Find the wiki

Just to let you know there'll be a new string to the bow from now on. Somewhere to post files without extensive editing so that they fit on the page. Products, activities, all that stuff.

http://BlackWalnutsdotCa.wikispaces.com

Not planning a full migration just yet, but we'll see. This is not yet a private wiki, so you should be able to access it, but just in case I convert it to a private site send me an email for your invitation to join. Tell me who you are, and why you're interested in black walnuts.

Line Index Explained

The following values have been calculated for five lines (trees) as an example. Please note that data collection on this portion of the farm only began in 2006, so not all variables were quantified every year. For the table to fit this window, 2006 data had to be excluded.

Line (Tree)			2007					2008
			A S	NY	SI	DBH	K%	NY	SI	DBH	ABNY
1	1	14	1	3.51	0.69	13.5	21.9	3.27	0.70	15.4	0.50
1	2	12	1	0.65	0.61	16.7	25.7	7.88	0.51	18.5	0.75
1	1	17	1	1.81	0.69	12.5	19.5	0.00	0.70	14.7	0.90
1	7	12	2	5.49	0.67	8.6	21.8	2.93	0.70	10.1	0.61
1	4	27	3	1.49	0.57	10.0	24.2	3.44	0.55	11.3	0.24

Codes

AS: Anthracnose Score - Incidence of Leaf Spotting Disease 1 (low) to 5

NY: Nut Yield - Number of nuts per sq cm trunk diameter at DBH

SI: Shell Index - Shell weight per cc nut volume

K%: Kernel Percentage - Kernel proportion of nut by weight

DBH: Diameter at Breast Height - Measure of tree size (at 135cm from ground)

ABNY: Alternate Bearing Index (from NY) - Annual variability in NY 0 (low) to 1

On the far right-hand side are the calculated (multi-year) Alternate Bearing Indices, where it can be seen that 1-4-27 and 1-1-17 are the two extremes, the latter so far expressing high alternate bearing (closest to 1). If you find this hard to understand, or want to know how to calculate it from the above data, several references to this characteristic can be unearthed by searching on the term on the internet. High ABI or ABNY is not desirable, unless the biennial compensation in NY makes up for non-production in the off years. I am not ready to thin out 1-1-17 just yet.

In a future post I will discuss using the combination of these variables as a selection tool.

Line Index Variables

What is the Line Index? It is my quantitative description of the best nut producers (the ‘3’ trees, if you are familiar with the term from previous blogs), using the variables I currently think the most important. These are:

· Anthracnose Score (AS)

· Nut Yield (NY)

· Shell Index (SI)

· Kernel Percentage (K%)

· And, derived from NY, the Alternate Bearing Index (ABI or ABNY)

Below is an explanation of each variable, but not the reason why I consider them the most important. Just be content for the moment that a range of quantitative descriptors has been attached to each line (line = a single tree, which may or may not have an identifiable maternal parent on or off-farm). DBH (Diameter at Breast Height) is included for interpretation.

Anthracnose Score (1-5). The expressed incidence of leaf-spotting disease (which may have non-anthracnose components), which is commonly considered to depress a tree’s productive ability. 1=low, 5=high, thus a 1 indicates nill expression, which can be considered a strong tolerance (if not outright resistance) to leaf-spotting disease.

Nut Yield (no.nuts per cm² of trunk diameter at DBH). A measure of productivity based on nut count per tree, adjusted for the tree’s size. All trees in a plantation will vary in growth rate.

Shell Index (shell wt proportional to nut volume: g per cm³). A measure of the energy partition occurring at the individual nut level.

Kernel Percentage (kernel weight as a proportion of dry nut weight). A measure of the edible yield of the nut. Can be used in combination with NY to determine Kernel Yield (KY).

Alternate Bearing Index (0-1). A measure of the consistency in nut production. Black walnut shows variable biennial productivity. Here adjusted for DBH, thus accounting for tree size, and calculated from NY, thus more truly ABNY, not ABI which, used by others, does not account for change in potential productivity across time based on tree growth.

Diameter at Breast Height (cm). A standard, convenient measure used to determine annual change in tree size at 135cm from the ground. DBH, for all its convenience, is a moving target. While it remains constant in relation to the ground, it does not remain constant in relation to the top of the tree. Thus, successive annual measures of DBH are taken at different points within a tree’s geometry.

Core Business - Line Index

Things have been a little slow among the walnuts for the past six months, or rather I have been. Catching my breath, and trying to refocus on the core business. Not so much a reconfiguration, as a reconfirmation. The result is the development of the Line Index, which will tell you about the top trees here at the farm, and the order in which I rank them. Look for the Line Index section. Removed from the blog will be that cursed entry of Nov 2007, which attracts every human soul who wants to know what happens when we take a chainsaw to a standing tree. I can’t actually use the description of the process, otherwise every search engine from here to Australasia might pick out those few words, thus defeating my purpose. Sorry about this, but my core business has to do with black walnut, not educating every Tom, Jane or Harry about the carbon cycle. There, I can already hear the hits….

As I walk the walnuts - 7

As I walk the walnuts, !st January 2009, -18ºC, I think about the year to come and how much farther we will get. First, though, Happy New Year to all my collaborators, from the tree end to the machinery end. None of this would work without you. To warm you up on a cold winter’s day, I have chosen a summer photo.

Then a swing past the barn, where, a short six weeks ago, I was finishing up the wet processing of the 2008 harvest. My rapid departure to warmer climes for a couple of work weeks is evident: the final pile of hulls is still there, along with the mess made by three squirrels I have recently managed to move out. The final nuts are still on the dryer, though the remainder are bagged up and labeled ready for weighing.

In the fields, the range scoring tape is evident, splashes of colour on the naked trees. How much that system has helped me to understand what is going on at the tree end. The tape will come off at pruning time to avoid confusing next summer’s work, when the trees will be re-scored.

Still to do is the nut report, which entails cracking and measuring the kernel and shell fractions of the ‘3’ trees. That will happen sometime in February. Observation of the samples suggested some surprising things to come, but I will wait for the hard data before saying anything more.

So, 2009 will be the year of ‘nutmastery’ and a separate blog to deal solely with that end of things – machinery, markets, etc., while this one may slowly wind down. We’ll see.

Those good seed trees

Rod Croskery (he of the only site currently on my blogroll) wrote to me recently posing a question that I suspect many would like to ask:

[About the tree in Westport] planted in 1937 by Dr. Ford Goodfellow, the parent tree has very little trunk but an enormous canopy. [The owner] assures me that it has borne heavily every year for the last twenty. If the nuts are well-filled, the parent might meet your criteria for a good orchard tree.

This is a bit of a challenge, because it is growing in a site distinct from the farm. I responded to Rod that currently I was only interested in selecting from the population that I had on the farm. Many rural Ontario communities have populations of black walnut trees, many of which (I am separately informed) would be descendents of the original parent stock brought up by United Empire Loyalists a couple of hundred years ago. This ignores the other common knowledge that First Nations’ peoples also spread the black walnut eastwards from southern Ontario.

These populations I have observed to be regularly productive, so here is my suspicion: that the environment in many of these communities reduces the risk of early spring frost damage to the trees’ flowering, mainly, I believe, through low-level mixing of exhaust gases from heating systems. Most of these trees are within or just moderately above the mean roof line of the community, where such effects could be expected.

How could we test this? If you have a potential seed tree in such a community that you are interested in, I suggest you hang a max-min thermometer on the trunk at breast height (1.35m) on the north side, inside some sort of shield to protect it from the elements, and compare the readings with Environment Canada’s values at the nearest observation site on those nights when spring frosts occur. Do the readings match or not? Remember to reset the thermometer daily.

Because my fields are frost prone, I believe my good seed trees must be relatively later flowering than the rest of the on-farm population. Alternatively, my non-seed bearers are too early for my site, something I must quantify this coming spring. More on this later.

2008 harvest report

Well, over 2 tonnes of fruit were harvested over about five weeks from about 10th October. This includes on- (75%) and off-farm (25%) sources. On-farm, harvesting of ‘3’ trees was independent of ‘1’ and ‘2’ trees (see earlier post on range scores). All nuts from fruiting trees were counted, though 1 and 2 trees were counted at time of pick up (three different sweeps of the fields), and the fruit pooled by field during each sweep. Fruit from each 3 tree was kept separate in plastic lugs in the field, and totals counted when there were no further nuts to fall.

All pooled fruit was processed first – weighed, hulled, then washed and dried. Fruit from 3 trees was weighed, hulled, washed, then sampled and dried. Three-nut samples of 3 fruit were retained for drying, then subsequent cracking and separating. This analysis will be reported under the 2008 Nut Report.

Within the global number reported above, there was much hidden. The two main experimental populations (Fields 1 & 3) are reported below (you can click on the image to open it in a larger format).

Firstly, the nut range scoring system was successful in separating trees by eventual yield (at harvest). In each of the two fields, there are in excess of 500 trees. In each field, more than half of the population did not fruit. The number of trees fruiting (total n) was 187 (F1) and 254 (F3). The average number of nuts per tree was 20 (R1), 94 (R2) and 299 (R3). The biggest contrast between fields was for R3, where F1 gave 448 nuts per tree and F3 gave 151 nuts per tree. Correction of these totals by cross-sectional area (CSA) at DBH (diameter at breast height; multiplied by 100 in the above graph to be able to use the same vertical axis) almost completely reduced this variability to 5.09 nuts per sq cm of CSA (F1) compared to 5.53 (F3). I have termed this value Nut Yield (NY), which you can see was, on average, >1 for R1 and between 2-3 for R2 (remember the 100 factor in the graph above). Groups of bars for same range score number are from fields 1 and 3, reading from the left.

So what? (you might say). Well, it confirmed that it is not just tree size (measured here as DBH) which accounts for NY. There are other factors which make some trees more productive than others. It also suggests that you could forget about harvesting R1 trees and still collect just about the same total weight of fruit, or, put another way, R1 trees contribute very little, individually, to the total harvest, though they make some of this up by sheer numbers. As we are embarked on an inter-generational venture, as long as NY is the main contributor to total kernel yield (KY) per tree, it is only from R3 trees from which we should wish to select. We would want to analyze this characteristic only within the population of R3 trees. It also offers the means (i.e. a sufficient number of very uniform nuts) to set a cracking machine to crack optimally for a given set of nut characteristics, which is some of the rationale underlying US selection of black walnut ‘cultivars’ based on kernel percentage (K%; sometimes measured in efficiency terms as ‘crack out’), though high K% is the other aspect.

In my top-yielding F1 tree, nut number was >1700, with a NY of 7.88. However the top NY (16.15) was from the top F3 tree which gave only 343 nuts. Correction for size is thus immensely important to understanding productivity within a relatively uniform environment, and were both trees to show the same K%, the first would be of greater economic importance to me at this point in time. The former had a 2007 K% of 26% in a nut weight of 15g, which suggests a total KY of 6.4kg from this tree this year. Not insignificant.

Why do I think so many trees are not producing? Probably because they are too early for my site. I shall test this next spring, comparing a random sample with the ‘3’ trees.

Finally, you probably think I’m crazy to do so much counting. Learn to do it, for it will tell you a lot. Use range scoring first, though, so you only count nuts from the ‘3’ trees.