UNIVERSITY PARK, Pa. — If action isn’t taken to protect the health of the world’s plants, the prognosis for some species is poor, especially in regions that lack plant protection policies and extension services, according to scientists who participated in an international workshop and conference that was co-led by a plant pathologist at Penn State.
Held in Toulouse, France, in October, the “Assessing the State of Global Plant Health in Natural and Cultivated Ecosystems” workshop was sponsored by the Organization for Economic Co-operation and Development's Co-operative Research Programme on Biological Resource Management for Sustainable Agricultural Systems and the International Society of Plant Pathology. These international nonprofits address social, economic and environmental challenges.
Plant health is related to human and animal health and economic stability, noted Paul Esker, associate professor of epidemiology and field crop pathology in the Department of Plant Pathology and Environmental Microbiology in the College of Agricultural Sciences.
“It is vital that we have a complete understanding of what is happening in various parts of the world — and why — so we can direct resources, enhance extension education, prioritize research, and develop public policies to improve plant health,” he said.
Esker added that the workshop was an essential step of the Global Plant Health Assessment, a project initiated with the support of the International Society of Plant Pathology. The goal is to provide a first-ever overall assessment of plant health in the natural and human-made ecosystems of the world.
At the workshop, experts from academia, industry, nongovernmental organizations and government agencies presented reports focused on different plant systems and ecoregions worldwide. Themes included climate change and plant health, plant health and global food security, the economics of plant health, and plant health within “One Health,” which is an initiative to attain optimal health for people, animals and the environment.
All terrestrial ecosystems were considered, ranging from agrosystems to urban vegetation. Recognizing that it is difficult to assess every specific disease, the reports used a qualitative assessment that was science- and fact-based and relied on teams of experts that provided evaluations on the overall state of plant health for a given plant system, Esker explained.
Those reports covered plant systems such as cereals; fruit trees and grapes; peri-urban horticultural systems and household gardens; forests and urban trees; and roots, tubers, bananas and plantains.
On a positive note, cereal crops such as wheat, maize and rice received a good score. However, Esker said there are situations where the provisioning services — which are benefits that can be obtained from an ecosystem such as food and fiber, drinking water, and timber — are declining in some parts of the world, including Western Europe, South America and sub-Saharan Africa.
He added that in East Asia, increasing trends for plant health and provisioning services are being undertaken for wheat production.
Fruit tree and grape trends suggest poor to good ecosystem services and plant health. Over the past 10 years, though, trajectories are only stable to declining, Esker said. One exception to this is for South Asia.
Peri-urban agriculture, which is the production and distribution of food, fiber and fuel in and around cities, has a middling outlook, which is likely due to the challenges with managing the major plant diseases that impact primary plant species such as tomato.
Overall, the state of plant health for forests and urban trees is fair.
“While ecosystem services are good to excellent, the tendency is for declining services over the past 10 years, particularly in the Western Hemisphere,” Esker said.
Root vegetables, tubers, bananas and plantains scored the lowest among the groups, receiving a poor to a fair level of plant health. Potato, banana and plantain crops are at risk in Western Europe, South America and sub-Saharan Africa, respectively, Esker pointed out, although cultural and production practices have improved in sub-Saharan Africa in the past decade.
There are many reasons for plant health decline; however, changing weather patterns, limited access to extension education and resources related to disease and pest management, and lack of field data are among the major factors.
Another problem is the absence of global plant-health policies that call for funding for extension systems and research, address the impact of climate change on plant health, promote breeding for plant disease resistance, and support mitigating the unsustainable use of pesticides.
“These discussions are important to address critical needs and opportunities for defining policy related to global plant health,” Esker said. “The workshop brought together the best of the best in plant health who share the same goal — saving the world’s plants.”