Flowering and pollination

By Murray Redpath

HGA newsletter September 2011

The warm autumn experienced this year has highlighted the importance of current research into flowering and pollination behaviour of different cultivars at different locations around the country.

  • In South Canterbury (Geraldine), Lansing was in flower in mid-July but of the others only Butler had any flowers. Merveille, Alex and Whiteheart were shedding pollen from early July at least. By late August, there was still some flower on Butler, Ennis and MT18/114 but Lansing flowering was over. Merveille pollen was finished but Alexandra and Butler were still shedding.
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The NZ hazelnut industry. Where to from here?

By Murray Redpath

HGA newsletter October 2010.
Originally presented at HGANZ AGM, 2010

NZ hazel industry 2010:

NZ has over 430 hectares planted, most since 2000. Almost 100% of this area is planted in Whiteheart plus pollinisers so we have an industry dependent on successfully growing and marketing Whiteheart.

There has been a change in the orchard size since 2000 – from mainly orchards of 200-1000 trees to mainly orchards of over 1000 trees (see graphs below).
Fig. 1: Number of hazel trees per grower, SNGA hazelnut seminar 1996 (McNeil, 1996)
Percentage of attendees
60 50 40 30 20 10 0

<200 200-399 400-999 1000->2000 1999
Orchard tree number

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International hazelnut quality characteristics

Niels Maness – Department of Horticulture, Oklahoma State University

HGA newsletter, June 2006

Quality Characteristics and Criteria

In-shell hazelnuts should be properly sized to meet the stated market type and should be properly filled with at least 50% of the shell cavity occupied by nutmeat. Shells should be free of cracks and noticeable mechanical injury, clean, brightly colored and coloring patterns should be characteristic of the stated variety. The pellicle should be smooth and devoid of husk attachments. Kernels should meet the stated market type, be free of any misshapen or underdeveloped kernels and be free of any shell or foreign material and off-odor, off-flavor or mold. Water content of kernels should not exceed 6% if shelled or 7% if in-shell, and the total water content of unshelled nuts should not exceed 10 to 12%. Size is specified with grade as a determinant of quality, and minimum sizes are used for specification of classes “Extra” and “Class I” in international trade. For in-shell markets, larger and particularly rounded types are preferred. Shelled markets accommodate both rounded and oblong types, and size preference is dependent on the intended end use. 

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The mechanics of pollination

HGA newsletter, June 2004

Bryan Thomas recently attended two lectures given by Professor Karl Niklas who is a visiting Erskine fellow at the University of Canterbury. He is the Liberty Hyde Bailey Professor of Plant Biology at Cornell University. The subjects of his lectures were “Allometry of plant growth” and “The Biomechanics of Wind Pollination”.

The Biometrics of Wind Pollination

In this lecture Professor Niklas demonstrated his work on airflow around female wind pollinated flower structures and how the shape influences the airflow, and the consequences for successful pollination. Using pine trees as the prime example he carried out wind tunnel tests on receptive pinecones and plotted the course of both neutrally buoyant bubbles and actual pollen grains around the cone. The cones were surprisingly efficient at trapping pollen grains in eddies circulating around and through the cones and that, by placing the actual flower deep within the cone in an apparently inaccessible position, the chance of a pollen grain landing in the right place was enhanced.

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Murray Redpath

HGA newsletter, January 2004

In this issue Murray Redpath of “Wairata Hazels”, near Opotiki, is sharing some of his vast experience of Hazelnut growing with us.

Wairata Hazels is part of Wairata Forest Farm, a 575 hectare property in the hills of the Eastern Bay of Plenty.  

Historically the property has been run as a sheep and cattle farm with occasional income from wild animals (deer, opossums), tourism, and forest products (primarily native timber).

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One in 8000!

From ‘Sun-Diamond Grower’, written by Jamie K. Hartshorn

HGA newsletter, January 2004

That’s about how many hazelnut seedlings Oregon plant breeders must go through before one is worthy of release.

It pays to be patient if you’re a plant breeder. Take scientists at Oregon State University’s Agricultural Experiment Station for instance. Their quest for a new hazelnut variety for the kernel market took some 17 years from initial trials to final release. Many thousands of seedlings later, along came ‘Willamette’, introduced in 1990. “The new variety has shown both positive and negative points,” says Dr. Shawn Mehlenbacher, associate professor and plant breeder with OSU’s Hazelnut Breeding Program. The largest planting to date is a 40 acre block that went in last Spring, “but most growers are taking a wait and see attitude,” he says.

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