Vitazyme on Grapes – 2007, LDS Fresno Raisin Vineyard, Madera, California
The interpretation of this raisin grape study for 2007 is rather difficult, in particular because all treatments in the vineyard received Vitazyme in 2006. The carryover effects of this product are well-known, so Treatments 2, 3, 4, and 7, while not receiving the product this year, nevertheless were affected by it.
Besides this difficulty, a comparison of Vitazyme alone (Treatment 5) with all of the other treatments car- ries with it the problem of comparing a non-nutrient biostimulant material with nutrient-containing seaweed formulations. Vitazyme works in part by making nutrients more available so by itself may reveal less growth response. Aside from these difficulties, it is apparent that Excite 1-1-17 at either the 1.0 or 2.0 lb/acre rate, applied three times, gave the highest yields. This seaweed formulation outperformed Excite 2-18-36 at the 4.5 lb/acre rate, or a combination of the two seaweeds (Excite 2-118-36 at 8.0 lb/acre + Excite 1-1-17 at 0.5 lb/acre). Vitazyme in combination with Excite 2-18-36 (4.5 lb/acre) or Excite 1-1-17 (1.0 lb/acre) produced yields less than the seaweed formulations at the same rate by themselves. Vitazyme alone produced a yield about average for the entire vineyard this year. Quality effects of the treatments showed no particular pattern, except that the two seaweed products together (Treatment 2), while producing one of the lowest yields, also produced the low- est B and B percentage and the highest level of substandard raisins.
It is of interest to know that Treatment 5 has received essentially the same Cascade treatments each year for the past five years.
It is instructive to note that, due to the unusual heat for part of the summer, the yields of grapes for 2007 were less than for any other year except 2006. During 2006, Vitazyme alone produced 4,110 lb/acre of raisins; Vitazyme + 1.0 or 2.0 lb/acre of Excite 2-18-36 gave somewhat lower yields: 3,844 and 3,721 lb/acre, similar to the yield depression in 2007. Only with Ethrel at 25% in 2006 did Excite 2-18-36 and Vitazyme combine to produce the highest yield (4.256 lb/acre).