Feeds:
Posts
Comments

Archive for the ‘Biorational products’ Category

Science News

NEWSARCHAEOLOGY

The oldest known grass beds from 200,000 years ago included insect repellents

The ancient bed remnants include fossilized grass, bug-repelling ash and aromatic leaves

South Africa’s Border Cave
South Africa’s Border Cave, shown here at its entrance, contains bits and pieces of the oldest known grass bedding, dating to around 200,000 years ago, researchers say.A. KRUGER

Share this:

By Bruce Bower

AUGUST 13, 2020 AT 2:00 PM

People living in southern Africa around 200,000 years ago not only slept on grass bedding but occasionally burned it, apparently to keep from going buggy.

Remnants of the oldest known grass bedding, discovered in South Africa’s Border Cave, lay on the ashes of previously burned bedding, say archaeologist Lyn Wadley of the University of the Witwatersrand in Johannesburg and her colleagues. Ash spread beneath bound bunches of grass may have been used to repel crawling, biting insects, which cannot easily move through fine powder, the researchers report in the Aug. 14 Science. Wadley’s team also found bits of burned wood in the bedding containing fragments of camphor leaves, an aromatic plant that can be used as a bug repellent.

Prior to this new find, the oldest plant bedding — mainly consisting of sedge leaves, ash and aromatic plants likely used to keep insects away — dated to around 77,000 years ago at South Africa’s Sibudu rock-shelter.

At Border Cave, chemical and microscopic analyses of excavated sediment showed that a series of beds had been assembled from grasses, such as Guinea grass and red grass. Guinea grass currently grows at Border Cave’s entrance. Bedding past its prime was likely burned in small fire pits, the researchers suspect. Remains of fire pits were found not far from Border Cave’s former grass beds.

Grass fragments uncovered in South African cave
Preserved grass fragments uncovered in a South African cave, left, are by far the oldest known examples of grass bedding, researchers say. Close-up images of those fragments taken by a scanning electron microscope, such as the one shown at right, helped to narrow down what type of grasses were used for bedding.L. WADLEY

Humans in southern Africa intentionally lit fires by around 1 million years ago (SN: 4/2/12). But Border Cave provides the first evidence that ancient grass bedding was burned on purpose.

Small, sharpened stones were also found among grass and ash remains, suggesting that people occasionally sat on cave bedding while making stone tools.

Questions or comments on this article? E-mail us at feedback@sciencenews.org

CITATIONS

L. Wadley et al. Fire and grass-bedding construction 200 thousand years ago at Border Cave, South Africa. Science. Vol. 369, August 14, 2020, p. 863. doi: 10.1126/science.abc7239.

Bruce Bower

About Bruce Bower

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeolo

Read Full Post »

Organised by

Promoted by

8th International Symposium

Plant Protection and Plant Health in Europe

Efficacy and risks of biorational products in IPM strategies – acceptable?

13-14 December 2017 – Braunschweig, Germany

Archives:

2015 –  2014201320112009 20072005

 Geschäftsstelle    Login    Suche    AGB    Impressum

 

8TH PPPHE SYMPOSIUM ON “EFFICACY AND RISKS OF BIORATIONALS IN ORGANIC AND INTEGRATED PLANT PROTECTION STRATEGIES – ACCEPTABLE?

The German Scientific Society for Plant Protection and Plant Health r.S. (Deutsche Phytomedizinische Gesellschaft e.V. , DPG), the Julius Kühn-Institut (JKI) and the Humboldt-University Berlin (HU) invite you to be part of the upcoming 8th International Symposium on Plant Protection and Plant Health in Europe (PPPHE) on „Efficacy and risks of biorationals in organic and integrated plant protection strategies – acceptable?”.  The symposium will be held December 13 and 14, 2017 at the Julius Kühn-Institut in Braunschweig, Germany.

Integrated Pest Management (IPM) and Plant Protection in Organic Agriculture (PPOA) should be science-based decision- making processes that identify and reduce risks from pests and pest management related strategies. They coordinate the consideration of pest biological factors, environmental conditions, and all available instruments to prevent unacceptable levels of pest damage, while concurrently combining economical means with the least possible risk to people, property, resources, and the environment.

We use the widely known term »biorationals« as an operative expression to speak about certain kinds of components of plant protection strategies, which are assumed to have advantages concerning risk characteristics on the one hand while at the same time provide acceptable efficacy in reducing pest impact. Nevertheless it is not our intention to propose a new legal category!

The products we want to speak about are often materials that are biologically-derived or, if synthetic, structurally similar and functionally identical to a biologically occurring material. Micro-organism, plant extracts, basic substances, semiochemicals, as well as non-pesticidal products like biostimulants, biological yield enhancers, plant health promoters, and soil conditioners are a matter of discussion.

Such »biorationals« alone do not reveal sufficient efficacy against pests, but are useful to be integrated in plant protection strategies. In addition, the risk-evaluation requirements under national and European regulatory frameworks of these diverse »biorationals« are very different from each other or there is even a lack of regulatory infrastructure to ensure that »biorationals« get a targeted risk assessment and approval procedure.

On this background, the symposium wants to work out

  • a critical perspective on the risk and efficacy evaluation of »biorationals«
  • an overview of agricultural and socio- economic experiences with »acceptable« instead of »sufficient« efficacy in pest managment strategies
  • impediments to introduce »biorationals« under the existing Sustainable Use Directive 2009/128
  • a conclusive statement to promote »biorationals« for use in agriculture

For registration and updated information please visit our homepage http://www.ppphe.phytomedizin.org/.

For more details:

Dr. Falko Feldmann Dr. Christian Carstensen
Email: Feldmann@phytomedizin.org Email: Carstensen@phytomedizin.org
Email2: falko.feldmann@julius-kuehn.de

Read Full Post »