He has found as yield potentials increase, growers usually increase nitrogen inputs, which may not be necessary. The USDA is using a deep soil probe to trace nitrogen applications to cotton. Defoliant studies are also part of Vargas's responsibility. He notes that defoliants may pose a public relations problem. He is investigating new materials and techniques that are odor-free and require lower application rates.
Preliminary data show a reduction in weed populations.
Current work is aimed at determining how often the treatment needs to be repeated, since the practice may actually bring up buried seed if repeated the following year. Vargas is also cooperating on Sean Swezey's UC Santa Cruz organic cotton project. The objective is to study the conversion from conventional to organic cotton production. The energy component was funded by a California Energy Commission grant. They are completing their third year.