scholarly journals Seasonal emergence of selected summer annual weed species in dependence on soil temperature

2010 ◽  
Vol 56 (No. 9) ◽  
pp. 444-450 ◽  
Author(s):  
M. Jursík ◽  
J. Holec ◽  
J. Soukup ◽  
V. Venclová
Keyword(s):  
Chenopodium Album ◽  
Soil Surface ◽  
Main Field ◽  
Weed Species ◽  
Soil Temperatures ◽  
Field Emergence ◽  
The Relationship ◽  
Galinsoga Ciliata ◽  
Surface Layer Temperature ◽  
Mass Field

This study aimed to describe emergence cycles of selected weed species under Central European conditions in relation to cumulative soil temperatures from the start of the vegetation season. Emergence of Chenopodium album, Echinochloa crus-galli, Galinsoga ciliata, and Abutilon theophrasti was observed from March to October during the period 2001–2006 at two locations. The beginning of main field emergence was determined as the day when the sum of effective hour temperatures was achieved, and was detected from the second decade of April to early May for C. album, in the second decade of May for E. crus-galli, from late April to the beginning of May for G. ciliata, and from the end of April to mid-May for A. theophrasti. The relationship between cumulative soil surface layer temperature and weed mass field emergence at the beginning of the growing season is very direct (differences ±7 days) – but only when soil moisture is sufficient. In a drier spring, the beginning of mass field emergence occurs with 1–4 weeks of delay and field emergence is usually slower and protracted.

scholarly journals Predicting broadleaf weed populations in maize from the soil seedbank

2004 ◽  
Vol 57 ◽  
pp. 281-285 ◽  
Author(s):  
A. Rahman ◽  
T.K. James ◽  
J.M. Mellsop ◽  
N. Grbavac
Keyword(s):  
White Clover ◽  
Chenopodium Album ◽  
Seedling Emergence ◽  
Soil Samples ◽  
Weed Species ◽  
Linear Relationships ◽  
Weed Seeds ◽  
Soil Seedbank ◽  
The Relationship ◽  
Field Plots

Investigations over three years studied the relationship between weed seeds in the soil seedbank and the resultant populations of broadleaf weeds in maize fields Plots were protected from preemergence herbicide after which soil samples (100 mm) were collected and weed seeds therein enumerated Emerged weed seedlings in field plots were counted over the following 8 weeks Up to 67 broadleaf weed species were identified although not all were found at every site and some were specific to a region or soil type On average 2182 of the seed in the soil seedbank emerged For most weeds strong linear relationships were noted between seedling numbers and the seed numbers in the soil although for some like white clover (Trifolium repens) only a weak relationship was observed In the case of fathen (Chenopodium album) which had the largest seedbank there was evidence of asymptotic behaviour with seedling emergence levelling off at high seed numbers

Effect of tillage and corn on pigweed (Amaranthusspp.) seedling emergence and density

Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Joseph O. E. Oryokot ◽  
Stephen D. Murphy ◽  
Clarence J. Swanton
Keyword(s):  
Soil Temperature ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Seedling Density ◽  
Weed Species ◽  
No Till ◽  
Prior Constraint ◽  
Soil Temperatures ◽  
Management Recommendations ◽  
Moldboard Plow

We studied the effect of no-till, chisel, and moldboard plow and the presence or absence of corn on soil temperature, moisture and, subsequently, the emergence phenology and density of pigweed seedlings at 2 sites from 1993 to 1995 inclusively. Tillage significantly affected the phenology of pigweed seedling emergence only during a June drought at one site in 1994. Soil temperature and moisture, measured at 2.5-cm depths, also were unaffected by tillage. Weed phenology is usually earlier in no-till because more seeds are located closer to the surface (< 5 cm deep) in no-till, thereby reducing the delay in penetrating through the soil, and because soil temperatures and moisture are nearer the germination and emergence optima. However, pigweed seedlings are already physiologically restricted to germination depths of less than 2.5 cm regardless of tillage; therefore, this prior constraint eliminated any potential differences in emergence phenologies caused by tillage. The presence or absence of corn also did not affect soil temperatures, soil moisture, or pigweed seedling emergence phenologies. Pigweed seedling density was significantly higher in no-till; this may have been caused by increased numbers of seeds near the soil surface in no-till. The presence or absence of corn did not affect pigweed seedling density; the lack of a significant effect probably reflects high variances in density. Although necessary for most weed species, tillage may be a less important factor to consider in predicting pigweed population dynamics and subsequent management recommendations.

EFFECT OF TEMPERATURE AND SOIL MOISTURE ON TIME OF EMERGENCE OF TOMATOES AND FOUR WEED SPECIES

1988 ◽  
Vol 68 (3) ◽  
pp. 877-886 ◽  
Author(s):  
S. E. WEAVER ◽  
C. S. TAN ◽  
P. BRAIN
Keyword(s):  
Soil Moisture ◽  
Lycopersicon Esculentum ◽  
Chenopodium Album ◽  
Soil Surface ◽  
Cumulative Distribution ◽  
Effect Of Temperature ◽  
Weed Species ◽  
Sowing Dates ◽  
Time Required ◽  
Response To Temperature

The relative times to emergence of seedlings of tomato (Lycopersicon esculentum L.) and four weed species were compared at five alternating temperatures and five levels of available soil moisture in a growth chamber. Weed seeds were sown either on the soil surface or 1.5 cm below it. A cumulative distribution function was used to describe the time required for emergence under a given set of conditions. Time to 50% emergence, base temperatures and accumulated degree days required for 50% emergence were calculated for each species. In general, total emergence decreased as soil moisture decreased, but the species differed in the optimum temperature for emergence. Time to 50% emergence decreased with increasing temperature and increased slightly with decreasing soil moisture. Base temperatures and thermal times required for 50% emergence varied among species, but were relatively insensitive to soil moisture above a critical level. Differences in relative times to emergence of crop and weeds in response to temperature can be used to suggest optimal crop sowing dates and to estimate potential crop yield losses.Key words: Germination, Solanum ptycanthum, Amaranthus powellii, Setaria viridis, Chenopodium album, Lycopersicon esculentum

AN EMPIRICAL METHOD OF ESTIMATING SOIL TEMPERATURE ON CROPPED LAND ON CANADIAN PRAIRIES

1981 ◽  
Vol 61 (3) ◽  
pp. 565-573 ◽  
Author(s):  
C. A. CAMPBELL ◽  
W. NICHOLAICHUK ◽  
V. O. BIEDERBECK ◽  
H. UKRAINETZ ◽  
J. BOLE
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Cropping Systems ◽  
Soil Surface ◽  
Growing Season ◽  
Empirical Method ◽  
Canadian Prairies ◽  
Cereal Production ◽  
Soil Temperatures ◽  
The Relationship

Agronomists often require quick, easy methods of estimating soil temperatures under cereal production, either to fill in missing experimental measurements or to help explain apparent discrepancies in results. Methods available in the literature allow such estimates to be made from meteorological measurements and soil physical characteristics, but these methods are often mathematically complex. In the present paper a simple empirical regression and correlation approach was used to relate soil temperatures under cereal and fallow cropping systems to air temperature, and also to soil temperature at corresponding depths under grass plots at Swift Current, Saskatchewan. Relationships for the top 22.5 cm of soil were developed for the growing season and also for the whole year. Relationships between soil and air temperature were good near the soil surface, but deteriorated with depth even though highly significant r2 values were obtained. The best relationships were obtained between soil temperatures under the cereal system and temperatures under grass (r2 > 0.8 for growing season and > 0.9 for whole year). The relationships between mean daily temperatures under cereals (y) and those under grass at corresponding depths (x) were generally represented by y = x. The best Swift Current relationships for the growing season were used successfully [Formula: see text] to predict data for different years at Swift Current and Scott, Saskatchewan and at Lethbridge, Alberta. The error in prediction at the 10-cm depth was, on the average, 1–3 °C and at the 20-cm depth, 0–4 °C. The relationship developed will be more accurate in drier regions such as the southern prairies.

Bio-efficacy of post emergence herbicides in boro rice nursery as well as main field and their residual effects on non-target microorganisms

2020 ◽  
Vol 57 (3) ◽  
pp. 199-210
Author(s):  
Rajib Kundu ◽  
Mousumi Mondal ◽  
Sourav Garai ◽  
Ramyajit Mondal ◽  
Ratneswar Poddar
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Block Design ◽  
Resistance Index ◽  
Residual Effects ◽  
Cost Ratio ◽  
Main Field ◽  
Weed Species ◽  
Similar Treatment

Field experiments were conducted at research farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India (22°97' N latitude and 88°44' E longitude, 9.75 m above mean sea level) under natural weed infestations in boro season rice (nursery bed as well as main field) during 2017-18 and 2018-19 to evaluate the herbicidal effects on weed floras, yield, non-target soil organisms to optimize the herbicide use for sustainable rice-production. Seven weed control treatments including three doses of bispyribac-sodium 10% SC (150,200, and 250 ml ha-1), two doses of fenoxaprop-p-ethyl 9.3% EC (500 and 625 ml ha-1), one weed free and weedy check were laid out in a randomized complete block design, replicated thrice. Among the tested herbicides, bispyribac-sodium with its highest dose (250 ml ha-1) resulted in maximum weed control efficiency, treatment efficiency index and crop resistance index irrespective of weed species and dates of observation in both nursery as well as main field. Similar treatment also revealed maximum grain yield (5.20 t ha-1), which was 38.38% higher than control, closely followed by Fenoxaprop-p-ethyl (625 ml ha-1) had high efficacy against grasses, sedge and broadleaf weed flora. Maximum net return (Rs. 48765 ha-1) and benefit cost ratio (1.72) were obtained from the treatment which received bispyribac-sodium @ 250 ml ha-1. Based on overall performance, the bispyribac-sodium (250 ml ha-1) may be considered as the best herbicide treatment for weed management in transplanted rice as well as nursery bed.

scholarly journals Factors affecting Cyperus difformis seed germination and seedling emergence

2013 ◽  
Vol 31 (4) ◽  
pp. 823-832 ◽  
Author(s):  
A. Derakhshan ◽  
J. Gherekhloo
Keyword(s):  
Seed Germination ◽  
Integrated Management ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Soil Surface ◽  
Weed Species ◽  
Factors Affecting ◽  
Cyperus Difformis ◽  
Emergence Patterns

Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. Laboratory studies were conducted to determine the effect of several environmental factors on seed germination and seedling emergence of Cyperus difformis. Germination of freshly harvested seeds was inhibited by darkness; however, when seeds were subsequently transferred to complete light they germinated readily. Our results showed that 2 wk of cold stratification overcome the light requirement for germination. Seeds of C. difformis were able to germinate over a broad range of temperatures (25/15, 30/20, 35/25, and 40/30 ºC day/night). The response of germination rate to temperature was described as a non-linear function. Based on model outputs, the base, the optimum and the ceiling temperatures were estimated as 14.81, 37.72 and 45 ºC, respectively. A temperature of 120 ºC for a 5 min was required to inhibit 50% of maximum germination. The osmotic potential and salinity required for 50% inhibition of maximum germination were -0.47 MPa and 135.57 mM, respectively. High percentage of seed germination (89%) was observed at pH=6 and decreased to 12% at alkaline medium (pH 9) pH. Seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of 1 cm.

scholarly journals Crop residues on short-term CO2 emissions in sugarcane production areas

2013 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mariana M. Corradi ◽  
Alan R. Panosso ◽  
Marcílio V. Martins Filho ◽  
Newton La Scala Junior
Keyword(s):  
Co2 Emissions ◽  
Field Experiments ◽  
Crop Residues ◽  
Soil Surface ◽  
Dry Mass ◽  
Agricultural Crop ◽  
Short Term ◽  
Sugarcane Production ◽  
Soil Temperatures ◽  
Production Areas

The proper management of agricultural crop residues could produce benefits in a warmer, more drought-prone world. Field experiments were conducted in sugarcane production areas in the Southern Brazil to assess the influence of crop residues on the soil surface in short-term CO2 emissions. The study was carried out over a period of 50 days after establishing 6 plots with and without crop residues applied to the soil surface. The effects of sugarcane residues on CO2 emissions were immediate; the emissions from residue-covered plots with equivalent densities of 3 (D50) and 6 (D100) t ha-1 (dry mass) were less than those from non-covered plots (D0). Additionally, the covered fields had lower soil temperatures and higher soil moisture for most of the studied days, especially during the periods of drought. Total emissions were as high as 553.62 ± 47.20 g CO2 m-2, and as low as 384.69 ± 31.69 g CO2 m-2 in non-covered (D0) and covered plot with an equivalent density of 3 t ha-1 (D50), respectively. Our results indicate a significant reduction in CO2 emissions, indicating conservation of soil carbon over the short-term period following the application of sugarcane residues to the soil surface.

scholarly journals Weed Interference Affects Dry Bean Yield and Growth

2012 ◽  
Vol 4 (3) ◽  
pp. 70-75 ◽  
Author(s):  
Hossein GHAMARI ◽  
Goudarz AHMADVAND
Keyword(s):  
Chenopodium Album ◽  
Growing Season ◽  
Amaranthus Retroflexus ◽  
Growth And Yield ◽  
Weed Competition ◽  
Weed Species ◽  
Dry Bean ◽  
Logistic Equations ◽  
Weed Interference ◽  
Minimum Number

Dry bean is one of the most important pulse crops in Iran. Field study was conducted in 2011 to evaluate effects of weed competition from a natural flora on growth and yield of dry bean (Phaseolus vulgaris L.). The treatments consisted of weed infestation and weed removal periods (10, 20, 30, 40 and 50 days) after crop emergence. Control plots kept weed-infested and weed-free throughout growing season. To assess the weed competition effect on crop characteristics, Richards, Gompertz and logistic equations were fitted to the data. The most abundant weed species were Chenopodium album and Amaranthus retroflexus. Increase in duration of weed interference decreased the stem height of dry bean. At the end of the growing season, dry bean was 20 cm taller in season-long weed-free treatment compared to the season-long weed-infested treatment. As the number of days of weed interference increased, a declining trend of LAI and number of pods was observed. The minimum number of pods was obtained in season-long weed-infested treatment (5.01 pods/plant). Weed interference during the whole growing season, caused a 60% reduction in yield. Considering 5% and 10% acceptable yield lost, the critical period of weed competition was determined from 20 to 68 and 23 to 55 days after planting (DAE), respectively.

scholarly journals EXAMINATION OF THE WEED FLORA OF RUDER HABITATS AND THE POSSIBILITY OF SUPPRESSION WITH HERBICIDES

2018 ◽  
Vol 6 (4) ◽  
pp. 329-332
Author(s):  
Milić Vojinović ◽  
Jelica Živić ◽  
Sanja Perić ◽  
Miroljub Aksić
Keyword(s):  
Chenopodium Album ◽  
Working Environment ◽  
Xanthium Strumarium ◽  
Weed Species ◽  
Construction Sites ◽  
Convolvulus Arvensis ◽  
Human Settlements ◽  
Time Of Application ◽  
Vegetation Complex ◽  
Selection Of

Ruderal flora, as well as the vegetation that flora forms, represent an extremely dynamic floristic-vegetation complex and arean integral part of the most immediate living and working environment of human. It is formed and developed mainly in human settlements, as well as in the other anthropogenic environments that are occasionally or permanently under direct or indirect influence of various forms of human activity. Ruderal vegetation is found not only directly around the settlements, but also around all urban and accompanying facilities: along roads, paths and fences around houses, yards, walls and roofs, in avenues, on ruins, construction sites, landfills, along railway tracks, road and defense embankments, on wet and nitrified banks of rivers, near human settlements, in abandoned lawns, on the street walks with sandy areas, cemeteries, in degraded pastures, forests, etc. This essay presents the distribution and representation of economically harmful, invasive and quarantine weed species (Abutilon theophrasti, Agropyrumrepens, Amaranthusretroflexus, Calystegiasepium, Cirsiumarvense, Chenopodium album, Chenopodiumhybridum, Convolvulus arvensis, Cynodondactylon, Daturastramonium, Sonchusarvensis, Sorghum halepense, Xanthium strumarium…) at ten sites in the Nisava district. The assessment of species representation was done in two shootings (May and August) according to scale 1-4. The proper selection of herbicides depends, in a large extent, on the presence of dominant weed species and on the time of application.

scholarly journals Evaluation of Different Weed Management Practices on Growth Variables and Yield of Wheat Varieties

2020 ◽  
pp. 7-30
Author(s):  
Md. Golam Mostafa ◽  
Syed Arvin Hassan ◽  
Md. Ehsanul Haq ◽  
Md. Ahasan Habib ◽  
Kaniz Fatema ◽  
...  
Keyword(s):  
Grain Yield ◽  
Weed Management ◽  
Management Practices ◽  
Cynodon Dactylon ◽  
Chenopodium Album ◽  
Cyperus Rotundus ◽  
Alternanthera Philoxeroides ◽  
Weed Species ◽  
Wheat Varieties ◽  
Hand Weeding

A field experiment was conducted in medium fertile soil at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during November 2017 to April 2018 in Rabi season with a view to evaluate the performance of wheat varieties under different weed control methods. The experiment was carried out with three varieties i.e. BARI Gom-28, BARI Gom-29 and BARI Gom-30 in the main plot and five weed management methods viz. control (no weeding), two hand weeding at 20 and 40 DAS, Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS pre-emergence, Afinity 50.75WP (Isoproturon) 1500 g ha-1 at 25 DAS as post-emergence herbicide and Panida 33EC (Pendimethalin) @ 2000 ml ha-1 at 5 DAS + Afinity 50.75WP (Isoproturon)1500 g ha-1 at 25 DAS in the sub plot in split plot design. Nine different major weed species were found in the field such as Cynodon dactylon, Cyperus rotundus, Echinochloa colonum, Eleusine indica, Chenopodium album, Alternanthera philoxeroides, Brassica kaber, Leliotropium indicum, Vicia sativa. Results reveled that BARI Gom-30 contributed the highest grain yield 3.01 tha-1. Pre-emergence application of Panida 33EC controlled weeds significantly which showed highest growth followed by yield achieved in wheat. BARI Gom-30 in combination with Panida 33EC produced the highest grain yield 3.52 tha-1 while the lowest grain yield 2.09 t ha-1 was obtained from BARI Gom-28 with no weeding treatment. Results reveled that Panida 33EC (pre-emergence) was found more effective to controlling weeds in wheat. Results of the study finally reveled that Panida 33EC might be considered as a feasible option for combating weed and ensuring higher yield in wheat cultivation.

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