Stem Fresh Weight Research Articles

Growth and Yield Characteristics of Field-grown Limonium sinuatum (L.)

Field studies were conducted on the potential of annual statice as an outdoor cut-flower crop for the Midwestern United States. Data was collected on seven cultivars in 1989 and 42 in 1990. In 1989, total fresh stem weight, stem count, and average stem weight differed significantly among cultivars. Yellow cultivars had more stems harvested than the rose, apricot, and blue cultivars, but stems of the yellow cultivars weighed less. The number of stems harvested over time tended to be concentrated in the first 8 weeks after flowering begins. In 1990, the average stem fresh weight was significantly different among the apricot, blue, and rose cultivars, but the number of stems harvested was significantly different only between the blue and rose cultivars.

550 PB 122 SOIL MOISTURE REQUIREMENTS FOR OPTIMAL GROWTH OF VEGETABLE AMARANTH

In literature, amaranth is described as a stress tolerant crop. However, most of the investigations have been concerned with the production of grain crop. The soil moisture regime which promotes maximum vegetative growth is yet to be established. During 1993, the vegetative growth response of amaranth to different soil moisture levels was determined in a greenhouse study. Amaranth cultivar Hin Choy was grown in Dothan sandy loam soil at four soil moisture levels of 6.0, 9.0, 12.0 and 14.0% (w/w) in a randomized complete block experiment with ten replications. Plant height, leaf number, leaf area, leaf fresh and dry weight, stem fresh and dry weight, root fresh and dry weight, leaf-stem ratio, and stem fresh and dry weight were recorded. All parameters gained significantly with each increment in the soil moisture level up to 12%. There was no difference in plant response between 12% and 14% soil moisture. The study indicated that for optimum vegetative growth, amaranth requires a moisture stress free soil environment.

遮光と培養液のNO<SUB>3</SUB>/NH<SUB>4</SUB>比がNFT栽培トウガラシの生育•収量に及ぼす影響

The effects of NO3 : NH4 mixture with a gram-N ratios of 10 : 0, 9 : 1 and 8 : 2 in the nutrient solution and shading pepper plants grown under NFT to 0, 25 and 50% full so- lar radiation on their growth, yield, and photosynthesis were investigated.Main stem and branch lengths increased significantly under shaded conditions. Fresh weight of leaf, stem, and roots of equally shaded plants were heavier at a NO3 : NH4 ratio of 9 : 1 compared to those grown at a ratio of 10 : 0.The pepper plants set fewer, smaller fruits in proportion to the degree of shading. Fruit yieid of the shaded plants increased significantly by replacing 10% of NO3-N with NH4-N in the nutrient solution.Dry weights of leaf and stem and leaf area increased under shaded conditions. As the NH4-N/NO3-N ratio in the nutrient solution increased, dry weight and leaf area decreased in fully exposed plants, whereas the trend was reversed in shaded plants.As the NH4-N/NO3-N ratio of the nutrient solution increased, leaf photosynthetic rates decreased in exposed plants, but increased slightly in shaded plants.Compared with exposed plants, shaded plants had considerably lower net assimilation rate (NAR) and relative growth rate (RGR) during the flowering and the early fruit development stage, 46 days after treatments, irrespective of the nitrogen sources in the nutrient solution. However, the differenes were observed in NAR and RGR during the later fruit maturing stage, 47 to 68 days after treatments.The results obtained in this study indicate that as a nitrogen source of NFT-grown pepper plants, 100% NO3-N is recommended under high solar radiation, whereas a NO3-N : NH4-N ratios of 9 : 1 or 8 : 2 is superior when the solar radiation is reduced.

Carbohydrate Storage and Mobilisation by the Culm of Wheat Between Heading and Grain Maturity: the Relation to Sucrose Synthase and Sucrose-Phosphate Synthase

Wheat plants grown under non-stress conditions at a dayhight temperature of 18/13�C under glasshouse conditions from head emergence to maturity showed a maximum accumulation of water-soluble, non-structural carbohydrates 20-25 days after anthesis. This storage was largely as fructans with the timing and amount of storage and mobilisation varying between cultivars, although the maximum concentration (fructose equivalents per unit stem fresh weight) was similar in all cultivars. The main storage in the culm was located in the lower part of the peduncle enclosed by the flag leaf sheath, in the penultimate internode and for one cultivar also in the flag leaf sheath. 14CO2 pulse-chase studies showed that there was a considerable delay in the incorporation of flag leaf assimilates into stem fructans, a delay probably associated with transfer and metabolic processes in the stem itself. At anthesis, when soluble carbohydrates were rapidly accumulating in the culm, the level of activity of sucrose synthase (SS) in the penultimate internode was much greater than that of sucrose phosphate synthase (SPS). The activity of SS declined rapidly as active storage ceased. This pattern was the reverse of that found in the leaf where SPS, rather than SS, was initially high and declined towards maturity. These changes are discussed in relation to the possible role of sucrose synthesising enzymes, particularly SS, in the accumulation and mobilisation of stem reserves in wheat.

711 (PS 6) EFFECT OF NITROGEN FERTILIZATION ON GROWTH AND YIELD OF AMARANTH

This study was conducted to establish the optimum level of N fertilization for the production of vegetable amaranth, Amaranthus tricolor, in middle Georgia. The soil fertilization treatments consisted of 0, 45, 90 and 135 kg N ha-1, applied in two equal doses, first at 18 days after planting and again when plants were 5 weeks old. Accession RRC 241 was planted on 19 June in randomized complete block design with four replications. The crop was harvested 48 days after planting and data on leaf number, leaf fresh weight, stem fresh weight, and green yield were collected. Green yield for treatments 0, 45, 90 and 135 kg N ha-1 were 5.3, 10.7, 13.2 and 13.5 Mg ha-1, respectively. Regression of N fertilization on all vegetative components were significant. A linear response was seen for stem fresh weight, a quadratic response for green yield and cubic responses for leaf number and leaf fresh weight. The R2 values for leaf number, leaf fresh weight, stem fresh weight, and green yield were 0.61, 0.63, 0.29 and 0.85, respectively. The results indicate that 90 kg N ha-1 of fertilization should provide optimal vegetative growth in amaranth.

LIGHT AND NITROGEN LEVELS AFFECT THE AGRONOMIC PERFORMANCE OF VEGETABLE AMARANTH

Three-week-old transplants of Amaranthus tricolor cultivars `RRC 241' and `Hinn Choy' were given split applications of supplemental N (0, 100 and 200 kg/ha). Five weeks after sowing both cvs. were exposed to 100, 70 and 50% of ambient solar radiation for nine and ten days, respectively. During shading, avg. daily photosynthetic irradiance was reduced from 11.6 to 7.7 and 5.0 KW/m2, respectively. Soil, air, and leaf temperatures were reduced by shading. Plants were harvested in the seventh week. Cultivars differed in leaf number and area, yield, height, mineral uptake, and stem fresh and dry weight. Increasing shade levels decreased the dry wt. of stems, leaf blades, and plants. Shading had no effect on leaf area, plant fresh wt. or yield, but increased stem length, plant water content and leaf blade pigments. Photosynthetic fixation rates were reduced by 50% shade. Leaf blade protein and most leaf blade mineral nutrients, including nitrates, were increased by shading. Nitrogen application increased stem length, stem, leaf blade and plant fresh and dry wt., leaf blade pigments and yield.

The original basal stem section influences rooting in Pinus banksiana cuttings

We tested the hypothesis that, during propagation, the basal stem of Pinus banksiana Lamb, cuttings contains a nonauxin endogenous root‐forming stimulus (ERS) whose effects are not replaced by auxin treatment; i.e., that auxin treatment of cuttings and surgical removal of their basal stems during propagation act additively on rooting, without significant interaction, as determined by analyses of variance. We studied the effects of ERS by severing the original basal (1 cm) stem from cuttings at days 3, 6 and 9 of a 30‐day period of propagation. To study treatment interaction, we applied the auxin N‐phenyl indolyl‐3‐butyramide to some surgically treated cuttings. Results for all variables (proportion of rooted cuttings, number of roots per cutting and fresh weight of basal stem plus roots, if any) indicated that removing the basal stem reduced rooting and that auxin treatment increased rooting, without significant treatment interaction. The results thus supported the hypothesis that P. banksiana seedling cuttings contain ERS. However, neither the present nor previous tests have shown that ERS is a chemical stimulus rather than, for example, a biophysical or anatomical one.

Effects of Growing Medium, Shade Level and Fertilizer Rate on Cladode Color, Yield and Vase Life of Ruscus hypophyllum

Abstract Ruscus hypophyllum L. (Israeli or Holland ruscus) liners were grown from tissue culture in either Florida sedge peat: builders' sand (3:1 by vol) or a commercial soilless medium (Vergro container mix A) until they were large enough to produce harvestable stems for use as cut foliage (florists' greens). Once established, plants were grown in a shadehouse at 50% or 70% shade and were fertilized with either 5, 10 or 15 g (0.18, 0.35 or 0.53 oz) of 17N-2. 6P-10K (17-6-12) controlled-release fertilizer applied every 2 months. Cladode color was not affected by fertilizer level but was affected by both shade level and growing medium, with shade level the more important of the two. Stem numbers and average fresh weight were affected by an interaction of fertilizer rate and growing medium. Maximum stem number occurred at the high fertilizer rate in Vergro and the medium rate in peat:sand while average stem weight was greatest at the high rate in peat:sand and at the medium rate in Vergro. Total stem fresh weight increased as a linear function of fertilizer rate, was 12% higher from peat:sand compared to Vergro, and was 14% greater under 50% compared to 70% shade. There were no commercially significant treatment effects on vase life.

Characteristics of normal-crowned and pendula spruce (Picea abies (L.) Karst.) examined with reference to the definition of a crop tree ideotype.

Sixty-four 19-year-old Norway spruce trees were felled and the roots excavated during 1987 and 1988. The trees were open-pollinated progenies from a small stand located in southern Finland. Several characteristics of stem, crown, and roots were measured and analyzed on 36 pendula and 28 normal-crowned trees in the sample. Total fresh weight, stem fresh weight, and crown fresh weight were 47.6, 27.5, and 61.4% greater in normal-crowned trees than in pendula trees. The mean harvest index (including roots) of pendula spruce was 0.32 compared with a value of 0.27 for normal-crowned trees. This difference reflects the difference in crown biomass between the two groups of trees. The crown structure of pendula spruce appears to permit higher stand densities than is possible with normal-crowned spruce. Thus the results indicate that genetically narrow-crowned trees with a small total crown mass could provide useful basic material for selection of crop trees with a high stemwood production per hectare.

Application of self-thinning in mesquite ( Prosopis glandulosa var. glandulosa) to range management and lumber production

To gain a better understanding of the relationships between stand density and tree volume in mesquite, seven native stands were examined. Stand densities ranged from 6 to 19 000 stems ha −1, and estimated biomass ranged from 0.65 to 1300 kg stem −1. Regression equations were used to estimate biomass from basal diameters. A plot of estimated tree biomass vs. stand and density defined by the estimated self-thinning line: log W = −1.17 log d + 5.22 (r 2=0.95), where: W is stem fresh weight (kg); and d stand density (stems ha −1). Regressiion of stand density on basal diameter, lumber volume stem −1 and total biomass ha −1 were also examined. When plots deemed to not be at full stand occupancy were excluded from the data set, a regression predicted that densities of 100 stems ha −1 would produce 35-cm-basal-diameter stems. This density also gave the highest lumber yield.

Reduced irradiance and applied auxin influence carbohydrate relations in Pinus banksiana cuttings during propagation

Untreated and indole‐3‐butyrie acid‐treated (IBA) cuttings from 90‐day‐old Pinus banksiana Lamb, stock plants were propagated under normal greenhouse irradiance (max. 900 $$mol m‐2 s‐1) and shade (max. 120 $$mol m‐2 s‐1) to determine effects on adventitious rooting and on reducing sugar and starch concentrations in needles and basal stems. In one experiment, cuttings were assessed at days 15 and 25 of propagation for basal 1‐cm stem fresh weight, proportion rooted, number of roots and longest root length. In a second experiment with cuttings, basal 1‐cm stem fresh weight and concentrations of reducing sugar and starch in needles and basal stems were measured each day for the first 10 days of propagation. Carbohydrate measurements were also made for seedling stock plants as controls for the second experiment. Carbohydrate data for cuttings were primarily evaluated based on net (cutting minus seedling) concentrations, to correct for changes in cuttings not related to adventitious rooting. Increase of basal stem fresh weight and rooting of cuttings, based on all measured variables, occurred in the order: light + IBA > light > shade + IBA > shade. The best rooting required the greater irradiance. Compared to results from cuttings in the light, shading resulted in lesser accumulations of reducing sugars and starch in needles and basal stems. Reducing sugar: starch concentration ratios were significantly greater in shade‐ vs light‐propagated cuttings, IBA treatment did not offset the effects of shade on rooting or on reducing sugar and starch concentrations or ratios. Overall, the results suggested that decreased reducing sugar and starch concentrations and/or their increased ratios are associated with shade‐induced poor rooting of P. banksiana cuttings.

Removal of the stem terminal and application of auxin change carbohydrates in Pinus banksiana cuttings during propagation

This study determined how surgical removal of the stem terminal, with indole‐3‐butyric acid (IBA) treatment, influenced concentrations and partitioning of carbohydrates in Pinus banksiana Lamb, cuttings during propagation. Seedlings and cuttings that originated from 90‐day‐old stock plants were untreated or treated by removing the stem terminal, followed by application of IBA to the severed apical or basal (cuttings only) stem. Fresh and dry weights of the basal 1‐cm stems of cuttings were determined daily for the first 10 days of propagation (i.e., before roots were visible). In addition, basal 1‐cm stems, upper (ca 9‐cm) stems and needles of seedlings and cuttings were analyzed for sucrose, soluble reducing sugar and total non‐structural carbohydrate. Net concentrations of each carbohydrate in cuttings were obtained by subtracting corresponding concentrations for similarly treated seedlings, yielding data directly related to only the physiology of rooting. Data for cuttings indicated that presence of the stem terminal combined with applied IBA positively influenced rooting through processes that increased basal stem fresh and dry weights before root emergence. Removal of the stem terminal influenced accumulation of net total carbohydrate in cuttings, but the major effect was on carbohydrate partitioning. Either type of IBA treatment after removal of the stem terminal usually resulted in different net carbohydrate concentrations in each tissue source of cuttings, compared with only removal of the terminal. Neither basal nor apical IBA treatment of cuttings without stem terminals yielded results for carbohydrate accumulation and partitioning like those obtained with intact cuttings. Removal of the stem terminal, even if followed by IBA treatment, may have lessened rooting potential of cuttings because it resulted in greater reducing sugarstarch concentration ratios in basal stems compared with those in intact cuttings.

Effects of sulphur dioxide and nitrogen dioxide on shoot and root growth of Kennebec and Russet Burbank potato plants

The effects of sulphur dioxide (SO2) and nitrogen dioxide (NO2), singly and in combination, on the shoot and root growth of two potato cultivars sensitive to these pollutant gases were determined using rooted cuttings in controlled conditions. Plants were exposed to 0.11 ppm SO2 and/or 0.11 ppm NO2 for 24 hours a day for 7 or 14 days. Kennebec plants had significantly lower root fresh and dry weights after 7 days in the mixture treatments and lower root fresh weight in the NO2 treatment. Russet Burbank plants were more sensitive to SO2 and NO2 than Kennebec. Russet Burbank plants had significantly reduced leaf area, and leaf, stem, and root fresh and dry weights after 7 and 14 days of mixture treatment, and the leaf to root dry weight ratio was higher than in control plants. The combination treatment and SO2 alone resulted in visible injury on leaves of both cultivars. Changes in tissue water concentration, decreased specific leaf area and decreased root growth suggested that SO2 and NO2 altered plant water status and interfered with partitioning of dry matter from the leaves to other plant parts.

Tomato response to concurrent and sequential NO 2 and O 3 exposures

In the ambient environment, concentrations of air pollutants vary on a diurnal cycle, resulting in various patterns of concurrent and sequential exposures of plants. The response of tomato plants to sequential and concurrent NO 2 and O 3 exposures was determined using pollutant levels equal to the maximum acceptable levels recommended by the National Ambient Air Quality Objectives of Environment Canada for a 1 h average. The concurrent treatment, 1 h of NO 2 + O 3, was compared to 1 h of NO 2, O 3 or control in plants at the 4 to 6 or the 9 to 11 leaf stage. At the 4 to 6 leaf stage, leaf and stem fresh weights were significantly reduced by the NO 2 + O 3 treatment relative to control, whereas these growth parameters were not reduced relative to control by the single pollutants indicating a coalitive response. Leaf area was significantly smaller as a result of the NO 2 + O 3 treatment relative to the NO 2 treatment. A main effect of O 3 was observed on leaf dry weight. The sequential treatments were: NO 2 followed by O 3 (NO 2O 3); O 3 followed by NO 2 (O 3NO 2); NO 2 at night followed by O 3 during the daytime (NO 2(N)−O 3(D)). Each gas exposure was 1 h; only plants at the 4 to 6 leaf stage were treated. Only the O 3NO 2 treatment significantly reduced leaf area, leaf fresh weight and stem fresh and dry weights relative to control plants. Inconsistencies among treatments occurring at different time periods of the day suggest that time period of exposure should reflect ambient time periods. The coalitive action, and the sequential treatment response, of these pollutants indicated that criteria based on single pollutants may not be adequate to establish air quality objectives when these pollutants occur together.

Chemistry and possible roles of cuticular alcohols of the larval atlas moth

1. 1. Cuticular wax from abdominal tubercles of Attacus atlas (Lepidoptera; Saturniidae) is primarily composed of 1-triacontanol in combination with 1-hexadecanol, 1-heptadecanol, 1-nonadecanol and 1-dotriacontanol. 2. 2. Evidence for the roles of wax in water conservation and defense against predators and parasitoids, and the defensive behavior associated with an additional thoracic defensive secretion are discussed. 3. 3. 1-Triacontanol at 2.28 × 10 −8 M, but not larval was containing this compound at the same concentration, increased the number of leaves, and leaf and stem fresh and dry weight of Ailanthus altissima seedlings, a host-plant of the Atlas moth.

Effect of Molybdenum on Cauliflower (Brassica oleracea L. Var Botrytis) in Sand Nutrient Culture

SUMMARYOne ppm molybdenum produced the greatest height, fresh and dry weight per plant; number, fresh and dry weight of leaves; diameter, length, fresh and dry weight of stem; length, fresh and dry weight of roots; yield and yield-attributing characters (height, diameter, fresh and dry weight of curd), and N content of component parts of cauliflower plants (curd, leaf, stem and root). The lowest values for these characters were obtained in the control (nil Mo). Reducing and non-reducing sugars and vitamin C (ascorbic acid) were favourably enhanced (0·5 ppm Mo). The lowest values for sugars and ascorbic acid were observed under 1·0 ppm and nil Mo respectively. The quadratic response curve was drawn in terms of fresh weight of curd and rates of molybdenum application.

Pattern of growth response of bean,Phaseolus vulgarisL. to naphthenic and cyclohexanecarboxylic acids

SummaryFourteen-day-old plants of green bush bean, Phaseolus vulgaris L., cv Top Crop, were sprayed with solutions of potassium naphthenate (KNap), 5000 mg per 1, or cyclohexanecarboxylic acid (CHC), 1280 mg per 1 (0.01 M). The treatment significantly increased height, stem and leaf fresh and dry weights, leaf area, green pod production and number and weight of ripe seed. The stimulative action of both KNap and CHC began immediately after their application and continued throughout the experimental period. In KNap-treated plants the contents of chlorophyll a, cholorophyll b, and carotene in trifoliate leaves, and of ascorbic acid in green pods at harvest and after three days storage at 22°C, were significantly higher than in control plants.