Author: Julyan Rawlings

The Clean Plant Center Northwest (CPCNW in Prosser, Washington State, is using the Air-Pot system to grow plants with healthier roots and greater resistance to disease. 

CPCNW are part of the National Clean Plant Network funded by the USDA (U.S. Dept of Agriculture) and commodity groups to ensure a supply of virus tested plant material.

The centre has a philosophy of “start clean, stay clean” emphasising the importance of planting with clean materials, to ensure high quality production from orchards, vineyards, and hop yards. The clean plant material is provided to nurseries, growers, and research agencies. The clean ‘mother’ plants at the centre are a cornerstone of state certification programs for the U.S. pome and stone fruit, grapevine, and hop industries.

Pictured here are Hops and grape vines thriving in Air-Pot containers. Vital resources for breweries and wineries seeking the highest quality ingredients, to make the fine brews we all seek on a hot summer days.

Find out more at the CPCNW website https://www.cpcnorthwest.com/s/

The Brooklyn waterfront in New York has been recently transformed by a new development and five acre park.The facade of the old sugar refinery has been preserved as the front of a new building and incorporates trees grown with the Air-Pot system.

This picture shows a Liquidambar “slender silhouette” squeezed between the old and the new. The healthy root system developed in an Air-Pot container has allowed the tree to flourish in it’s new home.

In the park a nursery has been established using Air-Pot containers to bring on more trees and also to grow vegetables.

In August 2023 Nelmac seedlings were transplanted from JIFFY 7C pellets to Air-Pot® containers and standard 5-litre Letaba bags using a mixed pine bark substrate. Within 4 months a clear difference between the Air-Pot® and bagged trees could already be seen. The Air-Pot grown trees were on average 10cm taller and the leaf span was double the length of the bagged trees. The Air-Pot grown trees also had greater girth.

Macadamia rootstocks are generally suitable for grafting when they are 15-18 months old and at least 10mm thick. By April of 2024, 90% of the Air-Pot grown trees had been grafted, 6 months ahead of the expected grafting time. By this time only 10% of the trees in bags were big enough to be grafted.

Mpumalanga Agri-forest Project
Marula – Sclerocarya Birrea, is a medium-sized dioecious tree indigenous to the Miombo woodlands of Southern Africa. The fruit is traditionally used for food and can be fermented to make Marula beer. Marula oil is also used in the cosmetic industry.

The fruits fall to the ground between December and March and are collected from the wild by members of rural communities for whom it  can be a vital source of income.

The Mpumalanga agri-forest project will plant 8000 trees in Air-Pot containers on 10 hectares of land, providing a livelihood for rural women who will benefit by becoming shareholders in the complete value chain.

In a trial in South Africa Hass variety avocado seedlings were grafted onto Bounty rootstock and transplanted into 5-litre Air-Pot containers. 18 months later a healthy and fibrous root system had developed, and the young trees were ready to be transplanted into 12-litre Air-Pot containers. The trees then put on much faster growth than those grown in bags and started producing flowers.

Avocado trees that are grown in bags have a limited nursery period of 12-18 months before they need to be transplanted. If the trees remain in the bags beyond this period, their roots become deformed, which can seriously affect their lifespan in the orchard. In the event of a client cancelling an order, the trees become worthless. The healthy roots on Air-Pot grown avocado trees allow them to remain in the nursery longer. In case of a cancelled order, the trees need not be discarded. Instead, they can be grown up to the production phase, resulting in an increase in their value.

The trial is ongoing and we will be able to post more information in due course.

Wollemi pines have been dubbed the ‘dinosaur tree’ because fossil records show they were living 200 million years ago alongside the dinosaurs. It was thought they had become extinct between 70 and 90 million years ago until a chance discovery in 1994, when a small group of living trees was found by an Australian explorer and botanist, David Noble, growing in a remote gorge in the Wollemi National Park in New South Wales.

The tree species is now classified as critically endangered and is on the IUCN’s red list. Since its discovery, there has been a concerted effort to insure the species against the loss of the remaining 100 wild trees, which are increasingly vulnerable to threats from diseases and wildfires.

As part of this project Forestry England Bedgebury National Pinetum and Forest has used Air-Pot containers to grow over 170 Wollemi pines for planting at 28 botanic gardens in the UK and Europe; with 6 being planted at Bedgebury.

It’s always hard to guarantee success growing a living thing, and all the more important when it’s a critically endangered plant. We therefore use the Air-Pot system – the best way we know to ensure successful establishment.
Dan Luscombe – Forestry England Bedgebury National Pinetum

You can find out more about the project at https://www.forestryengland.uk/bedgebury-national-pinetum-and-forest/wollemi-pines

A new block of flats at Eindhoven in Holland has trees grown in Air-Pot containers incorporated into the fabric of the building, bringing the forest to the city; reducing pollution and helping to keep the building cool in Summer.

The trees were grown by Van den Berk nurseries.

For the last three years a trial has been running in Holland to determine the increase in blueberry yield made possible by growing in Air-Pot containers compared to standard pots.

The trial is growing Duke and Liberty varieties and the pictures above demonstrate the huge difference in plant vitality and yield. By the third picking year there was a massive difference in weight of fruit produced in the two container types, with the Air-Pot grown plants producing a hugely increased yield.

The trial is ongoing and from March 2024 has been taken on by Delphy B.V. experts in agricultural research and data driven crop management.