Heating Up The Vineyard Creates Sustainable Results

Helping Mother Nature by applying Thermal Plant Treatment shows beneficial results from bud to harvest 

Everyone in the business of growing crops understands the importance of adequate climatic heat to bring plants out of dormancy, into and through production. Plant growth, fruit set, yields, photosynthesis, disease development and fruit maturity are dependent upon adequate ambient heat ranges. Heat is a primary, if not THE primary factor, necessary for agricultural success…and up to now it’s the one factor that growers couldn’t control.

Agriculture depends upon the cooperation of Mother Nature to provide necessary heat inputs at the point in time they are needed but she doesn’t always cooperate. Thermal Plant Treatment (TPT) in its most simplistic definition is the application of instantaneous heat (IH) onto crops from an in-vineyard machine. What this technology allows is the opportunity to utilize +200ºƒ IH levels to modify climatic shortcomings and thereby accomplish desired agronomic benefits. The biggest question this budding new technology faced was whether IH could equate to long-term climatic heat delivery. After several years of intensive study and numerous trials, the answer is “yes” in most cases. In other cases we have discovered that the plant can be manipulated by IH to produce its crop with somewhat different characteristics than those achieved by climatic heat. This result of IH is now under intensive study by Agrothermal Systems.

Some of the benefits of TPT that are easily understood include drying off dampness after a rainstorm thereby lessening fungal development and damaging or desiccating insects at their larval, egg or even adult stages. Despite the Infancy of the technology, early scientific study has shown that TPT works in two ways, with benefits to the canopy environment and quality of wine. The technique is relatively new and the actually scientific study of TPT and IH is still in its infancy.

1. Plant Environment: Machine delivered hot air surrounds and blasts through the grape vine canopy at a wind speed that can be varied by machine settings. The momentary blast disrupts and replaces the ambient canopy temperature that the grape vine normally maintains at 70-80ºF. This produces several beneficial effects. First, the wind blows old leaves, twigs and other debris from the canopy thus reducing insect and fungal habitats. Second, the very dry heat blast reduces or eliminates most moisture and humidity within the canopy. Third, microscopic organisms are immediately raised to the air temperature surrounding them. Bacteria, fungus and fungal spores are heated to the treatment temperature, an instantaneous change of more than 100ºƒ.

Remember the old physics principle “little things heat up faster than bigger things”?  Exposed tiny insects, eggs and larva are killed or badly disrupted by the IH blast while bigger insects heat up far less from the brief exposure. The IH change kills or severely damages exposed pests…smaller ones more so than larger ones.

Termites are eliminated by 30 minutes of hot dry air at 120ºƒ. Bed bugs, adult larvae and eggs are killed at 115ºƒ when exposed for 7 minutes. Extermination companies thrive on killing insects as large as termites and hardy as bedbugs with hot dry air.  So why should there be any surprise that +200ºƒ heat kills or greatly damages smaller insects, tiny eggs and larva? In agriculture, it is widely observed that most hardy grape insects head for cover when the ambient heat reaches 95-100ºƒ. Powdery mildew does not develop above 95ºƒ.

One customer just completed a TPT trial of leafhopper crawlers in an organic vineyard. Heat was able to reduce the crawler population to almost zero over 8 weeks, while pesticide took 10 weeks to get the numbers down to that level. If leafhoppers can be managed, just about any insect should be controlled using TPT with the correct temperature and protocol.

2. Plant Systemic:  In addition to affecting the plant environment, TPT creates systemic reactions that are quite remarkable. The grape vine canopy surfaces instantly heat up 15-20ºƒ above ambient. This would not be a big increase if it happened gradually over several hours as would normally occur in nature. The plant regulatory system is accustomed to slowly heating or cooling and it functions normally when heated over time. However, 15-20ºƒ instantaneous canopy surface changes don’t happen in nature, and there are many indications that the vine regulatory system interprets the instantaneous change as a threat and activates its self-defense system.

There are two key benefits we have seen from the plant systemic response to IH; 1) fruit set, defined as number of berries set per bunch, is increased and 2) the taste characteristics of the resulting wines are different.

We have observed fruit set for two seasons (2013 & 2014) using a specific protocol of treatments during bloom in both California and Oregon. Both seasons were warm and drier springs so fruit set was naturally good. Even with good climatic heat, TPT catapulted berries set per bunch an average of +24.3% in 2013 and +23.2% in 2014. This even occurred in a Central Valley California block (+23%) that traditionally yields 8-10 tons per acre! It is no secret that set requires heat and drier weather and that is what TPT provides when it is needed. It will be interesting to see how much fruit set can be pushed when weather gets cool and wet during bloom. TPT can create the ideal effect to set fruit even when Nature is working against that outcome. While some people feel they don’t want big crops, set fruit can always be thinned. But you can’t paste berries onto bunches if the set is weak.

The second effect we see is what we have valued as “better wine”, but that is perhaps not an accurate description. It is more accurate to say that TPT creates “different wine characteristics” than conventional growing methods within the same block. The differences lead to preferences for TPT wines in blind tasting comparisons resulting from their more youthful complexity, fruitier aroma and greater length on the palate.

The first TPT wine was a 2012 Pinot Noir from Adelsheim Vineyard that provided different sensory characteristics versus control block wine. Yet, chemistry analyses showed no differences other than higher resveratrol, an indication of self-defense system activation. Ultimately a different balance of tannin was found. Buoyed by the 2012 wine quality, in 2013 wine making was undertaken at a major University and test wines were produced and analyzed from 12 different treated and 12 matching control blocks (8 varietals) in California. As part of the evaluation, Philip Goodband, a Master of Wine with spectacular global tasting experience led two blind tasting events, one in October and another in December of 2013. Except for 1 of 8 varietals, the TPT wine was preferred over its matching control wine and there were definite sensory differences. There was no doubt that the TPT produced wines with different and preferred characteristics. However, no significant or consistent chemistry differences were evident and therefore it was unclear what was creating the differences that were clearly present in blind tastings.

Adelsheim Vineyards expanded its 2013 trials to two blocks of Pinot Noir. Again different characteristics led to blind tasting preferences for the TPT wines versus control.  The conclusion, thus far, is that TPT produces different wines that are preferred in almost all trials to date…these now number approximately 20 trial wines with matching controls. As to why this is occurring, we only have two possible explanations. 2014 trials will more than double the number of test wines, so learning will continue to expand and answers will eventually be isolated.

In the interim, it is believed that Thermal Plant Treatment creates heat shock that activates the natural self-defense system of the plant. We see this indication from a number of observations including more rapid crop development, bigger more vigorous canopies and higher levels of antioxidants in most, but not all cases. It is perfectly possible that this creates different chemistries that are not measurable by current techniques. The other possible explanation is that TPT grapes are more consistent in ripening and “cleaner” with less fungus and pest issues thereby providing less interference with the pure grape expression. There are also additional theories being explored.

However, regardless of what drives the differences it is apparent that TPT creates very significant differences in wine characteristics and ultimate wine quality preferences. Someday soon we will figure out why! In the meantime, it is clear TPT works and science will eventually provide the answers.