Stone fruit pest research

There has been a long history of research on horticultural pests based around research centres at Blackwood, Lenswood, Berri and Loxton. Some of the most significant developments are discussed below.

Post WW2, there was a major expansion of the range of chemicals for control of various pests and diseases, and these were rapidly adopted by industry. Efficient application of these chemicals in a cost effective manner was a major challenge.

In the late 1940s, a major program to adapt Canadian designed air blast sprayers to Australian conditions commenced. Most of this development work was done at Blackwood Experimental Orchard, with significant proving work for citrus and stone fruit crops being conducted at Berri Experimental Orchard. Further information on the introduction of air blast sprayers to Australia, see the special sub article on the Blackwood Experimental Orchard.

Since the late 1970s, there has been a further program to develop air assisted spray technology for a wide range of horticultural and agricultural crops conducted by Geoff Furness at Loxton Research Centre.

Wide spread use of chemicals in the 1940s and 1950s created a series of pest resistance problems. Many natural predators were killed by chemical applications, resulting in a series of previously unimportant pests becoming significant. The need for a more holistic integrated pest management system was recognised in the mid 1950s. Subsequently a major body of work into many horticultural pests, and pest ecology systems within orchards was commenced.

An insectary was established at Loxton Research Centre by Horticultural Research Officer, Noel Richardson in the mid 1960s. This program ultimately led to the commercial production and supply of range of predatory insects to orchardists. The use of these predatory insects in conjunction with new biological insecticides like Bacillus thuringiensis, and pheromones to disrupt insect mating and egg laying, provided industry with the tools for widespread adoption of Integrated Pest Management systems in orchards across South Australia during the 1970s and 1980s.

San jose scale and green peach aphid

San Jose Scale became a significant pest problem, particularly in peaches, through the 1960s with widespread use of broad spectrum insecticides.

Detailed studies of Green Peach Aphid by Noel Richardson and Ross Wishart in 1966 identified that it was resistant to Metasystox®, one of the popular systemic insecticides in use at the time.

Further research in the late 1960s identified that the reduced use of broad spectrum insecticides along with introduction of dormant and semi dormant oil sprays was effective in controlling San Jose Scale and Green Peach Aphid.

Oriental fruit moth

Oriental Fruit Moth (OFM) was discovered in the Renmark district in August 1959. A major pest of peaches, larvae attack growing tips of trees and tunnel into fruits causing up to 80% losses.

The OFM research program conducted through the mid to late 1960s comprised numerous projects including:

• Timing of spray applications for control across major irrigation districts.
• Aerial application techniques for control of OFM.
• Flight patterns for OFM in Riverland irrigation areas.
• Peach variety preferences of OFM.
• Assessment of lure materials OFM traps.
• Migration of adult OFM and defining of buffer zones to prevent movement.
• Assessment of OFM populations by counting infested peach tree shoot tips.
• Biological studies of OFM.
• Insect fauna in peach orchards.

In 1967, a major program was commenced to introduce OFM biological control techniques using lures and parasites. This utilised information from the Goulbourn Valley where 5 OFM parasites were introduced between 1935 and 1938. During the 1980s, pheromone products to interrupt mating and reduce egg laying became commercially available.

Cherry virus iIndexing program

A major virus testing program for cherry rootstocks was commenced in 1967. Initially this used seed imported from virus tested sources in California, with variable performance of the seed. In 1968, virus tested seed trees for the rootstocks Mazzard and Mahaleb were established at Lenswood and Northfield under the leadership of Dr Rip van Velsen. Between 1975 and 1981, almost 21,000 rootstocks were supplied to the cherry industry (via the SA Cherry Improvement Committee, a sub-committee of the Cherry Section, SA Fruitgrowers and Market Gardeners Association).

Between 1980 and 1982, procedures for propagating cherry rootstocks using summer cuttings were developed. These techniques were then provided to commercial nurserymen so the SA Department of Agriculture did not have to propagate rootstocks for industry.

A program to virus index cherry scion wood for prune dwarf and prunus necrotic ringspot viruses was also commenced in 1980–81.