harvesting – Hazelnut Growers' Association of New Zealand

Simple moisture content calculation

This simple way of determining the moisture content of your nuts using a microwave is adapted from Hazelnut Growers Handbook 1998 (Hazelnut Growers of Australia Ltd).

You will need:

Accurate scales
A sample of nuts (the exact number is not important, 40-50 is fine)
A microwave
A microwave-proof plate or container

Method:

Weigh the plate/container.
Crack the nut sample, keeping the shell and kernel together. Include all nut material including blanks and mouldy kernels.
Place the nut material on the plate, and weigh the plate plus the nuts to find the weight of the nuts. This is your wet weight.
Place in the microwave and heat for 1 minute on high power. Longer than 1 minute usually results in the nuts being burned. Re-weigh the nuts and record the results.
Repeat the process, weighing and recording the result, until the weight of the sample does not change with further heating. This may take 5 to ten bursts of heat. This final weight is the dry weight.
The difference in weight between the wet weight and the dry weight is the total weight of moisture removed.

% moisture =	(wet weight – dry weight)	x 100
	dry weight

Using a lawn sweeper for pre-harvest cleaning

Written by Mike Davenport. Originally published in the HGA newsletter November 2020.

Last season, Mike and Kathy Davenport purchased a John Deere tow-behind lawn sweeper, to conquer the mountain of clippings that spring and autumn grass growth causes. Mike realised that the basic principle lends itself to a wider range of orchard management, particularly pre-harvest preparation and perhaps even harvest itself. Mike has kindly agreed to share his experiences.

Basic moisture monitoring after harvest

You can determine how much moisture your hazelnuts have lost by regularly measuring their weight. You need accurate digital scales. This method won’t tell you the absolute moisture level, just whether they are stabilised.

This is essentially the same process as described in Simple Moisture Content Calculation, but this method happens naturally over a longer time.

Weigh the sample when nuts are first harvested. Re-weigh regularly until the weight is the same for 3 measurements.

% moisture =	(wet weight – dry weight)	x 100
	dry weight

Low cost harvester

Bey Allison

HGA newsletter – August 2011

Anyone who has used one of the popular blow/vac machines will appreciate that they blow far better than they suck.

With this in mind perhaps it would be worth trying to blow our nuts onto a tray rather than try to suck them up through a tube.

The Stihl 600 is a backpack blower. It has a four-stroke motor and produces a tremendous controllable blast which is ideal for shifting nuts on rough ground or in long grass, and it has no problem working nuts in damp conditions. This seems the ideal basis for a low-cost harvester.

Harvest musings

HGA newsletter 2005

A year’s worth of effort comes to an exciting but busy end as harvest is upon us. Like most things good, preparation is the key, as you never really know how it’s going to turn out until the very end.

Hazelnuts may start to fall in late February – early March with the majority fallen by the end of March. The colder nights, shorter days and warm midday temperatures in late summer cause the outer husks to swell (hot days) and then contract (cool nights) which eventually cause the nuts to drop. The leaves will also start to turn but should fall after the nuts. A bit of planning is often needed in order to get the nuts up off the ground before the leaves drop. Should the leaves begin dropping during the harvest, a leaf blower is a very useful tool.