Seed persistence of the invasive aquatic plant, Gymnocoronis spilanthoides (Asteraceae)

2009 ◽  
Vol 57 (8) ◽  
pp. 670 ◽  
Author(s):  
F. Dane Panetta
Keyword(s):  
Soil Moisture ◽  
Aquatic Plant ◽  
Field Capacity ◽  
Soil Seed Banks ◽  
Seed Persistence ◽  
Moisture Regimes ◽  
Invasive Aquatic Plant ◽  
Freshwater Habitats ◽  
Buried Seed ◽  
Moisture Conditions

Seed persistence of Gymnocoronis spilanthoides (D.Don) DC.; Asteraceae (Senegal tea), a serious weed of freshwater habitats, was examined in relation to burial status and different soil moisture regimes over a 3-year period. Seeds were found to be highly persistent, especially when buried. At the end of the experiment, 42.0%, 27.3% and 61.4% of buried seeds were viable following maintenance at field capacity, water logged and fluctuating (cycles of 1week at field capacity followed by 3weeks’ drying down) soil moisture conditions, respectively. Comparable viability values for surface-situated seeds were ~3% over all soil moisture regimes. Predicted times to 1% viability are 16.2 years for buried seed and 3.8 years for surface-situated seed. Persistence was attributed primarily to the absence of light, a near-obligate requirement for germination in this species, although secondary dormancy was induced in some seeds. Previous work has demonstrated low fecundity in field populations of G. spilanthoides, which suggests that soil seed banks may not be particularly large. However, high levels of seed persistence, combined with ostensibly effective dispersal mechanisms, indicate that this weed may prove a difficult target for regional or state-wide eradication.

Soil moisture conditions affect the sensitivity ofBromus catharticusdormant seeds to light and the emergence pattern of seedlings

2009 ◽  
Vol 19 (2) ◽  
pp. 81-89 ◽  
Author(s):  
Federico P.O. Mollard ◽  
Pedro Insausti
Keyword(s):  
Soil Moisture ◽  
Red Light ◽  
Soil Drought ◽  
Moisture Regime ◽  
Emergence Pattern ◽  
Light Pulses ◽  
Soil Moisture Regime ◽  
Moisture Regimes ◽  
Summer Temperatures ◽  
Moisture Conditions

AbstractThe soil moisture regime may affect dormancy of seeds and their sensitivity to signals that promote germination. We studied the effect of moisture regime on the sensitivity to light of dormantBromus catharticusseeds, and on the emergence pattern of seedlings. Seeds were incubated under continuously hydrated, continuously dehydrated, or fluctuating moisture regimes in a controlled environment (25°C, darkness) for 2 months. After moisture treatments, seeds were exposed to red or far-red light pulses, or to darkness, to determine germinability. In addition, grassland mesocosms with intact seed bank and vegetation were irrigated or subjected to a drought regime in a glasshouse at summer temperatures. After 2 months, the temperature was reduced to correspond to grassland temperatures in autumn; the canopy was removed and half of the mesocosms were covered with filters that exclude red light. Density ofB. catharticusseedlings was evaluated after 2 weeks. Dormancy decreased in continuously hydrated seeds but they still required red light for germination. In contrast, an important fraction of seeds that experienced continuously dehydrated or fluctuating moisture regimes germinated in darkness or after far-red light pulses. In the mesocosms that had experienced a soil drought, a higher density of seedlings emerged in the absence of red light than in the daily irrigated mesocosms. This indicates that a fraction ofB. catharticusseeds acquired the capability to germinate under the canopy, especially in the drought moisture regime. Results indicate that the soil moisture environment experienced during dormancy affects the sensitivity to light ofB. catharticusseeds, as well as the emergence pattern of seedlings.

The Influence of Soil Moisture on the Foliar Activity of Diclofop

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 534-539 ◽  
Author(s):  
W. A. Dortenzio ◽  
R. F. Norris
Keyword(s):  
Soil Moisture ◽  
Near Field ◽  
Field Capacity ◽  
Herbicide Application ◽  
Wild Oats ◽  
High Soil Moisture ◽  
Herbicide Activity ◽  
Moisture Conditions ◽  
Soil Moisture Status ◽  
Wilting Point

Loss in activity of foliar-applied methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} occurred under low soil moisture conditions. A loss in control of yellow foxtail [Setaria lutescens(Weigel) Hubb.], wild oats (Avena fatuaL.), little-seed canarygrass (Phalaris minorRetz.), and barnyardgrass [Echinochloa crus-galli(L.) Beauv.], was observed under greenhouse and growth chamber conditions. When soil was maintained at 2 to 3% above wilting point as compared to near field capacity, herbicide activity was decreased by 15 to 50%. High soil moisture (at or above 67% of field capacity) for at least 2 to 4 days following treatment was needed to achieve maximum effectiveness of the herbicide. Daily furrow irrigations for a period of 10 days following treatment of barnyardgrass in the field resulted in highest activity as compared to that under single irrigation regimes within the 10-day period. The effect of low soil moisture was minimized by increased rates of herbicide application. Hoe-29152 {methyl-2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoate} showed similar losses in activity associated with low soil moisture. No consistent changes in uptake or translocation of14C-labeled diclofop could be detected in association with altered soil moisture status.

scholarly journals Effect of Hydropriming and soil moisture regimes on yield and yield components of maize (Zea mays L.)

2015 ◽  
Vol 39 (3) ◽  
pp. 505-513
Author(s):  
KU Ahammad ◽  
MM Rahman ◽  
MAM Molla ◽  
MG Azam
Keyword(s):  
Soil Moisture ◽  
Zea Mays L ◽  
Agricultural Research ◽  
Field Capacity ◽  
Research Field ◽  
Research Station ◽  
Maize Seeds ◽  
Moisture Regimes ◽  
Days To Maturity ◽  
Wet Condition

The experiment was conducted at the research field of Regional Agricultural Research Station, Jessore during two consecutive rabi seasons of 2008-2009 and 2009-2010 to find out the effect of hydropriming on the performance of maize seeds under variable soil moisture regimes. The treatments of the experiment were two priming methods viz., i) Hydropriming, ii) Non-priming and four moisture regimes viz., i) Wet condition, ii) Field capacity, iii) 75% of field capacity, and iv) 50% of field capacity. Results showed that yield and yield contributing characters (plant population/m2, number of cobs/m2, length of cob, diameter of cob, 100-grain weight) were influenced significantly by hydropriming. Yield and yield contributing characters were highest when hydroprimed seeds were sown at field capacity whereas it was the lowest at 75% of field capacity from non- primed seeds. Days to tasseling, days to silking, and days to maturity were reduced when hydroprimed seeds were sown at field capacity. At 50% of field capacity, no germination was occurred. DOI: http://dx.doi.org/10.3329/bjar.v39i3.21993 Bangladesh J. Agril. Res. 39(3): 505-513, September 2014

Soybean (Glycine max) Response to AC 263,222 and Chlorimuron as Influenced by Soil Moisture

1995 ◽  
Vol 9 (3) ◽  
pp. 553-560 ◽  
Author(s):  
Larry J. Newsom ◽  
David R. Shaw
Keyword(s):  
Soil Moisture ◽  
Field Experiments ◽  
Sprinkler Irrigation ◽  
Moisture Stress ◽  
Yield Reduction ◽  
Moisture Regime ◽  
Natural Rainfall ◽  
Moisture Regimes ◽  
Ac 263,222 ◽  
Moisture Conditions

Field experiments conducted in 1992 and 1993 evaluated differential response of 20 soybean cultivars to POST application of AC 263,222 or chlorimuron, as influenced by soil moisture. Natural rainfall was supplemented with overhead sprinkler irrigation to achieve three moisture regimes: excessive (12.5 cm/wk), optimum (5 cm/wk), and low (non-irrigated). Chlorimuron and AC 263,222 injured soybean. Excessive moisture did not increase soybean injury with chlorimuron for any of the cultivars tested compared to optimum moisture; however, 17 of 20 cultivars were injured more by AC 263,222 in combination with excessive moisture than optimum moisture. AC 263,222 reduced the height of five cultivars. Photosynthetic rate of several cultivars was reduced by both AC 263,222 and chlorimuron. Neither herbicide affected the number of nodes per main stem or seed weight; however, pod numbers were reduced for several cultivars with both herbicides. In the low moisture regime, AC 263,222 delayed the maturity of 18 of 20 cultivars with ‘Hutcheson’ maturity delayed 7.1 d. Excessive moisture when combined with AC 263,222 reduced yields for 12 cultivars, compared to five cultivars with chlorimuron. Under optimum moisture conditions, AC 263,222 reduced the yield of 10 cultivars, whereas chlorimuron reduced the yield of 9 cultivars. Low moisture stress only resulted in a yield reduction with 3 cultivars treated with AC 263,222.

scholarly journals Inoculation with mycorrhizal fungi on the growth and tolerance to water deficit of coffee plants

2018 ◽  
Vol 22 (11) ◽  
pp. 747-752 ◽  
Author(s):  
Samuel D. Moreira ◽  
André C. França ◽  
Wellington W. Rocha ◽  
Evandro S. R. Tibães ◽  
Eudes Neiva Júnior
Keyword(s):  
Soil Moisture ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Field Capacity ◽  
Dry Mass ◽  
Mycorrhizal Colonization ◽  
Coffee Plants ◽  
Moisture Conditions ◽  
Water Contents

ABSTRACT Water stress can be alleviated in plants inoculated with arbuscular mycorrhizal fungi compared to that experienced by those without mycorrhizae. The objective of this study was to evaluate the growth of coffee plants colonized by arbuscular mycorrhizal fungi under different soil moisture conditions. Seeds of the coffee cultivar Catuaí Vermelho IAC 99 and three fungal inoculants (Rhizophagus clarus, Claroideoglomus etunicatum and Dentiscutata heterogama) were used in this study. The soil moisture contents tested were 40, 60, 80, and 100% of field capacity. Seedlings in the matchstick stage were inoculated with mycorrhizae, and then later planted in plastic pots when they developed four to five pairs of definitive leaves. Both the extent of mycorrhizal colonization and increases in leaf area were related to soil moisture content in a quadratic manner for plants inoculated with all three mycorhizzal fungi (R. clarus, C. etunicatum, and D. heterogama), as well as for non-inoculated ones. The highest value of colonization of coffee by mycorrhizae was 39%, which occurred in association with R. clarus at 71% of field capacity. The leaf areas of plants inoculated with fungi increased more than those of non-inoculated plants, regardless of the type of inoculum used. Plants inoculated with D. heterogama at 100% field capacity produced 21% more root dry mass than non-inoculated plants did. Inoculation with arbuscular mycorrhizal fungi and higher soil moisture increased the growth of coffee seedlings. The plants inoculated with R. clarus, C. etunicatum, and D. heterogama were tolerant to moderate water deficits (i.e. lower soil water contents). Mycorrhizal colonization was highest for plants in soils with moisture levels close to 75% of field capacity.

Effects of contrasting light and soil moisture availability on the growth and biomass allocation of Douglas-fir and red alder

2003 ◽  
Vol 33 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Samuel S Chan ◽  
Steven R Radosevich ◽  
Amy T Grotta
Keyword(s):  
Soil Moisture ◽  
Biomass Allocation ◽  
Competitive Ability ◽  
Field Capacity ◽  
Douglas Fir ◽  
Red Alder ◽  
Moisture Availability ◽  
Biomass Components ◽  
Soil Moisture Availability ◽  
Moisture Conditions

We examined growth and biomass allocation of individual Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.) seedlings grown for 3 years under contrasting combinations of light and water. Alder growth was always greater than Douglas-fir. Full sunlight and soil moisture at field capacity caused large differences in size between the two species. With limited light and water, differences were smaller. Under full light and limited water, Douglas-fir allocated a high portion of its biomass to roots, whereas red alder allocated a high percentage to aboveground biomass components. Under light and water resource-limiting situations, red alder allocated more mass to stem, whereas Douglas-fir allocated more to roots. Red alder growth responded negatively to water limitation, whereas Douglas-fir did not. Red alder exhibited greater foliage plasticity to light. Species differences in size and allocation in response to resource availability may determine pathways by which Douglas-fir and red alder interact in a mixed community. Our findings support the hypothesis that the potential of species to use growth-limiting resources is an indicator of competitive ability. We suggest that red alder and Douglas-fir can co-exist under conditions of full light and limiting soil moisture availability. Furthermore, when contrasted with red alder, Douglas-fir's relatively greater tolerances to low light allow it to better persist in the understory. Red alder's rapid early growth and competitive ability will be superior under full light and nonlimiting soil moisture conditions.

Alvar seed bank germination responses to variable soil moisture

2007 ◽  
Vol 85 (10) ◽  
pp. 986-993 ◽  
Author(s):  
Jeremy T. Lundholm ◽  
Kaeli E. Stark
Keyword(s):  
Soil Moisture ◽  
Environmental Heterogeneity ◽  
Seedling Recruitment ◽  
Soil Surface ◽  
Drought Treatment ◽  
Southern Ontario ◽  
Soil Seed Banks ◽  
Niche Differences ◽  
Moisture Conditions ◽  
Rarefaction Effects

Environmental heterogeneity can create differential opportunities for seedling recruitment among plant species. We collected soil seed banks from alvar habitats in southern Ontario and exposed them to three soil moisture treatments. Density and species richness of germinants were greatest in treatments kept moist compared with treatments where soil was either saturated with standing water at the soil surface or where drought was imposed. Contrary to previous studies, the drought treatment did not stimulate the germination of species that remained ungerminated in other treatments, but did increase the germination of five species that also germinated in wetter soils. Although 12 of the 40 species germinated in only one of the three treatments, overall community composition among watering treatments was relatively consistent; few species showed evidence of differential responses to soil moisture conditions. Variability in soil moisture in this system can alter population and community properties by rarefaction effects, as opposed to niche differences among species.

scholarly journals ANATOMICAL CHANGES IN Urochloa plantaginea AND Urochloa platyphylla UNDER DIFFERENT SOIL MOISTURE CONDITIONS

2021 ◽  
Vol 9 (8) ◽  
pp. 393-406
Author(s):  
Lucas Chagastelles Pinto de Macedo ◽  
Sylvio Henrique Bidel Dornelles ◽  
Liliana Essi ◽  
Matheus Bohrer Scherer ◽  
Jéssica Cezar Cassol ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Depth ◽  
Field Capacity ◽  
Adaptive Structures ◽  
Anatomical Changes ◽  
Randomized Experimental Design ◽  
Poorly Drained Soils ◽  
Moisture Conditions ◽  
And Behavior ◽  
Depth Condition

Urochloa plantaginea and Urochloa platyphylla are common weeds in the highland area. However, in recent years, they have been found in wetlands and poorly drained soils, but the biology and behavior of the species in these conditions are not known. Thus, the objective was to assess anatomical changes in plants of Urochloa plantaginea and Urochloa platyphylla grown under different soil moisture conditions, as well as the adaptive structures generated as a result of each environment. A completely randomized experimental design in the form of a 2x2 factorial design was used, with factor A being two species of Urochloa (U. plantaginea and U. platyphylla), and species B being three soil moisture conditions (50 and 100% FC and 5 cm water depth), with four repetitions. The assessments were performed by means of anatomical cuts, observing the number and diameter (micrometers - μm) of aerenchymas in stems, roots and leaves; total diameter and the central root cylinder (μm); diameter of the fistula medulla and cortex (μm) in stems; mesophyll thickness and leaf midrib (μm). It was found that, for the two species of Urochloa, the water depth condition induced an increase in the number and diameter of aerenchymas in roots and leaves and provided a larger diameter of the fistulous pith in stems. The diameter of the central cylinder and the thickness of the leaf mesophyll midrib were more compact at 50% FC, also, for both species. Therefore, the adaptive structures generated vary as a result of the field capacity of the soil.

Responses of Lucerne to Different Soil Moisture Regimes

1967 ◽  
Vol 3 (1) ◽  
pp. 21-28 ◽  
Author(s):  
J. J. Landsberg
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Ground Cover ◽  
Moisture Stress ◽  
Early Morning ◽  
Moisture Regimes ◽  
Sampling Programme ◽  
Daily Evaporation ◽  
Moisture Conditions

SummaryAn experiment in which irrigation intervals for lucerne were dictated by four factors applied to daily evaporation from a Class A pan has been reported by Landsberg (1966). This paper discusses data from a number of subsidiary measurements made during that experiment. An extensive soil sampling programme yielded data on the effects of treatments on soil moisture content, and plant height and per cent ground cover measurements enabled detailed evaluations to be made of crop responses. Both height and ground cover were decreased by soil moisture stress. Relative turgidity was closely related to soil moisture content in the early morning, dry treatments showing more rapid recovery of turgor than those where water was kept at more adequate levels. Radiation utilization by the crop was affected by soil moisture conditions, and also apparently by temperature.

Quality and morphological characteristics of alfalfa as affected by soil moisture, pH and phosphorus fertilization

1992 ◽  
Vol 72 (1) ◽  
pp. 147-162 ◽  
Author(s):  
Hélène V. Petit ◽  
A. R. Pesant ◽  
G. M. Barnett ◽  
W. N. Mason ◽  
J. L. Dionne
Keyword(s):  
Soil Moisture ◽  
Soil Ph ◽  
Plant Morphology ◽  
Field Capacity ◽  
Phosphorus Fertilization ◽  
Moisture Regime ◽  
Available Water ◽  
Soil Moisture Regime ◽  
Temperature Regimes ◽  
Moisture Regimes

Alfalfa (Medicago sativa L. ’Saranac’) was grown in a greenhouse on Ste-Rosalie clay and Danby gravelly sandy loam to determine the effects of phosphorus fertilization, air temperature, soil moisture regime and soil pH on chemical composition and plant morphology. The following treatments were applied in factorial combination: three moisture regimes (1, semi-dry, with soil moisture between field capacity or 100% of available water and wilting point or 0% of available water; 2, optimal, between field capacity and 70% of available water; 3, wet, between saturation point and field capacity), three rates of phosphorus in the form of disodium phosphate (0, 12.5 and 25.0 P kg−1 of dry soil) and three soil pH levels (natural, near 5.4, 6.5 and 7.5). Half the alfalfa was grown in a warm greenhouse section with a minimum daytime temperature of 25 °C and 19 °C at night and the other half was grown in a cool section with a daytime minimum of 15 °C and 9 °C at night. Quality of alfalfa was generally improved by water deficit as shown by decreased concentrations of acid detergent fiber (ADF) and acid detergent lignin (ADL) and increased concentrations of crude protein (CP). Cold temperatures decreased ADF content which indicates that quality of alfalfa grown under cold compared to warm temperature regimes is better. Phosphorus fertilization seemed to have more effects on plant morphology and quality under cold than warm temperature regimes. In general, concentrations of CP, ADF and ADL, stem length, leaf area and the number of stems increased in parallel with soil pH. The data indicate that low temperature and low soil moisture regimes were generally associated with higher quality alfalfa than were high temperature and wet soil moisture regimes.Key words: Alfalfa, soil moisture regime, air temperature, phosphorus fertilization, soil pH

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