Dry Weight Of Above-ground Parts Research Articles

Echinochloa crus-galli seedlings surviving florpyrauxifen-benzyl applications have a greater potential to produce resistant seeds

Abstract Florpyrauxifen-benzyl (FPB) is an important postemergence rice herbicide. This study tested the potential for seed production in an FPB-resistant barnyardgrass population. A barnyardgrass population (NL) collected from a rice field in eastern China was highly resistant to FPB with a GR50 dose (the FPB dose causing a 50% reduction in fresh weight of aboveground parts) of 50.2 g ai ha−1. No significant differences in the percentages of surviving seedlings after treatment with different doses of the herbicide were found between F1 lines collected from F0 plants surviving a 36 g ai ha−1 FPB treatment and those collected from nontreated control F0 plants. Additionally, no significant differences were found in the rate of surviving seedlings after treatment with varying doses of FPB among the F2 lines collected from F1 plants that survived varying doses of FPB. At a constant temperature of 30 C, seeds from different F1 and F2 lines showed germination percentages of 85% to 92.0% and 68.3% to 89.0%, respectively. In the absence of competition, plants from the NL population surviving 0–144 g ai ha−1 FPB showed no significant differences in plant height, dry weight of aboveground parts, effective accumulated temperature (EAT) from sowing to seed maturation, seed production per plant, or 1,000-seed weight. In the susceptible population (HJ), plants surviving 18 g ai ha−1 FPB showed no significant differences compared to the nontreated control plants of the same population for the above variables. This is the first report of FPB-resistant barnyardgrass in China. Barnyardgrass seedlings that survived FPB application showed a higher potential for accumulating in the soil seedbank and negatively affecting rice.

Counter Agronomic Systems and Maize Seed Vigour

Summary The quality and provenance of seed are of exceptional importance for the production and yield of cultivated plants. There are numerous tests for determination of seed vigour. The seed accelerated ageing test is one of the most important tests that provide determination of the degree of germination preservation and the seed longevity in storages. The aim of this study was to observe the effect of different production methods – organic and conventional – on seed vigour of maize (variety Rumenka), using the seed accelerated ageing test. Maize seeds were exposed to double stress conditions (temperature of 45 °C, air humidity of 100%) for 72h. Maize seed germination was determined by the standard germination test and was expressed as a percentage. The results of vigour of maize seeds organically produced indicated that the application of the seed accelerated ageing test increased the first count (78.5%) in relation to the standard germination test (70.75%), and a significantly higher percentage of nongerminated seeds (10.25%) were recorded. Furthermore, the radicle length decreased (120.75 mm), while the length of the seedling above-ground part (117.13 mm) and fresh weight (4.56 g) increased. In maize seeds conventionally produced, the first count and germination were higher (41.5% and 46.25%, respectively) after the application of the seed accelerated ageing test, while the percentage of nongerminated seeds were higher (38.75%). In addition, the length (105.88 mm) and fresh weight (4.43 g) of the seedling above-ground part decreased, while the values of the radicle length (137.5 mm), fresh weight (2.39 mm) and dry weight (0.28 mm) as well as dry weight of above-ground parts of seedlings (0.31 g) were higher than after the application of the standard laboratory method (127.88 mm, 1.89 g, 0.17 mm and 0.31 g, respectively).

绿豆种质资源苗期耐盐性鉴定及耐盐种质筛选

<p id="C3">Soil salinization has become one of the important factors affecting agricultural production in China. It is of great significance to screen germplasm resources of mungbean [<italic>Vigna radiate</italic> (L.) Wilczek] for the utilization of salinized land. In the present study, the seedlings of 346 domestic and foreign collections of mungbean were exposed to 150 mmol L ^-1 NaCl. To evaluate the salt-tolerance of different mungbean genotypes at seedling stage, 12 indicators were calculated, including plant height, fresh weight of above-ground part, fresh weight of root, dry weight of above-ground part, dry root weight, root length, and root volume. Salt tolerance of each sample was comprehensively evaluated and classified by principal component analysis, membership function analysis, salt tolerance comprehensive evaluation, and cluster analysis; and the regression equation of salt tolerance prediction was established by stepwise regression analysis. The results revealed that there were significant differences between treatment group and control group in each trait evaluation index, and the salt tolerance coefficients of the 12 indicators were correlated to some content. Combining the classification of salt damage symptoms and the comprehensive evaluation results of salt tolerance, 26 mungbean germplasms with high salt tolerance, 65 germplasms with high salt tolerance, 74 germplasms with salt sensitive, and 18 germplasms with extremely salt sensitive were selected at seedling stage. Among them, 10 varieties such as C04125 from Jiangxi and C06310 from the Philippines had the strongest salt tolerance, which could be used as excellent resources for mungbean salt tolerance breeding. Above-ground fresh weight, root fresh weight, root dry weight, root length, root volume, and root branch number could be used to predict salt tolerance of mungbean at seedling stage.

English

In order to promote the comprehensive production capacity and yield of farmland soil, the effects of subsoil tillage on soil structure, root activity, photosynthetic characteristics, dry matter accumulation, yield and water use through long-term positioning research in semi-arid areas were studied. This study was started in 2011 and investigated in the 2015–2016 research cycle. The experiment was conducted with five treatments including 30 cm subsoiling (SS-30) and 40 cm subsoiling (SS-40) before spring sowing, 30 cm (AS-30) and 40 cm (SS-40) between rows after autumn harvest and no subsoiling (CK). The effects of subsoiling on soil properties, crop growth, yield and water use of maize in semi-arid areas were investigated. The results showed that subsoiling significantly reduced the penetration resistance and bulk density of soil, and significantly increased the soil moisture content from subsoiling to the surface. Subsoiling increased GSand Ci, Tr, Pnand WUE in maize plants, and significantly increased root activity. Subsoiling significantly increased dry weight of aboveground part and root, significantly decreased root shoot ratio, and significantly increased WUE per plant. Subsoiling significantly increased 100 grain weight, yield and WUE of population. Subsoiling can effectively improve the soil structure, enhance the water storage capacity of the soil in arid areas, delay water loss, improve root activity, net photosynthetic rate, dry matter accumulation and WUE, and promote crop growth and yield of maize. Subsoiling in autumn has the best effect on soil improvement. Increasing the subsoiling depth properly can improve their effects, which will gradually less with the passage of time.© 2021 Friends Science Publishers

Differences in dry matter production, grain production, and photosynthetic rate in barley cultivars under long-term salinity

Soil salinity is a major environmental stress causing significant loss of crop productivity. Barley (Hordeum vulgare L.) is one of the few field crops that can grow in salt-affected fields and varietal differences in productivity under salinity conditions were known. To clarify the trait most responsible for grain production under salt stress, barley cultivars that were salt tolerant (OUE812) or salt sensitive (OUC613) were grown from seedling to harvest stage in vermiculite containing various concentrations of NaCl. Dry weight of aboveground parts and grain weight decreased significantly with increasing NaCl concentration. The dry weight of the aboveground parts and grain weight decreased more significantly in OUC613 than in OUE812 for plants treated with 150 mM and 200 mM NaCl. A marked reduction in ripening percentage caused significantly decreased grain production in OUC613 as compared with OUE812. In plants treated with 200 mM NaCl, the photosynthetic rate decreased three weeks after starting the NaCl treatment, but a significant difference between cultivars in photosynthetic rate did not appear until seven weeks of NaCl treatment. OUE812 kept a higher photosynthetic rate during ripening than did OUC613 and dry matter production during the period from ripening to harvest was significantly larger in OUE812 than in OUC613. Keeping a higher photosynthetic rate might have contributed to higher grain production in OUE812. Higher ripening percentage and higher rate of photosynthesis during ripening might be target traits in breeding to improve the tolerance of barley to long-term salt stress.

English

Angelica sinensis (Oliv.) Diels (family Apiaceae) is a perennial herb that has been widely used in Traditional Chinese Medicine. The soil sickness has become one of the major constrains in A. sinensis cultivation. A pot experiment was done to evaluate the role of biological nature in A. sinensis soil sickness. The pot experiment include three treatments (i) contol, which represent as the soil in pot taken from spring wheat stands, (ii) AA, which represent as the soil in pot taken from A. sinensis stands, (iii) S-AA, which represent as the soil in pot was sterilized by steam at 121°C for 4 h taken from A. sinensis stands. Results showed that the plant height, dry weight of aboveground part and roots, root yield and quality, and the activities of SOD and POD in leaves were significantly higher in sterilized replant soil than in non-sterilized replant soil treatment, while the activity of CAT and content of MDA in leaves were declined, which indicated that soil sterilization improved plant haleness and increased the activities of active oxygen scavenging enzymes. The results also demonstrated that soil sterilization can change the number of culturable microbial populations and the species diversity of bacterial functional group. Higher Shannon-Wiener index was found in rhizosphere soils under sterilized soil cropping than that under non-sterilized soil cropping. This suggests that the biological factor played a causal role in the development of A. sinensis soil sickness and sterilization of continuous cropping soil could change the composition and structure of soil microbial community, which further promote plant growth and alleviate A. sinensis soil sickness. © 2016 Friends Science Publishers

Response of Tomato Plants (Solanum lycopersicum) to Stress Induced by Sb(III)

Abstract Presented study evaluates effects of various Sb(III) concentrations on tomato plants (Solanum lycopersicum) cultivated hydroponically. Visual symptoms of antimony toxicity were observed only at two highest applied concentrations (50 and 100 mg/L). Dry weight of aboveground parts decreased significantly in variants treated with 25, 50 and 100 mg/L Sb(III), by ~12, 35 and 65 %, respectively, in comparison to the control. Statistically significant decrease of chlorophyll a and b was observed only after application of two highest studied concentrations 50 and 100 mg/L Sb(III). On the other hand concentration of total carotenoids in leaves rose with increasing external Sb(III) concentration. High concentrations (50 and 100 mg/L) of Sb(III) in nutrient solution caused that protein content in leaves dropped by ~20 and 39% relative to control. Accumulation of antimony in roots was about 5- (10 mg/L) to 27-times (25 mg/L) greater than that in shoots. The highest BAF factor value determined for shoots was ~55 at 10 mg/L Sb(III) and for roots it was ~821 at 50 mg/L Sb(III). Translocation factor values were in whole studied concentration range 5 – 100 mg/L Sb(III) &lt; 1. The most effective translocation of antimony from roots to shoots was observes for variants treated with 10 mg/L of Sb(III).

Effects of Temperature during Seedling Stage on Growth and Nutrient Absorbance of Gerbera jamesonii Growing in Organic Substrate

The effects of different temperature treatments during the seedling stage on growth and nutrient absorbance of Gerbera jamesonii cv ‘Sunshine Coast’ growing in the organic substrate were investigated. The temperature treatments were conducted in growth chamber where the day/night temperature were set to 15/10, 20/15, 25/20, and 30/25°C individually. The results showed that the fresh and dry weight of aboveground part and that of roots, average number of leaves and lateral roots were greater at 30/25°C than other treatments. The highest level of macro elements nitrogen (N), phosphorus (P), and potassium (K) in the leaf samples were also detected at 25/20°C and 30/25°C. However, there was no significant influence of different temperatures on zinc (Zn) levels in leaves. In general, the day temperature 25∼30°C and night temperature 20∼25°C are thought to be the better temperature condition for gerbera growth as well as the nutrient uptake and accumulation in the plants during the seedling stage.

Effects of Single-seed Sowing on Root Growth, Root-shoot Ratio, and Yield inPeanut ( Arachis hypogaca L.)

Peanut cultivar Huayu 22 was used to study the differences between single-seed sowing and double-seed sowing modes on root growth, root and shoot relationship, and yield under corresponding planting density. The two single-seed sowing treatments were 195 000 holes per hectare(S1) and 225 000 holes per hectare(S2), respectively with the double-seed sowing(150 000holes per hectare) as control. During the growth period, dry weights, length, volume and absorption area of the root under three treatments increased and reached the maximum at 40–50 days after flowering, and then decreased. The average root diameter decreased and reached the minimum at 50–60 days after flowering, and then increased. The dry weight of aboveground part and pod increased while the root-shoot ratio decreased continuously. S1 and S2 treatments could improve dry weight of the seedlings,the length, the volume, the absorption area of the roots and the root-shoot ratio, and reduce average root diameter during the whole growth period, especially at the late growth period. Additionally, S1 treatment saved 35% sowing seeds and improved peanut yield by 7.98%–8.38%. These results indicated that single-seed sowing could improve peanut yield through guaranteeing relatively stronger root growth predominance, regulating root-shoot ratio, and increasing the productivity potential for each seedling.

The influence of strip cropping on the state and degree of weed infestation in dent maize (Zea mays L.), common bean (Phaseolus vulgaris L.), and spring barley (Hordeum vulgare L.)

The experiment was conducted in the years 2008–2010 at the Experimental Station of the Faculty of Agricultural Sciences in Zamość, University of Life Sciences in Lublin. The following factors were analysed in the experiment: I. Cultivation method – sole cropping and strip cropping, which consisted in the cultivation of three plants: dent maize, common bean, and spring barley, in adjacent strips with a width of 3.3 m; II. Weed control methods – mechanical and chemical. The subject of the research was weed infestation of the 'Celio' variety of dent maize, the 'Aura' variety of common bean, and the 'Start' variety of spring barley. Weed infestation of the crops was assessed two weeks before harvesting by determining the species composi- tion as well as the number and dry weight of weeds. The dominant weed species in maize, common bean and spring barley were &lt;em&gt;Echinochloa crus-galli, Chenopodium album &lt;/em&gt;and &lt;em&gt;Galinsoga parviflora&lt;/em&gt;, constituting from 58% to 70% of the total number of weeds. Strip cropping clearly reduced the number of weeds per unit area in all the cultivated species and dry weight of aboveground parts produced by them in common bean and maize crops. The limiting effect of strip cropping on the weed infestation parameters was particularly clear in combination with the mechanical weed control method.

Effect of retardants on the content of selected macroelements in winter wheat cultivarsWpływ retardantów na zawartość wybranych makroelementów u odmian pszenicy ozimej

Summary The two-year field experiments (2009–2010) were carried out to compare the reaction of 10 winter wheat cultivars to retardants chlormequat chloride (Antywylegacz plynny 675 SL) and trinexapac ethyl (Moddus 250 EC) used together. Retardants were applied at three growth phases: BBCH 31, 32, 37. The total amount of active ingredients per 1 ha was 2.17 kg of chlormequat chloride and 150 g trinexapac ethyl. During wheat vegetation at the shooting (BBCH 33), heading (BBCH 51) and flowering (BBCH 65) phases, the amount of selected nutrients (P, K, Ca, Mg), in dry weight of above-ground parts of wheat plants was estimated. During the shooting, heading and flowering phase there was no significant difference in the amount of P, K, Ca, Mg in dry weight of above-ground parts of winter on the plots treated with retardants, in comparison to the control samples.

Host range and growth of Stem and Bulb Nematode (Ditylenchus dipsaci) populations isolated from garlic and chicory

Host range and growth of two &lt;I&gt;Ditylenchus dipsaci&lt;/I&gt; (Stem and Bulb Nematode) populations on onion, garlic, leek, spinach and chicory were compared. Inoculation was conducted by placing a droplet of 1.5% CMC suspension containing nematodes between the first leaves. The life cycle of the parasite was completed in variants of the original host plants, i.e. salad chicory was infected with the chicory population, and garlic and onion with the garlic population. Survival of the nematodes on garlic and spinach inoculated with the chicory population, and on chicory inoculated with the garlic population was determined. Nematodes of the chicory population did not survive on onion and leek, nor did the garlic population survive on spinach and leek. Nematode infection did not affect the dry weight of aboveground parts of plants, although a reduction would probably occur if the experiments had lasted longer. Symptoms of the infections were apparent in chicory inoculated with the chicory population. Nematodes in the substrate in which the plants were grown were found only in those variants with plants in which the life cycle was completed.

Comparison of dry matter production and associated characteristics between direct-sown and transplanted rice plants in a submerged paddy field and relationships to planting patterns

In a previous study, we demonstrated that rice plants, broadcast in a submerged paddy field, had a high grain yield that was due to the production of a greater weight of dry matter, as compared with conventionally transplanted plants, when lodging did not occur. In the present study, we examined possible causes of the greater production of dry matter by plants broadcast in a submerged paddy field by comparing the characteristics of plants subjected to different methods of cultivation [the direct-sown plants (DSP) and transplanted plants (TP)] and with different planting patterns (51.3 hills m −2 and one plant per hill, namely, planting pattern I; and 17.5 hills m −2 and three plants per hill, namely, planting pattern III). The dry weight of aboveground parts at harvest and the grain yield were larger for DSP than for TP when we compared plants with the same planting pattern, and they were larger for plants in planting pattern I than for those in pattern III when we compared plants with the same cultivation method. Differences in grain yield reflected differences in dry matter production. The factors responsible for the differences in dry matter production among plants depended on the growth stage. At the tillering stage, the number of tillers and, therefore, the leaf area index (LAI) increased rapidly and the interception of solar radiation by the canopy was larger in the DSP than in the TP, irrespective of the planting pattern. These factors were related to the higher crop growth rate (CGR) in the DSP than the TP. After the panicle formation stage, when the canopy closed completely and the interception of solar radiation exceeded 90%, the canopy consisted of more erect leaves and the extinction coefficient of the canopy was smaller for plants in planting pattern I than for those in pattern III, irrespective of the cultivation method. These features were responsible for the larger CGR of plants in planting pattern I than in pattern III. The plants in planting pattern I produced a larger number of crown roots than those in pattern III. During the ripening stage, the decrease in exudation rate was smaller, the amount of nitrogen accumulated was larger, and levels of chlorophyll and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) remained higher in the former plants than in the latter, irrespective of the cultivation method. These characteristics might also contribute to the elevated production of dry matter by the plants in planting pattern I.

Use of oxalic acid for screening intact sunflower plants for resistance to Sclerotinia in vitro

Three sunflower inbred lines differing in resistance to Sclerotinia were grown on nutritive medium supplemented with different concentrations of oxalic acid. After two weeks of culture, plant height, fresh and dry weight of above-ground part, length of first pair of leaves, root length, and fresh and dry weight of root were measured. Data obtained were analysed using ANOVA and LSD test. Out of the tested parameters, plant height and root length were found to be the most reliable indicators of plant resistance/susceptibility to Sclerotinia. Based on the data obtained, oxalic acid concentrations of 4 mM, 3 mM and 2 mM were chosen for further work in which test would be done on a larger number of genotypes.

Growth Characteristics and Yield of Sweetpotato Grown by a Modified Hydroponic Cultivation Method under Field Conditions in a Wet Lowland.

The hydroponic technique for sweetpotato cultivation was used under field conditions in a wet lowland. A plastic porous tube was placed in a soil ridge for aeration treatment. Water depth between the ridges was kept at 20 mm throughout the growing period in order to imitate the wet soil conditions in tropical and subtropical lowlands. The growth characteristics and yield of sweetpotato grown with the aeration treatment were compared with those grown in a conventional ridge as a control. The dry weight of above-ground parts was 1.8 times greater in the control than in the aeration treatment, while the dry weight of sub-ground parts was 3.1 times greater in the aeration treatment than in the control. The dry weights of stem and leaf, main stem length and leaf area were less in the aeration treatment than in the control. The dry weight of tuberous roots was 4.4 times greater in the aeration treatment than in the control, while the dry weight of roots excluding tuberous roots in the aeration treatment was almost half of that in the control. The edible biomass index was 4 times higher in the aeration treatment than in the control. Plants in the aeration treatment had greater edible parts (tuberous roots) and less non-edible parts (stems, leaves and roots excluding tuberous roots) than those in the control.

植物工場におけるレタスの成長予測手法の開発

Fresh weight at the harvest of lettuce plants (Lactuca saliva L. cv. Red-fire-W) grown in a plant factory with fluorescent lamps was estimated by the automatic plant growth measurement system with a personal computer. Growth curves of leaf area, fresh- and dryweight of above ground parts from sowing to about 30 days in age showed an exponential pattern (r2=0.90 or higher) . It is most suitable to use an exponential regression function during young stage of the growth, considering a declining pattern in specific growth rate. Standard deviations at 6.1-5.4 were observed between the top fresh weight in 30 days after sowing and specific growth rate revealed by the regression curve of leaf area. On the other hand, standard deviations obtained by the leaf area estimated from the regression curve were 6.4-3.9. Further, standard deviations were 3.6-3.1, where the initial leaf area and specific growth rate were regarded as describing parameter. The growth of lettuce plant was quantitatively represented as the function of leaf area by image processing. Specific growth rate of leaf area of individual plants in young stage of the growth showed periodic fluctuation. As the plant grew from sowing, its cyclic period became longer. The leafing velocity is defined as a cyclic period of changes in specific growth rate.

Control of volunteer alsike clover in timothy grown for seed

A study was conducted in 1-yr-old stands of timothy (Phleum pratense L.) to evaluate spring applications of several herbicide treatments for the control of volunteer alsike clover (Trifolium hybridum L.). In one 3-yr experiment, clopyralid at 0.2 kg a.i. ha−1, alone or with 2,4-D at 0.4 kg acid equivalent ha−1 effectively controlled alsike clover (flower production and the dry weight of aboveground parts were reduced by nearly 100% and 96% or more, respectively). Clopyralid at 0.1 kg ha−1, alone or with 2,4-D at 0.4 kg ha−1, and picloram/2,4-D (1:16) at 0.4 kg ha−1 provided similar control in 2 of 3 yr. In the other year, the clopyralid alone (0.1 kg ha−1) and picloram/2,4-D treatments reduced alsike clover flower production by 75% or more but the dry weight of aboveground parts was reduced by less than 55%. 2,4-D alone had little effect in reducing either the flower production or dry weight of aboveground parts of alsike clover. Seed yields of timothy were increased by herbicide treatments which provided effective control of alsike clover when vegetative growth of the latter species was vigorous. In another 3-yr experiment conducted in weedfree stands of 1-yr-old timothy, none of the above treatments had any effect on the seed yield, weight per 100 seeds or seed germination of the crop. Key words: Volunteer alsike clover, timothy, seed yield, seed quality, crop tolerance

Comparação entre sementes de trigo produzidas no México e no Brasil

Wheat seeds produced in Mexico (Ciudad Obregon-Sonora) and in Brazil (Passo Fundo, RS, Brasilia, DF) were compared in a field trial to assess the effect of origin on the stand, dry weight of above-ground part of plants, number of spikes, and yield. The experiment was conducted at the Centro Nacional de Pesquisa de Trigo - CNPT/EMBRAPA, in 1981 and 1982. The experiment was conducted in a completely randoming block design, with 15 treatments in split-plot arrangement (5 cultivars x 3 sources of origin, and four replications. Seeds were dressed with fungicide and the plants sprayed with fungicides and insecticide to control foliar diseases and pests. In spite of some difficulties to overcome dormancy of seeds produced in Brasilia and of extremely adverse environmental conditions in 1982, it was considered that the parameters were correctly assessed. Coefficients of variation were low and yield levels considered satisfactory. The results obtained in the two years under study, from the characteristics assessed, showed no consistent superiority for the seeds produced in Mexico as compared to the ones produced in Brazil.

Effects of Shading on the Growth and some Properties of Fiber Cells of Flax Plant, Linum usitatissimum L.

Flax plants (var. Saginaw No. 1) were grown in pots under different light intensities as follows: 100% (control), 43% (shaded I) and 17% (shaded II) of the solar radiation. The stem length of the plants grown in the shaded conditions became larger according to the larger elongation of internode of the stem. Dry weight of above-ground parts and bolls of the plant became smaller as the light intensity decreased. Number, diameter and cell membrane thickness of fiber-cells found in the cross section of the stem became smaller as the light intensity decreased. Particularly, the development of thickness of the cell membrane was greatly decreased by the lower light intensity. Thus, the fiber yield per plant and the fiber percentage in the dry weight of the stem became poorer as the light intensity decreased. The contents of α-cellulose in the crude cellulose were decreased by the shade treatment. On the contrary, the contents of (β+γ)-cellulose and lignin became higher by the same treatment. As the results, the shaded conditions not only reduce the fiber yield in the flax plant but also induce the reduction of the quality of the fiber.

Influences of Some Environmental Conditions upon the Growth and Development of the Flax Plant, Linum usitatissimum L.

Flax plants (var. Saginow No. 1) were grown in pots under different conditions as follows : control (soil moisture content 20.6 % per dry soil), moistened (grown in moistened soil, 34.8 %), dried (grown in dry soil, 10.7 %), and shaded (grown under shading, 22.4 %). The stem length of the plants became larger and stem diameter increased in the moistened plot. In the later stage of growth, elongation of the plant in the control and moistened plots ceased due to the reproductive growth. However, the shaded plot did not bloom, and the stem continued to elongate. On the other hand, in the dried plot, the flowering was not uniform according to the temporary elongation of the plant after every irrigation. Thus, number of leaves decreased after the flowering stage in the control and in moistened plots, but in the shaded and dried plots, the number of leaves did not decrease until the harvest time. Dry weight of above-ground parts of the plant became larger in the moistened plot and smaller in the dried plot. However, dry weight of boll in the moistened plot decreased more than the control plot, because of the reduction of the ratio of reproductive growth to vegetative growth in the moistened plot. Number of fiber-cells found in the cross section of middle part of the stem became larger in the control plot than other experimental plots. Although in the moistened and shaded plots, number of fiber-cells was reduced to one half of those of the control plot, diameter and thickness of cell-membrane of the fiber-cells were noticeably developed in the moistened plot compared to other plots. From the consideration of the above-mentioned causes, fiber percentage in the dry weight of stem became larger in the moistened plot and became smaller in the shaded and dried plots. The fiber obtained from the moistened plot was better than that from the control plot because of the higher content of α-cellulose and the lower content of β-and γ-cellulose. However, from the dried and shaded plots the fibers of poor quality were obtained because of the lower content of α-cellulose and the higher content of lignins than that of the control plot. Particularly, from the shaded plot the fiber of the worst quality was obtained.