SOIL WEED SEED BANK STATUS IN THE AGROECOLOGICAL CONDITIONS OF CHITRAL, PAKISTAN

A greenhouse experiment was carried out at the Agricultural Research Station (ARS), Shen Lasht, Chitral during 2016-17. There were five different locations in district Chitral from where the soil samples were collected which included Drosh, Shen Lasht, Garam Chashma, Ayun and BoonyLasht. A total of 300 samples were collected from all locations with 60 samples from each location. The 300 soil samples collected were placed in trays of medium sizes i.e. 27 cm x 21 cm x 4 cm = 2268 cm3. The trays were arranged in three repetitions having 100 samples in each repetition. Each repetition of 100 samples contained samples from 5 locations, in each location 4 sites (east, west, north and south each at 100 m distance from each other) and at each site samples were collected from 5 different depths, making a total of 100 samples in one repetition i.e. 5 x 4 x 5 = 100 and with repetitions making a total of 300 samples in one district. The results indicated that in the soil samples of district Chitral a total of 31 noxious weeds were recorded. Out of the 31 different weeds, 23 were broad leaves, eight were grasses and one was sedge. In another angle, 24 weeds were annuals while the rest were perennials out of the 31 weeds identified. A total of 17 different plant families were represented by the weeds recorded in the soil samples of Chitral region. Among the different locations of Chitral, the highest weed seed bank was recorded in the soil samples of ARS Shen Lasht area. Weed seed banks have always been higher in areas with mild winters, where the Shen lasht area is having milder winters as compared to the other areas in Chitral. The lowest seed bank was recorded in the soil samples of Garam Chashma, which was however statistically at par with the rest of the locations studied in Chitral. As far as the seed banks in the depths are concerned, largest weed seed bank was observed in the depth of 6 to 12 cm. The smallest seed bank was at the depth of 30 cm followed by the depth of 24 and 18 cm. Therefore, it is evident that the major weed seed bank lies in the upper 6-12 cm depth of the soil. In case of the interaction, the largest weed seed bank was recorded at ARS Sheen lasht at the depth of upper 6 cm of the soil profile whereas the weed seed bank was very low below the 12cm depth of soil upto 30 cm in the Garam Chashma area of Chitral. Out of the total 31 weeds recorded in soil samples of Chitral, the top 10 weeds in terms of the relative weed densities, relative weed frequencies and importance value indices were Convolvulus arvensis, Rumex crispus, Poa annua, Galium aparine, Avenafatua, Trianthemaportulacastrum, Silybum marianum, Sorghumhalepense, Euphorbia helioscopia, and Loliumtenulentumspecies. The IVI values for these weeds were 14.01, 13.96, 13.07, 11.83, 11.57, 11.12, 10.35, 10.09, 10.02, and 9.99, respectively. Moreover, these IVIs indicate that out of the topmost 10 problematic weeds eight weeds are broad leaved and two are grassy weeds.

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Weed Seed Banks in Established Strawberry Fields

HortScience ◽

10.21273/hortsci.33.3.459f ◽

1998 ◽

Vol 33 (3) ◽

pp. 459f-460

Author(s):

Faye Propsom ◽

Emily Hoover

Keyword(s):

Organic Matter ◽

Weed Control ◽

Seed Bank ◽

Cultural Practices ◽

Seed Banks ◽

Soil Samples ◽

Soil Types ◽

Twin Cities ◽

Weed Seed ◽

Metro Area

Weed control in strawberries, either in a new planting or one that is established, is a major source of problems for growers in Minnesota. To control weeds, growers need to know which weeds are a problem, which weeds are deleterious, and which weeds have the potential to become a problem. Weeds present, soil type, and weed seed bank information are needed in order to predict potential weed problems. With different weed control practices applied between and within the rows, we assumed weed seed bank populations would vary. In addition, we were interested in seeing if the seed banks differed between soil types and individual farmer's cultural practices. Soil samples were collected from 13 commercial strawberry fields located around the Twin Cities metro area. In 1996, samples were taken after renovation and before mulch was applied. In 1997, they were taken after mulch was removed and prior to renovation. The soil samples for each date, treatment, and farm were dried, and organic matter was separated from inorganic. The weed seeds were removed from the remaining organic matter, identified and counted. Soil types and cultural practices were used to compare the differences among the farms.

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Responses of weed community, soil nutrients, and microbes to different weed management practices in a fallow field in Northern China

PeerJ ◽

10.7717/peerj.7650 ◽

2019 ◽

Vol 7 ◽

pp. e7650 ◽

Cited By ~ 1

Author(s):

Xian Gu ◽

Yu Cen ◽

Liyue Guo ◽

Caihong Li ◽

Han Yuan ◽

...

Keyword(s):

Soil Fertility ◽

Soil Nutrients ◽

Seed Bank ◽

Weed Management ◽

Seed Banks ◽

Total Biomass ◽

Weed Seed ◽

Soil Biodiversity ◽

Deep Tillage ◽

Positive Effects

The long-term use of herbicides to remove weeds in fallow croplands can impair soil biodiversity, affect the quality of agricultural products, and threaten human health. Consequently, the identification of methods that can effectively limit the weed seed bank and maintain fallow soil fertility without causing soil pollution for the next planting is a critical task. In this study, four weeding treatments were established based on different degrees of disturbance to the topsoil: natural fallow (N), physical clearance (C), deep tillage (D), and sprayed herbicide (H). The changes in the soil weed seed banks, soil nutrients, and soil microbial biomass were carefully investigated. During the fallow period, the C treatment decreased the annual and biennial weed seed bank by 34% against pretreatment, whereas the H treatment did not effectively reduce the weed seed bank. The D treatment had positive effects on the soil fertility, increasing the available nitrogen 108% over that found in the N soil. In addition, a pre-winter deep tillage interfered with the rhizome propagation of perennial weeds. The total biomass of soil bacterial, fungal, and actinomycete in H treatment was the lowest among the four treatments. The biomass of arbuscular mycorrhizal fungi in the N treatment was respectively 42%, 35%, and 91%, higher than that in the C, D, and H treatments. An ecological weeding strategy was proposed based on our findings, which called for exhausting seed banks, blocking seed transmission, and taking advantage of natural opportunities to prevent weed growth for fallow lands. This study could provide a theoretical basis for weed management in fallow fields and organic farming systems.

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Effect of a Living Mulch on Weed Seed Banks in Tomato

Weed Technology ◽

10.1614/wt-d-10-00101.1 ◽

2011 ◽

Vol 25 (2) ◽

pp. 245-251 ◽

Cited By ~ 11

Author(s):

Kevin D. Gibson ◽

John Mcmillan ◽

Stephen G. Hallett ◽

Thomas Jordan ◽

Stephen C. Weller

Keyword(s):

Seed Production ◽

Seed Bank ◽

Critical Period ◽

Field Studies ◽

Seed Banks ◽

Weed Suppression ◽

Weed Seed ◽

Fresh Market ◽

Living Mulch ◽

Seed Rate

Weeds that emerge between rows in fresh market tomatoes after the critical period of competition are not suppressed by the crop and can produce large quantities of seed. A living mulch planted between rows might limit weed seed production. Buckwheat was seeded between tomato rows after the critical period in 2007 and 2008 in field studies near Lafayette, IN. Weeds were allowed to emerge after the critical period (CP), controlled throughout the growing season (no seed threshold [NST]), or mowed to limit seed production (MOW). Buckwheat and MOW plots were mowed twice after the critical period in 2007 and once in 2008. Seed banks were sampled after the critical period and in the following spring. Tomato yields were not reduced by growing buckwheat between rows. Seed bank densities for common purslane and carpetweed, which escaped mowing due to their prostrate habits, increased in all treatments. Germinable seed bank densities were 306 seeds m−2or less in the NST and buckwheat treatments but 755 seeds m−2or more in the CP treatments for species with erect habits in both years. Seed bank densities were lower in the MOW treatment than in the CP treatments in 2007 but not in 2008. In a parallel experiment conducted in adjacent plots, buckwheat was seeded at five rates (0, 56, 112, 168, and 224 kg seed ha−1). Plots were mowed and emergent weeds sampled as described for the intercrop experiment. Weed densities before mowing decreased linearly with buckwheat seed rate. After mowing, no relationship was detected between seed rate and weed densities. This study supports the hypothesis that a living mulch planted after the critical period can be used to limit seed bank growth without reducing tomato yields, but additional research is needed to better understand the effect of mowing on living mulch growth and weed suppression.

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The Effect of Organic Mulching and Irrigation on the Weed Species Composition and the Soil Weed Seed Bank of Tomato

Plants ◽

10.3390/plants9010066 ◽

2020 ◽

Vol 9 (1) ◽

pp. 66 ◽

Cited By ~ 1

Author(s):

Renáta Petrikovszki ◽

Mihály Zalai ◽

Franciska Tóthné Bogdányi ◽

Ferenc Tóth

Keyword(s):

Species Composition ◽

Seed Bank ◽

Soil Samples ◽

Management Technique ◽

Weed Seed ◽

Weed Species ◽

Tomato Production ◽

Organic Mulch ◽

Different Depths ◽

The Impact

Mulching is a management technique to control weeds in organic and integrated tomato production. Our experiment was designed to investigate the impact of organic mulch combined with irrigation on the weed species composition and weed seed bank of open-field tomato. For three consecutive years (2016–2018), treatment of microplots included mulch only, irrigation only, mulch and irrigation combined, and the untreated control. Marginal microplots (bordered by the surrounding mown grassland) were distinguished from inner microplots to check margin effect. We collected soil samples from different depths and let the weed seeds germinate in a greenhouse. Germinated weed seedlings were counted and identified. The number of weeds, and time needed for weeding was reduced by mulching, temperature, sampling date, and the succession of the study years. Irrigation, on the other hand, had no effect on weeding time. Margin effect and year had the highest influence on weed species composition. Regarding seed bank, year and mulching had the highest influence. The importance of other variables remained low, with mulching being the strongest explained variable. Regardless of treatments, weed composition of the study area was transformed during the three-year study.

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Weed Seed Banks Are More Dynamic in a Sod-Based, Than in a Conventional, Peanut–Cotton Rotation

Weed Science ◽

10.1614/ws-d-15-00003.1 ◽

2015 ◽

Vol 63 (4) ◽

pp. 877-887 ◽

Cited By ~ 6

Author(s):

Ramon G. Leon ◽

David L. Wright ◽

James J. Marois

Keyword(s):

Crop Rotation ◽

Seed Bank ◽

Seed Banks ◽

Community Diversity ◽

Weed Seed ◽

Weed Species ◽

Perennial Crop ◽

Seed Bank Dynamics ◽

Weed Seeds ◽

Grass Weed

Crop rotation promotes productivity, nutrient cycling, and effective pest management. However, in row-crop systems, rotation is frequently limited to two crops. Adding a third crop, especially a perennial crop, might increase crop-rotation benefits, but concerns about disruption of agricultural and ecological processes preclude grower adoption of a three-crop rotation. The objective of the present research was to determine whether weed seed banks differ between a sod-based rotation (bahiagrass–bahiagrass–peanut–cotton) and a conventional peanut–cotton rotation (peanut–cotton–cotton) and the importance of crop phase in weed seed-bank dynamics in a long-term experiment initiated in 1999 in Florida. Extractable (ESB) and germinable (GSB) seed banks were evaluated at the end of each crop phase in 2012 and 2013, and total weed seed or seedling number, Shannon-Weiner's diversity (H′), richness, and evenness were determined. ESB increased in H′ (36%), richness (29%), and total number of weed seeds (40%) for sod-based compared with conventional rotation, whereas GSB increased 32% in H′, 27% in richness, and 177% in total number of weed seedlings. Crop phase was a determinant factor in the differences between crop rotations. The first year of bahiagrass (B1) exhibited increases in weed seed and seedling number, H′, and richness and had the highest values observed in the sod-based rotation. These increases were transient, and in the second year of bahiagrass (B2), weed numbers and H′ decreased and reached levels equivalent to those in the conventional peanut–cotton rotation. The B1 phase increased the germinable fraction of the seed bank, compared with the other crop phases, but not the total number of weed seeds as determined by ESB. The increases in H′ and richness in bahiagrass phases were mainly due to grass weed species. However, these grass weed species were not associated with peanut and cotton phases of the sod-based rotation. The results of the present study demonstrated that including bahiagrass as a third crop in a peanut–cotton rotation could increase weed community diversity, mainly by favoring increases in richness and diversity, but the structure and characteristics of the rotation would prevent continuous increases in the weed seed bank that could affect the peanut and cotton phases.

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Management Filters and Species Traits: Weed Community Assembly in Long-Term Organic and Conventional Systems

Weed Science ◽

10.1614/ws-d-09-00054.1 ◽

2010 ◽

Vol 58 (3) ◽

pp. 265-277 ◽

Cited By ~ 52

Author(s):

Matthew R. Ryan ◽

Richard G. Smith ◽

Steven B. Mirsky ◽

David A. Mortensen ◽

Rita Seidel

Keyword(s):

Weed Control ◽

Seed Bank ◽

Community Assembly ◽

Species Traits ◽

Seed Banks ◽

Management Systems ◽

Conventional System ◽

Weed Seed ◽

Organic Systems ◽

Weed Communities

Community assembly theory provides a useful framework to assess the response of weed communities to agricultural management systems and to improve the predictive power of weed science. Under this framework, weed community assembly is constrained by abiotic and biotic “filters” that act on species traits to determine community composition. We used an assembly approach to investigate the response of weed seed banks to 25 yr of management-related filtering in three different row-crop management systems in southeastern Pennsylvania: organic manure-based, organic legume-based, and conventional. Weed seed banks were sampled in April of 2005 and 2006 and quantified by direct germination in a greenhouse. We also assessed the filtering effects of weed management practices and relationships between assembled seed bank and emergent weed communities by allowing or excluding weed control practices within each management system and measuring emergent weed community response. Germinable weed seed bank densities and species richness in the final year of the study were over 40% and 15% higher, respectively, in the organic systems relative to the conventional system. Seed bank community structure in the organic systems was different from the conventional system, and the relationships between assembled seed banks and the emergent flora varied. Primary tillage, weed control, timing of planting, and fertility management appeared to be the main filters that differentiated weed seed banks in the three systems. Weed life history, emergence periodicity, seed size, and responsiveness to soil fertility and hydrology appeared to be the most important functional traits determining how weed species responded to management-related filters. Our results suggest that management systems can exert strong filtering effects that can persist over relatively long (greater than one growing season) time scales. Legacy effects of community-level filtering might be more important than previously assumed, and should be incorporated into predictive models of weed community assembly.

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Soil weed seed bank at ploughingl layer on the Nałęczów Plateau in relation to cereal crops and sculpture elements

Acta Agrobotanica ◽

10.5586/aa.1997.009 ◽

2013 ◽

Vol 50 (1-2) ◽

pp. 77-86 ◽

Cited By ~ 1

Author(s):

Marian Wesołowski ◽

Michał Bętkowski ◽

Cezary Kwiatkowski ◽

Andrzej Woźniak

Keyword(s):

Seed Bank ◽

Soil Samples ◽

Cereal Crops ◽

Weed Seed ◽

Winter Cereals ◽

Loess Soils ◽

Weed Seeds ◽

Spring Cereals ◽

Degree Of Stability ◽

Seeds And Fruits

The weed seed bank in the ploughing layer (0-25) cm deep) of loess soils, located at top, slope and slope foot, is presented in the papaer. Soil samples, taken just affer the harvest of winter and spring cereals, in the Nal9cz6w surroundings (east-middle Poland) were the investigative material. It was proved that the most of weed seeds and fruits were the winter cereals bocated at the slopes and slopes foot. The diaspors of short-lived weeds were dominant III-V degree of stability in the soil covered all sculpture elements.

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Exploratory data analysis to identify factors influencing spatial distributions of weed seed banks

Weed Science ◽

10.1614/ws-03-068r ◽

2004 ◽

Vol 52 (6) ◽

pp. 936-947 ◽

Cited By ~ 22

Author(s):

L. Wiles ◽

M. Brodahl

Keyword(s):

Cluster Analysis ◽

Seed Bank ◽

Spatial Dependence ◽

Management Practices ◽

Spatial Dynamics ◽

Seed Banks ◽

Spatial Distributions ◽

Weed Seed ◽

Explanatory Variables ◽

Natural Dispersal

Comparing distributions among fields, species, and management practices will help us understand the spatial dynamics of weed seed banks, but analyzing observational data requires nontraditional statistical methods. We used cluster analysis and classification and regression tree analysis (CART) to investigate factors that influence spatial distributions of seed banks. CART is a method for developing predictive models, but it is also used to explain variation in a response variable from a set of possible explanatory variables. With cluster analysis, we identified patterns of variation with direction of the distance over which seed bank density was correlated (range of spatial dependence) with single-species seed banks in corn. Then we predicted patterns of the seed banks with CART using field and species characteristics and seed bank density as explanatory variables. Patterns differed by magnitude of variation in the range of spatial dependence (strength of anisotropy) and direction of the maximum range. Density and type of irrigation explained the most variation in pattern. Long ranges were associated with large seed banks and stronger anisotropy with furrow than center pivot irrigation. Pattern was also explained by seed size and longevity, characteristics for natural dispersal, species, soil texture, and whether the weed was a grass or broadleaf. Significance of these factors depended on density or type of irrigation, and some patterns were predicted for more than one combination of factors. Dispersal was identified as a primary process of spatial dynamics and pattern varied for seed spread by tillage, wind, or natural dispersal. However, demographic characteristics and density were more important in this research than in previous research. Impact of these factors may have been clearer because interactions were modeled. Lack of data will be the greatest obstacle to using comparative studies and CART to understand the spatial dynamics of weed seed banks.

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Herbicide Rate, Glyphosate/Glufosinate Sequence and Corn/Soybean Rotation Effects on Weed Seed Banks

Weed Science ◽

10.1614/ws-d-10-00162.1 ◽

2011 ◽

Vol 59 (3) ◽

pp. 398-403 ◽

Cited By ~ 2

Author(s):

Marie-Josée Simard ◽

Sébastien Rouane ◽

Gilles D. Leroux

Keyword(s):

Seed Bank ◽

Cropping System ◽

Conventional Tillage ◽

Seed Banks ◽

Weed Seed ◽

Ongoing Research ◽

Continuous Corn ◽

Annual Grasses ◽

Initial Seed ◽

Field Plots

The effect of herbicide rates on weed control and crop yield is the subject of countless and ongoing research projects. Weed seed banks receive very little attention in comparison. The seed bank resulting from 3 yr (2006 to 2008) of single herbicide rates in a cropping system where glyphosate/glufosinate and corn/soybean were rotated or not was evaluated in a field located in St-Augustin-de-Desmaures, Québec, Canada. Field plots under conventional tillage were seeded in corn every year, or corn and soybean (1 yr). These plots received the same herbicide every year or various glyphosate/glufosinate 3-yr sequences. Subplots were sprayed with a single POST application of the recommended rate of glyphosate (900 g ae ha−1) or glufosinate (500 g ai ha−1) or lower rates. Subplots received the same full (1.0×, recommended) or reduced (0.5×, 0.75×) rate every year. After crop harvest in 2008, soil cores were extracted and the weed seed bank was evaluated. Including soybean in the cropping system resulted in lower seed banks compared to those under continuous corn cropping. Including glufosinate in a glyphosate herbicide sequence increased weed seed banks due to the lower efficacy of the glufosinate rates tested at reducing the seed bank of annual grasses. Higher herbicide rates translated into lower seed banks, up to a certain rate. After 3 yr, the lowest seed bank (full glyphosate rates every year) still had 4,339 ± 836 seeds m−2and was higher than the initial seed bank (2,826 ± 724 seeds m−2).

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Soil weed seed bank: Importance and management for sustainable crop production- A Review

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v13i2.28783 ◽

2016 ◽

Vol 13 (2) ◽

pp. 221-228 ◽

Cited By ~ 15

Author(s):

MM Hossain ◽

M Begum

Keyword(s):

Life Cycle ◽

Seed Bank ◽

Crop Production ◽

Management Practices ◽

Sole Source ◽

Seed Banks ◽

Weed Seed ◽

Weed Species ◽

Surrounding Environment ◽

Weed Seeds

The seed bank is the resting place of weed seeds and is an important component of the life cycle of weeds. Seed banks are the sole source of future weed populations of the weed species both annuals and perennials that reproduce only by seeds. For this reason, understanding fate of seeds in the seed bank can be an important component of overall weed control. When weed seeds enter the seed bank, several factors influence the duration for which seeds persist. Seeds can sense the surrounding environment in the seed bank and use these stimuli to become dormant or initiate germination. Soil and crop management practices can directly influence the environment of seeds in the soil weed seed bank and can thus be used to manage seed longevity and germination behavior of weed seeds.J. Bangladesh Agril. Univ. 13(2): 221-228, December 2015

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