About Us
Pioneering Quality Assurance
- Stronger, healthier seed potatoes
- Reliable yields for growers
- Reduced risk of disease spread
- Assurance for end users, from processors to fresh market suppliers
How it Works
In 1976, Alex McDonald Ltd entered a Joint Venture with Crop Research DSIR for the production of potatoes using the tissue culture method. After 4 years trailling, this was accepted by NZ M.A.F and Crop Research DSIR as a worthwhile improvement in the production of quality seed potatoes, and we entered a long-term joint venture. This forms the basis of the Pathogen Tested Certification Scheme, which continues to this day and now handles approximately 65% of the seed potatoes required in New Zealand.
Alex McDonald Ltd produces disease-free seed potatoes through a process that starts with tissue culture. Plantlets are grown in our Templeton glasshouse and developed into Generation Zero mini tubers. From there, the potatoes move through carefully-managed generations (G1, G2, G3 and beyond), with every line tested along the way.
Independent inspections and laboratory testing by Potatoes New Zealand ensure that every batch meets rigorous health standards. Multiple field assessments are carried out during the growing season, and samples are graded for defects and resistance before being certified.
A Smarter Future
The benefit of pathogen-tested seed is clear: healthier potatoes mean better crops, stronger yields, and greater confidence for growers and consumers alike. By starting clean, we can ensure the ongoing strength and resilience of New Zealand’s potato industry.
The Pathogen Tested Scheme forms the backbone of New Zealand’s potato industry, with around 65% of seed potatoes in the country produced under this system. Alex McDonald Ltd is proud to have pioneered this process, and to continue leading it today.