Moving along in an ecologically friendly manner, we began 5 years ago to vastly decrease the amount of chemical herbicide we had been using. Pre-emergents were used which could keep an area of ground bare for up to 3-4 years. Without question, these chemicals are applied to and remain in the ground for years. We have now not used any of these pre-emergent herbicides for 4 years. Things don't look any different, but we do know we are not poisoning our water supply for years to come. Fact: one of the known causes of prostate cancer is...herbicide. That alone is enough reason to greatly reduce or completely get rid of pre-emergents. It does, however, allow more weeds to grow, but we hit these with the contactant, Round Up, which doesn't stay in the soil as pre-emergents do. Additionally, we have cut the # of spray nozzles per side of the spray rig to one each, thus cutting 50% more of our remaining herbicide use. Finally, we have cut our concentration of herbicide by half, again greatly decreasing the total amount of contact spray we use. Do the math and you will see we are now using 90-95% less of the herbicide than we formerly used. Yes, we do have a somewhat shaggier vineyard, and yes, more weeds do grow. But it is a small price to pay for being environmentally conscientious and ecologically sound.
There is another spray also used in vineyards, and that is pesticide spray. It is used for fungus, eg., mildew, with which we are all familiar. There can be other organisms that grow on grape leaves, not to mention grapes, but mildew is by far the most common offender. As recently as 5 years ago we were using 6-8 sprays/season, with a 10-20 day interval between sprayings. Fed up with that much spray use, we were looking for ways to either decrease pesticide sprays, or eliminate them entirely. As it turned out, that was the year, 2005, when we made the decision to drastically reduce our crop yields, and to go with 2.5-3.0 Tons/acre, rather than the 4-5 Tons/acre we had previously been pruned to. We had experimented with 5, 4.5, 3.5, 3.0, and 2.5 Tons/acre, and had found our
"sweet spot" to be somewhere in the 2.5-3.25 Tons/acre range. At the lower yields our flavors became markedly more aromatic, more vibrant, and the tastes more remarkable. The lower yields also yielded way less mildew, and pesticide spray was cut by 85-90% of what we had formerly used.
Lower yields don't just affect grapes, incidentally. Look at roses, for example. If you have a bush loaded with rosebuds and then pinch off every other bud, the resultant roses are more aromatic, more intense, richer in color, and larger flowers to boot. Same with a nectarine tree, or any other plant that produces either fruits or flowers. Additionally, we had been losing fruit from some ultra low yielding vines, which were located around the periphery of our Cab, Merlot, and Syrah blocs. This was because the wineries we had been selling to waited until the majority of the bloc was ripe, and then harvested. The fact that several hundred vines around the periphery of each of our 3 acre blocs were severely stressed due to competition with nearby oak trees for not only water, but also nutrients, resulted in those vines ripening 2-3 weeks before the majority of the vines contracted to other wineries were picked. Essentially, in 2006, we for the first time harvested those stressed vines for our own wines, instead of letting them just dry up and go to waste. The resultant wines from those vines yielded only 1 Ton/acre, but holy cow, were those grapes ever aromatic with flavors of blackberry, cherry, raspberry, cassis, occaisonal strawberry, some plum, and, of course, the minerality that our vineyard is known for, because of our chalk rock soil.
Recall that ecology is the branch of biology dealing with living organisms and their environment. Well, if you greatly improve the vine's environment, you likewise improve the vine...and its magnificent fruit. At Cerro Prieto that is our thrust...do everything we can to make the most favorable environment for our vines, and hence...our wines. Continued in Part 4.