The Horticultural Development Company (HDC)-funded work, conducted by EMR entomologist Dr Michelle Fountain, should result in more effective spray timing in two cases and encouragement of greater predator numbers in the third.
Fountain described the three projects concerned at BIFGA's Technical Day. The pests involved were mussel scale on apples, codling moth - which continues to cause significant economic damage in many orchards - and pear sucker, which has an increasingly effective resistance to insecticides.
"The mussel scale problem has been increasing since the demise of winter wash (tar oil)," said Fountain. "Heavy infestations can debilitate trees and consignments can be rejected due to scale in the fruit."
By monitoring the emergence of crawlers (larvae) from beneath the scales using sticky tape around the tree trunks, she found that they migrated over a period of six weeks or so - much longer than previously thought. She also discovered that two sprays of Calypso or Gazelle two weeks after the start of crawler migration and at the end gave very good control of the pest.
"Year on year we've not been getting any better control of codling moth," she explained. "We found that catches of male moths in traps preceded laying of the first eggs by four to five weeks in 2009 and by two weeks in 2010, so traps are not giving a good indication of the (best) spray timings."
The pest's smaller second generation does significant fruit damage, probably because the fruit is softer and more easily penetrated by the larvae. Fountain added: "Therefore, it's essential to maintain good control in August and September." She advised that to determine the optimum spray timings "growers should go into their orchards to find the eggs".
The pear sucker study was aimed at boosting the numbers of its predators, notably anthocorid bugs, particularly early in the season.