Total Acreage 4.4acres. 4200 vines total after 2003 replant. , 170 vines Merlot, 170 vines Carmenere, Remainder Cab
No documentation of farming during the 24 years prior to our purchase of the vineyard in late 2000. Verbal numbers of yield from prior owner were 2 tons and 7 tons on different occasions. Vineyard was previously planted in 1976. Farming became uneconomical and was discontinued sometime 3 -7 years before we purchased the vineyard. Reports vary. Seller reported vineyard size as 5 acres but, it was actually 3.9 acres. Very old irrigation lines were in place but not functional.
2001 1271 lbs. No water no fertigation. Just hacked through the blackberries enough to pick the grapes. About 3000 vines on 3.9 acres. Most fruit in most vigorous block (2)
2002 1574 lbs. Ripped out all but 342 best vines which were 27 years old. Interplanted 310 new vines in this block.
2003 1942 lbs. 3556 new green growing vines planted, in the spring of this year, all but 644 vines farmed in 2002.
2004 1573 lbs.; 200 lbs from 70 Two yr. old replants, + 1373 lbs. from 260 thirty year old Cab vines and 314 interplants
2005 ~4 tons First real yield from replants. High yielding year in general +25% for rest of the area. No cordons yet, fruit very uniform, lightly cropped exceptional fruint and wine quality as a result. Best yet. Wasn't prepared to vinify this much fruit. half in P.A. , half in Napa.
2006 8.4 tons total , Cabernet Sauvignon 6.86 tons sold, Cabernet Sauvignon 1.15 tons vinified at Camalie, Merlot 420 lbs = .21 tons. , Carmenere 370lbs. = .185 tons
2007 18.2 tons total; Cabernet Sauvignon 17 tons sold + Cabernet Sauvignon .412 tons. vinted at Camalie, Merlot .641 tons. for 166 vines or 7.7 lbs/vine, Carmenere 330 lbs= .156 tons. ; Merlot Pruning Wt 2 lbs/vine Fruit/Prunings = 3.85 which is toward the high end but good. Cab total was 16 tons, 32000 lbs 32000/3900vines = 8.2 lbs/vine Ave. pruning wt. 1.3 lbs not counting old vines Fruit/Prunings = 8.2/1.3 = 6.3 which is high but probably because the average pruning weight was really higher.
2008 9.7 tons total, Cab 8.08 tons sold, 1.20 tons vinted at Camalie, Merlot 800 lbs., Carmenere 120 lbs.
2009 17.5 tons total; Cab 16.52 tons, Merlot .9 tons, Carmenere .13 tons, 13.18 tons cab to Sherwin, 1.295 tons cab to Wood, 2.05 tons cab Holler
2010 10.9 tons total; Cab total 10.24, Cab Wood - 1.358, Cab Dexter-2.717, Cab McBride- 3.61, Cab Holler- 1.43,Cab Guillermo - .606, Cab Sporte - .293, Cab Shantz - .2, Merlot .643 tons, Carmenere, .03 tons.
|Merlot tons/acre||Carmenere tons||Caremenere tons/acre|
Acreage: 4.4 acres total, Cab 4.08 acres, Merlot .172 acres, Carmenere .143 acres(leaf roll virus in the Carmenere is responsible for its low yields); Vineyard replanted in 2003.
2009 forecast 17.5 tons, 50% confidence interval 12-23 tons.
Bunch counts and bunch weights taken 9/16 and 9/17/2009
Individual vines were totally stripped and all bunches weighed.
|Row||Vine||# bunches||Ave. Bunch Wt.||Std. Dev.||Total Wt. on Vine|
|39||42||33||5.3 oz.||2.1 oz.||10.9 lbs.|
|57||18||21||4.1 oz.||1.0 oz.||4.1 lbs.|
|57||60||39||5.9 oz.||1.8 oz.||14.4 lbs.|
|18||10||45||3.5 oz.||1.7 oz.||8.7 lbs.|
|Ave.||34||4.4 oz.||9.5 lbs. (std dev). 4.3 l lbs.|
|Vine weights||Bunch Counts|
|4.1||Avg. bunch count x avg. bunch wt. = 9.4 lbs.|
|14.4||Avg. per vine weight measured = 9.5 lbs.|
|8.7||Almost exactly the same as the average|
|Avg.||9.525||lbs./vine||vine weights measured. Good.|
|Bunch weights||900 vines/acre x 9.5 lbs/vine = 4.2 tons/acre|
|5.3||3700 vines x 9.5 lbs/vine = 17.5 tons 4200-300(Merlot+carm)-200 Al toxic- no fruit|
|3.1||3.8 acres x 4.2 tons/acre = 17.5 tons.|
|5.9||Minus 2 for Holler = 15.5 tons.|
|3.5||2007-- 17.5 tons, sold 17 vinted .5.|
The variance of this data is very high with fruit weights/vine varying from 4.1 lbs/vine to 14.4 lbs/vine along one long row traversing blocks 3 and 4. Assuming a normal distribution for the 4 vine yields where all bunches were weighed we can say the following. With 50 % confidence we can say the yield per vine will be between 6.3 and 12.2 lbs. With 90% confidence we can only say that the average yield will be between 0 and 21 lbs./vine.
If we take the bunch weights and bunch counts which were sampled with higher frequency we can make a little better estimates. If we just use the bunch count average and assume no variance in it and use the bunch weight variance over 138 samples we can say the following : With 50 % confidence we can say the yield will be between 6.5 and 12.3 lbs./vine. With 80% confidence we can say the yield will be between 4.0 and 14.9 lbs/vine. We really can't say much statistically.
Based on 3700 vines bearing: what we can say is that the total vineyard yield of cab will be between 12 tons and 23 tons with 50% confidence.
A better estimate is possible if one were to reconsider the problem taking into account some known sources of variance. The first source of variance is block to block variations. Considering the blocks separately each would have a lower variance and would have a tighter interval of confidence. In adding the blocks together there would be an RMS addition of block variances that there wouldn't be if all the data is considered together. The other source of predictable variance is in the variance of bunch weights across a vine. Middle and end bunches are larger than mid cordon bunches. This difference could be characterized and all vines subsequently bunch sampled at the same locations within vine, take one bunch from the end and one from mid cordon and handle their distributions separately. Still it is unclear how much better this estimate would be.
It may be true that the grower's or vineyard manager's experience looking at the fruit visually may provide the best estimate of yield. A radical approach calls for capturing video of the fruit zone for all or most rows and using computer vision to estimate the total crop load.
Appendix: Propagating bunch count and bunch weight variances to vine weight errors
The general method of getting formulas for propagating errors involves the total differential of a function. Suppose that z = f(w, x, y, ...) where the variables w, x, y, etc. must be independent variables!
The total differential is then
We treat the dw = Dw as the error in w, and likewise for the other differentials, dz, dx, dy, etc. The numerical values of the partial derivatives are evaluated by using the average values of w, x, y, etc. The general results are
|Using simpler average errors|
Example: Consider S = x cos (q) for x = (2.0 ± 0.2) cm, q = (53 ± 2) °= (0.9250 ± 0.0035) rad. Find S and its uncertainty. Note: the uncertainty in angle must be in radians!
S = 2.0 cm cos 53° = 1.204 cm
Hence S = (1.20 ± 0.13) cm (using average deviation approach) or S = (1.20 ± 0.12) cm (using standard deviation approach.)
Last updated 1/3/10 M.Holler