A note on the nutrient and mineral composition of Leucaena leucocephala in Western Nigeria

Analysis of Leucaena leucocephala from various localities in Western Nigeria shows that young leaves, pods and seeds contain more crude protein but lower crude fibre and ether extract than mature ones. The crude fat component was higher in the seeds (4.6% and 5.5% for green and ripe seeds, respectively) than in any other edible part of the plant, while the green and brown seed coats contain the least amount of ether extract and total ash. The mineral composition of the dry matter of mature leaves is 2.8% calcium, 0.26% phosphorus, 0.37% magnesium, 1.78% potassium, 0.21% sodium and 0.12% iron.     

Nutritional characterization of Mucuna pruriens: 1. Effect of maturity on the nutritional quality of botanical fractions and the whole plant

This study was conducted to determine the stage of maturity at which the dry matter (DM) yield and nutritive value of velvet bean (Mucuna pruriens) is optimized. Mucuna was harvested at 77, 110 and 123 days after planting (DAP) from quadruplicate 5 m × 1 m plots within each of 6 blocks. At each DAP, DM yield, chemical composition, botanical composition, in vitro rumen fluid-pepsin DM digestibility (IVDMD) and concentrations of total polyphenols, l-dopa and tannins were determined on the whole plant and botanical fractions. Whole-plant Mucuna DM yield increased (P<0.01) linearly with maturity; proportions of leaves and stems decreased linearly (P<0.01), whereas proportion of pods increased (P<0.01). Concentrations of neutral-detergent fiber (aNDF) in whole plant, leaf, and stem increased (P<0.05), or tended (P<0.10) to increase linearly with maturity, as did the acid-detergent fiber concentration of leaves and stems. Maturity decreased (P<0.05) ether extract concentrations of leaves linearly, and stems quadratically, but increased (P<0.05) whole-plant and pod starch concentrations. Pods contained relatively high concentrations of lysine, histidine, phenylalanine, aspartate, glutamate, leucine, isoleucine, and valine, but low concentrations of methionine and cystine. The essential amino acid index did not vary with maturity. Most minerals in Mucuna are concentrated in the leaves and the whole plant contains sufficient Ca, P, K, Mg, Fe, Cu, Na, Mo, Mn, and Zn for growing sheep, although their bioavailability of these minerals is unknown. Total polyphenol concentration quadratically (P<0.01) increased with maturity in the whole plant, tended to increase (P<0.10) in pods, linearly (P<0.01) decreased in stems and fluctuated in leaves. Maturity quadratically increased l-dopa concentration of the whole plant (P<0.05) and stems (P<0.01), but did not affect those of leaves and pods. Maturity quadratically increased (P<0.05) total tannin concentration in the whole plant, but decreased (P<0.10) that of pods. The l-dopa was concentrated in the seeds and pods of mature (110–123 DAP) plants, but tannins were concentrated in leaves and stems. Whole-plant IVDMD was not affected by maturity, but digestible DM yield linearly (P<0.01) increased with increasing DM yield. There was a 2-week harvest window (110–123 DAP) during which whole-plant crude protein and IVDMD remained unchanged. Nevertheless, harvesting at 123 DAP gave the best combination of biomass yield and nutritive value.     

Comparison of Techniques for the Extraction of Flavonoids from Cultured Cells of Saussurea medusa Maxim

Summary Room temperature, heat reflux, Soxhlet, ultrasound-assisted and microwave-assisted extractions were employed to extract flavonoids from dry cell cultures of Saussurea medusa Maxim. 24, 20, 6, 0.5 and 0.1 h exposures were necessary for room temperature, Soxhlet, heat reflux, ultrasound-assisted and microwave-assisted extractions to obtain the maximum yield of flavonoids of 3.0%, 4.1%, 3.9%, 3.5% and 4.1%, respectively. Microwave-assisted extraction showed obvious advantages in short duration and high efficiency to extract flavonoids from S. medusa cultured cells.     

Metabolic disturbances innicotiana glauca,a symptomless

Metabolic disturbances inNicotiana glauca, a symptomless carrier of potato witches’ broom were studied. The dry weight content of leaves of diseased plants was slightly decreased, that of the stems increased. The ash content in the dry weight of the whole diseased plant was decreased by 11%. Contrary to tomato plants which had shown considerable disproportions in the distribution of metabolites among the individual organs investigated (ULRYCHOVÁ, LIMBERK 1964), the content of the total nitrogen and of the individual nitrogen fractions of both leaves and stems of diseasedNicotiana glauca were decreased. The content of glutamine was increased in both organs in spite of the decrease of ammonia nitrogen by nearly 30% in both cases. The most striking disturbance found in the diseased plants ofNicotiana glauca was the 67% increase of a low-molecular phosphorus fraction (P extractable with 0-2N HCIO₄) in the leaves. This result agrees with that found in diseased tomato plants and may be primarily associated with the virus infection. The content of all other phosphorus fractions of both leaves and stems was decreased.     

Effects of pod removal on metabolism and senescence of nodulating and nonnodulating soybean isolines: I. Metabolic constituents

Field studies were conducted in 1981 and 1982 to ascertain the effects of pod removal on senescence of nodulating and nonnodulating isolines of soybean (Glycine max [L.] Merr. cv Harosoy) plants. Specifically, the test hypothesis was that nodules act as a nitrogen source and a carbohydrate sink which would in turn prevent or delay senescence in the absence of pods. Senescence was judged by changes in metabolite levels, in dry matter accumulation, and by visual observation.

For both nodulated and nonnodulated plants, pod removal had no effect on the magnitude or rate of dry matter and reduced-N accumulation by whole plants. Phosphorus accumulation was significantly less in both nodulated- and nonnodulated-depodded plants, compared with respective control plants with pods. These data suggested a role for pods in phosphorus uptake. Accumulation of dry matter, reduced N, and phosphorus ceased at approximately the same time for all treatments.

Pod removal did affect partitioning of plant constitments, with leaves and stems of depodded plants serving as a major alternate sink for accumulation of dry matter, reduced N, phosphorus, and nonstructural carbohydrates (primarily starch). While depodded plants eventually lost a significant amount of leaves, leaf drop was delayed relative to plants with pods; and depodded plants still retained some green leaves at 2 weeks past grain maturity of control (podded) plants.

The results indicated that senescence patterns of soybean plants were the same for nodulated and nonnodulated plants, and that pods did not control the initiation of senescence, but rather altered the partitioning of plant constituents and the visual manifestations of senescence.

     

Chemical constituents and energy content of two milkweeds,Asclepias speciosa andA. curassavica

Asclepias speciosa and A. curassavica were evaluated as potential renewable sources of chemicals for use as fuel and/or chemical feedstock. Leaves and stems of both plants were analyzed for acid-detergent fiber, acid-detergent lignin, cellulose and ash. Bomb calorimetry was performed onA. curassavica (leaves 4,590 cal/g; stems 4,219 cal/g; and latex 4,663 cal/g), andA. speciosa (leaves 4,404 cal/g; stems 4,514 cal/g; and latex 9,005 cal/g). Organic carbon inA. curassavica (leaves 41.20%; stems 41.18%; latex 48.03%) andA. speciosa (stems 45.71%; leaves 42.51%; latex 67.30%) were also determined. Major differences between the 2 plant species were in the chemical composition of the latex; A. speciosa latex contained primarily α- and β-amyrin and their acetates, and a small amount of rubber, whileA. curassavica latex is known to contain at least 50% cardiac glycoside.     

High-resolution gas-chromatographic analysis of the secondary metabolites obtained by subcritical-fluid extraction from Colombian rue (Ruta graveolens L.)

Subcritical (CO(2)) extraction, carried out in a J&W Scientific High Pressure Soxhlet Extractor, was used to isolate secondary metabolites from leaves, flowers, stems and roots of Colombian rue (Ruta graveolens L.). The various extracts were analyzed by capillary chromatography, on an HP-5 (30 m) column, using nitrogen-phosphorus, flame ionization, and mass selective detection systems. Kováts indexes and mass spectra (electron impact, 70 eV) were employed for compound identification. The extracts from the various parts of rue studied had different compositions. The number of compounds detected at concentrations above 0.01% (w/w) in the extracts from leaves, flowers, stems and roots, was 78, 45, 25 and 24, respectively. 2-Nonanone (8.9%), 2-undecanone (13.4%), chalepensin (13.0%), and geijerene (19.3%) were the main constituents found in the extracts from rue leaves, flowers, stems and roots, respectively. Furanocoumarins, furoquinolines, hydrocarbons and benzodioxol derivatives were the main compound families found in all extracts, at total concentrations between 3.7 and 33.9%, depending on the part of the plant. The extraction method used has low environmental impact and produced solvent-free extracts in good yield with no pigments, waxes, resins, or high-molecular weight compounds which may interfere with the isolation and analysis of the alkaloids responsible for rue's biological activity, which were extracted in relatively high yield.     

The Influence of Temperature and Water Deficits on the Partitioning of Dry Matter in Groundnut (Arachis hypogaea L.)

The partitioning of dry matter to stems, leaves and pods ofgroundnut was examined as a function of mean air temperatureand water stress. Different levels of stress were imposed bygrowing plants on stored moisture at five different mean temperaturesbetween 19 °C and 31 °C and at four levels of saturationvapour pressure deficit. Stands of plants were grown in controlledenvironment glasshouses. The ratio of pod to shoot weight (PWR) was greatest at 22 °Cand decreased from 0.28 to 0.04 as temperature increased to31 °C. PWR was closely related to the number of pods longerthan 5.0 mm but negatively correlated with stem weight ratio.In general, water stress had a minor influence on PWR althoughpeg and pod production were stimulated in five of the nine treatments.Mild water stress promoted peg and pod production because reproductivegrowth was less affected than the growth of leaves and stems,the major sinks early in the reproductive phase. In one treatment,mild water stress increased PWR by a factor of 2.2 indicatingthat when adequate water is supplied to relieve a mild stress,PWR can be greatly increased. Key words: Temperature, Water deficit, Partitioning, Groundnut     

Chemical Characterization,Antioxidant, Antimicrobial,Cytotoxicity and in Silico Studies of Hexane Extract and Essential Oils from Citrus limon Leaves

The present study investigates the chemical composition, antioxidant and antimicrobial bioactivities of essential oil and hexane extract from Citrus limon leaves. The isolation of essential oil was carried out using the Clevenger apparatus. The percentage yield of essential oil and hexane extract from Citrus limon leaves was 0.59 and 0.50 %, respectively. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging assay highlighted that Citrus limon leaves essential oil (CLEO) and hexane extract exhibited the significant antioxidant potential of 69.64 and 67.55 %, respectively, compared to the BHT standard. Similarly, a significant inhibition in linoleic acid peroxidation was recorded in both CLEO (81.93 %) and hexane extract (50.34 %). Characterization of chemical constituents in CLEO and extract was executed using GC/MS, where Limonene was detected as a major compound in CLEO (60.52 %) and hexane extract (73.62 %). The haemolytic activity ranged from 2.46 to 5.75 % revealing negligible cytotoxicity of CLEO and hexane extract. In silico studies agree with the in vitro antimicrobial studies, where vinimalol, taraxasterol, and moretenol present in CLEO showed strong interactions/inhibition against dihydroorotase and DNA gyrase from E. coli, and the tyrosyl-tRNA synthetase and DNA gyrase from S. aureus. Based on the current data, it may be concluded that both CLEO and hexane extract possessed significant bioactivities, such as antimicrobial and antioxidant activity, with minimal cytotoxicity.     

Physical and chemical plant characters inhibiting the searching behaviour of shape Trichogramma chilonis

Several plant characters are known to affect the searching behaviour and parasitization efficiency of Trichogramma spp. (Hymenoptera: Trichogrammatidae). In this study, plant characters contributing to the low Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) egg parasitism levels on pigeonpea (Cajanus cajan (L.) Millspaugh) were investigated. The efficiency of T. chilonis on pigeonpea was dependent on the plant structure on which the host eggs were found. In a cage experiment, more than 55% of eggs placed on leaves were parasitized, while 1% of eggs on calyxes and no eggs on pods were parasitized. In a filter paper bioassay, parasitoids were deterred by acetone and hexane surface extracts from pigeonpea pods but showed no response to water extract. The searching behaviour of the parasitoids was not affected by different solvent extracts from the surface of pigeonpea leaves. In a four-armed airflow olfactometer, T. chilonis was repelled by volatiles from pigeonpea pods but showed no response to volatiles derived from hexane extract of pod surfaces. Volatile infochemicals and hexane surface extracts from pods of two wild Cajanus species, C. scarabaeoides (L.) Thours and C. platycarpus (Bentham) van der Maesen, were similarly deterrent to T. chilonis. The movement of the parasitoids on pigeonpea pods and calyxes was inhibited by long trichomes and wasps were trapped by sticky trichome exudates. Parasitoids walked significantly faster on leaves than on pods. The walking speed on both pods and leaves increased significantly after washing with hexane. The results presented in this paper show that the plant growth stage and the plant structures preferred by H. armigera for oviposition are the least suitable for T. chilonis, contributing to the low parasitoid efficiency on pigeonpea.     

Coregulation of soybean vegetative storage protein gene expression by methyl jasmonate and soluble sugars

The soybean vegetative storage protein genes vspA and vspB are highly expressed in developing leaves, stems, flowers, and pods as compared with roots, seeds, and mature leaves and stems. In this paper, we report that physiological levels of methyl jasmonate (MeJA) and soluble sugars synergistically stimulate accumulation of vsp mRNAs. Treatment of excised mature soybean (Glycine max Merr. cv Williams) leaves with 0.2 molar sucrose and 10 micromolar MeJA caused a large accumulation of vsp mRNAs, whereas little accumulation occurred when these compounds were supplied separately. In soybean cell suspension cultures, the synergistic effect of sucrose and MeJA on the accumulation of vspB mRNA was maximal at 58 millimolar sucrose and was observed with fructose or glucose substituted for sucrose. In dark-grown soybean seedlings, the highest levels of vsp mRNAs occurred in the hypocotyl hook, which also contained high levels of MeJA and soluble sugars. Lower levels of vsp mRNAs, MeJA, and soluble sugars were found in the cotyledons, roots, and nongrowing regions of the stem. Wounding of mature soybean leaves induced a large accumulation of vsp mRNAs when wounded plants were incubated in the light. Wounded plants kept in the dark or illuminated plants sprayed with dichlorophenyldimethylurea, an inhibitor of photosynthetic electron transport, showed a greatly reduced accumulation of vsp mRNAs. The time courses for the accumulation of vsp mRNAs induced by wounding or sucrose/MeJA treatment were similar. These results strongly suggest that vsp expression is coregulated by endogenous levels of MeJA (or jasmonic acid) and soluble carbohydrate during normal vegetative development and in wounded leaves.     

Cellular sequestration of cadmium in the hyperaccumulator plant species Sedum alfredii

Spatial imaging of cadmium (Cd) in the hyperaccumulator Sedum alfredii was investigated in vivo by laser ablation inductively coupled plasma mass spectrometry and x-ray microfluorescence imaging. Preferential Cd accumulation in the pith and cortex was observed in stems of the Cd hyperaccumulating ecotype (HE), whereas Cd was restricted to the vascular bundles in its contrasting nonhyperaccumulating ecotype. Cd concentrations of up to 15,000 μg g(-1) were measured in the pith cells, which was many fold higher than the concentrations in the stem epidermis and vascular bundles in the HE plants. In the leaves of the HE, Cd was mainly localized to the mesophyll and vascular cells rather than the epidermis. The distribution pattern of Cd in both stems and leaves of the HE was very similar to calcium but not zinc, irrespective of Cd exposure levels. Extended x-ray absorption fine structure spectroscopy analysis showed that Cd in the stems and leaves of the HE was mainly associated with oxygen ligands, and a larger proportion (about 70% in leaves and 47% in stems) of Cd was bound with malic acid, which was the major organic acid in the shoots of the plants. These results indicate that a majority of Cd in HE accumulates in the parenchyma cells, especially in stems, and is likely associated with calcium pathways and bound with organic acid (malate), which is indicative of a critical role of vacuolar sequestration of Cd in the HE S. alfredii.     

Preferential Loss of an Abundant Storage Protein from Soybean Pods during Seed Development

A temporary vegetative storage protein, composed of similar 25 kilodalton and 27 kilodalton subunits, was found to be abundant in soybean (Glycine max (L.) Herr. var Hobbit) leaves, stems, pods, flower petals, germinated cotyledons, and less abundant in roots, nodules and seeds. Total pod protein was highest at 3 weeks after flowering and declined by 37% within 3 weeks during seed development. During this time the vegetative storage protein declined from 18% to 1.5% of the total pod protein and accounted for 45% of the protein lost from pods. This indicates that the vegetative storage protein makes a significant contribution to the pool of nutrients mobilized from pods for transport to developing seeds.     

Rapid N transport to pods and seeds in N-deficient soybean plants

Non-nodulated soybean (Glycine max (L.) Merr.) plants were cultivated hydroponically under N-sufficient (5 mM NaNO(3)) or N-deficient (0.5 mM NaNO(3)) conditions. (13)N- or (15)N- labelled nitrate was fed to the cut end of the stems, and the accumulation of nitrate-derived N in the pods, nodes and stems was compared. Real-time images of (13)N distribution in stems, petioles and pods were obtained using a Positron Emitting Tracer Imaging System for a period of 40 min. The results indicated that the radioactivity in the pods of N-deficient plants was about 10 times higher than that of N-sufficient plants, although radioactivity in the stems and nodes of N-deficient versus N-sufficient plants was not different. A similar result was obtained by supplying (15)NO(3) to cut soybean shoots for 1 h. The fact that the N translocation into the pods from NO(3) fed to the stem base was much faster in N-deficient plants may be due to the strong sink activity of the pods in N-deficient plants. Alternatively, the redistribution of N from the leaves to the pods via the phloem may be accelerated in N-deficient plants. The temporal accumulation of (13)NO(3) in nodes was suggested in both N-sufficient and N-deficient plants. In one (13)NO(3) pulse-chase experiment, radioactivity in the stem declined rapidly after transferring the shoot from the (13)NO(3) solution to non-labelled NO(3); in contrast, the radioactivity in the node declined minimally during the same time period.     

Effect of ascochyta blight (Mycosphaerella pinodes) on yield components of single pea (Pisum sativum) plants under field conditions

Field studies were made in 1992 and 1993 to examine the yield components of pea inoculated with Mycosphaerella pinodes and those of healthy pea (sprayed with a mixture of flutriafol + chlorothalonil), in a split-plot design with the cv. Solara sown at different plant densities. Ascochyta blight was severe on leaves and on internodes of the basal part of the plants; pods had few lesions. The number and length of stems per plant were the same for diseased and healthy plants. The number of reproductive nodes and pods per stem were affected by disease only in 1993. In 1992 and 1993 respectively, disease caused reductions in the number of seeds per stem of 18% and 25%, and in seed size of 13.5% and 16.7%, compared with healthy plants. The harvest index and total biomass were lower in diseased than in healthy plants and seed yield was reduced by 40% in diseased plots. These results show a high relationship between the disease parameters (disease mean on stipules/nodes 8–18/ and on internodes/nodes 5–15/, percentages of stipules or internodes with a disease score 4, and percentage of stems encircled by lesions), plant density and yield reduction.     

Remobilization patterns of C and N in soybeans with different sink-source ratios induced by various night temperatures

The effects of increased sink-source ratios, induced by elevating night temperatures, on remobilization of ¹⁴C-assimilates and N within field-grown soybeans (Glycine max [L.] Merr.) was investigated from preflowering to maturity. Raising the mean minimum night temperature for the entire growing season from 10 (check, uncontrolled) to 16°C increased seed growth without appreciable effect on final leaf area. Increasing this temperature to 24°C increased seed growth and reduced final leaf area. Leaves, stems, petioles, and pods acted as intermediate storage sites for ¹⁴C assimilates. Only plants with higher night temperatures remobilized some of the stored assimilates during the period of rapid seed growth. Even the seeds in the 24°C plants with the largest sink-source ratios did not utilize all the C-assimilates potentially available for remobilization. Nitrogen was readily remobilized from petioles, stems, and pods of all treatments as early as the beginning of seed development, but from the leaves only during late seed-filling. However, only plants with elevated night temperatures tended to remobilize all of the available N from vegetative tissues and pods. We concluded that a larger portion of stored assimilates may be remobilized to the seed if a strong seed sink can be sustained. It also appeared that with increasing sink-source ratios, N shortage might limit seed yield before a lack of C-assimilates would. A proposed model for soybean assimilate demand, distribution, partitioning, and remobilization is presented.     

Characteristics of Crassulacean Acid Metabolism in the Succulent C(4) Dicot, Portulaca oleracea L

Crassulacean acid metabolism (CAM) was investigated in leaves and stems of the succulent C₄ dicot Portulaca oleracea L. Diurnal acid fluctuations, CO₂ gas exchange, and leaf resistance were monitored under various photoperiod and watering regimes. No CAM activity was seen in well watered plants grown under 16-hour days. Under 8-hour days, however, well watered plants showed a CAM-like pattern of acid fluctuation with amplitudes of 102 and 90 microequivalents per gram fresh weight for leaves and stems, respectively. Similar patterns were also observed in detached leaves and defoliated stems. Leaf resistance values indicated that stomata were open during part of the dark period, but night acidification most likely resulted from refixation of respiratory CO₂. In water-stressed plants maximum acid accumulations were reduced under both long and short photoperiods. At night, these plants showed short periods of net CO₂ uptake and stomatal opening which continued all night long during preliminary studies under natural environmental conditions. Greatest acid fluctuations, in P. oleracea, with amplitudes of 128 microequivalents per gram fresh weight, were observed in water-stressed plants which had been rewatered, especially when grown under short days. No net CO₂ uptake took place, but stomata remained open throughout the night under these conditions. These results indicate that under certain conditions, such as water stress or short photoperiods, P. oleracea is capable of developing an acid metabolism with many similarities to CAM.     

Some metabolic disturbances in tomato plants infected with potato witches’ broom

The pathophysiology of tomato plants infected with potato witches’ broom was studied. Changes in dry weight, content and composition of ash and the amount of different phosphorus and nitrogen fractions were investigated. All analyses were carried out separately in leaves, stems and preliminarily also in flowers. Considerable disproportions found in the distribution of metabolites among the individual organs investigated correspond to a great extent to the morphological picture of the disease. The leaves of diseased plants are actually starving and their growth and development are greatly inhibited. On the other hand, the stems are overflowing with metabolites, in particular with nitrogenous ones. They are thickened and along their entire length rootlets and sprouts appear forming the characteristic brooms. The authors assume that the disturbances in flower formation in diseased plants are due to the lack of essential metabolites. Diseased plants contain an increased amount of alkaline metals and alkaline earths.     

春小麦对土壤中14C-辛硫磷残留物的转移规律和途径的研究

经拌土处理施入盆钵土壤中的~(14)C-辛硫磷经土壤微生物和光的作用会降解。土壤中的这些辛硫磷残留物能被春小麦根系吸收,经茎转运到植株地上部分。茎只起输导作用,滞留的残留物较少;而叶子,特别是旗叶中能保持较高的残留水平。不同层次叶片累积的~(14)C-辛硫磷残留物再通过蒸腾、代谢和光解等途径不断转移消解,或以~(14)CO_2,或以其他含~(14)C化合物的形式向周围环境中逸出。春小麦叶片中的~(14)C-辛硫磷总残留提取物中约有50％的非光敏性物质。农药在土壤—植物—空气三者之间具有连续性,是农药生态毒理研究中一个必须注意的问题。     

Effect of nodulation on assimilate remobilization in soybean

The objectives of this work were to determine the effect of nodulation on dry matter, reduced-N, and phosphorus accumulation and partitioning in above-ground vegetative parts and pods of field-grown soybean (Glycine max [L.] Merr. cv Harosoy).

From comparison of nodulated and nonnodulated isolines, it was estimated that nodulated plants attained 81 and 71% of total-plant (above ground) N from uptake of soil N in 1981 and 1982, respectively. These data, along with visibly greener leaves of nodulated plants, led us to assume that nonnodulated plants were under a moderate N stress relative to nodulated plants. Nonnodulated plants accumulated less total-plant N and partitioned less dry matter and N to the pods, compared with nodulated plants. This occurred even though net photosynthesis, as estimated by rate and amount of dry matter accumulation, was the same for both nonnodulated and nodulated plants. Rate of dry matter and reduced-N accumulation in pods was less for nonnodulated than for nodulated plants while duration of podfill was similar for both isolines. From these data we concluded that moderate N stress affected partitioning of photosynthate rather than net photosynthesis, and that N played a role in translocation of photosynthate to the pods. Total plants (above-ground portion) and pods of both nodulated and nonnodulated plants accumulated similar amounts of phosphorus, which indicated that phosphorus and N accumulation were independent.

Remobilization of nitrogen and phosphorus from vegetation to pods preceded dry matter remobilization. It appeared that either more nitrogen accumulation prior to podfill, or continued nitrogen assimilation during podfill would increase nitrogen and dry matter partitioning to pods, but that increasing photosynthesis without concomitantly increasing nitrogen input may not necessarily result in enhanced seed production.