NEOBIOME

OT_211: NZHGA Bulletin 2, Hazelnut Varieties. Percent kernel (crack-out) 39-50%; NZ yields are in-shell

Properties5
typesource
source_typeot
authorRedpath, Murray
year2016
topicsfood_systems_agriculture, nz_specific

8 min read

OT_211: NZHGA Bulletin 2, Hazelnut Varieties. Percent kernel (crack-out) 39-50%; NZ yields are in-shell

Source

https://hazelnut-growers.org.nz/wp-content/uploads/2019/08/bulletin_2_hazelnut_varieties.pdf — original source (opens in a new tab; the file is not redistributed)

NZHGA — Guidelines for Growing Hazelnuts in NZ, Bulletin 2: Hazelnut Varieties

The crack-out fraction that unblocks the hazelnut oil pathway

NZ Hazelnut Growers’ Association grower guidance (Murray Redpath, May 2016; hosted 2019). Verbatim: “Commercial varieties should have a high ratio of kernel weight to nut weight (percent kernel), to maximise the yield of saleable kernel per tonne of nuts harvested.” So percent kernel = kernel weight / whole-nut (in-shell) weight = the crack-out fraction. Per-variety NZ values: Whiteheart (the main NZ commercial variety) 47-50%, Butler 47-49%, Tonda Romana 44-48%, Lansing 44-50%, Tonda di Giffoni 44-47%, Ennis 43-46%, Barcelona 39-43%; poor crackers e.g. Keen’s Late 26-30%. Commercial band ~44-50%, central default ~0.46. 🔴 This settles the unit blocker. A “tonne of nuts harvested” is whole in-shell nuts, so OT_182’s per-ha yields (1 t/ha yr6, 2.5 t/ha yr10) are in-shell and must be multiplied by crack-out (~0.46) before applying LIT_096’s kernel-basis oil content (54.6-63.2%). Skipping crack-out overstates the oil estimate ~2×. ⚠ Attribution note: the raw assigns “26-30%” to Keen’s Late, not to Alexandra. Alexandra carries no numeric percent kernel here (qualitatively a poor cracker).

Summary

Bulletin 2 of the NZ Hazelnut Growers’ Association grower guidance series (companion to Bulletin 1, OT_182), authored by Murray Redpath (May 2016). It is a variety-selection guide: it describes the kernel and in-shell markets, the factors that determine variety choice, and per-variety characteristics for the main commercial and polliniser varieties grown in New Zealand.

Its decisive contribution to the model is a single definition and its per-variety values. The bulletin defines “percent kernel” as the ratio of kernel weight to whole-nut weight, i.e. the crack-out fraction that converts an in-shell (whole-nut) yield into a kernel yield. That is exactly the unit blocker at OT_182: OT_182 gives per-hectare yields but never declares their basis, and the only NZ hazelnut oil content in corpus (LIT_096, 54.6-63.2%) is explicitly kernel-basis. By framing yield as “kernel per tonne of nuts harvested” and naming in-shell and kernel as two distinct markets, this bulletin establishes that the harvested-nut yield is on a whole-nut (in-shell) basis, and supplies the crack-out fraction (per variety, ~0.39-0.50 commercial; Whiteheart, the dominant NZ variety, 0.47-0.50) needed to bridge it to the kernel-basis oil figure. This turns the previously ”⚠ blocked” hazelnut oil-per-hectare pathway into a computable one.

Key claims

- claim: "DEFINITION OF PERCENT KERNEL (= the crack-out fraction). Verbatim: 'Commercial varieties should have a high ratio of kernel weight to nut weight (percent kernel), to maximise the yield of saleable kernel per tonne of nuts harvested. This ratio is influenced by the thickness of the shell and the amount of kernel shrinkage during drying.' So percent kernel = kernel weight divided by whole-nut (in-shell) weight = the in-shell-to-kernel crack-out fraction. [verified verbatim against the raw PDF]"
  source_location: "NZHGA, Guidelines for Growing Hazelnuts in NZ, Bulletin 2: Hazelnut Varieties (Redpath, May 2016), 'Other factors' section, percent-kernel paragraph — p2 of 9."
- claim: "HARVEST YIELD IS ON A WHOLE-NUT (IN-SHELL) BASIS (this is what resolves RT_393). The percent-kernel sentence frames the crack-out as 'the yield of saleable kernel per tonne of nuts harvested', and the bulletin opens 'Hazelnuts are sold into two main markets: kernel and in-shell.' A 'tonne of nuts harvested' is therefore whole in-shell nuts, and kernel is obtained by multiplying by percent kernel. This establishes the basis missing at OT_182: its 1 t/ha (yr6) and 2.5 t/ha (yr10) are in-shell weights, to be multiplied by crack-out (~0.46) before the kernel-basis oil content of LIT_096. [verbatim phrases 'per tonne of nuts harvested' (p2) and 'two main markets: kernel and in-shell' (p1); the in-shell reading is the direct entailment of those two phrases]"
  source_location: "Bulletin 2 (Redpath, May 2016) — opening markets paragraph p1 ('two main markets: kernel and in-shell') and 'Other factors' percent-kernel paragraph p2 ('yield of saleable kernel per tonne of nuts harvested')."
- claim: "PER-VARIETY PERCENT KERNEL, kernel-market / commercial varieties, verbatim: Barcelona 39-43% ('yielding 39-43% kernel by weight'); Ennis 43-46% ('yielding 43 – 46% kernel'); Tonda di Giffoni 44-47% ('yielding 44 - 47% kernel'); Tonda Romana 44-48% ('yielding 44-48% kernel'); Whiteheart 47-50% ('yielding 47 to 50% kernel'). All five are confirmed identically in the summary table 'PRODUCTION CHARACTERISTICS OF FIVE HAZELNUT VARIETIES WITH POTENTIAL FOR COMMERCIAL PRODUCTION IN NEW ZEALAND' (Barcelona 39-43%, Ennis 43-46%, Tonda di Giffoni 44-47%, Tonda Romana 44-48%, Whiteheart 47-50%). Whiteheart is 'the main variety grown commercially in New Zealand.' [verified verbatim against the raw PDF — body descriptions and summary table]"
  source_location: "Bulletin 2 (Redpath, May 2016) — variety descriptions pp3-5 (Barcelona, Ennis, Tonda di Giffoni, Tonda Romana, Whiteheart) and 'PRODUCTION CHARACTERISTICS OF FIVE...' summary table p9."
- claim: "PER-VARIETY PERCENT KERNEL, pollinisers / other varieties, verbatim: Butler 'high percent kernel (47 – 49%)'; Lansing 'yielding 44 – 50% kernel'; Kentish Cob 'The shell is thin (48% kernel)'; Merveille de Bollwiller 'yielding 36 – 41% kernel'; Keen's Late 'yielding elongated nuts with 26 – 30% kernel'. Poor-cracker pollinisers 'are cracked and used to produce hazelnut oil or hazelnut paste.' [verified verbatim against the raw PDF]"
  source_location: "Bulletin 2 (Redpath, May 2016) — Butler p6, Keen's Late p6, Kentish Cob p7, Lansing p7, Merveille de Bollwiller p8; oil/paste use note p2."
- claim: "⚠ ATTRIBUTION CORRECTION. The raw assigns 26-30% to KEEN'S LATE, not Alexandra. Alexandra's own description carries NO numeric percent kernel — it is qualitatively a poor cracker only: 'nuts that are difficult to crack and yield poor quality kernels', with 'very thick shells' and 'small elongated kernels'. Both Alexandra and Keen's Late are late-flowering pollinisers (hence the conflation), but the 26-30% number is Keen's Late's. [verified against the raw: Alexandra description searched, no percent figure present; Keen's Late = '26 – 30% kernel']"
  source_location: "Bulletin 2 (Redpath, May 2016) — Alexandra description p5 (no %); the 'difficult to crack' note p2; Keen's Late description p6 (26-30%)."

Neobiome Intelligence relevance

Feeds d02_smart_food_systems. It supplies the crack-out fraction that was the sole unit blocking the NZ hazelnut kg-oil-per-hectare cell.

The hazelnut oil pathway had all its legs except one. This bulletin provides that leg and the basis statement that lets the legs combine:

TermValueSource
Yield, mature (in-shell)2.5 t/ha by yr10 (1 t/ha by yr6)[[ot_182_hazelnut-growers-bulletin1
Crack-out (percent kernel)~0.46 default (band 0.44-0.50); Whiteheart 0.47-0.50this source
Oil content (kernel basis)54.6-63.2%[[lit_096_savage-1998-nz-hazelnut

The corrected calculation (three steps, no longer blocked):

  1. kernel_yield = in-shell_yield × crack-out → 2.5 t/ha × 0.46 ≈ 1.15 t kernel/ha.
  2. oil_yield = kernel_yield × oil_content → 1.15 t/ha × ~0.59 (mid of 54.6-63.2%) ≈ ~0.68 t oil/ha (band ~0.63-0.73).
  3. If the dominant NZ variety Whiteheart is modelled specifically (crack-out ~0.485): 2.5 × 0.485 × 0.59 ≈ ~0.71 t oil/ha.

🔴 The crack-out step is not optional. Multiplying the in-shell yield straight into the kernel-basis oil content (2.5 × 0.59 ≈ 1.47 t/ha) overstates output by roughly 2.2×. Recommended engine input: crack-out = 0.46 as a conservative central default across the commercial band, or 0.47-0.50 if the model assumes Whiteheart (the main NZ commercial variety). Poor-cracker polliniser varieties (Keen’s Late 0.26-0.30, and Alexandra qualitatively) are the ones “cracked and used to produce hazelnut oil or hazelnut paste”, so a low-crack-out oil-orientated variety mix would sit nearer the bottom of the band.

No engine cell is changed by this page. Wiring the crack-out step into the d02 food oil pathway is a separate modelling step.

Notes

  • Capture format. The raw is a directly-downloaded first-party PDF of the NZHGA bulletin (9 pages), not an AI-synthesised document. sha256 (71da424a…) is of the single PDF at source_path.
  • data_quality: high. A named-author (Murray Redpath), dated (May 2016) NZ industry primary; every figure extracted verbatim from the PDF (pdftotext -layout) and cross-checked against the summary table. Higher than sibling OT_182 (medium, which was undated in its draft record) because this document is dated, attributed, and internally corroborated (body values match the summary table exactly).
  • Authored May 2016, hosted 2019. Dated by the document byline (“Murray Redpath. May 2016”); the 2019 hosting date is the web-availability date only. Variety crack-out ratios are a stable cultivar property, so vintage is a weak objection (same reasoning as LIT_096’s 1995 composition data).

Research targets

Documents to retrieve

  • (none new)

Research gaps

  • Resolved by this source. The crack-out fraction (percent kernel) is now sourced NZ-specifically, and OT_182’s per-ha yields are established as in-shell. The hazelnut kg-oil/ha figure is now computable (see NI relevance).
  • Lower-value refinements, recorded but not pursued:
    • A processor crack-out specification / measured NZ dressing figure. The bulletin’s percent-kernel ranges are grower-guidance cultivar properties; a processor’s realised crack-out (after drying loss and defects) could refine the 0.46 default. Low value: the cultivar band is adequate for a model coefficient.
    • An oil-orientated variety mix. If a community planted poor crackers specifically for oil/paste, the crack-out would sit at the low end (0.26-0.30). Only relevant if the model ever distinguishes oil-variety from kernel-variety orchards; not needed for the default pathway.

Connections

Links to

Sources (2): LIT_096 · OT_182

Referenced by

EDT domains (1): D02: Smart Food Systems & Agriculture

Graph View

Backlinks