A small company of Fresno State viticulture and enology students has found that summer vacation may provide a break from studies, but little time away from academic work.

That’s because they are employed as full-time research assistants on research projects directed by Ph.D.-level faculty and staff of the Viticulture and Enology Research Center (VERC). Some of the students’ work is supporting research that may prove significant for San Joaquin Valley wine grape growers in the years ahead.

Case in point: Graduate student Erik Mallea is assisting viticulture research specialist and professor Sanliang Gu in a study of the application of abscisic acid (ABA) to red wine grapes to enhance color development. According to standard wine-making protocols, richer color in the grape at harvest means richer color and flavor components in the resulting wine.

A traditional problem in California’s San Joaquin Valley has been the high summer temperatures which often exceed the optimum for color development needed for high-quality wine, Gu said.

“It is well-established that ABA application improves color development and fruit ripening in grapevines,” Gu said. The obstacle to commercialuse has been the price of ABA. Until recently the complex compound costup to $1,000 per gram – far too expensive to use for spraying vines. Advances in production methods, however, have reduced ABA costs to a much lower price. Suddenly ABA is an option for consideration, and many in the industry are interested.

As one of the leaders of the student technician group, Mallea finds himself right in the middle of the ABA research, managing chemical applications, berry sampling and other aspects of the project. The importance of the work, however, doesn’t necessarily fill it with nail-biting intensity. In most cases, sound scientific research simply
means hours of routine data collection and analysis, in the field and in the lab, day after day, month after month, sometimes year after year.

A typical day for the student research assistants may involve work on several different research projects, Mallea noted. Duties include leaf sampling, berry sampling, cane sampling in the field; taking dozens, hundreds or more samples over multiple days and weeks, recording when and where all samples were taken. Samples are usually brought to the lab for analysis – under a microscope, or through a variety of chemical or highly-specialized equipment assays.

In spite of the routine, a certain drama emerges as Mallea describes the different processes involved in the scientific method, and the potential for discovery and breakthrough. Students often propose new ideas that could help improve methods. In some cases they even conduct secondary research that provides additional data relevant to the main project.

As a graduate student in viticulture and enology, Mallea is conducting his own thesis research project, studying phenolics and tannin development in grapes in the hot climate of the San Joaquin Valley.

As part of that project, he and two student colleagues recently spent several hours in a vineyard on Fresno State’s university farm cutting more than 3,000 individual green grape berries off experimental Syrah vines.

Later in the laboratory, they categorized and labeled the berries according to row number and vine number in the vineyard, placing them in plastic bags of 100 each. Then they began slicing open each of the 3,300 berries individually and pulling out two or three seeds and placing them in solution. The seeds will later be examined for the level of tannins and other compounds.

When discussing his own project, Mallea is enthusiastic about its potential to help the grape and wine industry.

“This is going to provide an important record. If we know how tannin develops in a hot climate, it will help growers. And it will help them make better wine,” he said. “The best research that’s going on is all about the interface – the effects of all management techniques working together. That’s the coolest research.”

Mallea plans to complete his thesis and earn his M.S. in viticulture and enology in the spring of 2009. He said he would someday like to operate a small winery, overseeing both the viticulture and winemaking. His summer work should help him to reach that goal.

(Copy by Steve Olson of the California Agricultural Technology Institute at Fresno State.)