Digitaria ciliaris (southern crabgrass).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
Seed Production ◽  
Farmyard Manure ◽  
Soil Surface ◽  
Post Harvest ◽  
Fluctuating Temperatures

Abstract As an annual weed, D. ciliaris depends on seed production for its spread. There is some post-harvest dormancy which may last several months. Germination then occurs at temperatures above 20°C and is perhaps greatest under fluctuating temperatures of 20 and 35°C (Holm et al., 1977). Most germination occurs at or close to the soil surface (Osa et al., 1988), but some may occur from 5 cm depth (Takabayashi and Nakayama, 1979). Seeds can survive passage through cattle and thus contaminate farmyard manure (Takabayashi et al., 1979).

Growth, seed production and effect of defoliation in an early flowering perennial grass, Alloteropsis semialata (Poaceae), on Cape York Peninsula, Australia

2001 ◽  
Vol 49 (6) ◽  
pp. 735 ◽  
Author(s):  
Gabriel M. Crowley ◽  
Stephen T. Garnett
Keyword(s):  
Plant Growth ◽  
Seed Production ◽  
Perennial Grass ◽  
Soil Surface ◽  
Plant Size ◽  
Perennial Grasses ◽  
Wet Season ◽  
Cape York ◽  
Seed Dynamics

Alloteropsis semialata (R.Br.) A.Hitchc. is one of the first perennial grasses in monsoonal Australia to produce seed at the start of the wet season. Patterns of growth and seed production and seed dynamics of Alloteropsis semialata were examined in this study, along with the effects of partial defoliation. Growth of Alloteropsis semialata tussocks started with the first pre-wet-season rains, and was then interrupted during a period with little rain. Growth ceased before the end of the wet season, indicating that factors other than moisture availability were limiting. Seeds of Alloteropsis semialata were germinable on production, but did not remain viable or persist on the soil surface through the dry season. Most seeds and young seedlings were harvested and no seedlings were recruited. Inflorescence production increased with plant size. Moderate defoliation in the early wet season had no impact on plant growth, but reduced inflorescence and seed production for at least 2 years. Absence of a seed bank and early wet-season flowering mean that Alloteropsis semialata is likely to be sensitive to long-term over-grazing.

scholarly journals The effect of manuring with undersown catch crop, and production system on the potato tuber content of microelements

2019 ◽  
Vol 14 (3) ◽  
pp. 176-182
Author(s):  
Anna Płaza ◽  
Barbara Gąsiorowska ◽  
Emilia Rzążewska ◽  
Anna Cybulska ◽  
Rafał Górski
Keyword(s):  
Potato Tuber ◽  
Production System ◽  
Production Systems ◽  
Farmyard Manure ◽  
Soil Surface ◽  
Favourable Effect ◽  
Catch Crop ◽  
Two Factors ◽  
Iron And Zinc ◽  
Persian Clover

The potato tuber content of microelements is lower than that of macroelements but they are equally important. With this respect, there has been noticed a favourable effect of natural and organic manuring. The objective of the study reported here was to determine the effect of manuring with an undersown catch crop, either autumn-incorporated or left on the soil surface as mulch for spring incorporation, and production system on the potato tuber content of microelements. The study involved a field experiment, which was conducted in 2009-2012. The following two factors were examined: I − manuring with undersown catch crop: control, farmyard manure, Persian clover, Persian clover + westerwolds ryegrass, westerwolds ryegrass, Persian clover − mulch, Persian clover + westerwolds ryegrass − mulch, westerwolds ryegrass − mulch; II − production system: integrated and organic. Potato tubers were sampled to determine microelement contents. The highest iron and zinc contents were recorded in the tubers of potato manured with autumn-incorporated Persian clover whereas boron content was the highest in the tubers of potato manured with Persian clover, regardless of when it had been incorporated, as well as an autumn-incorporated Persian clover + westerwolds ryegrass mixture. Organic potatoes contained more iron and boron whereas tubers grown in the integrated production system were higher in zinc, manganese and copper. Potato manuring with undersown catch crops and farmyard manure in both the production systems studied increased the potato tuber content of microelements, excluding copper and manganese.

Sequestration of Organic Carbon Influenced by the Application of Straw Residue and Farmyard Manure in Two Different Soils

2014 ◽  
Vol 28 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Majid Mahmoodabadi ◽  
Elina Heydarpour
Keyword(s):  
Organic Matter ◽  
Surface Layer ◽  
Carbon Sequestration ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Depth ◽  
Farmyard Manure ◽  
Soil Surface ◽  
Organic Carbon Content ◽  
Uncultivated Soil

Abstract Soil organic carbon is one of the most important soil components, which acts as a sink for atmospheric CO2. This study focuses on the effect of different methods of organic matter application on the soil organic carbon sequestration in a 4-month experiment under controlled greenhouse conditions. Three rates of straw residue and farmyard manure were added to uncultivated and cropland soils. Two treatments of straw residue and farmyard manure incorporation were used into: a soil surface layer and 0-20 cm soil depth. The result showed that the application of organic matter, especially the farmyard manure incorporation led to a significant increase in the final soil organic carbon content. Higher amounts of soil organic carbon were stored in the cropland soil than in the uncultivated soil. On average, the soil surface layer treatment caused a higher sequestration of soil organic carbon compared to the whole soil depth treatment. If higher rates of organic matter were added to the soils, lower carbon sequestration was observed and vice versa. The result indicated that the carbon sequestration ranged farmyardmanure > strawresidue and cropland soil > uncultivated soil. The findings of this research revealed the necessity of paying more attention to the role of organic residue management in carbon sequestration and prevention of increasing global warming.

Decomposition of residues and loss of the δ-endotoxin from transgenic (Bt) corn (Zea mays L.) in soil

2005 ◽  
Vol 85 (1) ◽  
pp. 19-26 ◽  
Author(s):  
D. W. Hopkins ◽  
E. G. Gregorich
Keyword(s):  
Limit Of Detection ◽  
Detection Threshold ◽  
Soil Surface ◽  
Bt Corn ◽  
Plant Materials ◽  
Harvest Residues ◽  
Post Harvest ◽  
Fresh Plant ◽  
Crop Residue Decomposition ◽  
Soil Colloids

Corn and other crops genetically modified to express the insecticidal δ-endotoxin from Bacillus thuringiensis (Bt) are grown widely across north America. Studies have shown that the δ -endotoxin can be stabilised on soil colloids where its activity is retained, but reports of direct ecological effects of the δ-endotoxin on soil processes are limited. We have determined the concentrations of the δ-endotoxin in organic residues fro m Bt-corn plants at increasing stages of ageing and decay, and the subsequent decomposition in soil of these residues and the δ-endotoxin in them. The δ-endotoxin concentrations declined from 6.8 μg g-1 in the fresh plant material, to 0.82 μg g-1 in the post-harvest residues collected in the fall, and to 0.026 μg g-1 in the residues collected from soil surface the following spring. The concentration of δ -endotoxin in buried residues collected in the spring was not significantly different from zero. When incubated in soil in the laboratory over 84 d, the δ-endotoxin decomposed more rapidly than bulk plant C by factors of 1.85 for the fresh plant materials and 3.21 for the post-harvest residues. Within 14 d of incubation, the δ-endotoxin concentration in the residues collected at the soil surface was below the limit of detection. We contrasted the laboratory decomposition data with data from a field experiment to estimate the period that the δ-endotoxin in corn residues may survive in the field. Based on estimates derived from this comparison, we predict that following an October harvest in eastern Ontario the δ-endotoxin would fall below the detection threshold during November for post-harvest residues. Since stabilisation of the δ-endotoxin on soil colloids depends on it surviving (i.e., not being decomposed) for long enough to be released from the plant residue matrix and come into proximity with colloid surfaces, the rapid decay of the δ-endotoxin suggests that only a small fraction of the δ-endotoxin from post-harvest residues persists long enough to become stabilised in the field. Key words: Bt, corn, crop residue decomposition, maize

scholarly journals Percolation and Survival of Escherichia coli O157:H7 and Salmonella enterica Serovar Typhimurium in Soil Amended with Contaminated Dairy Manure or Slurry

2009 ◽  
Vol 75 (10) ◽  
pp. 3206-3215 ◽  
Author(s):  
Alexander V. Semenov ◽  
Leo van Overbeek ◽  
Ariena H. C. van Bruggen
Keyword(s):  
Escherichia Coli ◽  
Survival Data ◽  
Salmonella Enterica ◽  
Farmyard Manure ◽  
Soil Surface ◽  
Dairy Manure ◽  
Bulk Soil ◽  
Nuclear Magnetic Resonance Method ◽  
Survival Times ◽  
Serovar Typhimurium

ABSTRACT The effect of cattle manure and slurry application on percolation and survival of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium was investigated for different soil depths after the addition of water. Four treatments were chosen for the first set of experiments: (i) addition of inoculated farmyard manure on the soil surface, (ii) mixing of inoculated farmyard manure with the top 10 cm of soil, (iii) addition of inoculated slurry on the soil surface, and (iv) injection of inoculated slurry into the top 10 cm of the soil. Homogeneity of water distribution in the soil profile was confirmed by a nondestructive nuclear magnetic resonance method. Survival data were fitted to a modified logistic model, and estimated survival times were compared. In the second set of experiments, pathogen-inoculated farmyard manure or slurry was applied to soil columns with 1-month-old lettuce plants. More pathogen cells percolated to greater depths after slurry than after manure application. Survival of E. coli O157:H7 was significantly longer in soil with slurry than in that with manure, while survival of Salmonella serovar Typhimurium was equally high with manure and slurry. The densities of the pathogens were not different in the rhizosphere compared to the bulk soil with manure, while the densities were higher by 0.88 � 0.11 and 0.71 � 0.23 log CFU per g (dry weight), respectively, in the rhizosphere than in bulk soil after slurry application. Our results suggest that surface application of manure may decrease the risk of contamination of groundwater and lettuce roots compared to injection of slurry.

Limiting Green and Yellow Foxtail (Setaria viridisandS. glauca) Seed Production Following Spring Wheat (Triticum aestivum) Harvest

1999 ◽  
Vol 13 (1) ◽  
pp. 43-47 ◽  
Author(s):  
George O. Kegode ◽  
Frank Forcella ◽  
Beverly R. Durgan
Keyword(s):  
Seed Production ◽  
Great Plains ◽  
Spring Wheat ◽  
Soil Surface ◽  
The United States ◽  
Northern Great Plains ◽  
University Of Minnesota ◽  
Tillage Systems ◽  
Hard Red Spring Wheat ◽  
Main Plot

Green and yellow foxtail seed production following harvest of spring wheat is a concern of producers in the northern Great Plains of the United States and the Prairie Provinces of Canada. Experiments were conducted in 1996 and 1997 in three tillage systems, no till (NT), chisel plow (CP), and moldboard plow (MP), at the University of Minnesota West Central Experiment Station, Morris, MN, to determine whether time of glyphosate application or tillage after spring wheat harvest could reduce postharvest foxtail seed production. In both years, hard red spring wheat was planted in late April and a packaged mixture of fenoxaprop and 2,4-D ester and MCPA ester was applied at a rate of 53 g and 81 g and 246 g ai/ha for grass and broadleaf weed control. Following spring wheat harvest, each main plot was subdivided into seven subplots, including an untreated control. One subplot was disked twice at 4 to 6 d after harvest (DAH) of spring wheat, and five other subplots had glyphosate (0.25 kg ai/ ha) applied on different days (1 to 31 DAH). Foxtail seeds were collected from the soil surface following first frost, and the number of green and yellow foxtail seeds were determined. Tillage immediately after spring wheat harvest eliminated foxtail plants, and no new foxtail seedlings emerged in either tilled or glyphosate-treated plots despite ideal postharvest conditions for foxtail germination and emergence in 1997. Most viable green foxtail seeds were consistently obtained in NT plots, whereas yellow foxtail seed production varied among tillage systems. Either tillage soon after spring wheat harvest or glyphosate application within 16 DAH reduced green and yellow foxtail seed production by greater than 70%.

Germination Ecology of Two Troublesome Asteraceae Species of Rainfed Rice: Siam Weed (Chromolaena odorata) and Coat Buttons (Tridax procumbens)

Weed Science ◽  
2008 ◽  
Vol 56 (4) ◽  
pp. 567-573 ◽  
Author(s):  
Bhagirath S. Chauhan ◽  
David E. Johnson
Keyword(s):  
Dry Matter ◽  
Crop Residue ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Chromolaena Odorata ◽  
Weed Species ◽  
Control Programs ◽  
Rainfed Rice ◽  
Tridax Procumbens ◽  
Fluctuating Temperatures

Siam weed and coat buttons are among the most troublesome Asteraceae weed species of rainfed rice. The influence of various environmental factors on seed germination and seedling emergence of these weeds was determined. Germination response of both species was greater at the warmer fluctuating temperatures (30/20 and 35/25 C) than at the colder temperatures (25/15 C). Light stimulated germination in both species; however, some seeds still germinated in the dark. Both species were moderately tolerant of salt and water stress, but Siam weed tolerated more stresses than coat buttons. At the soil surface, Siam weed and coat buttons emergence was 75 and 76%, respectively, but this declined rapidly with increasing soil depths. Neither species emerged from depths exceeding 3 cm. Seedling emergence and seedling dry matter of both species were greatly reduced with the addition of crop residue to the soil surface at rates equivalent to 4 to 6 t ha−1. The information gained in this study will be used to facilitate development of effective weed control programs.

The reproductive biology of the introduced root holoparasite Orobanche ramosa subsp. mutelii (Orobanchaceae) in South Australia

2015 ◽  
Vol 63 (5) ◽  
pp. 426
Author(s):  
Jane Prider
Keyword(s):  
Seed Production ◽  
Invasive Plant ◽  
South Australia ◽  
Reproductive Traits ◽  
Soil Surface ◽  
Flower Senescence ◽  
Self Pollination ◽  
Orobanche Ramosa ◽  
Large Populations ◽  
Successful Control

An understanding of the timing and constraints on seed production is necessary for the successful control of many invasive plant species. In the present study, we investigated the reproductive traits of the annual root holoparasite, Orobanche ramosa L. subsp. mutelii (F.W.Shultz) Cout. (branched broomrape), which occurs in the western Murray mallee area of South Australia. Flowering stems emerge above the ground from early September. Each flower spike has from 2 to 24 flowers and the first flower opens on the base 8 days after emergence and senesces 6 days later. An additional flower opens acropetally every 1–2 days. The species is autogamous and self-pollination can occur before anthesis. Mature seeds were observed from 9–10 days after flower senescence and capsules dehisced 12 days later. Although each plant is in flower only for an average of 20 days, in large populations or multi-branched plants, the flowering period extends over several weeks, with a peak in mid-October. Seed production in sampled populations was highly variable, ranging from 1000 to over 200 000 per plant. Large plants with several branching stems produced the most seeds, although capsules produced per stem and seeds per capsule were also variable. There is a brief window of opportunity for control of O. ramosa subsp. mutelii after it emerges above the soil surface and before it sets seed. Weedy root parasites such as Orobanche ramosa can have devastating impacts on host crops, but are difficult to control because most growth occurs underground. We identified key characters that contribute to the success of this introduced plant, including self-pollination, rapid maturation of the reproductive stages and high seed output. Vigilance is required so that plants can be controlled before they set seed.

Biology and control of Reseda lutea L. 2. Life cycle: seedling emergence, recruitment, and vegetative reproduction

1997 ◽  
Vol 48 (4) ◽  
pp. 517 ◽  
Author(s):  
J. W. Heap
Keyword(s):  
Life Cycle ◽  
Seedling Recruitment ◽  
Vegetative Reproduction ◽  
Seedling Emergence ◽  
Soil Surface ◽  
First Year ◽  
Shoot Production ◽  
Tap Root ◽  
And Control ◽  
Fluctuating Temperatures

The reproductive biology of Reseda lutea L. was studied in the laboratory and field in southern Australia. Seedling emergence was greatest from 5 mm depth (57%) to 10 mm (53%) but also occurred from 80 mm. Seeds on the soil surface did not germinate. Following cultivation of a field population, seedling emergence was high (144/m2) in the first winter and recruitment to the perennial population was estimated at 10·2%. Seedling emergence in subsequent winters was low. Perennial shoot numbers increased gradually in the first year after cultivation, from seedling recruitment and daughter shoots, and then stabilised at around 28/m2. Shoots formed on root fragments at a range of constant and fluctuating temperatures between 10° and 35°C, with a maximum of 17·3 shoots per 50-mm fragment at 15°C. Shoot production increased with root fragment length and diameter. Shoots were produced on root fragments as short as 10 mm and as thin as 1 mm. Fragments from the upper tap root produced more shoots than those from further down the tap root, or from laterals. An illustrated model of the life cycle of R. lutea in Australia is presented.

Regeneration of annual winter legumes at Tamworth, New South Wales

1974 ◽  
Vol 14 (66) ◽  
pp. 57 ◽  
Author(s):  
MW Hagon
Keyword(s):  
Seed Production ◽  
New South ◽  
New South Wales ◽  
Soil Surface ◽  
Moisture Stress ◽  
Late Spring ◽  
South Wales ◽  
Hard Seeds ◽  
Improved Cultivars

The seed production and regeneration of a range of naturalized and introduced cultivars of annual clovers and medics was studied at Tamworth, New South Wales, between 1971 and 1973. Seed production was correlated with maturity grading within species only when moisture stress occurred in late spring. The proportion of seed lost as summer seedlings and the proportion of unrecovered seed were greater the lower the level of hardseededness. A greater proportion of unrecovered seed was recorded for those cultivars which bore their burrs at the soil surface. As a group the medics had a higher proportion of residual hard seeds than did the clovers. The results are discussed in relation to the likely persistence of improved cultivars compared to the successful persistence of the naturalized medics and clovers in the Tamworth district.

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