Dry Matter Accumulation Patterns Research Articles

Dry matter accumulation and plant type of the high yielding soybean grown under converted rice paddy fields.

For the last decade the high level yields, 5t-6t/ha, max. 6.5t/ha, of soybean (cv. Okushirome) have been recorded continuosly under the upland conditions converted from rice paddy fields at Saihoku Branch of the Yamagata Prefectural Agricultural Experiment Station, located in Shinjo (38°45'N, 140°18'E). In 1982 and 1983, dry matter accumulation pattern, canopy structure and light penetration for Okushirome under the converted fields at Saihoku Branch were compared with those of some cultivars (Table 2) grown under the fields of Experimental Farm of Hokkaido University (Sapporo, 43°35'N, 141°20'E). Okushirome produced the highest yields in both years, 5.3t/ha in 1982 and 4.6t/ha in 1983. It had also large LAIs (about 6), small light extinction coefficients (K:0.38 and 0.42), long leaf area duration (LAD) and high harvest indices (62% and 56%) compared with those of the cultivars grown in Sapporo (Table 3 and Fig. 5). Grain yield was closely correlated with number of pods (r = 0.886), LAD (r = 0.800) and grain filling period (r = 0.813), regardless of years, locations and cultivars. The K value was related to number of pods per maximum LAI (r = - 0.796), though not related directly to grain yield. As shown in Fig. 6, in 1982 Okushirome showed a peculiar unique plant form that the upper 3 to 4 large leaves on main stem had vertical and long (25 cm to 30 cm) petioles though stem height was very short (Table 2). In addition, leaflets of Okushirome did active solar tracking movements in both years during early morning to late afternoon, suggesting the relation to effective light penetration within the canopies (Fig. 4).

Above- and Below-ground Growth of Forest Stands: a Carbon Budget Model

The utilization and allocation of carbon by a forest stand are examined through a simple dynamic, mechanistic model which incorporates radiation interception, photosynthesis, respiration, assimilate partitioning, litterfall, root mortality and turnover. Qualitative mathematical analysis of the balance between carbon gains and losses provides an intuitive insight into the determinants of above- and below-ground growth. The patterns of dry matter accumulation produced by the model are compared with observed trends in stand development. Reported differences between biomass distribution on sites of high and low productivity are reproduced by adjusting the coefficients of assimilate partitioning.

Lipoxygenase Activities in Developing and Germinating Soybean Seeds with and Without Lipoxygenase-1

Dry-matter accumulation, extracted protein, lipoxygenase-1 (L-1), and lipoxygenase-2 plus -3 (L-2 plus -3) were investigated in two genotypes and two genotypes lacking L-1 activity in mature seeds. Dry-matter accumulation patterns during seed development were similar in all four genotypes. Protein extracted during seed development or the first week of germination also showed similar profiles for the four genotypes. Changes in L-2 plus -3 activity per milligram extracted protein and total L-2 plus -3 activity per seed again showed similar profiles for all four genotypes during seed development and germination. L-2 plus -3 activity was maximal between days 5 and 20 before physiological maturity and again maximal between days 4 and 7 of germination. The two soybean genotypes that did not have L-1 activity in mature seeds also lacked detectable L-1 activity throughout seed development and the first week of germination. The two normal soybean genotypes displayed similar profiles of L-1 activity. L-1 a...

Comparative Growth Analysis of Two Spring Wheats and One Spring Barley1

Two cultivars of spring wheat, Triticum aestivum L., cvs. ‘Neepawa’ and ‘Pitic 62’, and one cultivar of spring barley, Hordeum vulgare L., cv. ‘Bonanza’, were compared for grain yield and its relationship to patterns of leaf area development and dry matter accumulation. Each cultivar was planted at an early and a late seeding date at Saskatoon in 1980 and in 1981. Leaf area (cm2/plant) and biological yield (g/m2) were determined at weekly intervals commencing five weeks after seeding. Grain yield, components of grain yield, and final biological yield were measured at maturity. Grain yield was found to be a curvilinear function of final biological yield in Pitic 62 and Bonanza but the relationship appeared to be linear for Neepawa. Within a cultivar, higher biological yield gave higher grain yield.Bonanza barley produced more dry matter and greater leaf area than either wheat cultivar early in the season. This advantage disappeared as the crop approached maturity. Pitic 62, although having greater maximum leaf area index and greater leaf area duration than Neepawa, tended to have a similar pattern of dry matter accumulation early in the season. Pitic 62 had greater final biological yield and grain yield by virtue of its later maturity. Yield of wheat might be increased without delaying maturity by searching for types which grow quickly under cool spring conditions.

Dry Matter Accumulation Patterns and Seed Yield Components of Two Indeterminate Soybean Cultivars1

AbstractThe Maturity Group II soybean [Glycine mar (L.) Merr.] cv. Corsoy often produces seed yields in central Illinois that are equal or greater than many full‐season, Maturity Group III cultivars. A field study was conducted during two growing seasons at Urbana, Ill. in order to gain a better understanding of the yield physiology of Corsoy. Dry matter accumulation patterns of various plant parts, leaf areas, seed yields, and seed yield components of Corsoy were compared with those of Maturity Group III cv. Williams.Corsoy accumulated seed dry weight more efficiently than Williams by producing seed yields as great as or greater than Williams with less leaf area and less total vegetative dry weight than Williams. Although Corsoy produced less leaf area than Williams, crop growth rates of Corsoy and Williams were similar. This suggested that Corsoy possessed a greater net assimilation rate than Williams. Although Corsoy reached harvest maturity (RS) 2 weeks earlier in the growing season than Williams, duration of the seed filling periods of Williams and Corsoy were similar. Differences in seed yield were attributed to differences in rates of seed dry weight accumulation per unit‐area. Corsoy accumulated reproductive (seed and pod wall) dry weight at a greater rate than Williams by setting a greater number of pods containing at least one seed. Corsoy initiated reproductive development earlier in the growing season than Williams which resulted in Corsoy accumulating less vegetative dry weight and leaf area than Williams. The results suggested that earlier reproductive development might enable the pod filling period to be lengthened without affecting the harvest maturity date.

Crude Protein, IVOMD, and Yield of Stockpiled Limpograsses1

AbstractMost tropical grasses show a marked decline in digestibility with age, thus a system of field stockpiling is not suitable. The purpose of this research was to investigate the use of three limpograss (Hemarthria altissima [Poir] Stapf. et C. E. Hubb) cultivars as autumn‐winter conserved forage. In 1976, plots of each cultivar were clipped and allowed to regrow from 1 July, 29 July, and 26 August. Six yield and quality harvests were taken at 6 week intervals beginning on 23 Sept. 1976. In 1977 all plots were clipped and allowed to regrow from 1 August with five harvest for yield and quality taken at 4‐week intervals beginning on 26 Sept. 1977. The yield results from 1976 suggest that stockpiling should begin by 1 August to allow for adequate dry matter accumulation by first freeze. ‘Redalta’ had higher yields than either ‘Greenalta’ or ‘Bigalta’ in both years, but dry matter accumulation patterns were similar for all grasses. In vitro organic matter digestion (IVOMD) of Bigalta was higher than Redalta or Greenalta at all sampling dates in both years. Regression analysis indicated a higher intercept and lower rate of decline in IVOMD of Bigalta than either Redalta or Greenalta.Log transformation of crude protein (CP) increased (P > 0.05) the fit over the linear model for all grasses. The decay in CP occurred rapidly in all grasses and by the time the grasses would be consumed as a stockpiled forage it had dropped below the level necessary to maintain zero N balance in the grazing animal. No meaningful differences in CP among grasses were observed. Our results suggest that Bigalta Limpograss has potential fot autumn‐winter stockpiling, but Redalta and Greenalta are probably not acceptable.

Production and regrowth characteristics ofLotus pedunculatusCav. cv. ‘Grasslands Maku’

Abstract Herbage production of Lotus pedunculatus cv. ‘Grasslands Maku” was measured for 6 cutting regimes and regrowth was characterised in terms of dry matter accumulation patterns, shoot densities, and leaf area indices. Regrowth was consistently slow for the first 2–3 weeks after cutting. Production increases were therefore recorded where regrowth intervals were extended and higher growth rates were allowed to be expressed. Higher cutting improved shoot regrowth, but greater dry matter losses from the death of stubble and the disappearance of dead material resulted in little, if any, improvement in net productivity. With lower and/or less frequent cutting, canopy growth was dominated by rhizome shoots and the amount of stubble shoot, stubble and dead material within the canopy declined. Rhizome shoots were the major source of potential shoot production; however, the full realisation of this potential through the manipulation of defoliation strategies was difficult. The implications of these regrowth p...

Dry Matter Accumulation, Mineral Concentrations, and Nutrient Distribution in Winter Wheat1

AsbtractFew studies measuring dry matter accumulation and nutrient distribution in hard red winter wheat (Triticum aestivum L.) over the life cycle of the plant have been reported. Therefore, we established an experiment to study the growth and development pattern of ‘Centurk’ wheat in eastern Kansas and to measure changes in the N, P, K, Ca, Mg, Cu, Mn, and Zn concentrations in various plant parts collected throughout the growing season. Total dry matter accumulation was measured by collecting all above ground plant material. Plant samples were fractionated into living leaves, senescing leaves, stems, heads, head parts, grain, and crowns which were dried, ground, wet‐digested, and analyzed. Regression analyses were computed to identify significant trends. Total dry matter accumulation averaged 0.8 metric tons/ha in the fall, and reached a maximum of 13.0 metric tons/ha at physiological maturity. Nitrogen, P, K, Ca, and Cu concentrations in whole plant samples collected during the fall decreased gradually, while Mg and Zn concentrations remained relatively constant. The S and Mn concentrations were extremely variable and showed no significant statistical trends. Nitrogen, P, K, Ca, Cu, Mn, and Zn concentrations decreased in whole plants as they approached physiological maturity. Magnesium concentrations were relatively constant at approximately 0.18% during the spring. Analysis of individual plant fractions showed nutrient changes similar to those found in the whole plant samples. Grain yields from these experiments were similar to those reported for ‘Centurk’ wheat in performance trials. We feel that this information is useful in identifying the pattern of dry matter accumulation and in illustrating changes in nutrient concentrations during the life cycle of hard red winter wheat.

Plant Water Stress Effects on Irrigated Grain Sorghum. II. Effects on Nutrients in Plant Tissues1

A field study was conducted to determine nutrient concentration and dry matter and nutrient accumulation patterns in grain sorghum [Sorghum bicolor (L.) Moench] plants and to determine the effects of plant water stress on these parameters. Grain sorghum hybrid ‘Pioneer 8311’ was grown under five irrigation treatments to givestress periods varying in timing and duration.Samples were collected at weekly intervals from plants grown with and without stress from (i) early boot until early grain filling, (ii) heading until late grain filling, (iii) early grain filling until near physiological maturiy, and (iv) from early boot until mid‐grain filling. Plants were partitioned into component parts for dry matter estimation and analysis for N, P, K, Ca, Mg, and NO3. Plant water stress reduced N and P concentrations in leaves and increased N concentration in stalks and heads, but did not affect NO3−N, K, Ca, and Mg concentrations.In unstressed plants, dry matter accumulation proceeded at a near constant rate from about 40 days after planting until physiological maturity. Nutrient accumulation rates tended to be near‐constant from 40 days after planting until flowering and then slowed somewhat. At flowering, plants had accumulated 59, 77, 72, 90, 88, and 65% of their total dry matter N, P, K, Ca, and Mg, respectively. Plant water stress reduced dry matter and nutrient accumulation. Nitrogen and P were affected more than K, Ca, and Mg.

Pattern of dry-matter accumulation, and nitrogen concentration and uptake as influenced by levels and methods of nitrogen application in rainfed-upland rice

Dry-matter accumulation, and concentration and uptake of nitrogen increased with increasing level of nitrogen at all the stages of crop growth. The differences in nitrogen concentration due to nitrogen levels were greatest at panicle initiation stage and started becoming narrower with the advancement in crop age. Split application of nitrogen with its heavier fractions at tillering and panicle initiation stages either through soil alone or soil+foliage (1/3+1/3+1/3) resulted in higher dry-matter accumulation, and higher nitrogen concentration and uptake than other methods. The crop, on an average, removed 61 kg N/ha. Plants accumulated nearly 15% of the total absorbed nitrogen, up to tillering, 50% up to panicle initiation and 85–90% up to heading. Proportionately lesser nitrogen uptake and dry-matter accumulation at post-heading stage is an indicative of a major constraint for production efficiency of rainfed-upland rice culture.

Comparative Studies on Dry Matter Production, Plant Type and Productivity in Soybean, Azuki Bean and Kidney Bean : I. Differences in dry matter accumulation patterns under the low population density

The object of this study is to investigate the differences in dry matter production, plant type and productivity in soybean (Glvcine max Merr.), azuki bean (Vigna angularis) and kidney bean (Phaseolus vulgaris L.). For the first trial of this study, dry matter accumulation patterns of three crops including twelve varieties were compared under the low population density (60cm × 45cm, singling). The results obtained were summarized as follows: 1. Varietal differences in dry weight of vegetative portion were cleared up after about the initiation of flowering in each crop. Indeterminate types of soybean and kidney bean, and late varieties of azuki bean produced more vegetative matter than determinate and early ones. 2. The distribution ratio of dry matter to leaves was the highest in the early growth stage and gradually declined with time in all varieties. However, some of them were found to show a peak at the initiaI branch-elongation stage just before the flowering. 3. The distribution of dry matter produced during the overlapping period of vegetative and reproductive growth were closely related with the degree of determinancy and earliness; the distribution ratios (%) into vegetative portion were higher in indeterminate and late varieties than in determinate and early ones, and those into reproductive portion indicated the opposite relation with vegetative one. 4. In azuki bean there were little differences in number of leaves and dry weight on main stem among varieties. Varietal differences of total dry matter weight (g/pl.) which were heavier in late varieties resulted mainly in the differences in branches. Main stem ratios (main stem/main stem+branches, %) in dry weight wcre lower in late varieties, especially in viny types. 5. Two peaks of net assimilation rate (NAR) appeared in some varieties of each crop. One occurred at the initial branch-elongation stage in each crop, the other at young pod stage in soybean and at pod filling stage in azuki bean. The patterns of relative growth rate (RGR) were similar to those of NAR, and the peaks were more remarkable in RGR. In kidney bean, values of NAR of indeterminate types decreased rapidly after the flowering. 6. At the initial branch-elongation stage, NAR was corrclated positively, but not significantly, with the distribution ratio of dry matter to leaves (r=0.85) in kidney bean. NAR also indicated positive and significant correlations with the pod growth rate (r=0.83) and the distribution ratio into pod (r=0.95) of main stem at pod filling stage in azuki bean. 7. Grain yield per plant was positively correlated with the growth period, number of node per plant and maximum leaf area. Grain weight per maximum leaf area (g/m2) was, however, lower in indeterminate types than in determinate ones in kidney bean.

Dry Matter Accumulation Patterns in Indeterminate Phaseolus vulgaris L. Cultivars1

It has not been determined how extent of continued vegetative growth after flowering in dry bean (Phaseolus vulgaris L.) affects yield potential. Since indeterminate dry bean cultivars range in stature from short and erect to tall vines, it is important to determine to what extent continued shoot elongation after flowering influences dry matter partitioning into developing pods. ‘Monteigao Fosco’ (MF), ‘Rico 23’ (R23), and ‘Ricopardo’ (RP) are erect, semi‐erect, and vining indeterminate cultivars, respectively, with approximately equal maturity dates. Central leader length, total shoot length, numbers of lateral shoots, nodes, flowers, pods, and leaves, and dry wt of shoots, leaves, and pods were determined for each cultivar at biweekly sampling dates beginning at the second trifoliate leaf stage and continuing until maturity. At initial flowering, MF, R23, and RP had reached 88, 46, and 57% of central leader length, 53, 53, and 31% of total shoot growth, and subsequently developed two, six, and seven additional nodes, respectively. MF developed more lateral shoots than both R23 and RP. Despite these variations in growth habit, dry matter accumulation patterns were similar for the three cultivars, suggesting that plant type may not be an important factor in determining yield potential.

Variation between and within species of rapeseed (Brassica campestris and B. napus) in response to drought stress. II.* Growth and development under natural drought stresses

Two rapeseed species and cultivars within each of these species differed significantly with respect to the influence of variation in sowing date on growth, development and yield on two different soil types. Soil moisture stress, particularly after anthesis, was the major environmental factor affecting these processes. Grain yield declined markedly with later sowings in both species, and B. napus, despite its later maturity, was more tolerant of severe soil moisture deficits since its grain yield was consistently higher than B. campestris in the more stressed environments. The major distinguishing feature between species contributing most to this difference in yield was the pattern of dry matter accumulation. In B. campestris most of the dry weight of the plant was accumulated after anthesis when drought was most severe, whereas in B. napus dry weight accumulation occurred before anthesis. This resulted in a greater contribution of reserves accumulated by anthesis to grain-filling in B. napus. Most of the variation in seed yield resulted from differences in sowing dates and soil types. When these environmental effects were excluded, the main determinants of genotypic variation in yield were the numbers of pods and branches and harvest index in both species, growth rate in the post-anthesis phase in B. campestris, and plant weight and root/shoot ratio at anthesis in B. napus. Selection strategies for yield improvement in rapeseed growing in drought-stressed environments are discussed. _____________________ *Part I, Aust. J. Agric. Res., 29: 469 (1978).

HERBAGE DRY MATTER PRODUCTION: THE BALANCE BETWEEN GROWTH AND DEATH

Dry matter accumulation patterns in pastures are the net result of two processes: the growth of new herbage and the death, and disappearance of old herbage. The relative importance of these two processes in influencing regrowth is discussed and illustrated with data from two markedly different pasture types. In a Nui ryegrass/ white clover pasture and a pure Maku lotus sward, defoliation intensity and season markedly influence the accumulation of dead material, its subsequent disappearance, and hence net dry matter production. The effect of new growth on dry matter accumulation was greatly diminished by within-canopy dry matter losses. The implications of herbage death and disappearance are discussed with reference to the adequacy of certain experimental techniques in estimating herbage dry matter production.

Standing crop dry matter accumulation and quality patterns of certain subtropical pasture species

Abstract Nine‐week production curves and quality values of eight subtropical pasture species were studied under supplemental spray irrigation to characterize their productive capacity, periodicity and quality. All species exhibited a slow dry matter regrowth rate for two to three weeks after defoliation to 7,5 or 10 cm height. Thereafter, there was an ever increasing rate of production up to nine weeks with the exception of certain species in certain seasons, which reached the point of inflection in production rate after a shorter regrowth period. When dry matter accummulation is most rapid, quality is unsatisfactory. Bushman Mine and Sabi panicums gave their highest dry matter production in the late season; Pennisetum clandestinum, Eragrostis curvula and Anthephora pubescens in the early season; whereas, Cenchrus ciliaris, Cynodon nlemfuensis and Medicago sativa differed little in early and late season. All species lost quality fairly suddenly, or steadily, after 4,5 to 6 weeks regrowth without moisture ...

Dry Matter Accumulation in Maize in Response to Defoliation1

AbstractPrior investigations have reported the effect of leaf removal at various stages of development on yield of corn (Zea mays L.), but none have studied the pattern of grain dry matter accumulation. Therefore, this study was conducted to evaluate the effect of leaf loss on dry matter accumulation patterns of corn grain and grain yields. Defoliation was begun 10 days after 50% silking and continued at 10‐day intervals for the next 40 days. Leaf removal treatments consisted of removing 1) no leaves (control), 2) all leaves below the ear, 3) all leaves above the ear, and 4) all leaves. Dry matter accumulation was monitored by sampling ears at 5‐day intervals from 50% silking to black layer formation.Regardless of severity, defoliation within 30 days after silking significantly reduced total accumulated dry matter. Complete defoliation was more detrimental (6.4 to 82% yield loss) than partial defoliation (1.5 to 32.7% yield loss). These losses varied with time (after 50% silking) of treatment application. The effect of removing all leaves above the ear was not significantly different from that obtained by removing all leaves below the ear.Yield component affected most by leaf loss, for the overall treatment period, was kernel weight (12.7 to 53% decrease). However, number of kernels was greatly reduced (62.3%) when all leaves were removed 10 days after silking. Complete leaf removal thereafter and partial leaf removal affected number of kernels considerably less (approximate decline, 20%).This study showed that severe leaf loss at the onset of silking and until at least 10 days after 50% silking decreased grain yields because of fewer kernels. However, yield decreases associated with less severe leaf loss or loss 20 days or more after 50% silking were largely related to a decline in kernel weight. In addition to providing a better understanding of patterns of dry matter accumulation, these data may be useful to individuals required to estimate grain yield after a significant loss, to natural causes, in plant leaf area.

Defoliation studies in hybrid maize: II. Dry-matter accumulation, LAI, silking and yield components

SUMMARYData are presented from an experiment made in two crop seasons, to examine the effects of plant density and degree of defoliation at different stages of growth in maize at Pantnagar, India, on the dry-matter accumulation in different plant parts, leaf area index (LAI), time of silking and grain yield components.Different patterns of dry-matter accumulation in various plant parts was observed. Silking was delayed by increasing plant density. Defoliation (even partial) at the 16th fully expanded leaf stage resulted in substantial reduction in LAI and such yield components as number of ears, ear length, ear diameter and 1000-grain weight. On the other hand, partial defoliation done at the 10th fully expanded leaf stage to simulate an ‘erectophile canopy’ led to yield increases even under high plant density (90000 plants/ha) in the Kharif (rainy season), mainly through an increase in number of ears, 1000-grain weight and grain to stover ratio coupled with a reduction in barrenness and percentage of lodging. It is suggested that an increase in the photosynthetic efficiency per unit area of leaf resulting from the ‘erectophile canopy’ is the reason for these effects.

Sorghum Growth and Nutrient Uptake in Relation to Soil Fertility: I. Dry Matter Accumulation Patterns, Yield, and N Content of Grain1

AbstractAn understanding of the seasonal dry matter accumulation pattern of the sorghum [Sorghum bicolor (L.) Moench] plant under varying fertility levels is important for planning an efficient fertilization program. Field experiments were conducted to determine the effects of varying rates of N (0, 60, and 120 kg/ha) on the dry matter accumulation pattern, yield, and grain N content of a sorghum hybrid. Plant samples were collected at weekly intervals and partitioned into component parts for dry matter estimation.The rate of dry matter accumulation in fertilized plants was rapid early in the season and continued almost linearly until maturity (91 days after sowing), but in unfertilized plants it began to drop after 70 days. In general, dry matter weight of leaves and stems reached a maximum by the 56th and 70th days, respectively, and then remained almost constant. The subsequent increase in total dry weight was due to increased head weight. Accumulation rate in the heads of fertilized plants at 70 and 77 days was very high in comparison to that of unfertilized plants. Contributions of stem, leaves, and head to the total dry matter yield with N0P0 and N120P26 treatments were 41, 23, and 36%, and 32, 18, and 50%, respectively.Dry matter yield of whole plant, grain yield, and grain N content were higher with 60 kg N/ha than with no nitrogen by 26, 47.6, and 14.5% respectively. They were also higher (9.2, 8.8, and 10.9% respectively) with 120 N/ha. Dry matter and grain yields were higher with 26 kg P/ha than with no P by 25.6 and 46.2% respectively. N content of grain was unaffected by addition of P.

Dry Matter Accumulation Patterns in Determinate and Indeterminate Soybeans1

Comparisons were made of the accumulation of dry matter in the various plant components of a determinate (D66‐5566) strain had an indetermate (‘Kent’) soybean [Glycine max (L.) Merrill] cultivar using field‐grown plants for 2 years at Lexington, Ky. Kent and D66‐5566 are of similar maturity and yielding ability.At initial flowering D66‐5566 had reached 84% of its maximum height, compared with 64% for Kent. At this point the stem dry weight of D66‐5566 was 67% of the maximum compared with 30% for Kent. Although stem elongation of the determinate type was nearly complete when flowering began, it continued to increase in dry weight.At initial flowering Kent had produced 58% of its total vegetative material, compared to 78% for D66‐5566. Both types produced very little vegetative growth after a measurable amount of dry weight had accumulated in the pods and seeds. Kent produced more vegetative material during flowering and pod set, and the potential for competition for photosynthate between reproductive and vegetative growth was greater.The rate of accumulation of dry matter in the pods and seeds was greater for D66‐5566 than Kent in 1970, but there was no significant difference in 1971. The rates of both types were greater in 1970 than 1971, although grain yields were greater in 1971 than 1970. The length of the effective filling period, i.e., the grain yield divided by the rate of grain filling, was longer for both types in 1971 than 1970, and was thus positively associated with grain yields.

The Characterization of Dry Matter and Nitrogen Accumulation by Loblolly Pine (Pinus taeda L.) on Poor Sites

Twenty-five trees, equally distributed to represent five tree developmental stages, were sampled on uplands with a site index of 65 feet in central Mississippi. The aerial portion of the trees was divided into seven components and dry matter and total nitrogen contents of each determined. The pattern of dry matter accumulation by the individual trees and stands through the series of developmental stages differs. The individual tree and all its parts make accretions throughout development, while some portions of the stands reach a fairly constant level at 23 years. At 60 years the stand contained 126,000 pounds of dry matter per acre of which 56% was accumulated during the first 23 years. The pattern of nitrogen accumulation within the individual tree and its parts is similar to that of dry matter while for the stand the similarity is not so striking. This variation is chiefly brought about by the variations in crown and canopy development. At 60 years a standing crop contained approximately 170 pounds of N per acre of which 77% was accumulated during the first 23 years.