Lester R. McNall

Dr. Lester R. McNall passed away peacefully at his home in La Habra, California, surrounded by love, at the age of 98 ½. Known affectionately by his family as "PK," Lester was a true Renaissance man whose interests spanned chemistry, agriculture, business, genealogy, finance, technology, classical guitar, literature, art, and world travel.

Lester was born on a wheat farm in Gaylord, Kansas, on October 28, 1927, the youngest of ten children. Seeking relief from the Dust Bowl, the family moved to a dairy farm in Janesville, Wisconsin, in 1936. Lester often joked that he became a chemist to escape farm work, though he ultimately dedicated his life's work to making important contributions to agriculture.

After graduating from Janesville High School in 1944, Lester earned his Bachelor of Science in Chemistry from the University of Wisconsin in 1950 and his PhD in Chemistry from UCLA in 1955. Following a brief period with Esso Research in New Jersey, he returned to California in 1957 to head Chemical Research for the Paper Mate division of Gillette in Santa Monica. There, his work improved ballpoint pen ink formulas, including the specialized inks used in space exploration and those capable of writing over grease and butter.

In 1966, Lester joined the Leffingwell Chemical Company in Brea, California, as Technical Director, rising to General Manager by 1976. At Leffingwell, he developed a lifelong passion for foliar feeding—supplying nutrients to plants directly through their leaves. His pioneering research proved that nutritional sprays could immediately manipulate plant responses, directly influencing yield, quality, and ripening, while preventing crop diseases. He also introduced the standard global practice of using spray adjuvants to control pesticide pH, providing more effective pest control with lower chemical rates.

When Uniroyal acquired Leffingwell in 1980, Lester was appointed manager of their Western Regional Experimental Station in Porterville, California, focusing on the plant cuticle and nutrient penetration. In 1984, he established his own laboratory, and in 1986 founded Nutrient Technologies, Inc., introducing the world-renowned "Tech-Flo" line of flowable foliar nutrients. He successfully grew the company for decades before retiring at the age of 88 in December 2015, selling the business to De Sangosse, a global agricultural chemical company based in Agen, France.

In retirement, Lester turned his sharp mind to philanthropy, writing, and genealogy. He meticulously built two genealogical family trees for the McNall and Heide families, connecting over 100 relatives and publishing more than 100 life recollections online. Deeply loyal to his alma mater, he endowed the Lester McNall Professorship at the University of Wisconsin Chemistry Department and funded a Lecture-Laboratory Classroom in a major new wing of the chemistry building in 2019. He also self-published The Road Too Far, an extraordinary account of a 10,000-mile road trip his sister Marie took with friends along the Pan-American Highway to Santiago, Chile, in 1948.

Lester was a steady, wise presence, an avid reader of The Wall Street Journal, a devoted viewer of Jeopardy! and Wheel of Fortune, and a fiercely loyal supporter of Wisconsin Badgers athletics and the Green Bay Packers. His daily walks with his friend Bobbie and his beloved Shelties brought him lifelong friendships in his neighborhood.

Lester was preceded in death by his parents, Webster and Bertha (Heide) McNall, and all nine of his siblings: Irene Lee, Lula Van Amburg, Ambrose McNall, Margaret Nelson, Webb McNall, Francis Neumann, Dorothy McNall, Marie Jaastad, and Richard McNall.

Having survived rheumatic fever as a teenager, Lester lived each day with deep gratitude. He is survived by nine nephews: Richard Lee, Tom McNall, Dan McNall, Michael McNall, Matthew McNall, Scott McNall, Larry Van Amburg, Gerald Van Amburg, and Bill McNall; six nieces: Mary Boettcher, Elaine Bailey, Marcia Rouse, Randine Larson, Tammy Janizec, and Heidi Grafft; as well as a large extended family, colleagues, and friends. In his later years, he was lovingly cared for by Lisa Van Amburg, Marcia Rouse, Randine Larson, and his godson, Kent Kruse.

A memorial celebration will be held at 1st Congregational Church, 310 Bluff, Sheboygan WI, 53081 on Saturday, September 19, 2026, a visitation at 11am and service at 12pm. A lunch reception to follow at the the Blue Harbor Resort.

Interment of ashes will take place on May 30, 2027 during the McNall Family Reunion in Smith Center, Kansas.

Memorials may be made in Lester's name to the following: University of Wisconsin Foundation-Department of Chemistry, St. Jude Memorial Foundation, or UCLA College of Letters and Sciences/College of Chemistry and Biochemistry Fund