Nteyi S.M.,Nelson Mandela Metropolitan University |
Auerbach R.M.B.,Nelson Mandela Metropolitan University |
Ferreira M.I.,Plant science |
Labuschagne J.,Plant science
South African Journal of Plant and Soil | Year: 2016
Under the Mediterranean climatic conditions of the Western Cape province, the Swartland region is intensively cropped, producing spring wheat (Triticum aestivum L.), but due to ryegrass competition, yield is reduced. In addition, ryegrass has developed resistance to herbicides. This necessitates the use of integrated weed management practices for suppressing ryegrass in wheat fields. The objectives were to quantify and qualify the impact of crop rotation and tillage systems used in combination with reduced herbicide input and to determine whether these could reduce ryegrass population numbers. Analyses of variance of data were used to determine crop rotation×tillage system response in field and shade-netting experiments. Wheat monoculture, in both tillage systems, was associated with the highest ryegrass population increase in both years. The results of both the field and shade-netting experiments showed that there was no significant difference between minimum-tillage and no-tillage in reducing ryegrass numbers. Results obtained from the shade-netting experiment indicated that the three crop-rotation treatments under minimum-tillage differed significantly from the control. In the field wheat–medic–wheat–medic rotations under no-tillage out-performed all other rotations, followed by wheat–lupin–wheat–canola under minimum-tillage. It is essential to use competitive crop sequences that decrease particular weed population numbers. © 2016 Taylor & Francis
Ferreira M.I.,Plant Science |
Reinhardt C.F.,University of Pretoria |
Lamprecht S.C.,Agricultural Research Council Plant Protection Research Institute |
Sinclair M.,Veterinary Services |
And 2 more authors.
South African Journal of Plant and Soil | Year: 2015
Weed resistance to herbicides present one of the greatest current economic challenges to agriculture. Herbicide resistant ryegrass (Lolium spp.) is a serious problem in Western Cape grain-producing areas. Morphological and pathogenic analyses were performed on ryegrass samples. Morphologically, 50% of specimens were classified as rigid ryegrass, 48% as a hybrid, namely L. multiflorum × L. perenne and 2% as perennial ryegrass. Fusarium pseudograminearum (cause of Fusarium crown rot) was isolated from six localities. Pathogencity tests confirmed that F. pseudograminearum isolates obtained from ryegrass and wheat are pathogenic on both crops, indicating that ryegrass can act as an alternative host and a source of inoculum of this important soilborne pathogen. Grass weed infestation can favour the disease, and grass weed control is therefore recommended as part of an integrated strategy to manage crown rot. Knowledge on morphological differences among ryegrass may be important to guide differential weed management of ryegrass. Smother cropping, as part of conservation farming, should receive more prominence to suppress herbicide-resistant ryegrass and simultaneously reduce the occurrence of crown rot. © 2015 © Southern African Plant & Soil Sciences Committee.
Jondle R.J.,Plant science |
Hill K.K.,Plant science |
Sanny T.,Swanson and Bratschun L.L.C
Crop Science | Year: 2015
Numerous intellectual property protection options are available for plants and plant-based inventions both in the United States and abroad, including utility and plant patents, plant variety rights, plant breeders’ rights, trade secrets, contract law, and trademarks. Careful planning and consideration of these options is critical to obtaining and maintaining optimum intellectual property protection. Recent court cases concerning patent law, as well as other current intellectual property topics such as genetically modified organism labeling and protection for essentially derived varieties, lend additional guidance to consideration of these important intellectual property options. © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved.
Saayman N.,Plant Science |
Morris C.,University of KwaZulu - Natal |
Botha H.,Plant Science
African Journal of Range and Forage Science | Year: 2014
Currently, the methods used to assess the veld condition of the Lambert's Bay Strandveld along the West Coast of South Africa require that the operator knows all the plants encountered in the survey area. In this study data were collected from several farms in the Lambert's Bay Strandveld to establish a degradation gradient from which a minimum number of species necessary to monitor trends in the condition of the veld were determined, making it user-friendly for land-users, extension officers and others. The key indicators were also tested using a second set of data. © 2014 NISC (Pty) Ltd.
Beal E.J.,Plant science |
Henricot B.,Plant science |
Peace A.J.,Center for Ecosystems |
Waghorn I.A.G.,Plant science |
Denton J.O.,Plant science
Forest Pathology | Year: 2015
The effect of allicin (a stabilized garlic extract product) at five different concentrations (0, 20, 30, 50 and 100 mg/l) was studied in vitro on the growth rate of 100 isolates of Armillaria gallica and A. mellea. Isolates were obtained from 41 host genera growing in gardens located in 39 counties in the United Kingdom. Agar plugs of the actively growing Armillaria isolates were added to the centre of malt agar plates infused with allicin, and radial mycelium growth was measured on days 7, 14 and 21. The total number of rhizomorphs and length of rhizomorphs were also measured. Relative growth rates were calculated as the growth rate relative to the controls (0 mg/ l). The relative growth of each isolate at each allicin concentration was used to estimate EC50 values for A. mellea and A. gallica populations as well as individual isolates. EC50 values for both Armillaria spp. increased over time. The mean EC50 values for A. mellea of 16.0, 26.4 and 102 mg/l (days 7, 14 and 21, respectively) were higher than those for A. gallica (8.8, 7.9 and 11.0 mg/l) and probably relate to the more aggressive nature of A. mellea. Isolates with higher EC50 values were also more likely to produce more rhizomorphs. At allicin concentrations of 20 and 30 mg/l, the production of rhizomorphs and the growth rates of A. mellea isolates were stimulated, when compared to the control treatments. From this study's findings, it appears that the field use potential of allicin is limited, due to better inhibition of the less virulent A. gallica, than the more aggressive A. mellea. © 2015 Blackwell Verlag GmbH.
McCary M.A.,University of Illinois at Chicago |
Martinez J.-C.,University of Illinois at Chicago |
Umek L.,Plant Science |
Umek L.,Northwestern University |
And 2 more authors.
Biological Conservation | Year: 2015
Restoration of woodlands that have been invaded by exotic plants has primarily focused on restoring vegetation structure by removing invaders and planting native species that have declined in abundance. Management practices to date continue to focus on plant communities, but if restoring ecosystem integrity is the goal of restoration, knowledge of how the fauna has recovered is essential. We examined the impact of vegetation restoration and management on the surface-active arthropod community across a spectrum of 22 woodland sites in the greater metropolitan Chicago region. Sites were grouped into three categories based on existing condition. Invaded sites had never been restored or managed ("Control", n=5); had been undergoing restoration for 3-21years ("Managed-int", n=12) but were not yet near the management goal; or were restored plots (11-21years of management) that land managers identified as representative of their restoration target based upon the vegetation present ("Managed-REF", n=5). Each site was a one-ha plot containing four pitfall traps used to assess activity-densities of 35 taxa of epigeic arthropods. Permutational analysis of variance (PERMANOVA) and subsequent canonical analysis of principal coordinates (CAP) revealed that arthropod community structure varied between Control and Managed-REF sites, with the Managed-int sites demonstrating convergence toward the Managed-REF. The activity-densities of non-native isopods (detritivores) were nearly twice as high in Control sites compared to Managed-REF sites, whereas traps in Managed-REF sites had four times the number of Collembola (fungivores). Distance-based redundancy analysis (dbRDA) revealed that invasive woody plant cover and rates of uptake of soil P and NO3- by root simulators explained over 40% of the variation in arthropod community structure. Our findings suggest that restoration management targeted at the vegetation also restores the arthropod community in woodlands to a composition that has fewer non-native arthropods. © 2015 Elsevier Ltd.