M2 Of Leaf Area Research Articles

Evaluación de parámetros relacionados con el crecimiento de plantas de café (Coffea arabica L.) en respuesta al déficit hídrico del suelo

Contextualization: Water is indispensable for plant development, and its response to water deficit varies according to the species and their growth stages. Knowledge gap: The magnitude of the effect of soil water deficit on the growth of young coffee (Coffea arabica L.) plants evaluated over time is unknown. Purpose: Research was carried out to identify the effect of soil water deficit and, therefore, the sensitivity to drought in young coffee plants. Methodology: The deficit irrigation method was used. Coffee plants of the Cenicafé 1 variety were planted at three months old in cylindrical pots and conditioned for four months in mesh houses at Cenicafé - Planalto. After conditioning, the effect on plants' growth and dry matter subjected to five ranges of soil matric potential was evaluated over 140 days. Potentials ranged from -20±10 kPa (control) to -1600±100 kPa. Results and conclusions: The results showed that soil water deficit affects the growth of young coffee (C. arabica) plants, which could define C. arabica at this stage as drought sensitive. Plants subjected to the least stress and the extreme drought showed a 30% and 57% decrease in dry matter, respectively. For growth variables, the effect of water deficit was evident in the evaluations at 77, 113, and 140 days of treatment application. In all cases, the results showed differences between the extreme drought and the control of up to 30cm in height and equatorial diameter, 0.9 m2 of leaf area, 132 leaves, 3 branches, and 66 nodes. The mathematical models that explained the effect of drought on dry mass were of the logarithmic type. It was identified that for weather and soil conditions similar to those in the study, young coffee plants begin to deteriorate after 40 days of drought. With a soil matric potential close to -40 kPa, for a time of 120 days, coffee plants can lose 10% of dry mass, and when the potential exceeds -90 kPa there can be further losses in dry matter and decreases in the number of branches between the 77 and 113 days.

Growth and nutrient accumulation metrics of Diodia saponariifolia plants as a potential native cover crop in southeastern Brazil

Competition for resources between crops and weeds hinders the increase of production in agroecosystems. The trait-based plant species selection of cover crops can be a useful tool to suppress competing plants in addition to providing environmental services. Here, we assessed the growth and macronutrient accumulation metrics in Diodia saponariifolia (Rubiaceae) plants, a native cover crop found in family farming systems in southeastern Brazil. Under greenhouse conditions, three viable D. saponariifolia cuttings were planted per tray. The experimental design was entirely randomized, with treatments consisting of plant sampling times, at regular intervals of 7 days between 16 and 93 days after transplanting (DAT) and 15 days between 93 and 138 DAT. Based on dry mass and chemical analysis of leaves, stems, and roots; we fitted the logistic model to explore the metrics of growth and macronutrient accumulation. Overall, the increment in plant dry mass was slow about halfway through the experimental period, being subsequently replaced by a phase of rapid growth. The stem was the plant fraction with the highest relative biomass accumulation. The total macronutrient concentration followed the descending order of K > N > Ca > Mg > P, varying along the plant ontogeny. Considering the nutrient content, the estimated 200 g m−2 of aboveground dry mass, and 0.3 m2 of leaf area, it is suggested to perform the first mechanical weeding along the third month of growth. Our results suggest that D. saponariifolia has satisfactory agronomical features for its establishment as a cover crop in different agricultural contexts.

Potted plants can remove the pollutant nitrogen dioxide indoors

Nitrogen dioxide (NO2) is a significant pollutant in both outdoor and indoor environments with exposure linked to serious respiratory illnesses, decreased lung function and airway inflammation. Here, we investigate whether potted plants can contribute as a simple and cost-effective indoor air pollution mitigation technique. Our study investigates the ability of the combination of the three plant species Spathiphyllum wallisii ‘Verdi’, Dracaena fragrans ‘Golden Coast’ and Zamioculcas zamiifolia with two different growing media to remove in situ concentrations (100 ppb) of NO2 in real-time at two typical indoor light levels (0 and 500 lx) and in ‘wet’ and ‘dry’ growing media conditions. All studied ‘growing medium–plant systems’ were able to reduce NO2 concentrations representative of a polluted urban environment, but to varying degrees. The greatest NO2 removal measured inside a 150 L chamber over 1-h period in ‘wet’ growing media at ~ 500 lx was achieved by D. fragrans. When accounting for dilution, this would correspond to a removal of up to 3 ppb NO2 per m2 of leaf area over the 1-h test period and 0.62 ppb per potted plant over the same period when modelled for a small office (15 m3) in a highly polluted environment. Depending on building ventilation rates and NO2 concentration gradients at the indoor-outdoor interface that will vary massively between polluted urban and rural locations, potted plants offer clear potential to improve indoor air quality—in particular in confined indoor spaces that are poorly ventilated and/or located in highly polluted areas.

Increase of Onion Productivity by Regulation of Growing Technology Elements

This article describes the impact of growth regulators used as foliar dressing on the high-quality commercial production of Mars and Candy F1 hybrid onion bulbs grown in the Rostov Region. The highest yield of finished product per 1 thousand m2 of leaf area and 1 thousand units of photosynthetic potential (PSP) was observed when the Candy and Mars hybrids were treated with Novosil (3.9-4.1 t and 45.0-47.0 kg, respectively), which also produced the highest rates of net photosynthesis productivity: 8.5-8.7 g / m2 per day. The effect of the agent on growth processes was slightly more effective in the Candy hybrid. It was established that the use of Novosil and Immunocytophytes foliar dressing in growing technology makes it possible to obtain the Mars and Candy hybrids at the level of 49.0-50.1 t / ha, reduce the consumption of additional irrigation water per unit of production and improve the quality of commercial onion bulbs and their storage for a long winter period. The increase in storage resulting from the use of Novosil occurred due to the decrease in the natural loss and mass of the sprouted bulbs.
 Keywords: onion, hybrid, yield, stimulant fertilizer, storage, quality

Invertebrate Abundance, Biomass, and Richness Associated with an Exotic Invasive Shrub (Lonicera morrowii A. Gray)

Exotic bush honeysuckles (Lonicera spp.) are becoming increasingly common in the eastern and mid-western United States, but little is known about their impacts on invertebrates. We used a modified leaf vacuum to sample invertebrates in the shrub strata and understory of three shrub types (and open plots in the understory): single Morrow’s honeysuckle (L. morrowii A. Gray) shrubs, single native southern arrowwood (Viburnum recognitum Fernald) shrubs, and dense thickets of Morrow’s honeysuckle, in southwestern PA, USA during 2004 and 2005. We also assessed the degree of herbivory on the two species of shrubs. Within the shrub strata, invertebrate biomass was lower in southern arrowwood shrubs, but there was no difference in invertebrate abundance or family richness. Invertebrate abundance and richness were lowest in August, but there was no difference in biomass among the months. Invertebrate abundance, biomass, and family richness were lowest in the understory below dense thickets of Morrow’s honeysuckle. Overall, the percent cover of herbs was the proximate factor responsible for driving patterns of invertebrate abundance, though ultimately these patterns were being driven by shrub type. Abundance and biomass of larval leaf chewers were highest in the native shrub; Morrow’s honeysuckle had a mean of 29.7 cm2 of leaf area consumed per 1 m2 of leaf area, while the native shrub had a mean of 284.3 cm2 of leaf area consumed. Our results suggest that areas dominated by the exotic shrub negatively impact invertebrate biomass, which may in turn affect organisms at higher trophic levels.

Fruit, mesocarp, and endocarp responses to crop load and to different estimates of source: sink ratio in olive (cv. Arauco) at final harvest

Abstract The annual fluctuations in olive crop load due to alternate bearing and other factors often lead to large differences in fruit size and oil content between years at harvest. A better understanding of how fruit parameters respond to the different leaf: fruit (i.e., source: sink) ratios that occur with contrasting crop loads would provide important information for crop management. Thus, the primary objectives of this study conducted with the cv. Arauco in three growing seasons were to: 1) determine the weight and size responses of the fruit and its main tissues, mesocarp (pulp) and endocarp (pit), to crop load; and 2) obtain relationships between different estimates of the source: sink ratio versus various fruit and oil parameters. Fruit thinning was performed by hand on uniform trees with high initial crop loads four weeks after full bloom the first season to obtain different crop loads at harvest. The thinning percentages the first season were 24%, 48% and 87%, along with an unthinned control. The same trees were then monitored the following two seasons without any further thinning. Fruit were sampled at harvest each season to determine fruit and tissue weights and diameters, oil weight per fruit, and oil concentration (%). Fruit weight was reduced 30–40% by high crop loads in each growing season with the mesocarp being much more affected than the endocarp. Oil weight per fruit (−50%) showed a somewhat greater reduction than fruit weight to crop load due to both fruit diameters and fruit oil concentration being decreased at high crop loads. Fruit and tissue weights and oil weight per fruit all displayed bilinear functions versus source: sink ratio when the source was expressed as canopy volume (a surrogate for leaf area) and sink on both a fruit number and glucose equivalent (GE) basis. Source limited fruit growth at both medium and high crop loads due to limited photoassimilate availability based on the bilinear functions, and the slope of the endocarp response to source: sink ratio was 15 times less than that of the mesocarp when expressed on a GE basis. A quantitative comparison with previously published studies indicated that maximum fruit weight appears to be obtained in olive between 1–2 m2 of leaf area per kg of GE. The bilinear relationships of source: sink ratio versus fruit weight observed in this study could contribute to crop modelling, and further research concerning how and when the mesocarp and endocarp respond to crop load is needed to aid crop management in obtaining sufficient fruit size and quality for table olive cultivars.

Environmental and crown related factors affecting street tree transpiration in Helsinki, Finland

We investigated the drivers of street tree transpiration in boreal conditions, in order to better understand tree water use in the context of urban tree planning and stormwater management. Two streets built in Helsinki in 2002, hemiboreal zone that had been planted either with Tilia × vulgaris or Alnus glutinosa f. pyramidalis were used as the study sites. Tree water use was measured from sap flow over the 2008–2011 period by the heat dissipation method. Penman-Monteith based evapotranspiration models of increasing complexity were tested against the tree water use measurements to assess the role of environmental and tree related factors in tree transpiration. Alnus and Tilia respectively used 1.1 and 0.8 l of water per m2 of leaf area per day under ample water conditions, but the annual variation was high. The Penman-Monteith evapotranspiration estimate and soil water status changes explained over 80 % of the variation in tree transpiration when the model was parameterized annually. The addition of tree crown surface area in the model improved its accuracy and diminished variation between years and sites. Using single parameterization over all four years instead of annually varying one did not produce reliable estimates of tree transpiration. Tree transpiration, scaled to different canopy cover percentages, implied that the columnar Alnus trees could transpire as much as all annual rainfall at or less than 50 % canopy cover.

Optimizing Substrate Moisture Measurements in Containerized Nurseries

The primary goal of this study was to determine the optimum number of substrate moisture sensors needed to accurately determine substrate water content for 10 tree species in a containerized nursery. We examined variation in volumetric water content (VWC, m3·m−3) within containers, within species, among species, and over time. Across time, differences among species were not significant (P = 0.14). However, differences among time periods and the interaction effect between species and time periods were significant (P < 0.001). Seasonal differences in within-species variation were also evident in nine of the 10 species. In an attempt to understand species-specific mechanistic factors that influence within-species variation in VWC, we accounted for physiological and morphological differences affecting transpiration with a spatially explicit mechanistic model, MAESTRA. Neither estimated transpiration rate per whole crown or m2 of leaf area could explain variation in VWC. Based on our results, we recommend species-specific sensor deployment and report sensor quantities that estimate the mean substrate VWC of each species within a confidence interval of ± 5% VWC. Given the economic value of water and its control on biomass production, we conclude that nursery managers can maintain optimal substrate moisture with minimal sensor deployment.

Relações entre transpiração máxima, evapotranspiração de referência e área foliar em quatro variedades de mangueira

Nas condições edafoclimáticas de Cruz da Almas - BA, na Embrapa Mandioca e Fruticultura Tropical, foi realizado um estudo no qual se relacionou a transpiração máxima (Litros m-2 folha/dia -1) de quatro variedades de mangueira (Tommy Atkins, Palmer, Haden e Van Dyke, com áreas foliares totais de 14; 8; 33 e 12 m², respectivamente) com a evapotranspiração de referência (ETo). A transpiração das plantas (L dia-1) foi estimada por meio de sensores que realizam o balanço de calor no caule (modelos SAG13; SGB9; SGB16; SGB19 e SGB25, Dynamax Inc.) dispostos nos sentidos norte (N), sul (S), leste (E), oeste (W) e centro (C) de cada planta. A transpiração por unidade de área foliar (Lm-2 folha dia-1) variou em média de 1,58 ao longo do período estudado, e linearmente com o aumento da área foliar total da planta, independentemente da variedade estudada. A transpiração (Litros m-2 folha/dia -1) variou de 0,36 a 3,00, dependendo da demanda atmosférica. A transpiração máxima (T) das quatro variedades de mangueira (Litros m-2 folha/dia -1) relacionouse linearmente com a ETo (T = 0,44. ETo; r² = 0,78), sendo um excelente subsídio para o manejo de irrigação por gotejamento nesta cultura.

Leaf uptake and subsequent partitioning of urea-N as affected by the concentration and volume of spray solution and by the shoot leaf position in apple (Malus domestica) trees

SummaryIn a ®eld experiment on `Golden Delicious' apple trees, different combinations of labelled (10 at. % 15N) urea concentrations (4, 20 and 40 g l±1) and spray volumes (1500, 300 and 150.l ha±1) were used in mid summer to foliar apply 920.mg N per tree by the following treatments: 1) low concentration-high volume, 2) medium concentration-low volume, 3) high concentration-ultra low volume. The fate of urea-N sprayed on leaves was followed during a 5.d period from spraying by determining 15N concentration on leaf samples collected at different timings and on entire branches, previously girdled. Basal and apical leaves were sampled 1, 5, 24, 48 and 120.h after spraying. Leaves intercepted on average 24.mg labelled N per m2 of leaf area, regardless of treatment and leaf age. Leaf N uptake within 48.h was highest when urea was sprayed at low concentration-high volume. At the end of the experiment (120.h), however, no signi®cant effect of treatments on leaf uptake was recorded. Urea-N penetrated at higher rates on apical than basal leaves. While about 50% of the intercepted urea-N was recovered in the leaves sampled 120.h after application, the sum of fertilizer N recovered in the different organs of the girdled branches accounted for 84% of the estimated amount of N intercepted. The discrepancy between these two estimations can be explained considering that part of the N taken up from the leaves was rapidly exported and recovered in the fruits. Application of low volume with a high concentration of urea should be considered as a tool to decrease costs while maintaining a high N use ef®ciency.

Effects of crop load on tree water use in apple (Malus x domestica Borkh.)

Sap flow rate measurements were carried out during two consecutive ('on' and 'off') years in an apple orchard cv. 'Florina' M.26 to analyse the effects of various crop load on tree water use. Sap flow rate was measured by thermal dissipation method in trunks of nine trees from June to the harvest. Crop load was between 0.2-9.0 fruits • cm -2 of trunk cross section area (equal to 0.5-35.0 fruits•m-2 of leaf area), trunk diameter varied between 4.7-8.7 cm.
 Total leaf area was estimated by leaf counting or using shoot girth and leaf area relationship. In both years, fruit growth rate was determined by measuring diameter of 280 marked fruits with 7 days frequency. Fruit volume calculated as a function of fruit diameter based on a previously determined relationship.
 Total leaf area of trees ranged from 4.4 to 19.5 m2 and it was closely related to trunk cross section area. At high crop load the fruit growth rate peaked in August with 0.51.tree-l.day-1 and the leaf area specific total fruit volume reached 61 m2 before the harvest.
 There was a linear relationship between total leaf area and daily water use, while the leaf area specific water use was influenced by crop load rate. The relationship was described by piecewise linear regression with the breakpoint at crop load rate of 12 fruits•m2 of leaf area. At low crop load the slope of the fitted regression line was less than at high crop load rate.

The historical reconstruction of growth efficiency and its relationship to tree mortality in balsam fir ecosystems affected by spruce budworm

The growth efficiencies (E; stemwood growth per unit leaf area) of balsam fir (Abiesbalsamea (L.) Mill.) trees from 20 stands were reconstructed over the 30-year period from 1960 to 1989 in order to determine if E could be used to predict tree mortality occurring during and after an epidemic of eastern spruce budworm (Choristoneurafumiferana (Clem.)). Growth efficiencies were reconstructed based on the relationship between age and the number of annual growth rings in the cross-sectional area of heartwood at breast height (R2 = 0.97) and on the previously demonstrated relationship between sapwood area and leaf area of balsam fir across a wide geographic area. Profile and logistic regression analyses demonstrated that apparent E (i.e., the historically reconstructed E) of surviving trees was greater than that of dead trees for every year of the 30-year analysis period. For trees in the 25- to 35-year age-class in 1960, apparent E was the only variable measured prior to the epidemic that was significantly related to balsam fir mortality. For all trees (aged 11 to 46 years in 1960), both tree age and apparent E were significant factors prior to the epidemic. During and following the epidemic, several of the more standard mensurational variables (e.g., diameter and basal area growth) were also significantly associated with balsam fir mortality, but apparent E had the highest levels of significance. Using logistical regression, critical E values below which trees would be predicted to die were calculated as 5-year running averages for the period prior to the epidemic (1960–1968). These were stable at around 0.17 × 10−4 m2 basal area growth•(m2 leaf area)−1•year−1. Following the epidemic, critical E values were again stable but at a lower level of around 0.07. There was a negative exponential relationship between apparent E and leaf area. Furthermore, for the same level of leaf area, surviving trees had a higher apparent E than trees that died, up to approximately 30 m2 of leaf area. These results suggest that growth efficiency should be considered as part of standard forest inventories in the balsam fir zone because of its ease of measure and its apparent ability to provide a sensitive, physiologically based index of forest health. Furthermore, the technique of historically reconstructing E demonstrated in this study may be of interest for other types of dendrochronological research.

The Spatial Distribution of Herbivory, Mines and Galls Within an Australian Rain Forest Tree

The spatial distribution of herbivory, mines and galls was investigated within the crowns of the canopy tree Argyrodendron actinophyllum (Sterculiaceae) in a subtropical rain forest near Brisbane, Australia. Apparent leaf damage amounted to 11 percent of leaf area removed, was significantly higher in sun than in shade leaves, was not significantly higher in the upper crown (>25 m) than in the lower crown (15-25 m), and did not differ significantly among compass orientations. Leaf biomass removed by herbivores was significantly higher in the upper crown and in sun samples. Overall leaf damage, including leaflets entirely eaten and leaf-mining, ranged from 11 percent to 19 percent. However, actual leaf consumption was mainly restricted to young leaves, and amounted to about 16 percent; this was more dependent on the location of isolated, abundant, and sunny patches of young foliage than on local differences in foliar nutrient characteristics, such as total nitrogen and water content. Lepidopteran biomass and numbers were correlated with leaf damage in the samples. Leaf-mining, averaging 31 mines per m2 of leaf area, was significantly higher in the lower canopy. Gall densities approached three galls per m2 of leaf area. Galled leaves were significantly larger and less heavily grazed. Patterns of herbivory and leaf-mining observed are discussed in light of current information and theories relevant to insect-plant interactions in rain forests.

Water Relations of High-Elevation Phreatophytes in Wyoming

High-elevation phreatophytes were studied to identify environmental parameters influencing daily and seasonal water consumption. The water relations of Salix planifolia, S. wolfii and Betula occidentalis at 2865 m were similar throughout the day. Transpiration was reduced before 1000 hr as a result of dew on the leaves, but high stomatal conductances to water vapor (>15 mm s-1) and transpiration rates (>100 mg m-2 s-') occurred from 1000 to 1600 hr, resulting in daily water losses per unit leaf area of 4.5, 5.2 and 4.0 kg m2, respectively. Maximum stomatal conductances declined after 1 September in conjunction with minimum air temperatures consistently below 0 C and increased leaf senescence. The period of significant water consumption was from 10 July through 20 September. Diurnal variations in stomatal conductance of Salix exigua and S. amygdaloides at 2255 m were similar to those at the high-elevation site, but maximum stomatal conductances were only 51 % as great. However, transpiration occurred from sunrise to sunset at the lower elevation, resulting in daily water losses of 3.7 and 3.4 kg m2 of leaf area, respectively. Midday depressions in leaf conductance at the lower site may have been in response to xylem pressure potentials below 1.7 MPa. Seasonally, conductances were constant until a decrease occurred after 15 September, probably due to low temperatures and leaf senescence. The growth season at the low-elevation site was estimated to be from 15 June-30 September. Although there were differences between the two sites in maximum transpiration rates, microclimate and length of growth season, the data suggest that for both sites and all species examined, stomatal conductance and seasonal water use were most influenced by solar irradiance, dew on leaves, minimum air temperatures and phenology. INTRODUCTION At high elevations throughout the western United States, species of Salix often form dense thickets along streams. Although temperatures are relatively cool in these riparian communities, many high-elevation Salix species are very tolerant to low air (Sakai, 1970, 1974) and soil temperatures (Anderson and McNaughton, 1973), indicating a possibly prolonged growth season and continued water consumption when compared to other sympatric shrub species. Indeed, significant water consumption has been inferred for Salix-dominated communities based on estimates of evapotranspiration from environmental data (VanKlaveren et al., 1975). However, little information exists concerning the effects of environmental factors on the water relations of high-elevation phreatophytes, especially Salix. Bliss (1960) compared arctic and alpine Salix species with potometers, and found significantly greater transpiration rates in the alpine plants. Although he related transpiration to wind speed, air temperature and water vapor deficit of the atmosphere, measurements were not conducted throughout the growth season. Stoner and Miller (1975) and Miller et al. (1978) provided more in-depth evaluations of the water relations of Salix species on a seasonal basis, but their research was restricted to species of the wet coastal tundra of Alaska. The objective of the present study was to examine daily and seasonal patterns in the water relations of high-elevation phreatophytes. We present 'Present address and address for correspondence: Department of Biology, Virginia Commonwealth University, Richmond 23284.

カンキツの着果程度と樹の生長および収量との関係 (第1報)

The relationships between fruit load, fruit size, shoot growth and dry matter productivity of leaves were investigated with 5-year-old trees of Miyagawa Wase, an early ripening satsuma mandarin, grown under field conditions. After the fruits were harvested, 16 sample trees were dug out and various tree components such as current and older leaves, current shoots, older branches and roots were separately weighed. The growth of older branches during the last year was estimated based on their diameter and length measured two times at the time of sampling and one year before. As an indicator of fruit load, fruit number per kg of dry leaves in each tree was defined as “index of fruit load”.1. The total annual growth increment per tree (fruits+new leaves+current shoots+increment of older branches+increment of roots) was positively correlated with the total amount of leaves per tree.2. The production of both new leaves and current shoots per unit leaf biomass (1kg in dry weight) was found to decrease with increasing indices of fruit load.3. Higher index of fruit load resulted in the reduction of average fruit weight and the remarkable promotion of fruit productivity per unit leaf biomass. The trees bearing 1 fruit per 40-60 leaves, which was approximately equal to or slightly less than the normal level of fruit load in ordinary commercial orchards, produced 1.0-1.1kg of fresh fruit per m2 of leaf area.4. The annual growth increment per kg of leaves (nearly equal to the dry matter productivity of leaves) was 2.3-2.5kg/kg leaf•yr in extremely light bearing trees, while it increased up to about 3.7kg/kg leaf•yr with increasing fruit load in most heavily loaded trees.5. The relationships between the fruit load and average fruit size or fruit yield per unit leaf biomass seemed to be more or less similar to those between planting density and mean plant weight or yield per unit area proposed by Shinozaki and Kira (23). The quantitative formulation of the latter relationships, however, was inapplicable to the former case.

Growth Analysis of Grain Sorghum as Affected by Planting Density and Amount of Nitrogen

This study was conducted to clarify the dry matter production of grain sorghum and growing behavior with relation to planting rate and amount of fertilizer in order to obtain high grain yield. The hybrid variety, GS76Y was seeded on May 24 in 1972. The dry weight of each organ of plant was measured at intervals about 2 weeks apart ranging from the early stages of growth to ripening time. Irrigation was applied at half bloom stage. The results obtained were as follows; 1. The maximum rate of dry matter production was 42 g per m2 of field per day with the high planting density and heavy manuring plot during 14 days near heading date. In this period, mean daily solar radiation was 502 cal per cm2 of field and mean daily temparature was 28.4°C. 2. The mean maximum value of net assimilation rate in heavy manuring plots and in light manuring plots were 17.7 and 14.2 g per m2 of leaf area per day, respectively. The value of net assimilation rate was high at the early stages of plant growth and decreased with grow. 3. Grain yield was significantly varied with the planting density. The highest grain yield per are was 82 kg on the basis of dry matter. lt was obtained at planting densities of 25 and 40 plants per m2 of field on heavy manuring plots. 4. Total dry matter produced in ripening period ranged from 62 to 81 kg per are and was equivalent to above 90 percent of grain yield. 5. Dry matter production was depended largely upon leaf area before heading, and net assimilation rate after heading. The value of net assimilation rate during the ripening period decreased with higher leaf area index. However, in case 4 and beyond that of leaf area index, net assimilation rate was increased as the percent of nitrogen content of leaf blade, namely, there was positive correlation between net assimilation rate and percent of nitrogen content of leaf blade in the ripening period. 6. It was recognized that the number of grains per unit field was closely related to the amount of nitrogen absorption of top at heading date. The amount of nitrogen, phosphorus, and potassium absorption at ripening time were in the range of 17.8 to 25.1, 3 to 4 and 26 to 34 kg per 10 are, respectively.