Related Experiment Video
Updated: Jan 28, 2026

Potato Virus X-Based microRNA Silencing VbMS In Potato.
Published on: May 11, 2020
Potato Late-Blight Management in the Toluca Valley: Forecasts and Resistant Cultivars
Niklaus J Grünwald1, Oswaldo A Rubio-Covarrubias2, William E Fry3
1Cornell-Eastern Europe-Mexico (CEEM) Potato Late Blight Project, c/o PICTIPAPA, Conjunto Sedagro, Metepec, Edo. de México 52142, México and Department of Plant Pathology, Cornell University, Ithaca, NY 14853.
Abstract:
We evaluated host resistance and fungicide forecasting as components of integrated management in the Toluca Valley of central Mexico. Potato cvs. Rosita and Norteña showed high levels of resistance (20 and 4% final disease severity, respectively) in the no-spray controls, whereas susceptible cv. Alpha was at 90% defoliation well before the end of the season. Disease on Alpha was well managed with a weekly spray of chlorothalonil. None of three published forecast systems was entirely appropriate for this pathosystem. SIM-CAST accurately allocated fungicide for a susceptible cultivar but needs to be adapted for the high level of resistance of Rosita and Norteña. TOM-CAST and BLITECAST did not recommend the initial fungicide application until after disease was well established in the plots. We believe that the low-temperature response of Phytophthora infestans needs to be reevaluated for the highland tropics.
Related Concept Videos
Resistivity
Resistance
Resistance and Conductance
Various factors impact the resistance of a conductor. Spiraling in stranded conductors increases their...
Equivalent Resistance
Vascular Resistance
The primary determinants of vascular resistance are vessel diameter, blood viscosity, and vessel length. Among these, vessel diameter plays the most significant role due to the fourth power relationship described by...
Rolling Resistance
For instance, imagine a hard cylinder rolling on a comparatively soft surface. The cylinder's weight compresses the surface beneath it. As the cylinder moves, the material in front of it slows down due to...

