Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
Authors
Ari Hietala Ahto Agan Nina Elisabeth Nagy Isabella Børja Volkmar Timmermann Rein Drenkhan Halvor SolheimAbstract
No abstract has been registered
Abstract
Bacterial diseases in woody plants are best characterized for ornamental and fruit trees and much less is known for forest trees. There are many diseases of forest trees whose etiology remains to be clarified and likely more bacterial diseases of forest trees will be discovered in the next years. An overview of the main bacterial pathogens that cause diseases in forest and ornamental trees is described in this chapter and the general differences between fungal and bacterial diseases are outlined. For bacteria pathogenic to trees, six types of diseases are described: Bacterial blight diseases, represented by Erwinia amylovora, the fireblight disease; Bacterial wilt disease, represented by Ralstonia solanacearum species complex; Root and stem galls of trees, represented by Agrobacterium tumefaciens; Wetwood disease, caused by several bacterial genera like Clostridium, Bacillus, Enterobacter, Klebsiella, and Pseudomonas, Xanthomonas and Pantoea; Bacterial scorch disease represented by Xylella fastidiosa with all its subspecies; Bacterial canker represented by Pseudomonas syringae with all its pathovars. Finally, the current diagnostic methods and specific issues related to bacteria detection, together with the main results of the scientific efforts and challenges in the genetic breeding to increase bacterial resistance of trees, are outlined.
Authors
Björn Andersson Annika Djurle Jens Erik Ørum Marja Jalli Antanas Ronis Andrea Ficke Lise Nistrup JørgensenAbstract
No abstract has been registered
Authors
Mladen Cucak Dalphy Ondine Camira Harteveld Lisa Wasko DeVetter Tobin L. Peever Rafael de Andrade Moral Chakradhar MattupalliAbstract
No abstract has been registered
Authors
Jason Tyler Magnuson Zoe Longenecker-Wright Ivo Havranek Giovanna Monticelli Hans Kristian Brekken Roland Kallenborn Daniel Schlenk Magne Olav Sydnes Daniela Maria PampaninAbstract
No abstract has been registered
Authors
Elizabeth Tettey Owusu Fordjour Aidoo Linda Arhin Ritter Atoundem Guimapi Fred Kormla Ablormeti Frank Dampare Richard Ampadu-Ameyaw Jeffet Ekow Cobbah Yayra Afram Frank Kwarteng Ndede YankeyAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Harvest weed seed control takes advantage of seed retention at maturity by collecting weed seeds as they pass through the harvester. We assessed the seed production and shedding pattern of common weed species in two wheat and two oat fields in Denmark. The aim was to evaluate the possibility of harvesting retained seeds on weeds at crop harvest by a combine harvester based on estimation of weeds seed retention. Before flowering, ten plants of each weed species were selected and surrounded by a seed trap comprising of a porous net. When the plants started shedding seeds, the seeds were collected from the traps and counted weekly until crop harvest. Just before crop harvest, the retained seeds on the plants were counted and the ratio of harvestable seeds and shed seeds during the growing season were determined. The seed production and shedding patterns varied between the species. In oat, Anagallis arvensis L., Capsella bursa-pastoris (L.) Medik., Chenopodium album L., Fallopia convolvulus (L.) Á. Löve, Geranium molle L., Persicaria maculosa Gray, Polygonum aviculare L., Silene noctiflora L., Sinapis arvensis L., Sonchus arvensis L., Spergula arvensis L., Stellaria media (L.) Vill.,Veronica persica Poir., and Viola arvensis Murray retained on average 61, 52, 67, 44, 58, 32, 59, 95, 67, 23, 45, 56, 51, and 33%, respectively, of their produced seeds at crop harvest. In wheat, Alopecurus myosuroides Huds. and Apera spica-venti (L.) P. Beauv. retained on average 34 and 33%, respectively, of their seeds at harvest. Silene noctiflora was classified as a good target for harvest weed seed control; A. myosuroides, A. spica-venti, C. bursa-pastoris, C. album, F. convolvulus, G. molle, P.maculosa, Sinapis arvensis, Sonchus arvensis, Spergula arvensis and V. arvensis were classified as intermediate targets; and A. arvensis, P. aviculare, S. media and V. persica were classified as poor targets. The research shows that there is a great potential to reduce the input of weed seeds to the soil seed bank by harvest weed seed control. Keywords: Harvest weed seed control; Soil seed bank ; Weed seed retention
Abstract
Harvest Weed Seed Control (HWSC) systems are used to collect and/or kill weed seeds retained on the weed plants at crop harvest. The effect of HWSC methods depends on the weeds seed retention at harvest. Therefore, delay in crop harvest reduces the efficiency of HWSC. In 2018, we studied the seed production and shedding pattern of Alopecurus myosuroides in a semi-field experiment in Taastrup, Denmark, to find the seed shedding time range of this species. In 2017 and 2018, we also followed the seed shedding pattern of A. myosuroides in a wheat field. Seeds of A. myosuroides were planted in pots in a greenhouse with a constant temperature of 5°C. In December 2017, the seedlings were transplanted in a box (120 × 80 cm2) located outdoor. In spring 2018, the number of plants was reduced to 14 providing a space of 685 cm2 for each plant. We surrounded each plant with a porous net to collect the seeds. The nets were checked once a week to record the beginning of the seed shedding period. Hereafter, seeds were collected weekly using a portable vacuum cleaner. Plants in the box started seed shedding in the second week of June and seed shedding continued for 12 weeks (end of August). In the wheat field, A. myosuroides plants surrounded by a net started to shed seeds in the third week of June and continued until wheat harvest on 31 July in 2017 and in the second week of July and continued until wheat harvest on 15 August in 2018. We found a significant difference between the weekly number of shed seeds in all three experiments (P