhibited negative quadratic relations. In conclusion, accumulation of essential nutrient elements in green bean leaf tissues and increasing phytonematicide concentrations exhibited density-dependent growth patterns prior to the eventual expression of plant growth responses.     

Aerial accumulation and partitioning of nutrients by hard red spring wheat

Abstract

Periods of maximum hard red spring (HRS) wheat (Triticum aestivum L.) nutrient demand need to be determined in order to develop best nutrient management practices, and to provide data for nutrient uptake modeling. Aerial (aboveground biomass) whole plant samples of irrigated HRS wheat were collected from the field at 16 growth stages and separated into leaves, stems, heads, and grain for dry matter determinations and analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), chloride (Cl), zinc (Zn), manganese (Mn), iron (Fe), and copper (Cu) concentrations. Accumulation curves were computed for each plant part for the growing season from compound cubic polynomial models based on accumulated growing degree units (GDUs). Total aerial accumulations of dry matter, N, P, K, Ca, Mg, S, Cl, Zn, Mn, Fe, and Cu were 14400, 116, 30.8, 103, 9.2, 9.3, 15.2, 32.3, 0.18, 0.58, 2.05, and 0.045 kg/ha, respectively. Grain at maturity accumulated greater than 78% of the total aerial N, P, and Zn, while it contained less than 20% of the aerial accumulated K, Ca, Cl, and Fe. Nitrogen and Fe were rapidly accumulated near 200 GDU, while P, K, Ca, Mg, S, Cl, Zn, Mn, and Cu were most rapidly accumulated near 600 GDU. Accumulation rates were 183, 2.9, 0.90, 0.72, 0.008, 1.41, 0.29, and 0.12 kg/ha/d for dry matter, N, P, K, Ca, Mg, S, and Cl, respectively, and 136, 1.7, 0.48, 0.13, 0.004, 0.78, 0.20, and 0.02 g/ha/d, respectively, during grainfill. This plant information suggests the timing of in‐season nutrient applications and, when integrated with other agronomic practices, could improve overall nutrient management for HRS wheat in the northern Great Plains.     

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.     

In Vitro digestibility,crude protein,and mineral concentrations of Leucaena leucocephala accessions in a wet/dry tropical region of venezuela

Abstract

An experiment was conducted on a commercial farm located in the western part of Venezuela (10.5°N and 72°W; mean annual rainfall of 1000 mm; mean annual temperature of 28°C; sandy‐loam Alfisol with pH of 5.5). The purpose of the experiment was to evaluate the in vitro organic matter digestibility (IVOMD), crude protein (CP) content and mineral composition of four Leucaena leucocephala (Lam.) De Wit accessions under rotational grazing by heifers over a 6‐month period covering dry and rainy seasons, using a split‐plot experimental design with two replications. Neither accessions nor the accession x season interaction affected (P>0.05) any of the variables. The mean IVOMD was 68.6%, whereas CP content during the rainy season (26.5%) was higher (P<0.05) than in the dry season (24.3%). Average mineral content of the accessions were adequate in relation to grazing ruminant requirements with the exception of phosphorus [(P) 0.13%], sodium [(Na) 0.038%], copper [(Cu) 6.9 ppm], and zinc [(Zn) 19.7 ppm]. Forage P concentration may have been influenced by the low soil P content of the experimental site. The mean forage Ca:P ratio (11.3:1) was considerably wider than desirable. During the dry season, ash content increased (P<0.05), Na, iron (Fe), and cobalt (Co) decreased (P<0.05), but Fe and Co still remained above the critical levels. Mean concentrations of other elements were not affected (P>0.05) by season. Forage molybdenum (Mo) concentrations were low and, therefore, would not result in conditioned Cu deficiency. The four L. leucocephala accessions had similar feeding value for grazing ruminants and their quality was not markedly reduced in the dry season. Mineral supplementation of ruminants grazing this legume may be needed to correct specific deficiencies and imbalances.     

Nitrogen,calcium, and magnesium fertilization affects growth and leaf elemental content of ‘dormanred’ raspberry

’Dormanred’ raspberry (Rubus species) plants grown in sand culture were subjected to varying concentrations of N, Ca, and Mg over a two‐year period. Increasing nitrogen fertilization resulted in linear reductions of leaf Ca, K, Zn, Fe, and Mn but did not affect leaf Mg. Leaf Ca and K increased linearly with Ca fertilization, but applied Ca had an antagonistic influence on leaf Mg. Magnesium fertilization had a positive influence on leaf Mg but negatively affected leaf K, Ca, and Mn. Plant growth was negatively correlated with leaf Ca and leaf K, but had a positive correlation with leaf Mg and Mn. Nitrogen fertilization increased plant growth up to the mid‐level of applied N, but additional N reduced plant growth.     

Effects of different magnesium levels on some morphophysiological characteristics and nutrient elements uptake in Khatouni melons (cucumis melo var. inodorus)

A nutrient solution experiment was carried out to evaluate effects of different magnesium (Mg) concentrations (0, 25, 50, 75 and 100 percent of magnesium concentration of Hoagland solution) on growth and physiological characteristics of Iranian melons (Cucumis melo var. inodorus subvar. Khatouni). The experiment was done based on completely randomized design using plastic pots and sand culture. The results showed that SPAD value of leaves, plant leaf number, stem diameter, shoot fresh and dry weight, root fresh weight, chlorophyll b, carotenoids, protein, catalase and peroxidase activities were constantly increased by increasing Mg levels of nutrient solution until 75 or 100% Mg levels, while leaf area, petiole length, internodes length were highest in lower levels of Mg compared to full Mg of nutrient solution. Moreover, the leaf concentrations of nitrogen (N), phosphorus (P), potassium (K), magnesium, and iron (Fe), but not calcium (Ca), were increased by increasing magnesium concentration to full Hoagland nutrient solution Mg level.     

Dynamics and Distribution of Nutrition Elements in Bamboos

ABSTRACT

Mao bamboo (Phyllostachys pubescens) with a high production and wide utilization has been planted in large scale in southern China, but little information about bamboo nutrition is available. The objective of this study was to reveal the dynamics of nutrition with growing time and the distribution of nutrition in different organs. It was found that the nutrition concentration of the whole plant generally declined with time during the period of 1–6 weeks owing to a dilution effect with the result of quickly increasing the biomass. The leaf concentration of nitrogen (N), phosphorus (P), and potassium (K) changed regularly with high concentrations observed at age 1, 2, 4, and 6, and lower at age 3 and 5. While the concentration of N, P, and K in the branch and stem generally declined with the weeks, a rapid decrease occurred from weeks 1 to 2. The concentrations of calcium (Ca) and magnesium (Mg) in bamboo leaf, branch, and stem appeared to be opposite to those of N, P, and K in corresponding plant parts. The elemental concentrations were greater (P < 0.05) in the leaves than in the branches and stems, while the storage of nutrition was greater (P < 0.05) in stem than in leaves and branch. A relative large total storage of nutrition, except P and Mg, were found in bamboo under an intensive management (IM) stand than those under extensive management (EM) stand. The total storage of different nutritions in the above-ground parts was in the order: K (243.0–285.6 kg ha^?1) > N (154.5–207.8 kg ha^?1) > P (10.4–12.2 kg ha^?1). The nutrition stored in the bamboo plant would be removed away from the soil in every other year by the means of harvest of the bamboo trunk which is the largest nutrition pool of the bamboo plant. Therefore, supplementary nutrients, especially N and K, are strongly recommended in order to keep the productivity of bamboo.     

Seasonal Changes of Mineral Nutrients in Fruit and Leaves of ‘Newhall’ and ‘Skagg's Bonanza’ Navel Oranges

In southern Jiangxi province of China, ‘Newhall’(Citrus sinensis Osbeck) navel orange presented a conspicuous symptom of boron (B) deficiency in mature leaves, whereas B deficiency symptoms were not manifested on ‘Skagg's Bonanza’(C. sinensis Osbeck) navel orange. In this study, changes in concentrations of B, calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), and zinc (Zn) were comparatively investigated in the structural parts of the fruit (rind and pulp) and leaves (old leaves from last season and spring-flush leaves from current year) of ‘Newhall’ and ‘Skagg's Bonanza’ navel orange during the growing season. Two peaks of B concentrations were observed in the rind of the two cultivars during fruitlet growth and fruit enlargement, respectively. Boron concentrations were relatively high in the rind during fruitlet growth, and then decreased in both rind and pulp, whereas, during middle and late fruit enlargement significant increases were found for B in both rind and pulp of the two cultivars. Boron concentrations in old leaves of ‘Newhall’ decreased progressively and remained relatively low, whereas that of ‘Skagg's Bonanza’ was relatively high and changed slightly as the season progresses. Both Ca and K concentrations were above the critical threshold values, while their dynamics were reverse to that of B in fruit and leaves during certain times. Old leaf Mg concentrations of samples at 140 days after full bloom from the two cultivars and spring-flush leaves from ‘Newhall’ were below the threshold limit for sufficiency. In addition, Mg in old leaves was much lower from ‘Newhall’ than from ‘Skagg's Bonanza’. Spring-flush leaf concentrations of Mn and Zn and Mn concentrations in old leaves from ‘Newhall’ were relatively lacking during middle and late season, which accelerated the occurrence of B deficiency symptoms on mature leaves of ‘Newhall.’     

Fruit growth and mineral element accumulation in pacific rose™ apple in relation to orchard management factors and calyx‐end splitting

Abstract

The effect of irrigation and crop load of apple (Malus domestica Borkh cv. Pacific Rose) on the fruit growth and mineral element accumulation was investigated. Fruit growth and changes in the concentration and contents of nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), and potassium (K) in the flesh of Pacific Rose? apple fruit were recorded over a growing season at the Massey University Fruit Crops Units orchard in the 1998–99 crop season. Fresh mass showed a linear growth while fruit diameter followed a curvilinear growth pattern during the growing season. Low crop load significantly increased fruit size, particularly during the final expansion phase, whereas irrigation had little effect on this attribute. Both low crop load and frequent irrigation treatments increased fruit growth rate, but the effect of the irrigation treatments fluctuated considerably during the season. The incidence of frait splitting was detected at about 20 WAFB when the fruit attained an asymmetrical growth in shape (L/D). The concentrations of N, P, Ca, Mg, and K declined throughout the sampling period. There was however, an increase in concentrations of P and K at the last harvest. The quantity of individual nutrient elements accumulated by the fruit showed an increasing trend during the season. Nitrogen accumulation however, reached maximum at 16 WAFB after which it declined until the last harvest. Fruit mineral element analysis of sound and split fruit revealed that split fruit had higher concentrations and contents of Mg and K and lower contents of Ca and P. As a result, the ratios of Ca: Mg and Ca: K were lower in split fruit as compared with sound fruit.