Issue link: http://winesandvines.uberflip.com/i/74662
GRAPE GRO WING NA VIGA TION My education and experience have taught me that these principles do not always hold true. For example, even the most diverse forest ecosystem can still ex- perience pest outbreaks—sometimes over very large areas. Therefore I have come to realize that diversity and stability are relative terms. Another example is that re- search has shown some pest populations are not regulated by natural enemies but by the quality of their food source. And fi- nally, while I am a big believer in healthy plants being less susceptible to pest prob- lems, this can only be taken so far. Yes, some plants have secondary chemicals that help ward off pests, but growers must real- ize that while the plant is evolving chemi- cals to ward off pests, insects and fungi are evolving to break down these defenses. Alien crops and pests There are other things to keep in mind when dealing with crops and pests. Many of the crops we grow did not evolve in the locations where we grow them now. For example, Vitis vinifera did not evolve in North America, nor did it evolve on hill- sides planted in rows. Furthermore, many of our important pests did not evolve in ar- eas where they are now causing problems. Anagrus epos wasps (above) parasitize grape leafhopper eggs. The vine mealybug is from the Mediter- ranean region, and the light brown apple moth is from Australia. Finally, we harvest fruits and vegetables Castoro_Nov08 10/8/08 1:54 PM Page 1 because they are packed full of nutrients, and many other creatures are attracted to those crops for the same reason. In fact, some scientists believe that the grapevine evolved so that the fruit would be inedible while the seeds ripened, but once they were ripe, sugar would increase and secondary plant compounds decrease, causing ani- mals to be attracted to them, to eat them and spread the seeds in their droppings. The grapevine wants birds to eat its fruit. Unfortunately, that means our farm- ing systems are ecologically unstable due to the exotic pests that covet our highly nutritious fruits and vegetables. Yes, we should endeavor to increase the diversity of our farming systems as best we can, and keep our crops as healthy as we can, but we must realize that de- spite our best efforts, pest problems will occur. When they do, IPM is the best way to deal with these problems, be- cause it directs us to understand the in- teractions in the pest/plant system that are not functioning the way we would like, and figure out how to manipulate it so pest populations are at a tolerable level. IPM has us do this in a way that minimizes economic, environmental and health risks. I cannot answer the question "Is IPM dead?" because I am not sure how many growers are using this approach to manage their pests. However, I can say it is by far the best way to manage a pest problem. Dr. Cliff Ohmart is vice president of profes- sional services for SureHarvest. Previously he served as research/IPM director at the Lodi- Woodbridge Winegrape Commission. He has been writing about sustainable winegrowing issues for Wines & Vines since 1998. Contact him through edit@winesandvines.com. • VELCORIN DOSING NOW AVAILABLE! • Bottle cleaning, sparging & gravity filling • Vacuum corking & multiple head corkers • All types of capsules including SCREW CAP • Single or dual web PS labeling • NEW – 187ml bottling • 20 years of hands-on bottling experience • Supported by a winery • Experienced bottling line technicians • Technical support for bottling prep & packaging • Competitive prices QSEE US AT UNIFIED, BOOTH #805 128 Wines & Vines JAnUARY 2011