Stem Yield Research Articles

Relationship of Photosynthetic Carbon Assimilation Related Traits of Flag Leaves with Yield Heterosis in a Wheat Diallel Cross

In spite of commercial use of heterosis in agriculture, the physiological basis of heterosis is poorly understood. Photosynthetic carbon assimilation related traits of flag leaves, including photosynthetic capacity, stomatal conductance, intercellular CO 2 concentration, transpiration rate, water use efficiency, and efficiency of primary conversion of light energy, were measured at early, middle, and post grain-filling stages in a wheat ( Triticum aestivum L.) diallel cross containing 20 hybrids and 9 parents. The purpose of this study was to determine the relationship between yield heterosis and these traits. The magnitude of heterosis varied subject to cross combination, trait, and developmental stage. Further analysis indicated that heterosis of photosynthetic carbon assimilation related traits was not correlated with that of spike length and spike number per plant, but significantly correlated with that of other yield components. At middle grain-filling stage, the heterosis of photosynthetic rate, intercellular CO 2 concentration, water use efficiency, and efficiency of primary conversion of light energy were significantly and positively correlated with those of fertile spikelets per plant, thousand-grain weight, yield per plant, and yield of main stem. These results suggested that higher photosynthetic capacity and water use efficiency could be one of the important physiological bases of wheat hybrid vigor.

Influence of Soil Sodicity on the Growth, Alkaloid Yield, and Cation Accumulation of Catharanthus roseus

The effects of soil sodicity (exchangeable sodium percentage, or ESP) on the growth, alkaloid yield, and cation accumulation of two cultivars of Catharanthus roseus (Nirmal and Dhawal) was studied in a pot experiment. The leaves and stem yield of C. roseus significantly increased with an increase in soil ESP from 4.3 (control) to 16.9, but thereafter yield decreased with further increases in soil ESP. The severe leaf injury symptom from soil sodicity was exhibited in both cultivars at 32 weeks after transplanting into soil at ESP levels of 44.9 and above. Root yields of C. roseus were also significantly reduced with an increase in soil ESP. Total alkaloid yield in leaves increased with increases in soil at ESP levels of 32.0 and 16.9 for the cultivars Nirmal and Dhawal, respectively, but further increases in soil ESP the total alkaloid yield significantly decreased. The vindoline content in leaves of C. roseus significantly decreased with an increase in soil ESP. In the shoot and root tissues of C. roseus, the concentration of sodium significantly increased and that of potassium, and calcium decreased in plants grown in soil with high sodicity (ESP 44.9 and above) as compared with the control.

Growth and Main Stem Yield in Kenaf Grown at Different Planting Densities

Growth and Main Stem Yield in Kenaf Grown at Different Planting Densities

Corretivos da acidez do solo e níveis de umidade no desenvolvimento da cana-de-açúcar

Sugar caner (Saccharum spp.) cultivation is quite disseminated throughout Brazilian territory due to its easy cultivation and its multiple uses such as  sugar and alcohol yield and animal feeding. In order to have a satisfactory yield, the combination of factors such as humidity and soil acidity correction should be corrected. This work had the objective of evaluating use of correctives (limestone and slag) in three levels of soil humidity, dry matter yield of shoot, culm, root and culm number of plant. Five levels of limestone and metallurgy slag corrective were evaluated, so that saturation by bases (V%)  remained after incubation with: N1 (control, V = 21.4%), N2 (V = 40%); N3 (V = 60%); N4 (V = 80%) and N5 (V = 100%). Incubation was carried out in plastic sacks for 21 days, with humidity close to 70%. After 150 days of cultivation, counting of culm (CC) and cut of shoot were carried out by separating culm from leaves, determining dry matter of shoot (DMAP), dry matter of leaf (DML), dry matter of culm (DMC) dry matter of root (DMR). Usage of soil acidity correctives, level of water and level of saturation by bases influenced the development and mineral nutrition of sugar cane. Slag yield greater production of dry matter of shoot of sugar cane in relation to limestone for the lowest levels of water in soil (60 and 80%CC). Increase of saturation by bases with appliance of increasing doses of limestone and slag increased yield of aerial, leaves, stem and roots dry matter of sugar cane.

Evaluation changing of essential oil of balm (Melissa officinalis L.) under water deficit stress conditions.

An experiment was carried out using a randomized complete block design with 4 replications to study the effect of water deficit stress on essential oil of balm. The factors studied included 5 levels of water deficit stress that were T1 (100% field capacity), T2 (80% field capacity), T3 (60% field capacity), T4 (40% field capacity) and T5 (20% field capacity) respectively. The results showed that water deficit stress significantly affected biological yield, essential oil yield, essential oil %, leaf yield, height of plant, tiller number, stem diameter, stem yield and internode length in P < 0.01. Highest biological yield and height of plant were achieved under T1, highest essential oil yield was achieved under T3 and highest stem diameter and essential oil % were achieved under T5. The results of this experiment showed that essential oil yield was reduced under water deficit stress but essential oil % increased under this condition.

Effect of Nitrogen, Phosphorus, and Potassium Fertilization on Nutrional Status of Fiber Hemp

This study was conducted to determine the optimum time for plant analysis, which can provide useful indications of nutrient deficiencies in plants, and to establish limit values for nutrient supplies to fiber hemp (Cannabis sativa L.). The effect of nutrient supplies on the nutritional status of fiber hemp was estimated by leaf analysis in a long‐term field fertilization experiment at four nitrogen–phosphorus–potassium (NPK) levels on Chernozem meadow soil in Szarvas, Hungary, in 1999 (good water supplies) and 2003 (dry). The optimum time for the diagnostic analysis of fiber hemp was found to be late May or early June, when plants in the five‐ to ‐seven‐leaf stage are 70–100 cm in height, with a biomass of 2–5 t ha−1 dry matter, depending on water and nutrient supplies, variety, and production condition. Nutrient supplies to hemp can be considered satisfactory if plant analysis reveals 5–6% N, 0.5–0.6% P, and 2.7–3.0% K in the youngest fully developed leaves in late May. A stem yield (10% moisture content) of 12–17 t ha−1 was achieved when rainfall supplies were adequate (1999), whereas in the dry year (2003), the lower nutrient concentrations in the uppermost leaves, indicating nutrient deficiency, resulted in a maximum stem yield of only 6–8 t ha−1. The low, satisfactory, and high values for the concentrations of N, P, K, calcium, magnesium, iron, manganese, zinc, and copper reported in the article could be used to elaborate a fertilizer recommendation system for hemp.

Effect of spring defoliation pattern on the mid‐season production and morphology of swards of perennial ryegrass cultivars of different maturity

AbstractThe effect of three spring management treatments on the vertical distribution of dry‐matter (DM) yield and morphology of four cultivars of perennial ryegrass (Fennema, Corbet, Foxtrot, Melle) in mid‐season was investigated. The management treatments commenced with cuts on 15 February (Early), 1 March (Medium) and 29 March (Late), each followed by a 28‐day re‐growth period until the next cut and then further 21‐day re‐growth periods after each subsequent cut. This created four mid‐season measurement periods across the management treatments at cut 3 (5 April–17 May), cut 5 (17 May–28 June), cut 6 (7 June–19 July) and cut 7 (28 June–9 August). Tiller and sheath height and their ratio, and leaf lamina length, were measured prior to the four mid‐season cuts (cuts 3, 5, 6 and 7) when measurements of DM yield and proportions of leaf, stem and dead material in three herbage horizons (Lower, 0–8 cm; Middle, 8–15 cm; Upper, &gt;15 cm) were made. There were significant responses in mid‐season to the management treatments involved complex interactions between management treatment and cutting date, which modified seasonal patterns in DM yield and leaf:stem ratio. There were significantly greater tiller heights, tiller:sheath ratios and leaf lamina lengths but lower sheath heights from the Early to Late management treatments. The greatest responses in morphological characteristics occurred in the Middle horizon compared with either the Lower (predominately stem and pseudo‐stem), or the Upper (predominately leafy) horizons. Distribution of DM yield between Middle and Lower horizons but not overall DM yields was significantly affected by management treatment. Morphological differences between cultivars were mostly in the Middle horizon and ranking of the cultivars was similar across the management treatments. The different responses of cultivars Fennema and Melle showed that genotype had a significant effect regardless of management. The leafiest mid‐season swards were achieved by delaying initial spring defoliation in the cultivar which had the lowest stem production.

Plant Density and Hybrid Impacts on Corn Grain and Forage Yield and Nutrient Uptake

ABSTRACT Corn (Zea mays L.) production recommendations should be periodically evaluated to ensure that production practices remain in step with genetic improvements. Since most of the recent increases in corn grain yield are due to planting at higher densities and not to increased per-plant yield, this study was undertaken to measure the effects of plant density and hybrid on corn forage and grain yield and on nutrient uptake. Plant density (4.9, 6.2, 7.4, and 8.6 seeds m−2) and hybrid relative maturity (RM) [early (108 day RM); medium (114 day RM); and late (118 day RM)] combinations were evaluated over five site-years under irrigated and non-irrigated conditions. The interaction of hybrid with plant density was never significant for grain, stem, or leaf biomass. The latest RM hybrid out-yielded the medium and early hybrids by 550 and 1864 kg ha−1, respectively. Grain yield was highest at 8.6 plants m−2. Total stem yield was also greatest at the highest plant density but by only 340 kg ha−1 more than at 7.4 seeds m−2. Based on grain yield response over sites, the estimated optimum density was 7.6 seeds m−2, which is 0.7 seeds m−2 higher than the current recommendation at this average yield level (11.5 Mg ha−1). Grain nitrogen (N), phosphorus (P), and potassium (K) uptakes were highest for the medium RM hybrid. Nutrient uptake levels varied by planting density, with the lowest levels observed at the lowest and highest plant densities. At 4.9 seeds m−2, the reduced uptake is explained by lower biomass yields. At the 8.6 seeds m−2 rate, N and K levels may have been lower due to dilution.

Effect of harvesting time on phytomass production and essential oil yield in "alecrim-pimenta" (Lippia sidoides Cham.)

The aim of this study was to evaluate fresh and dry mass, as well as essential oil yield, in Lippia sidoides cultivated in the north of Minas Gerais State, Brazil. The experimental design was in randomized blocks, with five treatments and four replicates. Treatments consisted of the following harvesting intervals: 120, 180, 240, 300 and 360 days after transplanting. Measurements on each harvesting included plant height, stem base diameter, leaf, stem and shoot fresh matter yield, and shoot dry matter yield, besides essential oil content and yield per plant. The highest essential oil content was detected at 180 days, whereas the highest dry matter production was observed at 390 days. Essential oil yield per plant was 2.34±1.15 g and productivity was 124.8 kg ha-1. Thus, harvesting at 180 days is recommended.

The Influence of Fructification Managing and Fertilization on Greenhouse Cucumbers

In the experiment effectuated in 2008, at the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, in a “Venlo” type greenhouse, the influence of fructification managing and fertilization of greenhouse cucumbers on their harvests dynamic, early and total yield as well as fruit commercial quality was studied. In case of variants for which fructification was managed only on main stem yield efficiencies of 15.5% for early yield and 24.9% for total yield were recorded in comparison with variants for which fructification was managed both on main stem and on fruit-bearing springs, placed on upper one third of pergola. Fertilization method influenced total yield, very significant positive difference of yield being obtained with root and foliar fertilization in comparison with root fertilization. Under combined influence of experimental factors, both for early and for total yield, the best results were obtained at variant for which fructification was managed only on main stem and was root and foliar fertilized.

Sorghum stem yield and soluble carbohydrates under different salinity levels

The aim of this study was to select the most suitable cultivar for salty land in this geographical area. Two sweet sorghum cultivars (Keller and Sofra) and one grain sorghum cultivar (Kimia) were grown in greenhouse benches under four salinity levels of 2, 4, 8 and 12 dSm-1 to evaluate the effects of salinity on stem yield and soluble carbohydrate (sucrose, glucose and fructose). The results showed that in all cultivars as salinity increased, the amount of stem yield and soluble carbohydrate decreased. In all salt concentrations, Keller and Kimia had the highest and the lowest stem yield and sucrose, respectively. At the highest salt concentration (12 dSm-1), Keller had the lowest stem yield reduction (less than 1%) and the highest sucrose content while Kimia had the highest stem yield reduction (more than 18%) and the lowest sucrose content. Therefore, Keller and Kimia can be considered as salt tolerance and salt sensitive cultivars, respectively. As salinity increased, the amount of glucose and fructose in Keller decreased while they increased in Sofra. Increasing glucose and fructose in Sofra is not an indication of its salt tolerance. At the physiological maturity stage, the plant has the highest stem yield and sucrose content while it has the lowest glucose and fructose content than flowering stage. Base on the results, Keller is recommended to be planted under soil salinity conditions and harvested at physiological maturity stage.

네이피어 풀줄기의 혐기성 분해: 외부에서 가해준 철과 니켈의 효과

Batch laboratory-scale anaerobic digestion experiments were carried out with the aim of investigating the effect of nickel and iron, singly and in combination, on the methane yield of napiergrass stem. Iron, nickel and an iron-nickel mixture were added to the substrate as iron (III) chloride (FeCl ), nickel (II) chloride (NiCl ), and a 1:1 FeCl and NiCl molar mixture, respectively. The inoculum used to inoculate the digestion experiments was obtained from the rumen fluid of a freshly slaughtered 5 year old male bovine. The biogas produced was collected for 30 days by 2 days intervals and the methane yield was measured using gas chromatography (GC). The results obtained show that the cumu- lative methane yield, rate of methane production, and time lag before methane production were enhanced with the addi- tion of iron, nickel, and the iron-nickel mixture. The study also show that the cumulative methane yield of the napiergrass stem increased as the amount of added FeCl , NiCl , and FeCl -NiCl mixture increased. Furthermore, the cumulative methane yield was highest when nickel ion was added. Addition of iron and nickel ions to substrate reduced the time lag before methane production from 8 days to 6 days and addition of the iron-nickel ions mixture to substrate reduced the time lag to 4 days.

Northern Limits to Fiber Hemp Production in Europe

ABSTRACT During the 1900’s fiber hemp was commercially grown in Scandinavia at latitudes as far north as 65°N and 66°N. Hemp is sensitive to temperature and day length with a quantitative short-day requirement, though long days can be beneficial for fiber production in late varieties, provided that other growing conditions are optimal. The response of fiber hemp varieties to photo period and low temperatures at northern latitudes was studied in Finland in 2003 and 2004. The article also reports on risks and prerequisites of hemp growing at high latitudes showing that if a suitable variety is used, stem yields of more than 10 t ha−1 are possible. If a variety adapted to southern European climates should be grown, however, the short growing season and the frosts in the beginning and at the end of the summer can restrict the plant growth. The northern limit for hemp production in Europe is currently at 64 to 65°N.

Hemp as a Feedstock for Biomass-to-Energy Conversion

ABSTRACT An increase in the demand for biomass for conversion to heat by combustion is likely. The potential role for hemp in supplying this demand is discussed in this article. For hemp, key characteristics such as net calorific value, ash content, and melting behavior, and the risk of corrosion or polluting emissions, are all favorable. Low bulk density and size reduction difficulties might limit its use for pellet production and in small boilers; its use in electricity generating plants and medium-to-large boilers would have better prospects. To maximize profitability, an agronomy program to achieve high yields at the lowest cost is required. In the Irish climate, this would entail early sowing (late March/early April), a low seed rate (∼30 kg/ha), and variety selection for maximum stem yield regardless of fiber content. With an optimal program, trial results suggest that a dry matter yield over 10 t/ha is attainable. Cost analysis shows that an energy price of about e6/GJ is required to achieve a prof...

Eco-Friendly Methods Of Spear grass (&lt;i&gt;Imperata cylindrica&lt;/i&gt; L.) Control in the Derived Savanna Zone Of Nigeria.

Spear grass (Imperata cylindrica, L.) is one of the most serious weed problems facing farmers in the derived savanna zone of Nigeria. The study was designed to evaluate various control methods that would effectively control this noxious weed and increase crop yield in an environmentally sustainable way. The treatments were laid out in a randomized complete block design and these included: Glyphosate only applied at 1.8kg per hectare eight weeks after planting cassava; Glyphosate applied at 1.0kg per hectare eight weeks after planting cassava followed by the planting of Mucuna pruriens; Hand weeding followed by the planting of Mucuna pruriens eight weeks after planting cassava; and Three hand weedings at four, eight and twelve weeks after planting cassava. Analysis of variance (ANOVA) was used to analyse the data. Glyphosate effectively eliminated Imperata shoot both at 1.8kg and 1.0kg active ingredient per hectare but not all the rhizomes were killed. Imperata rhizome dry weight were significantly (P < 0.05) lower in glyphosate plus M. pruriens cover crop (0.5kg/ha) seconded by hand weeding plus M. pruriens cover crop (4.0kg/ha) as against 8.6kg/ha and 25.7kg/kg obtained in glyphosate alone and hand weeding alone, respectively. Cassava tubers and stem yields were significantly (P < 0.05) high in glyphosate applied at 1.0kg/ha plus M. pruriens cover crop (34.9kg/ha and 76.8 bundles/ha respectively). The next significantly (P < 0.05) high yield of cassava tubers and stems (29.5kg/ha and 65.4 bundles/ha respectively) were obtained in glyphosate alone treatment. There was no significant (P > 0.05) difference between Hand weeding plus M. pruriens cover crop and Hand weeding alone in terms of cassava tuber and stem yields. Glyphosate (1.0kg/ha) plus M. pruriens cover crop was recommended as the best method of speargrass (Imperata cylindrica , L.) control Keywords: Ecofriendly, Speargrass control, Cassava, Derived Savanna zone, Nigeria. Ethiopian Journal of Environmental Studies and Management Vol. 1 (1) 2008: pp. 64-69

Integrated Leafy Spurge (Euphorbia esula) Control Using Imazapic, Aphthona spp. Biological Control Agents, and Seeded Native Grasses

Abstract Chemical, cultural, and biological methods have been developed to control leafy spurge in a variety of environments. Aphthona spp. biological control agents have established throughout the northern Great Plains and Rocky Mountain region and successfully controlled leafy spurge in many areas, but notable exceptions include areas with sandy soils. Leafy spurge control can be improved by combining methods such as chemical, biological, or cultural treatments, compared to a single method used alone. The effects of Aphthona spp., imazapic herbicide, and interseeded native grass species alone or in combination for leafy spurge control were evaluated at two locations in southeastern North Dakota for 5 yr. Both the Sheyenne National Grassland (SNG) and Walcott, ND, study locations had greater than 80% sand soil. Leafy spurge stem density, canopy cover, and yield were reduced for 1 to 2 yr in all treatments that included imazapic, with no difference in control between single and combination treatments. Aph...

Cooling and Long-day Lighting Influences Growth and Flowering of Phlox paniculata L. ‘Ice Cap’ Used for Cut Flowers

In two studies, rooted cuttings of Phlox paniculata L. ‘Ice Cap’ (summer phlox) were cooled for 0, 4, 8, 12, or 16 weeks. Plants were forced in a glasshouse averaging 18 °C nights under extended-day and night-interruption lighting from incandescent lamps providing a minimum of 14 μmol·s−1·m−2 at plant level or continuous lighting from metal halide (HID) lamps providing a minimum of 400 μmol·s−1·m−2 at plant level. The influence of cooling duration on forcing days to flower, flowering stem counts, and flowering stem length was evaluated. Cooling plants promoted longer stems, higher flowering stem yields, and decreased days to flower when forced under long days provided by incandescent lamps, but when forced under HID lamps, days to flower for cooled plants were similar to those of noncooled plants regardless of cooling duration. Phlox forced in extended daylighting flowered in fewer days, had longer stems, and produced more flowering stems than those forced in night-interruption lighting. With continuous HID lighting, stem lengths and stems harvested per plant increased in a linear manner as cooling increased from zero to 16 weeks. Stem lengths ranged from 63.6 cm for noncooled plants to 96.3 cm for those receiving 16 weeks cooling, and flowering stem yields ranged from seven stems per plant for noncooled plants to 13 for those cooled 16 weeks. Phlox forced under HID lights flowered in substantially fewer days and had longer stems than those forced under incandescent lamps.

Forage yield performance and nutritive value of selected wild soybean ecotypes

Field experiments were conducted to evaluate the yield, yield components and quality of three wild soybean (Glycine soja Sieb. and Zucc.) ecotypes (FJW-9, SDW-12 and HLW-18) as forage in Dongying Forage Experiment Station of China in 2004 and 2005. Biomass yield and nutritional quality were observed using leaf, stem and whole plant taken from five harvest dates. The results show that the harvest dates had significant effects on leaf, stem, pod and whole-plant dry matter yields and forage quality (P &lt; 0.01). Wild soybean ecotypes included in the study produced whole-plant drymatter from 2.3 to 6.5 Mg ha-1 at different harvest dates. The highest dry matter yield came from the Sep. 17 harvest date, with average crude protein (CP) concentration of 191 g kg-1, neutral detergent fiber (NDF) concentration of 355 g kg-1 and acid detergent fiber (ADF) concentration of 254 g kg-1. Ecotype FJW-9 had higher dry matter yields of leaf, stem and whole plant than SDW-12 and HLW-18 (P &lt; 0.05). Mean CP concentration in whole plant of FJW-9 was higher (212 g kg-1) compared with the other two ecotypes (205 and 199 g kg-1), while the mean NDF and ADF concentrations of FJW-9 were lower than HLW-18 and SDW-12. Dry matter partitioning of wild soybean plant parts was greatly affected by harvest dates. There were statistically significant differences between wild soybean ecotypes in leaf, stem and whole-plant yields. The correlation between whole-plant dry matter yield and pod yield was not statistically significant (r = 0.13). These results suggest that wild soybeans have the potential to provide forage of high quality and adequate quantity for animals. Key words: Wild soybean, yield, nutritive value

Human embryonic stem cell derivation from poor-quality embryos

During in vitro fertilization, embryos deemed clinically useless based on poor morphology are typically discarded. Here we demonstrate a statistical correlation between the developmental stage of such poor-quality embryos and the yield of human embryonic stem (hES) cell lines. Early-arrested or highly fragmented embryos only rarely yield cell lines, whereas those that have achieved blastocyst stage are a robust source of normal hES cells.

Variation Laws of Anthocyanin Content in Roots and Their Relationships with Major Economic Traits in Purple-Fleshed Sweetpotato [ Ipomoea batatas (L.) Lam

Variation laws of anthocyanin content in root during the development and among the varieties, and their relationships with major economic traits in purple-fleshed sweetpotato [ Ipomoea batatas (L.) Lam] were studied in the present article. The dynamics of 20 economic traits in 13 purple-fleshed sweetpotato varieties at 20, 40, 60, 80, 100, 120, and 140 d after their transplanting were investigated, and these traits included anthocyanin content in root, length of the longest vine, number of base branches, root number, dry matter contents in stem, foliage and root, fresh/dry weight of root, fresh/dry weight of stem, fresh/dry weight of foliage, fresh/dry weight of stem and foliage, fresh/dry weight of whole plant, and rations of photosynthate to root, stem, and foliage. The correlations between the variations of anthocyanin content and the other 19 economic traits among varieties and during the whole developing stages, and the correlations of daily increase of anthocyanin content with other 10 kinds of yields were analyzed. The results showed that: (1) During the whole development, the anthocyanin content had three variation types, i.e. a slow-increase type, a fluctuating-change type, and a deviousrising type, and had different responses to the growth of length of the longest vine, number of base branches, fresh/dry yield of root, and photosynthate allotments. (2) The anthocyanin contents among 13 varieties began to have significant difference after 20 d, and showed completed differentiation during 40–100 d, which had significantly negative correlationships with the number of base branches, fresh/dry yield of root, photosynthate allotment ratio to root, and had significant positive correlationships with dry matter content of root, length of the longest vine, fresh/dry yield of stem, dry yield of whole plant and photosynthate allotment ratio to foliage. (3) Because of the significantly negative correlation between daily increase of anthocyanin content and dry matter weight of root, the anthocyanin accumulation competed with dry matter accumulation for photosynthate in root, and the competitive relation was resolved in different ways in different purple-fleshed sweetpotato (PFSP) varieties. So, there had three variation types of anthocyanin content among PFSP varieties during their development, and had different correlations between these variations of anthocyanin content and the major economic traits.