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Research on the origins of agriculture in western Asia has placed great emphasis on the location and pace of domestication. However, much less attention has been given to reconstructing the specific nature and social implications of early cultivation practices across the agricultural transition, and to the potentially varied land management strategies involved. By employing a functional ecological approach to the interpretation of arable 'weed' taxa associated with early cultivars, this research addresses this gap in archaeobotancial research by enabling detailed analysis of the growing conditions and farming methods involved in early plant cultivation in western Asia. The core methodology analyses the functional ecological attributes (e.g. leaf area and thickness; canopy dimensions; stomatal density and distribution) of the relevant arable weed taxa isolated from archaeological contexts to determine the specific growing conditions of early crops and hence the nature of management practices. Functional attributes are morphological or behavioural characteristics that predict species' potential in relation to major environmental variables, such as soil productivity, disturbance and moisture. Statistical analysis incorporating these attributes is used to explore variation amongst early cultivation contexts and compare them with weed survey data from contrasting (semi-)arid modern regimes, including a recent study of traditional cereal farming in Morocco. Ecological 'signatures' were determined using the isolated weed dataset from four well documented and contextually rich Pre-Pottery and Pottery Neolithic sites, which were strategically selected to explore agricultural strategies from its initial stages through to the established Neolithic, as well as to exploit detailed sample-by-sample data and extensive in situ deposits. The sites investigated are PPNA Jerf el-Ahmar and PPNA/EPPNB Dja'de in northern Syria, PPNB Tell Aswad in southern Syria, and PPN-PN Çatalhöyük in Central Anatolia. Refined identification of selected weed genera at these sites enabled more accurate indications of their arable ecologies. The results generated suggest that early farming practices were highly variable within sites, reflecting the specific affordances of local climate and surrounding landscapes, but relatively labour-intensive in comparison with later urban agrosystems. Furthermore, there are indications for greater cultivation intensity over time, as households became more autonomous.

The goal of the project was to enhance the period of weed growth prior to seeding in order to reduce weed emergence and weed competition after the crop has been planted. Weed growth was stimulated using either light tillage or by applying nitrogen fertilizer early in the spring. Light disturbance significantly increased pre-seed weed emergence while early applied nitrogen did not appear to have an effect. Post seeding weed emergence levels and weed biomass were similar among the light tillage and early nitrogen treatments. Therefore the goal of decreasing weed competition after seeding was not attained. Future research should focus on long-term strategies to reduce weed populations in field rather than seasonal strategies. / October 2006

The goal of the project was to enhance the period of weed growth prior to seeding in order to reduce weed emergence and weed competition after the crop has been planted. Weed growth was stimulated using either light tillage or by applying nitrogen fertilizer early in the spring. Light disturbance significantly increased pre-seed weed emergence while early applied nitrogen did not appear to have an effect. Post seeding weed emergence levels and weed biomass were similar among the light tillage and early nitrogen treatments. Therefore the goal of decreasing weed competition after seeding was not attained. Future research should focus on long-term strategies to reduce weed populations in field rather than seasonal strategies.

The goal of the project was to enhance the period of weed growth prior to seeding in order to reduce weed emergence and weed competition after the crop has been planted. Weed growth was stimulated using either light tillage or by applying nitrogen fertilizer early in the spring. Light disturbance significantly increased pre-seed weed emergence while early applied nitrogen did not appear to have an effect. Post seeding weed emergence levels and weed biomass were similar among the light tillage and early nitrogen treatments. Therefore the goal of decreasing weed competition after seeding was not attained. Future research should focus on long-term strategies to reduce weed populations in field rather than seasonal strategies.

<p>  </p> <p>Annual bluegrass (<em>Poa annua</em> L.) is the most troublesome weed in turfgrass systems and the second most troublesome weed across all grass crops. Controlling annual bluegrass is exceptionally complicated due to its high genetic adaptability to new environments. Additionally, prolific seed production allowed the rapid development of herbicide resistance to 12 herbicide modes of action. Experiments were initiated with the goal to better understand annual bluegrass ecology and resistance to ethofumesate. A dose-response experiment was initiated in 2022 to determine the potential level of ethofumesate resistance in annual bluegrass collected from seed production systems. Seed from 55 annual bluegrass populations was obtained from three sources: seed production fields (31 populations), seed cleaning process (6 populations), and seed testing prior to retail distribution (18 populations). </p> <p>Individual seedlings (2–3 tillers) were treated with ten doses of ethofumesate: 0, 0.6, 1.1, 2.8, 5.6, 8.4, 11.2, 16.8, 22.4, and 44.8 kg ai ha−1; with 1.1 to 2.2 kg ha−1 as the label application rates for perennial ryegrass (<em>Lolium perenne</em> L.). The resistance to susceptible ratio of populations across all sources ranged from 0.48 to 5.48. The most resistant populations from production fields, removed during the seed cleaning process, or found in seed testing lots had ED50 values of 12.1, 13.1, and 9.4 kg ai ha−1, respectively. Further, 68% of the populations found in production fields had ED50 higher than 6 kg ai ha−1, which indicates that annual bluegrass resistance is common in grass seed production. A garden study was initiated in November 2020 to assess the development, reproduction, and survival of ten annual bluegrass populations in Indiana. Annual bluegrass plants were maintained in the absence of turf competition and not subjected to typical turfgrass management practices including irrigation, mowing and fertilization. Data collected in included growth rate, biomass production, ground cover, morphology, flowering time, seed production and morphology, and both winter survival and subsequent summer survival of plants. Principal component analysis indicated that certain populations grouped together based on their development, morphology, stress tolerance, and seed production. Plants from the cooler climates (OR, PA, and IN) were characterized by higher growth rates and biomass compared to southern ecotypes. These three populations survived the longest during the summer, with the PA population averaging the highest ground cover of 276 cm2 on 23 July 2021. Plants from warm climates (AL, FL, NC, SC, TN, TX) had poor summer survival. Additionally, the FL population had the highest winterkill of 68%, followed by TX at 45%. The NJ population was distinct from other populations, and plants had robust aboveground biomass and high seed production. The results indicate that the development, reproduction, and survival of different annual bluegrass biotypes are dependent on the climate of origin. A third experiment was designed to understand patterns of germination and seed longevity in populations from five climates across the U.S. at two depths of burial. Seed was retrieved in 6-month intervals up to 24 months. Seed viability by depth (surface vs. 5-cm deep) of burial differed only 18 months after the initiation of the study. However, seed viability did differ among populations on each date of seed retrieval. Viability was low ranging from 0.21 to 0.91%, and populations originating from cool climates (New Jersey, Pennsylvania, and Oregon) generally had higher viability than populations originating from warmer climates. Annual bluegrass seed tested in this study typically had low levels of survival (<0.5%); however, all populations retained some level of viability 24 months after burial, which would allow future reproduction of this troublesome weed. Overall, this research determined that herbicides alone will likely be ineffective at controlling annual bluegrass and that knowledge of the development, reproduction, and survival of local annual bluegrass populations should be factored into an integrated weed management strategies created for each site. </p> <p>  </p>

Weeds interfere in the development and soybean yield and infestation is directly related to the soil seed bank that reflects the agricultural practices adopted. They can also be host of insect pests and / or their natural enemies. So, knowledge of weeds and arthropod community associated with weed is information that can assist decision-making in management. Thus, this thesis aimed to: I - study the seed bank of weeds (BSS) under different soil management systems and cultures - conventional system (SCS) and no tillage (SDS) in soybeans / wheat and conventional system (SCR) and no tillage (SDR) rotation with winter and summer, in the years 2010/2011 and 2011/2012 and II - to verify the incidence of associated arthropod genetically modified soybean resistant to glyphosate, in coexistence with plants weeds in crop years 2010/2011 and 2011/2012. In all management systems predominate species of dicots, and the Asteraceae family with greater diversity. Of Monocotyledonous, dominates the family Poaceae. In the SDS and SDR systems the family Amaranthaceae is the most representative. In the SCS system, Portulacaceae is the most abundant family, while the SCR, Poaceae dominated in 2010/2011 and Portulacaceae in 2011/2012. In the SD system, the seed bank is higher in crop rotation and succession in the surface layer, and in the succession of cultures in the deepest layer. In crop rotation, in the deeper layers is larger in SC system. The relative importance of species is variable depending on the management systems used and the agricultural year. Portulaca oleracea L. is the specie of greater relative importance in the SCS and SCR systems and Amaranthus hybridus var. paniculatus (L.) Thell in the SDS and SDR systems. The similarity of species seed bank is high among systems and between the composition of the seed bank and aboveground field is high in 2010/2011 and lower in 2011/2012. The population of Anticarsia gemmatalis, Pseudoplusia includens and set defoliator caterpillars is higher in the absence of weeds in soybean breeding period. The weed management does not affect the population in the reproductive Piezodorus guildinii culture. However, there is a higher population in the absence of weeds in the crop year 2011/2012, from the R6 growth stage. Populations of Euchistus heros, Nezara viridula, Acrosternum hilare, Edessa meditabunda, Dichelops melacanthus and Diabrotica speciosa not suffer influence of weed management, considering the reproductive soybeans. The weed management does not affect the occurrence of spiders, Geocoris punctipes, Cycloneda sanguinea and Eriopis connexa. / As plantas daninhas interferem no desenvolvimento e produtividade da soja e a infestação está diretamente relacionada com o banco de sementes do solo que reflete as práticas agrícolas adotadas. Também podem ser hospedeiras dos insetos-pragas da cultura e/ou seus inimigos naturais. Então, o conhecimento das plantas daninhas e da artropodofauna associada a comunidade infestante são informações que podem auxiliar a tomada de decisão nas práticas de manejo. Assim, esta tese teve como objetivos: I - estudar o banco de sementes de plantas daninhas (BSS) sob diferentes sistemas de manejo de solo e culturas - sistema convencional (SCS) e semeadura direta (SDS) com sucessão soja/trigo e sistema convencional (SCR) e semeadura direta (SDR) com rotação de inverno e verão, nos anos agrícolas 2010/2011 e 2011/2012 e; II - verificar a incidência da artropodofauna associada à cultura da soja geneticamente modificada resistente ao glifosato, em convivência com plantas daninhas, nos anos agrícolas 2010/2011 e 2011/2012. Em todos os sistemas de manejo predominam espécies de dicotiledôneas, sendo Asteraceae a família com maior diversidade. Das Monocotiledôneas, predomina a família Poaceae. Nos sistemas SDS e SDR, a família Amaranthaceae é a mais representativa. No sistema SCS, Portulacaceae é a família mais abundante, enquanto no SCR, predomina Poaceae em 2010/2011 e Portulacaceae em 2011/2012. No sistema SD, o banco de sementes é maior em sucessão e rotação de culturas na camada superficial, e em sucessão de culturas na camada mais profunda. Em rotação de culturas, nas camadas mais profundas, é maior no sistema SC. A importância relativa das espécies é variável em função dos sistemas de manejo utilizados e do ano agrícola. Portulaca oleracea L. é a espécie de maior importância relativa nos sistemas SCS e SCR e Amaranthus hybridus var. paniculatus (L.) Thell nos sistemas SDS e SDR. A similaridade das espécies do banco de sementes entre os sistemas é alta e entre a composição do banco de sementes e a flora emergente em campo é alta em 2010/2011 e baixa em 2011/2012. A população de Anticarsia gemmatalis, Pseudoplusia includens e do conjunto de lagartas desfolhadores é superior na ausência de plantas daninhas, no período reprodutivo da soja. O manejo das plantas daninhas não interfere na população de Piezodorus guildinii no período reprodutivo da cultura. Porém, ocorre maior população na ausência de plantas daninhas, no ano agrícola 2011/2012, a partir do estádio fenológico R6. As populações de Euchistus heros, Nezara viridula, Acrosternum hilare, Edessa meditabunda, Dichelops melacanthus e Diabrotica speciosa não sofrem influência do manejo de plantas daninhas, considerando o período reprodutivo da soja. O manejo das plantas daninhas não interfere na ocorrência de aranhas, Geocoris punctipes, Cycloneda sanguinea e de Eriopis connexa.

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