scholarly journals Analysis of linseed (Linum usitatissiumum L.) plant branching as related to variability and interdependence of traits

2013 ◽  
Vol 57 (1-2) ◽  
pp. 187-205 ◽  
Author(s):  
Tadeusz Zając
Keyword(s):  
Morphological Traits ◽  
Branching Process ◽  
Weather Conditions ◽  
Planting Density ◽  
Young Plant ◽  
Plant Groups ◽  
Lateral Shoots ◽  
Weed Infestation ◽  
Biometric Measurements ◽  
Plant Shoots

Branching process of two linseed cultivars ('Hungarian Gold' and 'Opal') was analysed each year of vegetation between 1999 and 2002 characterised by different weather course. The estimation included also the extent and variability of selected morphological traits and structural traits. as well as correlation between them. On the basis of biometric measurements the hierarchy of plant shoots has been established within a plant, and four plant groups were distinguished: 1-. 2-, 3- and 4-shoot plants. It was demonstrated that the intensity of linseed branching depended mainly on young plant planting density and, to a certain extent also the weather conditions in April and May. In the years when the weather course favoured vegetation. between 23 and 40% plants per stand were branched. Beside increasing its productivity linseed branching may also inhibit a development of secondary weed infestation of the canopy. Similar plant groups with analogous shoot hierarchy formed in both linseed cultivars. Bio social position of shoot on a plant determined the extent of its traits. A dominance of the maiii shoot over lateral shoots was marked, especially concerning the number of seed vessels. Particularly big prevalence of the main shoot over lateral ones was visible in 3- and 4-9hoot plants. Lateral shoots had greater variability of morphological traits, especially concerning the number of seed vessels per shoot. Linear, exponential and power interdependencies between traits of linseed cultivars were also revealed.

scholarly journals Planting density impact on weed infestation and the yield of Miscanthus grown on two soil types  

2016 ◽  
Vol 62 (No. 8) ◽  
pp. 384-388 ◽  
Author(s):  
J. Maksimović ◽  
R. Pivić ◽  
A. Stanojković-Sebić ◽  
M. Vučić-Kišgeci ◽  
B. Kresović ◽  
...  
Keyword(s):  
Biomass Yield ◽  
Weather Conditions ◽  
Planting Density ◽  
First Year ◽  
Initial Growth ◽  
Miscanthus Giganteus ◽  
Weed Infestation ◽  
Commercial Yield ◽  
The Impact ◽  
Commercial Harvesting

The assessment of the weed infestation effect on biomass yield of Miscanthus × giganteus in the first year of its commercial yield was conducted on two types of soil with different productive ability – Luvic Chernozem and Calcic Gleysol. The formed mass of weeds was higher on Luvic Chernozem and the infestation had grown according to the stages of Miscanthus growth. The biomass of weeds depended on the planting density of Miscanthus as well as on the weather conditions during the studied years. Weed infestation of crops very significantly influenced the formation of aboveground biomass of Miscanthus, so that the yields in the first year of commercial harvesting in the control where the weeds were removed manually were significantly higher compared to the crops in which weeds were not removed. The obtained results showed that weeds significantly affect the initial growth and development of Miscanthus plants that are, in general, slow, especially in the year of the crop establishment. The study evaluates the impact of a manual method of suppression and weed infestation of crops on the commercial yield of Miscanthus.  

scholarly journals Are Wheat Hybrids More Affected by Weed Competition than Conventional Cultivars?

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 526
Author(s):  
Marco Milan ◽  
Silvia Fogliatto ◽  
Massimo Blandino ◽  
Francesco Vidotto
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Weather Conditions ◽  
Hybrid Wheat ◽  
Wheat Varieties ◽  
Canopy Development ◽  
Productivity Losses ◽  
Crop Density ◽  
Weed Infestation ◽  
Wheat Hybrids

Seeding rates of hybrid wheat varieties are typically much lower than conventional varieties due to their higher seed costs, which could potentially delay canopy development leading to greater weed pressures. To test whether hybrid wheat crops are more affected by weed pressure than conventional cultivars, a conventional variety (“Illico”) and a hybrid (“Hystar”), were compared in a three-year (2012–2016) field study at two sites in Northern Italy. Weed infestation was mainly characterized by weeds with an early growth pattern, and in only a few seasons did the hybrid crops show a higher weed density than the conventional cultivar. Despite the lower sowing rate, hybrids were able to achieve a similar crop density to the conventional cultivar even in years of delayed sowing or dry weather conditions. Normalized Difference Vegetation Index values were generally similar between cultivars across the years, regardless of the presence of weeds, except during the springtime. Occasionally, the test weight was significantly higher in weeded plots than un-weeded plots. Overall, the two cultivars showed similar yields within the same year. These results indicate that on fields with a low weed burden, and where these weeds emerge early, cultivars may not be significantly affected by productivity losses.

scholarly journals Sinapis alba L. weed infestation depending on the seeding rate and N fertilizer dose in the steppe Crimea

2020 ◽  
Author(s):  
Ye.N. Rostova ◽  
Keyword(s):  
Crop Yields ◽  
Dry Weight ◽  
Weather Conditions ◽  
Sinapis Alba ◽  
Mineral Fertilizers ◽  
White Mustard ◽  
Weed Species ◽  
Seeding Rate ◽  
Sinapis Alba L ◽  
Weed Infestation

Dense white mustard (Sinapis alba L.) can suppress weeds, however excessive density negatively influences crop yields. The search for the optimal parameters for applying mineral fertilizers and the consumption of seed material will increase the crop yield and will improve its competitive ability. This work aimed to identify the seeding rate and doses of nitrogen fertilization at which white mustard plants can actively suppress weeds without reducing the productivity of the crop. In the course of this research, we established that S. alba sown at a rate of 2, 2.5 and 3 million seeds per ha suppressed the growth and development of weeds as much as possible. On average, in 2017-2019, the dry weight of weeds in the aforementioned variants was the least and reached 57.9; 42.3 and 38.4 g/m2, respectively. Weed species composition and quantitative parameters of weed infestation depended on the weather conditions of the year. The application of nitrogen fertilizer did not affect significantly the weediness of S. alba crops. The optimal density white mustard plant formed at a seeding rate of 2 million units/ha and, on average, for three years of research, the seed yield in this variant was the highest (0.6 t/ha).

scholarly journals Causes and consequences of variation in early-life telomere length in a bird metapopulation

2021 ◽  
Author(s):  
Michael Le Pepke ◽  
Thomas Kvalnes ◽  
Peter Sjolte Ranke ◽  
Yimen G. Araya-Ajoy ◽  
Jonathan Wright ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Population Density ◽  
Telomere Length ◽  
Environmental Conditions ◽  
Early Life ◽  
Morphological Traits ◽  
Weather Conditions ◽  
Population Fluctuations ◽  
Individual Quality ◽  
Pace Of Life

1.Environmental conditions during early-life development can have lasting effects on individual quality and fitness. Telomere length (TL) may correlate with early-life conditions and may be an important mediator or biomarker of individual quality or pace-of-life, as periods of increased energy demands can increase telomere attrition due to oxidative stress. Thus, knowledge of the mechanisms that generate variation in TL, and the relation between TL and fitness, is important in understanding the role of telomeres in ecology and life-history evolution. 2.Here, we investigate how environmental conditions and morphological traits are associated with early-life TL and if TL predicts natal dispersal probability or components of fitness in two populations of wild house sparrows (Passer domesticus). 3.We measured morphological traits and blood TL in 2746 nestlings from 20 cohorts (1994-2013) and retrieved data on weather conditions. We monitored population fluctuations, and individual survival and reproductive output using field observations and genetic pedigrees. We then used generalized linear mixed-effects models to test which factors affected TL in early-life, and if TL predicted dispersal propensity, or was associated with recruitment probability, mortality risk, or reproductive success.4.We found a negative effect of population density on TL, but only in one of the populations. There was a curvilinear association between TL and the maximum daily North Atlantic Oscillation (NAO) index during incubation, suggesting that there are optimal weather conditions that result in the longest TL. Dispersers tended to have shorter telomeres than non-dispersers. TL did not predict survival, but we found a tendency for individuals with short telomeres to have higher annual reproductive success.5.Our study showed how early-life TL is shaped by effects of growth, weather conditions and population density, supporting that environmental stressors negatively affect TL in wild populations. In addition, TL may be a mediator or biomarker of individual pace-of-life, with higher dispersal rates and annual reproduction tending to be associated with shorter early-life TL in this study. However, clear associations between early-life TL and individual fitness seems difficult to establish and may differ between different populations in the wild.

scholarly journals Evaluation of Selected Fine-leaf Fescue Cultivars for Their Turfgrass Quality and Weed Suppressive Ability in Field Settings

2009 ◽  
Vol 19 (3) ◽  
pp. 660-668 ◽  
Author(s):  
Cécile Bertin ◽  
Andy F. Senesac ◽  
Frank S. Rossi ◽  
Antonio DiTommaso ◽  
Leslie A. Weston
Keyword(s):  
Root Exudates ◽  
Field Studies ◽  
Weed Suppression ◽  
Planting Density ◽  
Weed Suppressive Ability ◽  
Practical Standpoint ◽  
Weed Infestation ◽  
Turfgrass Quality ◽  
Allelopathic Interference ◽  
Fine Leaf Fescue

A series of field studies were conducted from 1999 to 2005 in Ithaca, NY, at the Cornell Turfgrass Research Center as part of the National Turfgrass Evaluation Program (NTEP) to evaluate a collection of 78 fine-leaf fescue cultivars (Festuca spp.) for turfgrass quality, seedling vigor, and ability to inhibit the establishment of common annual and perennial weeds. Using these criteria, we evaluated the overall suitability of the cultivars for use in turfgrass settings, as well as their potential weed suppressive or allelopathic ability. The ability of fine-leaf fescue to displace weeds was visually evaluated by density-wise comparison, and several cultivars of the 78 studied consistently established well and provided good to very good suppression (greater than 70%) of common turf weeds when established at the same planting density. Other cultivars provided moderate (between 35% and 70%) to (< 30%) little weed suppression. Greater weed suppressivity is likely associated with the differential ability of fescue cultivars to establish rapidly and to form a dense canopy, as well as potential allelopathic interference. This study was conducted in conjunction with laboratory experiments that revealed that certain fine-leaf fescue cultivars produced phytotoxic root exudates that were released into the rhizosphere over time. Additional field studies conducted in Ithaca showed that cultivars Intrigue, Columbra, and Sandpiper were consistently more weed suppressive than the other fine-leaf fescues evaluated. Although our understanding of the dynamics of production and degradation of fine-leaf fescue root exudates in the rhizosphere is limited, recent field studies also suggest that allelopathic interference as well as the ability to rapidly establish influence subsequent weed infestation in fine-leaf fescue stands. From a more practical standpoint, certain fine-leaf fescue cultivars, including Intrigue, Columbra, Sandpiper, and Reliant II, could be recommended for use in low-maintenance turf settings in the northeastern United States due to their aesthetic appeal and their limited weed infestation in circumstances where herbicides are not applied.

scholarly journals Research on the Optimum Shape and Size of Potato Ridges

2013 ◽  
Vol 70 (1) ◽  
pp. 243-250
Author(s):  
Ivan Zoltan VITOS ◽  
Gavrilă MORAR ◽  
Luiza MIKE ◽  
Cristina MOLDOVAN
Keyword(s):  
Weather Conditions ◽  
Planting Density ◽  
Optimum Shape ◽  
Average Weight ◽  
Optimal Size ◽  
Cross Sectional ◽  
Class A ◽  
Trapezoidal Shape ◽  
Significant Difference ◽  
Potato Tuberization

The partial results from the research carried out in 2012 at the Potato Research and Development Station Tg. Secuiesc on the size and shape of the ridges and the influence of planting density in the case of two varieties and two types of ridges (ridges in one row and two rows) are presented. The results were heavily influenced by the unfavorable weather conditions in 2012 when there was a smaller amount of precipitation compared to the multiannual average rainfall during the growing season: -115.4 mm. The insufficient moisture resulted in the inhibition of potato tuberization, reabsorption of stolons and young tubers and in this period some of the water content in tubers passed into the leaves. In the study of the optimal shape of potato ridges three different shapes have been studied: triangular shape, trapezoidal shape and double-trapezoidal shape. In the study of the optimal size of potato ridges three different ridge sizes were made: with cross-sectional areas of  800 cm2 , 1200 cm2 and 1600 cm2. The biological material used in these two experiments was the Bella Rosa variety, which is part of the class A biological category. The research on the influence of planting density was conducted on two potato varieties planted in ridges in a single row and in two rows: one that forms many but small tubers, the class A Gared variety and the second one that forms fewer but larger tubers, the class A Bella Rosa variety. Experiments with three different planting densities for each type of variety and each type of ridge (ridges in one row and two rows) were carried out: 40.000 plants/ha, 60.000 plants/ha and 80,000 plants/ha. For all variants four rows were planted and the process was repeated four times. The common technology of ridge ploughing was used and mechanically performed phytosanitary treatments were executed with the usual products. To achieve the objectives the following elements were taken into consideration: yield and production (kg/ha), average weight of a tuber (g), average number of tubers in the nest. An analysis of variance was carried out for completely randomized plots and the data processing was accomplished by using average values, the “t-test” at 5%, 1%, 0.1% significant difference levels and the Duncan Multiple Range Test.

scholarly journals PLANT DENSITY AND FIELD GERMINATION OF WINTER TRITICALE DEPENDING ON VARIETY AND NORMAL SEEDING SEEDS

2018 ◽  
Vol 13 (4) ◽  
pp. 83-86
Author(s):  
Леонид Шашкаров ◽  
Leonid Shashkarov ◽  
Светлана Толстова ◽  
Svetlana Tolstova
Keyword(s):  
Plant Density ◽  
Maximum Yield ◽  
Stand Density ◽  
Weather Conditions ◽  
Planting Density ◽  
Seeding Rate ◽  
Southeastern Part ◽  
Winter Triticale ◽  
Field Germination ◽  
Plant Stand

The article deals with the issues of plant density and field germination of winter triticale on gray forest soils of the southeastern part of the Volga-Vyatka zone depending on the variety and seeding rates. The question of establishing the optimum density of sowing, the area of food for grain crops served as the object of study by many researchers. The urgency of the issue of creating optimal sowing density is explained by the fact that the factors that determine the magnitude of the yield are constantly changing. The plant stand density and field germination of winter triticale are significantly influenced by the weather conditions formed during the growing season of winter triticale plants. With an increase in seeding rates, the plant stand density and seeding rate increases, respectively, is important for the formation of a given density of productive stalks. In production, these elements of technology are often underestimated and often unjustifiably overestimate the seeding rate, which is absolutely unnecessary, since the really possible yield is achieved at an optimal seeding rate with minimal seed consumption. The winter triticale seeding rates, both in Russia and in the world as a whole varies from 2 to 8 million viable seeds per hectare. The urgency of the issue of creating optimal sowing density is explained by the fact that the factors that determine the magnitude of the yield are constantly changing. Until now, there is no consensus on the dependence of planting density on the degree of fertility. Some researchers believe that nutrient-rich soil requires less seed for maximum yield. Under these conditions, the plants develop better, they bush more, the maximum yield can be obtained with a lower seeding rate. The opposite opinion that it is necessary to sow thicker on rich soils has become widespread, especially in recent years. Advocates of the bottom conclusion explain their point of view by the fact that fertile soil has a greater supply of food and moisture, therefore, more plants can be grown on the same area, which means that the seeding rate should be increased [1,2.3,4.5,6,7]. Research results indicate that winter triticale with increasing seeding rates increases plant density and field germination of winter triticale plants.

scholarly journals MAX1 and MAX2 control shoot lateral branching in Arabidopsis

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1131-1141 ◽  
Author(s):  
Petra Stirnberg ◽  
Karin van de Sande ◽  
H. M. Ottoline Leyser
Keyword(s):  
Positional Cloning ◽  
Leaf Shape ◽  
Shoot Meristem ◽  
Axillary Shoot ◽  
Axillary Meristem ◽  
Axillary Shoots ◽  
Recessive Mutations ◽  
Lateral Shoots ◽  
Plant Shoots ◽  
Shoot Meristems

Plant shoots elaborate their adult form by selective control over the growth of both their primary shoot apical meristem and their axillary shoot meristems. We describe recessive mutations at two loci in Arabidopsis, MAX1 and MAX2, that affect the selective repression of axillary shoots. All the first order (but not higher order) axillary shoots initiated by mutant plants remain active, resulting in bushier shoots than those of wild type. In vegetative plants where axillary shoots develop in a basal to apical sequence, the mutations do not clearly alter node distance, from the shoot apex, at which axillary shoot meristems initiate but shorten the distance at which the first axillary leaf primordium is produced by the axillary shoot meristem. A small number of mutant axillary shoot meristems is enlarged and, later in development, a low proportion of mutant lateral shoots is fasciated. Together, this suggests that MAX1 and MAX2 do not control the timing of axillary meristem initiation but repress primordia formation by the axillary meristem. In addition to shoot branching, mutations at both loci affect leaf shape. The mutations at MAX2 cause increased hypocotyl and petiole elongation in light-grown seedlings. Positional cloning identifies MAX2 as a member of the F-box leucine-rich repeat family of proteins. MAX2 is identical to ORE9, a proposed regulator of leaf senescence (Woo, H. R., Chung, K. M., Park, J.-H., Oh, S. A., Ahn, T., Hong, S. H., Jang, S. K. and Nam, H. G. (2001) Plant Cell13, 1779-1790). Our results suggest that selective repression of axillary shoots involves ubiquitin-mediated degradation of as yet unidentified proteins that activate axillary growth.

scholarly journals Maize-Pigeonpea Intercropping Outperforms Monocultures Under Drought

2020 ◽  
Vol 4 ◽  
Author(s):  
Leah L. R. Renwick ◽  
Anthony A. Kimaro ◽  
Johannes M. Hafner ◽  
Todd S. Rosenstock ◽  
Amélie C. M. Gaudin
Keyword(s):  
Grain Yield ◽  
Drought Resistance ◽  
Smallholder Farmers ◽  
Cropping Systems ◽  
Low Cost ◽  
Weather Conditions ◽  
Gliricidia Sepium ◽  
Fertilizer Application ◽  
Planting Density ◽  
Adverse Weather

There is an urgent need to develop resilient agroecosystems capable of helping smallholder farmers adapt to climate change, particularly drought. In East Africa, diversification of maize-based cropping systems by intercropping with grain and tree legumes may foster productivity and resilience to adverse weather conditions. We tested whether intercropping enhances drought resistance and crop and whole-system yields by imposing drought in monocultures and additive intercrops along a crop diversity gradient—sole maize (Zea mays), sole pigeonpea (Cajanus cajan), maize-pigeonpea, maize-gliricidia (Gliricidia sepium, a woody perennial), and maize-pigeonpea-gliricidia—with and without fertilizer application. We developed and tested a novel low-cost, above-canopy rainout shelter design for drought experiments made with locally-sourced materials that successfully reduced soil moisture without creating sizeable artifacts for the crop microenvironment. Drought reduced maize grain yield under fertilized conditions in some cropping systems but did not impact pigeonpea grain yield. Whole-system grain yield and theoretical caloric and protein yields in two intercropping systems, maize-pigeonpea and maize-gliricidia, were similar to the standard sole maize system. Maize-pigeonepea performed most strongly compared to other systems in terms of protein yield. Maize-pigeonpea was the only intercrop that consistently required less land than its corresponding monocultures to produce the same yield (Land Equivalent Ratio &gt;1), particularly under drought. Despite intercropping systems having greater planting density than sole maize and theoretically greater competition for water, they were not more prone to yield loss with drought. Our results show that maize-pigeonpea intercropping provides opportunities to produce the same food on less land under drought and non-drought conditions, without compromising drought resistance of low-input smallholder maize systems.

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