Requirement For Maximum Growth Research Articles

Nitrogen and Water Demands for Maximum Growth of Solanum tuberosum under Doubled CO2: Interaction with Phosphorus Based on the Demands

Crop growth promotion utilizing elevated carbon dioxide concentrations (e[CO2]) may be limited by soil nutrient availability. Although numerous studies have suggested the importance of nitrogen (N) for the promotion of growth under e[CO2], N requirement for maximum plant growth is rarely examined. We have found that increase in potato (Solanum tuberosum L.) biomass depends on phosphorus (P) availability under doubled [CO2] conditions. To address whether the N requirement for maximum growth under e[CO2] is dependent on P supply or not in potatoes, we quantified potato growth and water consumption in response to five N supply rates at low P (LP) and high P (HP) conditions. A pot experiment was conducted in controlled-environment chambers with ambient CO2 concentrations (a[CO2]) and an e[CO2] level of double a[CO2]. Foliar critical N concentration per area (critical [N]area), the minimum N requirement for 90% maximum plant growth, was similar (1.43 g m-2) regardless of [CO2] conditions under LP. Under HP, however, the critical [N]area increased under e[CO2] conditions (1.65 g m-2) compared with a[CO2] conditions (1.52 g m-2). Water use did not change with e[CO2] under HP conditions, whereas it decreased with e[CO2] under LP conditions despite the increase in biomass owing to higher water-use efficiency (WUE). Although WUE with e[CO2] or HP was independent of N supply, biomass increment with e[CO2] or HP depended on N supply. We concluded that the N and water required by potato plants under e[CO2] would be dependent on P supply. Although under HP, e[CO2] increased N but not water required to obtain maximum growth during the early growth stage, N demand was unchanged and water demand decreased by e[CO2] under LP conditions, probably owing to growth limited by P availability.

Effects of increasing protein level on the performance, enzyme activity and body composition of the Brazilian sardine, Sardinella brasiliensis (Steindachner, 1879)

A six-week growth trial was performed to estimate the dietary protein requirements for maximum growth of juvenile Brazilian sardine (Sardinella brasiliensis) based on growth performance, feed utilization, body composition and digestive enzyme activity. Six isoenergetic diets were formulated to contain protein levels that increased from 250 to 500 g/kg. Each diet was randomly assigned to triplicate groups of 160 fish with mean initial body weight of 0.93 ± 0.13 g, which were fed four times a day to apparent satiation. Growth tended to increase with the increase in the dietary protein level up to 400 g/kg. Total protein intake was indirectly correlated to apparent protein utilization. No significant differences in whole-body composition were found between fish fed the different protein levels. Acid protease and neutral lipase activities did not show significant differences among the different protein dietary groups. Alkaline protease activity increased in fish fed up to 350 g/kg of protein and amylase activity in fish fed up to 400 g/kg. Using polynomial regression, 367 g/kg was estimated to be the optimum dietary protein requirement for maximum weight gain of juvenile Brazilian sardines.

Vitamin C supplementation to optimize growth, health and stress resistance in aquatic animals

AbstractVitamins are organic compounds that can be synthesized from other essential nutrients; however, they are required in trace amounts from an exogenous source for normal growth, reproduction and health. Vitamin C (ascorbic acid, AA) is an essential micronutrient for normal growth and physiological function of most aquatic animals. In terrestrial animal nutrition, vitamin C has recently spurred scientific interest because of the increasing knowledge on vitamin C involvement in gene expression, cell cycle and reproduction in mammals; in addition, recent advances in molecular biology techniques allow the more effective estimation of the effect of vitamin C on metabolism and physiology. In contrast, this information is scarce in aquatic animal nutrition, as studies have essentially focused on the estimation of minimum vitamin C requirement for maximum growth and immune response as well as for the formulation of least‐cost diet. This scarcity of information is also due to the lack of well‐established indicators of vitamin C status in aquatic organisms. The present review summarizes and discusses information about vitamin C sources, bioavailability, deficiency and requirement in aquatic animals to plan further studies. In the future, vitamin C nutrition studies in aquaculture should also include immune responses, histopathology of the gills, liver, gonad development, gamete quality and quantity, fecundity, larvae survival and gene expression. Dietary vitamin C requirements should be estimated at every life‐history stage of cultured species. All this information will allow a better understanding of the essentiality of vitamin C in aquatic animal growth, development, reproduction and health.

Rhizosphere carboxylates and morphological root traits in pasture legumes and grasses

The legumes most often used in temperate pastures such as Trifolium subterraneum have relatively high external P requirements for maximum growth. We investigated root traits associated with P acquisition in current and novel pasture legumes, as well as temperate grasses which have lower P requirements. Thirteen legume species, two pasture grasses, and three high carboxylate-exuding crop species (Lupinus albus, L. angustifolius, Cicer arietinum) were grown in a glasshouse for six weeks. Rhizosphere carboxylates and root morphological traits were measured. Ornithopus spp. had rhizosphere carboxylates in similar quantities to the Lupinus spp. (> 40 μmol g−1 root dry mass). Trifolium subterraneum lines had relatively large average root diameter, reduced specific root length and very short average root hair length resulting in specific root hair cylinder volumes (RHCVs) only 14–20 % of the grasses. However, O. sativus, O. compressus and Biserrula pelecinus had specific RHCVs more comparable to the grasses. Novel pasture legume species with root morphology more comparable to that of grasses than T. subterraneum were identified. Of these, Ornithopus spp. were notable as they also had high rhizosphere carboxylates relative to root dry mass.

Growth and antioxidant status of oriental river prawn Macrobrachium nipponense fed with diets containing vitamin E

A feeding trial was carried out to investigate the dietary vitamin E requirement of the oriental river prawn Macrobrachium nipponense (weight of 0.3–0.4 g) and its effect role on antioxidant activity. Prawns were fed with seven levels of vitamin E (0, 25, 50, 75, 100, 200, and 400 mg/kg diet) for 60 days. The results show that dietary vitamin E supplementation could significantly increased the prawn weight (P 0.05). The contents of vitamin E in the hepatopancreas and in the muscle increased with increasing dietary vitamin E. There was a linear correlation between the vitamin E level in diet and that in muscle, and between the vitamin E level in diet and that in the hepatopancreas. All the above results indicated that dietary vitamin E can be stored in the hepatopancreas and muscle and lower both the activities of SOD and CAT in the hepatopancreas, suggesting that it is a potential antioxidant in M. nipponense. Broken line analysis conducted on the weight gains of prawns in each diet group showed that the dietary vitamin E requirement for maximum growth is 94.10 mg/kg.

Demand-driven fertilization. Part II: Influence of demand-driven fertilization on shoot nitrogen concentration, growth rate, fructan storage and playing quality of golf turf

The ability of demand-driven fertilization, based on the growth potential provided by solar radiation and temperature, to regulate golf turf characteristics such as growth rate, leaf nitrogen (N) concentration, carbohydrate storage and playing quality was investigated in a 2-year field experiment at Landvik, Norway. Three N regimes (100, 60 and 40% of the estimated N requirement for maximum growth) were applied on a sand-based green with a turf cover consisting of creeping bentgrass, colonial bentgrass, velvet bentgrass, slender creeping red fescue or chewings fescue. In the 100% treatment, this corresponded to 3 (creeping bentgrass), 2.1 (colonial and velvet bentgrass) and 1.5 (chewings and slender creeping red fescue) kg N 100 m−2 yr−1. The weekly liquid fertilizer dose basically followed the potential growth curve provided by solar radiation and temperature from early April to late October. The turf was exposed to artificial wear and daily maintenance followed conventional standards. Growth, leaf N concentration, carbohydrate storage in clippings, green appearance and playing quality were determined once per month. The results indicated that solar radiation and temperature can successfully be used as driving variables when quantifying turf fertilizer requirements from early spring to late autumn. The desired leaf N concentration, i.e. growth rate, and the resulting effects on fructan content and playing quality can be achieved by raising or lowering the seasonal fertilizer curve. A leaf N level of 3.1–3.5% was indicated as the lower limit for producing healthy-looking turf with high playing quality.

The extracellular polysaccharide produced by Rhizobium sp. isolated from the root nodules of Phaseolus mungo

The symbiont isolated from root nodules of Phaseolus mungo L., a widely grown legume in India was identified as a Rhizobium sp. a Rhizobium sp. close to R. multihospitium based on a biochemical and 16S rRNA gene-based phylogenetic approach. This Rhizobium sp. was able to produce large amounts of extracellular polysaccharides (EPS) in a yeast extract mannitol (YEM) broth medium. Both growth and EPS production started simultaneously though each had different stationary phases. EPS production increased enormously with supplementation by the preferred carbon, nitrogen and vitamin sources. Attempts were made to optimize the cultural requirements for maximum growth and maximum EPS production. The EPS produced by the symbiont contained large amount of mannose together with small amounts of arabinose and xylose. The possible role of EPS production on the Rhizobium—root nodule symbiosis is briefly discussed.

The performance of West African dwarf goat on dietary magnesium sulphate supplements

A 56-day feeding trial was conducted to evaluate the effect of dietary magnesium sulphate on the performance of West African Dwarf (WAD) goat using 12 does weighing 7 - 10kg. There were four dietary levels of MgSO 4 (Dl), 0.5(D2), 1.0 (D3) and 1.5% (D4). Dry matter intake, growth and Mg retention were used as the criteria for judgment. Result showed that addition of magnesium sulphate significantly (P<0.05) increased mean daily gain from 34.00 -46.00g. The dry matter intake declined (P<0.05) with increased level of dietary magnesium sulphate (3.21-2.34Kg/W 07S kg) Goat fed diet D4 depicted an optimum feed conversion ratio (10.50) while the least was observed for animals fed Dl (14.50). The result further showed that the magnesium requirement for body maintenance was 0.003g/kgBW/day while the requirement for maximum growth was 1.5% of the diet. Key words: Magnesium sulphate, goats, performance, maintenance requirement

Root hair morphology and mycorrhizal colonisation of pasture species in response to phosphorus and nitrogen nutrition

Root hairs and arbuscular mycorrhizal fungi (AMF) increase the absorptive surface area of a root and the volume of soil explored and as such are important for nutrient acquisition in infertile soil. Root hair morphology and colonisation by AMF were compared for 10 temperate pasture species, and responses to N and P deficiency characterised. Vulpia spp., Holcus lanatus, and Lolium rigidum had the longest root hairs (range 1.02–2.36 mm) while Trifolium subterraneum had the shortest (~0.27 mm). In contrast, T. subterraneum had a much higher density of root hairs than any of the other species. In response to P deficiency, the length and density of root hairs generally increased; in response to N deficiency, both increases and decreases in the length and density of root hairs were observed. The annual dicotyledons T. subterraneum and Arctotheca calendula had much higher mycorrhizal colonisation on roots grown at low P availability than the grasses. Root colonisation decreased with increasing P availability in all species. A yield advantage from mycorrhizal colonisation was demonstrated only for T. subterraneum when P was deficient. The potential root cylinder volume of each species was calculated as an index of the ability of the species to explore soil. Although all plant species were colonised by AMF, a positive linear relationship was observed between relative P uptake rate from the soil and the rate at which potential root cylinder volumes were developed by most species. Development of potential root cylinder volume also largely explained the critical external P requirements of most species. No such relationships were observed for N. It was concluded that knowledge of root length and the length of root hairs grown in nutrient-poor conditions may be used to predict the potential of many plant species to acquire P, and also their critical external P requirement for maximum growth. However, the study also highlighted some exceptional species.

Phosphorus Deficiency Delays the Onset of Nodule Function in Soybean

ABSTRACT Effects of phosphorus (P) deficiency on nodulation were examined in soybean grown in nutrient solution for 7 weeks. Increasing P supply increased shoot growth of nitrogen (N2)-fixing plants from week 5 and that of nitrate-fed plant from week 4 after treatment. Nitrogen (N2)-fixing plants had a greater P requirement for maximum growth at week 5. Increasing P supply from 1 to 16 μ M increased N concentration in N2-fixing plants at week 4 but did not affect it from week 5. By contrast, P deficiency increased N concentration in nitrate-fed plants. Increasing P supply improved nodule formation from week 3. Nodule mass was affected more by P supply than nodule number, which, in turn, was affected more than plant growth. However, P supply did not decrease nodule specific N2 fixation from week 5. The results suggest that P deficiency impaired symbiotic N2 fixation through delaying onset of nodule function and decreasing nodule development.

Morphology and response of roots of pasture species to phosphorus and nitrogen nutrition

The root morphology of ten temperate pasture species (four annual grasses, four perennial grasses and two annual dicots) was compared and their responses to P and N deficiency were characterised. Root morphologies differed markedly; some species had relatively fine and extensive root systems (Vulpia spp., Holcus lanatus L. and Lolium rigidum Gaudin), whilst others had relatively thick and small root systems (Trifolium subterraneum L. and Phalaris aquatica L.). Most species increased the proportion of dry matter allocated to the root system at low P and N, compared with that at optimal nutrient supply. Most species also decreased root diameter and increased specific root length in response to P deficiency. Only some of the species responded to N deficiency in this way. Root morphology was important for the acquisition of P, a nutrient for which supply to the plant depends on root exploration of soil and on diffusion to the root surface. Species with fine, extensive root systems had low external P requirements for maximum growth and those with thick, small root systems generally had high external P requirements. These intrinsic root characteristics were more important determinants of P requirement than changes in root morphology in response to P deficiency. Species with different N requirements could not be distinguished clearly by their root morphological attributes or their response to N deficiency, presumably because mass flow is relatively more important for N supply to roots in soil.

Energy and protein requirements for maximum growth and maintenance of bodyweight of yellowtail

SUMMARY: Six feeding experiments were conducted to determine energy and protein requirements of different sized yellowtail seriola quinqueradiata (8–280 g) for maximum growth and maintenance of bodyweight under different water temperatures (21.7–27.1°C) in 500 L polycarbonate tanks. For each experiment, fish were fed to satiation or fed at levels between 0 and 80% of the satiation level twice a day. The experimental diets were extruded dry pellets with known digestible energy (DE) and protein (DP) values. The growth rate was highest for the satiation group and decreased proportional to the feeding levels. The DE (kcal/kgBW per day)and DP (g/kgBW per day) requirements for maximum growth, calculated on the basis of the daily feeding rate of the satiation group, were 225 and 21.7, 136 and 14.8, 125 and 11.2, 111 and 10.7, and 92 and 8.2, respectively, for fish with an average initial bodyweight of 8, 63, 160, 237, and 280 g. The requirements for maintenance of bodyweight, based on when the growth rate was zero for the above sizes, were 61 and 5.9, 15 and 1.7, 15 and 1.3, 24 and 2.3, and 12 and 1.0, respectively. The requirements for maintenance of body energy content, estimated on the basis of the relationship between the DE intake and energy retention, were significantly higher than those for maintenance of bodyweight.

Soil phosphorus requirements for maximum growth of northern California subclover‐annual grass pastures

Abstract Annual grassland soils of California are generally quite deficient in phosphorus (P), but the amount of fertilizer P required to obtain optimum pasture production is quite variable. This paper reports on the relationships between five soil‐P tests and the amount of applied P required to obtain near maximum growth of subclovergrass pasture on 12 sites representing four soil series in the north coastal range of California. Dry matter (DM) yield response curves resulting from application of nine levels of P were fitted to the Mitscherlich equation: y = a{l‐b([EXP(‐cx)]}, where: y = DM when x = kg/ha of P were applied, a = maximum DM when P was not limiting, and b and c are constants that were adjusted to give the best fitting curves buy an iterative algorithm. This equation was used to calculate the amount of P required to bring yields to 90% of the maximum DM represented by “a”; in the equation. Then the regression equations relating P requirements to soil‐P extracted by the Bray‐1, Olsen, and modi...

Vitamin D Requirements of Juvenile Hybrid Tilapia Oreochromis niloticus *O. aureus.

A feeding trial was conducted to estimate the optimum vitamin D requirement in the diet for juvenile hybrid tilapia Oreochromis niloticus×0. aureus. Eight vitamin D levels, ranging from 0 to 2, 100IU/kg diet at a 300IU increment were fed for 16 weeks to triplicate groups of tilapia weighing 0.78g in a recirculated double filtered rearing system. Results indicated that fish fed with diets lacking supplementary vitamin D had poor growth and feed conversion ratio (FCR), and low hemoglobin, hepatosomatic index values, and plasma alkaline phosphatase activity. Plasma calcium and phosphorus concentration were similar in all the dietary groups. Weight gain analyzed by broken line regression indicated the vitamin D requirement for maximum growth in tilapia to be 374.8IU/kg.

Factors which affect the growth of grain legumes on a solonized brown soil. II. Genotypic responses to soil chemical factors

Lupins (Lupinus angustifolius cvv. Yandee, 75A-258 and P22872, and L. pilosus cv. P20957) and field peas ( cv. Dundale) were grown in the glasshouse in a sieved solonized brown soil. The soil was taken from sequentially deeper zones in the B horizon of the natural profile (8-83 cm below the surface). The pH (in CaCl2) increased from c. 6.3 to c. 8.2 with depth while sodium and chloride concentrations reached 83 and 62 mol m-3 (soil solution) respectively in the deepest unfertilized subsoil. Sodium concentrations reached 159 mol m-3 when the subsoil was fertilized. When plants were grown in the deepest subsoil, the growth of shoots and roots was inhibited by up to 75% in L. angustifolius but less severely in L. pilosus and pea. Roots of pea were affected least by the deep subsoil. Shoots of L. angustifolius, but not L. pilosus or pea, had severe chlorosis in the expanding tissue and necrosis of the oldest leaflets when grown on the deepest soil. Expanded leaflets of L. angustifolius had sodium and chloride concentrations up to 200 mol m-3 while iron concentrations were less than 208g g-1 dry weight in expanding tissues. Concentrations of manganese and zinc exceeded requirements for maximum growth but copper concentrations were sufficiently low to suggest deficiency in growing tissue of Yandee and 75A-258. No symptoms of deficiency were apparent. It is concluded that adverse chemical factors in the subsoil restrict root growth of L. angustifolius in the field. L. pilosus and field peas, on the other hand, appear to be significantly better adapted to these sodic, alkaline subsoils.

Growth and nutrient concentrations of alfalfa and common bean as influenced by soil acidity

Growth and nutrient utilization of alfalfa (Medicago sativa L. cv. Arc) and common bean (Phaseolus vulgaris L. cv. Carioca) were studied in an acid soil adjusted to eight levels of soil acidity by lime addition. Application of lime significantly (P<0.05) increased shoot and root growth for both species. However, common bean was far less sensitive to soil acidity than alfalfa. Maximum alfalfa growth was obtained at a soil pH of 5.8 and maximum bean growth was achieved at pH 5.0. Root and shoot growth of both legumes was positively correlated (P<0.01) with soil pH, exchangeable Ca and exchangeable Mg and negatively correlated (P<0.01) with soil exchangeable Al. Common bean had a lower internal P requirement for maximum growth and was more efficient than alfalfa in taking up Ca and Mg. These characteristics would contribute to the favorable growth of common bean in acid-infertile soils.

Response of ryegrass and white clover to phosphorus on an allophanic soil, Egmont black loam

Abstract A phosphorus(P)-deficient, allophanic soil, Egmont black loam, was used in a pot trial to investigate the availability of P adsorbed onto the surface of soil particles. The growth of perennial ryegrass (Lolium perenne L.) was compared with that of white clover (Trifolium repens L.) over a range of P additions to the soil both with and without mycorrhiza. Ryegrass and clover desorbed P from soil surfaces but clover had a higher P requirement for maximum growth than did ryegrass. Results from the trial and the adsorption curves indicated that soil solution P levels of 10 and 2 fLMP are required for near optimum growth of clover and ryegrass respectively. Clover responded to mycorrhiza at low levels of P but ryegrass showed no significant response.

Relationships between dietary levels of each essential amino acid and hepatic polysome profiles in rats.

The relationships between dietary levels of the essential amino acids and hepatic polysome profiles of rats were investigated with special attention to the amino acid requirement pattern for the maximum rat growth as determined by other investigators. The basal diet contained a 7% essential amino acid mixture and a 3% non-essential amino acid mixture, with appropriate amounts of other nutrients. Rats were fed test diet for 5 hours and then the polysome profile was determined. The amounts of essential amino acids needed for maximum aggregation of polysome were low for methionine-cystine, leucine and tryptophan as compared with requirements for maximum growth. But in other essential amino acids, the amounts were in almost the same range as those reported for maximum growth by others. The differences between the amino acid requirement patterns for maximum aggregation of hepatic ribosomes and for maximum growth of rats might be due to a difference in amino acid requirements of the liver and whole body. Therefore, the hepatic polysome profile might be used to measure the effect of amino acid supplementation on dietary proteins. The requirement pattern of essential amino acids in other organs may be studied by polysome profile determination.

Zinc nutrition and salt preference in rats.

Zinc-deficient rats have an increased preference for sodium chloride (saltwater). We investigated the possibility that this elevated saltwater preference is due to nonfunctional taste receptors. In experiment I, zinc-deficient rats consumed more saltwater than zinc-sufficient rats at most sodium chloride concentrations tested (0.001-1.0 M). When the zinc-deficient rats were fed a zinc-sufficient diet, the clinical symptoms of zinc deficiency rapidly disappeared. However, the rats still preferred saltwater to a greater extent than rats maintained on the zinc-sufficient diet. In experiment II, rats fed diets supplemented with levels of zinc below the requirement for maximum growth had an increased preference for saltwater (0.15 M NaCl). In experiment III, electrophysiological responses of the taste nerves to various concentrations of sodium chloride, sucrose, quinine . HCl, and hydrochloric acid were the same in both zinc-deficient and zinc-sufficient rats. We conclude that the taste receptor sensitivity of the rat is not impaired by zinc deficiency. The increased salt preference of zinc-deficient rats might be related to some endocrine or central nervous system disorder precipitated by inadequate dietary zinc.

Relationships between Nutritional Quality of Dietary Proteins and Hepatic Polyribosome Profiles in Rats

Rats were adapted to a feeding period of 5 hours per day and meal-fed a diet containing 10% casein, wheat-gluten, corn-gluten, soya protein, gelatin or whole egg protein as a source of protein. The aggregation of hepatic polyribosomes was highest with whole egg protein as the protein source, followed by casein, soya protein, corn-gluten, wheat-gluten and gelatin in that order. The supplementation of each limiting amino acid to each dietary protein caused more aggregation of hepatic polyribosomes as compared with each non-supplemented diet. These differences of the aggregation of hepatic polyribosomes were closely correlated with their proportion of fullness of the limiting amino acid toward the requirement for maximum growth in young rats and with the biological value for these proteins. These results suggest that the polyribosome profile might directly reflect the hepatic protein synthesis in vivo and could be used as an index of nutritional evaluation of dietary proteins.