John Martzen is a grower and pest control advisor who lives in Reedley, CA.

John Martzen: The Plant Doctor

John Martzen is a pest control advisor for the Gar Tootelian, Inc., (Reedley, CA) where his job is to advise growers on how to manage pest and disease on their farms. Collectively, John consults with growers who control thousands of acres of productive farmland.

John literally walks several hundred acres everyday. He is looking for signs of a lurking pest or disease. In the industry, this is called walking the field or scouting.

“Scouting means you are looking for different pest issues in the field. The pest you are looking for varies according to the time of year and most scouting occurs in the summer time — although it will vary by the type of crop. I am looking for disease, worms or mites — both aboveground and below ground. Along with that, I am trying to determine the nutritional needs that might exist,” John said.

John’s craft is to make recommendations about how to control or eliminate damaging pests while taking into consideration all of the variables that could affect the plants and soil. Pest issues are an inevitable aspect of farming, buts it’s the art of the application — what, how and when — that can make or break an operation’s viability for the year.

The crops that John services include: citrus, raisin grapes, table grapes, almonds, tree fruit, vegetable crops and hay.

“The business has changed a lot for me,” John said referring to the type of crops he oversees. Instead of table grapes and stone fruit dominating his portfolio, he is spending more time with nut, olive and citrus crops. The area he covers is south of Fresno and north of Visalia which is dominated by permanent crops.

The crops that John services, include: citrus, raisin grapes, table grapes, almonds, tree fruit, vegetable crops and hay.


John Martzen grows 55 acres of citrus and almonds. He is a pest control advisor who has worked with growers for more than 35 years.

John Martzen grows 55 acres of citrus and almonds. He is a pest control advisor who has worked with growers for more than 35 years.

Getting Started

John’s family moved onto a 20-acre raisin vineyard in Fresno County when he was in the 8th grade. Thus, began his journey into production agriculture.

His dad, Joe Martzen, worked as an Elementary School Principal in Selma. His dad, who was born to German-Russian immigrants, was raised on a raisin ranch in Dinuba, along with his seven siblings.

John’s grandparents were founding members of Sun-Maid — a grower-owned cooperative that was started in 1912 to pool advertising dollars in an effort to stabilize raisin prices. Sun-Maid operates today with approximately 800 members, which is a dramatic change from the once robust membership of 6,000 members. The Martzens’ maintained their membership up until a few years ago when John decided to replace the family raisin vineyards with almonds.

With the experience of growing up on a raisin vineyard, John decided to study plant science after graduating high school. He started out at a local community college, called Reedley College, and transferred to Fresno State to complete his Bachelor of Science’s degree.

While in college, John worked on his family farm and neighbors’ farms driving tractors, irrigating fields, harvesting raisins or hauling crops. In 1979, he graduated from Fresno State as a Plant Science/ Viticulture Major and landed his first job as a farm manager. In that same year, he married his sweetheart, Dotti, and they are married today with two grown sons, a daughter-in-law and two grandchildren.

Shortly after graduating, John obtained his Pest Control Advisor (PCA) license which required certification beyond the four-year degree.

The term “PCA” is a standard term in the ag-industry. Some PCAs are “in-house” advisors who worked for a single farming operation or “outside” advisors who work for a third part to provide expertise as a service. The PCA is responsible for writing a prescription to treat a pest or disease and the dose and application must be followed explicitly. All applications are highly regulated with every application reported to the California Department of Pesticide Regulation for oversight and enforcement.

In the agriculture community, an individual’s reputation is the most important characteristic in working with growers.

John has an impeccable reputation and prides himself in being honest and reliable. The legacy he lives seems to be in large part influenced by his father.


Dynamic Duo

Around 1982, John and his dad, leased farm land together. Father and son both worked day jobs and farming served as a second job. At the time, John was working as a plant health distributor.

Their farming venture was focused on selling fruit at farmers’ markets. Selling at the farmers’ markets requires that the seller have access to multiple varieties of fruit available throughout the summer season which means have early season, mid season and late season varieties.

Netting is used to keep the bees from pollinating the flowering citrus trees. This cultural practice keeps the easy-peel fruit.

Netting is used to keep the bees from pollinating the flowering citrus trees. This cultural practice keeps the easy-peel fruit.

“We leased a ranch with 40 different varieties of tree fruit and grapes,” John said. “It would go the whole summer into December.”

John also remembers the hectic schedule that came with harvesting, especially when crops overlapped.

“On our little operation, we had 200 workers at the peak of harvest when we were picking peaches, juice grapes and raisins,” he said.

On a year-round basis, they had four employees who supplemented the Marten-dou’s efforts to irrigate, operate equipment or harvest fruit. Acreage-wise their side venture peaked around 150 acres made up of tree fruit and raisin grapes. As John and Dottie’s sons grew, eventually they joined their dad and grandpa in the family’s farming side gig.

“When my kids were in high school this was their summer job,” John said about farming.

In the late 1990s, John and his dad decided it was time for John to transition from working part-time into working full-time. John began working as a PCA for Gar Tootelian.



A few years after moving into full-time work, John’s Dad passed away. After this, he realized that the ranches were not financially sustainable and let the leased farmland go. Today, John still farms “on the side” but there is less land and the crops aren’t as labor intensive as what he and his Dad grew together.

John purchased his Mom, Barbara Martzen, ranch a few years ago and replanted it with almonds last Spring, which is a crop that can be mechanically harvested.

John and Dottie, live on the ranch where Dottie grew up, in Reedley. They purchased it from her family in 1989. In 2005, they converted the stone fruit orchard into citrus. In addition to their own acreage, John also helps manage 60 acres of citrus for his employer.

John’s sons are grown and have careers outside of the agricultural industry. His 30-year-old son, Scott, lives on the ranch where John was raised, with his wife Megan, and their six-year-old son, Maverick. Scott works for Selzi Enterprises, a local company that manufactures utility truck beds. His second son, 27-year-old Geoff, works for Colorado State and has a 10-year-old daughter named Macy.


Want to learn more?

  • Listen to John on the Central Valley ag report featured on KMJ’s Ag Report hosted by Don York that is broadcasted on weekdays.
  • Visit Gar Tootelian’s web site to learn about company’s services and history in California agriculture.
1 Comment

Post a Comment

%d bloggers like this: