Editor's Note: This week we have the first of two special reports on pesticide drift.

In this week's Quest radio piece, I talk to two pregnant organic onion workers who got sick after an apple farmer sprayed pesticides on a nearby orchard. Following a nearly three month investigation, the Kern County Ag Commissioner issued citations finding both the apple grower and the organic company at fault (see the citations here and here). Workers told me that even after the drift started, the organic farm's supervisor encouraged them to keep bunching onions, telling them to put handkerchiefs over their mouths to block out the smell of the insecticides.

Whenever a big pesticide drift accident like this happens, it raises important questions: How often do these kinds of incidents occur? Are things getting better for people in communities near where pesticides are sprayed?

That's hard to tell, because of the way the Department of Pesticide Regulation (DPR) and County Ag Commissioners keep track of the data. There's no single enforcement code to categorize incidents as "agricultural drift affecting humans."

DPR does keep a statewide database of acute illness related to pesticides, as documented in worker’s comp or physician's records. Pesticide activists say those numbers are low, because many victims don't see a doctor. And doctors don't always know how to recognize symptoms of pesticide illness, or that they are supposed to report those cases.

And here's another twist: back in 2000, DPR changed its criteria for how it evaluates pesticide illness. So you can't compare the number of incidents from the 1990s with incidents today. All that makes it very difficult to determine if growers and regulators are really doing a better job keeping the public safe from chemicals drifting off the farm, especially after the passage of bills like the 2004 law sponsored by State Senator Dean Florez.

While that law clarified rules for emergency responders and required growers to pay medical bills for uninsured victims, it doesn't seem to have led to a dramatic drop in pesticide drift incidents.

In 2006, Governor Arnold Schwarzenegger vetoed a bill that would have sped up pesticide drift investigations and increased penalties. Instead, he directed DPR to streamline the enforcement guidelines for counties. Ag Commissioners can now issue a maximum fine of 5,000 dollars for each person sickened by pesticide drift.

That's a penalty some advocates, like Californians for Pesticide Reform think is far too low to act as a deterrent.

Meanwhile, County Ag Commissioners are facing budget cutbacks that may shrink their enforcement teams. Many agriculture commissioners already have just six or seven pesticide enforcement inspectors to police thousands of farms.

The Department of Pesticide Regulation says it can't enforce the law unless drift incidents are reported. The department has launched a new campaign to educate fieldworkers about pesticide drift, printing up wallet-sized cards with a toll-free hotline number in English and Spanish.

Listen to the Catching the Drift radio report online.

In our radio story, we feature the stylishly high tech Vineyard 29 and the Robert Mondavi Winery, but scores of other wineries are using a similar toolbox of technology to help them monitor the soil's water content to grow better grapes. The technology ends up conserving water, too. Remote sensing, ground penetrating radar and satellite technology have helped Mondavi cut back on water use by 30% in recent years.

Winemakers are using some of the same technology that NASA uses to study Mars and engineers use to build hi-rises and freeways. A typical toolbox includes multi-spectral imaging, weather stations, neutron moisture probes, and pressure bombs and there is a plethora of newer technologies in the pipeline. But enough with all the high tech gizmos. How does wine from high tech vines taste? The answer might be found in the success of the winery. Mondavi has won numerous awards over the years and there is a two-year waiting list just to purchase Vineyard 29 wines.

Check out our slide show to see some of these technologies or listen to our radio report on high tech in the vineyards.

You may listen to the "Stamping out the Apple Moth" Radio report online, as well as find additional links and resources. Also don't miss our photo set for this story on flickr.

Andrea Kissack is Senior Editor for QUEST at KQED Public Radio.