scholarly journals Weed species richness, density and relative abundance on farms in the subtropical grain region of Australia

2005 ◽  
Vol 45 (6) ◽  
pp. 711 ◽  
Author(s):  
L. J. Rew ◽  
R. W. Medd ◽  
R. Van de Ven ◽  
J. J. Gavin ◽  
G. R. Robinson ◽  
...  
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Weed Management ◽  
Management Practices ◽  
Raphanus Raphanistrum ◽  
Weed Species ◽  
Separate Species ◽  
Obvious Effect ◽  
Lactuca Serriola ◽  
Weed Species Richness

Weed management is one of the most important economic and agronomic issues facing farmers in Australia’s grain regions. Weed species occurrence and abundance was monitored between 1997 and 2000 on 46 paddocks (sites) across 18 commercial farms located in the Northern Grain Region. The sites generally fell within 4 disjunct regions, from south to north: Liverpool Plains, Moree, Goondiwindi and Kingaroy. While high species richness was found (139 species or species groups), only 8 species occurred in all 4 regions and many (56 species) only occurred at 1 site or region. No species were observed at every site but 7 species (Sonchus spp., Avena spp., Conyza spp., Echinochloa spp., Convolvulus erubescens, Phalaris spp. and Lactuca serriola) were recorded on more than 70% of sites. The average number of species observed within crops after treatment and before harvest was less than 13. Species richness tended to be higher in winter pulse crops, cotton and in fallows, but overall was similar at the different sampling seasons (summer v. winter). Separate species assemblages associated with the Goondiwindi and Kingaroy regions were identified by correspondence analysis but these appeared to form no logical functional group. The species richness and density was generally low, demonstrating that farmers are managing weed populations effectively in both summer and winter cropping phases. Despite the apparent adoption of conservation tillage, an increase in opportunity cropping and the diversity of crops grown (13) there was no obvious effect of management practices on weed species richness or relative abundance. Avena spp. and Sonchus spp. were 2 of the most dominant weeds, particularly in central and southern latitudes of the region; Amaranthus spp. and Raphanus raphanistrum were the most abundant species in the northern part of the region. The ubiquity of these and other species shows that continued vigilance is required to suppress weeds as a management issue.

scholarly journals Weed community structure and soybean yields in a long-term organic cropping systems experiment

Weed Science ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 673-681 ◽  
Author(s):  
Margaret G. Ball ◽  
Brian A. Caldwell ◽  
Antonio DiTommaso ◽  
Laurie E. Drinkwater ◽  
Charles L. Mohler ◽  
...  
Keyword(s):  
Community Structure ◽  
Weed Management ◽  
Management Practices ◽  
Cropping Systems ◽  
Nutrient Inputs ◽  
Weed Species ◽  
Soybean Yield ◽  
Weed Density ◽  
Weed Species Richness

AbstractWeed management is a major challenge in organic crop production, and organic farms generally harbor larger weed populations and more diverse communities compared with conventional farms. However, little research has been conducted on the effects of different organic management practices on weed communities and crop yields. In 2014 and 2015, we measured weed community structure and soybean [Glycine max (L.) Merr.] yield in a long-term experiment that compared four organic cropping systems that differed in nutrient inputs, tillage, and weed management intensity: (1) high fertility (HF), (2) low fertility (LF), (3) enhanced weed management (EWM), and (4) reduced tillage (RT). In addition, we created weed-free subplots within each system to assess the impact of weeds on soybean yield. Weed density was greater in the LF and RT systems compared with the EWM system, but weed biomass did not differ among systems. Weed species richness was greater in the RT system compared with the EWM system, and weed community composition differed between RT and other systems. Our results show that differences in weed community structure were primarily related to differences in tillage intensity, rather than nutrient inputs. Soybean yield was lower in the EWM system compared with the HF and RT systems. When averaged across all four cropping systems and both years, soybean yield in weed-free subplots was 10% greater than soybean yield in the ambient weed subplots that received standard management practices for the systems in which they were located. Although weed competition limited soybean yield across all systems, the EWM system, which had the lowest weed density, also had the lowest soybean yield. Future research should aim to overcome such trade-offs between weed control and yield potential, while conserving weed species richness and the ecosystem services associated with increased weed diversity.

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.

scholarly journals Relation between Soil Weed Seedbank and Weed Management Practises and Diversity in Farms in Kisii Central Sub County, Nyanza

2020 ◽  
Vol 10 ◽  
pp. 1-14
Author(s):  
Charles N. Nyamwamu ◽  
Rebecca Karanja ◽  
Peter Mwangi
Keyword(s):  
Seed Bank ◽  
Weed Management ◽  
Management Practices ◽  
Soil Seed Bank ◽  
Shannon Index ◽  
Weed Seed ◽  
Weed Species ◽  
Western Kenya ◽  
Weed Diversity ◽  
Hand Weeding

This study sought to determine the relation between soil weed seed bank and weed management practices and diversity in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Weed soil seed bank was assessed from soil samples collected from each of the farms; a sub-sample was taken from a composite sample of ten soil cores of 5cm diameter and 15cm deep and placed in germination trays in a greenhouse. Weed diversity in soil weed seedbank was calculated using the Shannon index (H’). Twelve weed species from 12 genera of nine families were recorded. Diversity of the weed species in soil weed seed bank was (H'=1.48). Weed management practises significantly affected weed species soil weed seedbank reserves. Use of inefficient and ineffective hand-weeding techniques resulted in high weed species diversity and abundance.

scholarly journals Agroecological service crops managed with roller crimper reduce weed density and weed species richness in organic vegetable systems across Europe

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
David Navarro-Miró ◽  
José M. Blanco-Moreno ◽  
Corrado Ciaccia ◽  
Lourdes Chamorro ◽  
Elena Testani ◽  
...  
Keyword(s):  
Species Richness ◽  
Weed Species ◽  
Weed Density ◽  
Weed Species Richness

Group characteristics of tea growers relative to weed management: a case study in southwestern China

2019 ◽  
Vol 33 (6) ◽  
pp. 847-854
Author(s):  
Guoqi Chen ◽  
Bin Zhang ◽  
Qiong Wu ◽  
Linhong Jin ◽  
Zhuo Chen ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Guizhou Province ◽  
Cooperative Groups ◽  
Weed Species ◽  
Training Experience ◽  
Farmer Training ◽  
Group Characteristics

AbstractFarmer training is important to improve weed management practices in tea cultivation. To explore the group characteristics of tea growers, we interviewed 354 growers in Guizhou Province, China. Sixty-one percent of the respondents planted tea for companies or cooperative groups, and 56% managed tea gardens larger than 10 ha. Self-employed tea growers tended to be older and smallholders, and to apply herbicides and conduct weed control less frequently (P < 0.05). Approximately 87% of the respondents conducted weed control two to four times yr−1, 83% spent between $200 and $2,000 ha−1 yr−1 for weed control, and 42% thought weed control costs would decrease by 5 years from this study. Twenty-eight species were mentioned by the respondents as being the most serious. According to canonical correspondence analysis, latitude, altitude, being self-employed or a member of a cooperative, having training experience in tea-garden weed management, and frequency and cost of weed control in tea gardens had significant (P < 0.05) influence on the composition of most troublesome weed species listed by respondents. Among the respondents, 60% had had farmer’s training on weed management in tea gardens. Of these, a significant number (P < 0.05) tended to think weed control costs would decrease, and a nonsignificant number (P > 0.05) tended to conduct weed control more frequently and have lower weed management costs in their tea gardens.

Weed infestation during the transition phase from conventional to conservation agriculture

2020 ◽  
Author(s):  
Felice Sartori ◽  
Donato Loddo ◽  
Ilaria Piccoli ◽  
Antonio Berti
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Conservation Agriculture ◽  
Soil Disturbance ◽  
Transition Phase ◽  
Effective Control ◽  
Silty Clay ◽  
Weed Species ◽  
Number Of Species ◽  
Weed Species Richness

&lt;p&gt;Despite conservation agriculture and, overall, the reduction of soil disturbance are considered soil improving cropping systems, these practices could conflict with weed control. Indeed, reduced tillage is usually linked to increased weed species richness and abundance and, thus, it could increase the dependence on chemical treatments. Weed management is one of the reasons behind the distrust of European farmers in the conservation agriculture, that is still not widespread, despites European subsidies. In fact, conservation agriculture is implemented only in the 2.8% of European cropland.&lt;/p&gt;&lt;p&gt;The aim of this study is to evaluate the effect of different tillage intensities on spring-summer weeds richness and abundance in a maize monoculture, during the transition phase from conventional to conservation agriculture.&lt;/p&gt;&lt;p&gt;The weed survey was conducted in June 2019 on an experiment comparing three levels of tillage management: conventional agriculture (CT), which represents the most common choice in Veneto region, involving deep ploughing and harrowing in spring; minimum tillage (MT), consisting only in harrowing at 20 cm; and no tillage (NT), namely sod seeding. The experiment started in 2018, at Padova University experimental farm, in a sub-humid area, with a silty clay loam soil. The survey was conducted with a set of random throws of a 30&amp;#215;30 cm square frame in each plot (ca. 3300 m&lt;sup&gt;2&lt;/sup&gt;). &amp;#160;Weed plants found within the frame were classified and counted. Subsequently, data analysis assessed which botanical families were promoted by each treatment.&lt;/p&gt;&lt;p&gt;The NT resulted the treatment with the highest weed density (915 plant/m&lt;sup&gt;2&lt;/sup&gt;): 6% higher than MT (823 plant/m&lt;sup&gt;2&lt;/sup&gt;) and four-fold more than CT (209 plant/m&lt;sup&gt;2&lt;/sup&gt;). The latter showed to be the treatment with higher diversity, according to both Shannon and Simpson indices. The survey evidenced higher weed species richness in MT, where both annual and perennial species were identified, while the lowest number of species were detected in NT. Plantago major and Chenopodium album were the species with the highest density in CT (&gt;32 plant/m&lt;sup&gt;2&lt;/sup&gt;) while they are negligible in NT and MT (7 plant/m&lt;sup&gt;2&lt;/sup&gt;, on average). Digitaria sanguinalis was instead the dominant species in MT and NT (&gt;600 plant/m&lt;sup&gt;2&lt;/sup&gt;) while a lower density was observed in CT (11 plant/m&lt;sup&gt;2&lt;/sup&gt;). Low levels of Asteraceae weeds were measured in all treatments. These results shows that the actual flora rapidly changes depending on tillage intensity, with an increase of both dominance and number of species in MT. Differently, only a limited number of adapted species germinated in NT, despite higher infestations if compared with the other treatments.&lt;/p&gt;&lt;p&gt;It should be expected that other species more adapted to conservation agriculture (namely Asteraceae), still marginally present in the seed bank, will spread in the next years. This stresses the importance of a continuous monitoring and effective control of weeds to avoid uncontrolled evolutions of the weed flora and increase of seed bank in the transition phase from conventional to conservation agriculture.&lt;/p&gt;

Flooding to manage dodder (Cuscuta gronovii) and broad-leaved weed species in cranberry: An innovative use of a traditional strategy

2010 ◽  
Vol 25 (4) ◽  
pp. 257-262 ◽  
Author(s):  
Hilary A. Sandler ◽  
Joanne Mason
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Management Plan ◽  
Cultural Practice ◽  
Weed Species ◽  
Short Term ◽  
Poison Ivy ◽  
Flood Period ◽  
Summer Flood ◽  
Flooding Events

AbstractThe implementation of new uses for traditional cultural and pest management practices has been prompted by renewed interest in sustainable approaches for farming. The use of floods (for various durations) has been an inexpensive and historical cultural practice in cranberry (Vaccinium macrocarponAit.) horticulture. The onset of a serious economic crisis in the cranberry industry in 1999–2000 brought about an urgent need to find inexpensive methods of pest control that would allow growers to remain fiscally solvent. Initially, anecdotal evidence from several farms indicated that holding short-term spring floods suppressed dodder infestations. Based on these findings, a 2-year demonstration-style project was initiated in 2002 to determine the efficacy of short-term floods (24–48 h) for the management of dodder in cranberry in Massachusetts. The project was expanded to include evaluating a 10-day summer flood for control of broad-leaved weed species at one commercial cranberry farm. Species richness and diversity and percentage weed coverage were lower after the implementation of the 10-day flood period compared to pre-flood assessments. Weed species dead or not detected after the 10-day flood included ground nut, asters, narrow-leaved goldenrod, chokeberry and poison ivy. Comparison of paired sites (flooded and nonflooded bogs) indicated dodder stem dry weights were lower on flooded areas in three out of the seven locations in year 1. At two additional locations, the flooded bog had higher stem weights when paired with a historically low-infestation bog, which may have masked any dodder reduction from the flooding practice. In year 2, no differences in the number of germinated seedlings between any treatment pairs were noted. Data from a cranberry company representing 12% of the cranberry acreage in Massachusetts indicated a 65–89% reduction in pesticide use when short-term spring floods were implemented during 2001–2003 compared to the previous 3-year period. Short-term flooding may offer a sustainable option that can be integrated into the overall management plan for several problematic cranberry weed species, especially dodder. Additional research is warranted to further define the most effective environmental conditions needed and to validate the efficacy of short flooding events for effective cranberry weed management.

Effects of Initial Seed-Bank Density on Weed Seedling Emergence during the Transition to an Organic Feed-Grain Crop Rotation

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Richard G. Smith ◽  
Randa Jabbour ◽  
Andrew G. Hulting ◽  
Mary E. Barbercheck ◽  
David A. Mortensen
Keyword(s):  
Seed Bank ◽  
Weed Management ◽  
Cover Crop ◽  
Management Practices ◽  
Transition Period ◽  
Red Clover ◽  
Weed Seed ◽  
Weed Species ◽  
Organic Certification ◽  
Weed Seeds

The transition period to certified organic production can present a significant weed management challenge for growers. Organic certification requires that prohibited fertilizers and pesticides must not have been used for 36 mo before harvest of the first organic crop. Understanding how organic management practices and initial weed seed-bank densities affect weed population dynamics during the transition period may improve weed management efficacy and adoption of organic practices. We examined how tillage systems (full or reduced) and cover crop species planted during the first transition year (rye or a mixture of timothy and red clover) affect the seedling densities of three common annual weed species, common lambsquarters, velvetleaf, and foxtail spp., during the 3-yr transition period. Weed seeds were applied in a one-time pulse at the beginning of the study at three densities, low, medium, and high (60, 460, and 2,100 seeds m−2, respectively), and cumulative seedling densities of each species were assessed annually. Treatment factors had variable and species-specific effects on weed seedling densities. In general, the full-tillage system, with an initial cover crop of timothy and red clover, resulted in the lowest density of weed seedlings following seed-bank augmentation. There was little consistent association between the initial densities of applied weed seeds in the weed seed bank at the start of the transition and weed seedling densities at the end of the transition period. This suggests that when multiple crop and weed cultural management practices are employed during the organic transition period, initial failures in weed management may not necessarily lead to persistent and intractable annual weed species management problems following organic certification.

Weed management practices affect the diversity and relative abundance of physic nut mites

2014 ◽  
Vol 65 (3) ◽  
pp. 359-375 ◽  
Author(s):  
Althiéris de Sousa Saraiva ◽  
Renato A. Sarmento ◽  
Eduardo A. L. Erasmo ◽  
Marçal Pedro-Neto ◽  
Danival José de Souza ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Weed Management ◽  
Management Practices ◽  
Physic Nut

scholarly journals Studies on weed cover and diversity in coriander (Coriandrum sativum L.) as influenced by weed management and balanced fertilization techniques

2017 ◽  
Vol 5 (3) ◽  
pp. 387-395
Author(s):  
Raj Kumar Nagar ◽  
Dinesh Kumar Jain
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Cyperus Rotundus ◽  
Weed Species ◽  
Significant Interaction Effect ◽  
Weed Density ◽  
Chenopodium Murale ◽  
Balanced Fertilization ◽  
Biological Yield ◽  
Hand Weeding

A field experiment was conducted to analyze the types of flora, intensity, cover and effects on yields of coriander. Pooled analysis of data indicated that Goose foot (Chenopodium murale L.), Corn spurry (Spergula arvensis L.) among dicots and Purple nutsedge (Cyperus rotundus L.) among monocots were found most dominant weeds at all stages of crop growth. Of the total eight weed species reported dicot weeds were found most dominating weed species and comprises 78-80 percent of total weed density throughout crop cycle. All weed management practices significantly reduced the density of monocot and dicot weeds and improved the yield (seed and biological yield) of crop as compared to control. Two hand weeding at 30 and 45 DAS resulted in maximum reduction in total weed density and gave the highest seed (15.84 q/ha) and biological yield (41.11 q/ha) of coriander. However, seed and biological yields was obtained at par by pendimethalin 1.0 kg/ha + one hand weeding at 45 DAS. This treatment also resulted in favorably lowest weed competition index as compared to rest of other practices. Balanced fertilization with N+P+K+S also improved monocot and dicot weed density but the effect was not significant over N+P and N+P+K fertilization. N+P+K+S fertilization significantly enhanced crop seed and biological yields over N+P (1.86 q/ha and 4.36 q/ha, respectively) and N+P+K application (0.94 q/ha and 2.20 q/ha, respectively). Weed management and balanced fertilization practices also found to have significant interaction effect on seed and biological yield of coriander.

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