Whether you garden, farm, research plants, or develop new plant varieties, healthy seeds are critical to your success. Seeds are also big business. In 2018, global seed exports were worth more than $13.8 billion. Imports were worth more than $13 billion.

But a risk comes with those imports and exports. Seeds that move in global trade can carry pests. These include disease-causing microbes like bacteria, viruses, viroids, and fungi. Planting infected seeds could introduce a devastating disease once the seeds grow into plants. From there, the disease could spread to other farms, orchards, and nurseries. That could threaten entire industries and livelihoods.

The U.S. Department of Agriculture’s Plant Protection and Quarantine (PPQ) program works hard to reduce this risk. PPQ collaborates with the U.S. seed industry, other countries, multi-national organizations, universities, and scientific organizations. Their goal is to make the global movement of seed safer and regulations more consistent among trading partners.

Examples of Seed-Borne Diseases

Seed-borne diseases can affect a wide array of crops. Here are just three examples of highly-damaging diseases that could harm important North American crops:

• Cucumber green mottle mosaic virus can infect cucurbit species like watermelon, melon, cucumber, pumpkin, squash, and gourds, resulting in stunted fruit and premature fruit drop.
• Tomato brown rugose fruit virus can cause major fruit loss in tomatoes and peppers.
• Pospiviroids can produce serious disease symptoms in plants, including potatoes, tomatoes, and peppers, such as severe stunting and deformed fruit.

The Complex Movement of Seed in Trade

Seeds travel a complex, multi-country route before they reach their final destination. Seed could become contaminated with pests at any point along this route. Consider: Seed companies may locate breeding programs in several countries. They may distribute seeds from those countries to many other countries. In addition, they might export seeds produced in one country to a second country for processing. Then they may send the seeds to many other destinations—including back to the country of origin.

To complicate matters, when seed is produced, the destination countries and their import requirements may not be known. Several years can pass between when the seed is produced and when it is exported to its final destinations. In the interim, a country’s seed import regulations could change. That makes it difficult to verify that the seeds meet the importing country’s import requirements.

Working Globally

PPQ has worked through the International Plant Protection Convention on seed health issues for many years. This Convention is a treaty made up of 184 countries and other parties. Its goal is to protect the world’s plant resources from the spread of invasive pests and to promote safe trade.

Its members adopted a standard for the international movement of seed. This standard helps countries identify, assess, and manage the pest risk associated with the global movement of seeds for planting. It also provides guidance on how countries inspect, sample, test, and certify seeds for export and re-export based on common standards.

Working Nationally

PPQ is collaborating with industry, state and federal officials, universities, and others to develop a new approach consistent with the agreed-upon standards. It is called the Regulatory Framework for Seed Health (ReFReSH). ReFReSH will use industry best practices for managing pest risk to make international seed movement safer. It is based on recognized principles for reducing food safety hazards. Its goal is to effectively and efficiently manage the pest risk of international seed movements. ReFReSH will be based on common, global standards.

The concept behind this approach is gaining strength internationally. PPQ is developing pilot projects with Brazil and Chile. These projects will allow PPQ to monitor how well ReFReSH is working before fully implementing it. PPQ is also working with Canada, Australia, and New Zealand to develop a similar pilot.

Moving in the Right Direction

These efforts show how seriously countries and seed companies take this issue. A global solution may be a few years away. But we are steadily heading toward that solution. Our success will mean farmers have access to new varieties of pest-free seeds to safely enhance production and satisfy consumer demand.

Answered by Osama El-Lissy, USDA Plant Protection and Quarantine program

This blog is part of Crop Science Society of America’s Seed Week celebration. Why celebrate seeds? Anyone who plants a seed is investing in hope. That’s one of the attractions of seeds. For the gardener, it could be hope for a beautiful flower, or perhaps a delicious zucchini squash. For our farmers, seeds are the hope of this year’s yields of produce, cash crops or forage. No matter the size or shape of the seed, they all can bring forth new life. At Crop Science Society of America, we hold seeds in very high regard. Please visit our Seed Week webpage for news stories, blogs and more information about seed research and facts.

To read more about the USDA’s program, read this blog

Please visit our Please visit our Seed Week webpage for more information.

Read the other blogs in our seed series!

How can you prevent weed seeds from germinating in your garden?

How are seeds labeled for a farmer’s purchase?

Protecting Seeds: The What, Why, and How of Seed Treatments

The Incredible, Edible Seed

Why are seeds of different sizes and shapes?

What are seeds made of – and how can they grow into fruitful plants?!

About us: This blog is sponsored and written by members of the American Society of Agronomy and Crop Science Society of America. Our members are researchers and trained, certified, professionals in the areas of growing our world’s food supply while protecting our environment. We work at universities, government research facilities, and private businesses across the United States and the world.