Integrated Fruit Production (IFP) practices for pipfruit are being adopted by New Zealand growers initially to maintain access to key supermarkets in the UK for about 25% of our total pipfruit exports. Subsequent advantages of the programme include implementation of more environmentally sustainable pest and disease control practices, reduced pesticide loading in the environment, and compliance with local and international regulatory requirements. The programme was largely successful in the first year of implementation. The methodologies for programme development and technology transfer are described, together with the constraints and opportunities that affect further adoption of the programme.

In seven field trials conducted over four seasons, black spot incidence was consistently greater in treatments where fungicide use was reduced by timing sprays with weather information compared to standard calendar-based treatments. Fungicide use was measured as the total number of label-rate applications of fungicides with activity against black spot and the individual components of mixed applications of fungicides were counted separately. Over all trials, the mean disease incidence at harvest increased logarithmically as the number of fungicide applications decreased. A regression equation describing disease increase in terms of number of fungicides and number of infection periods was used in an economic analysis of apple production. When the savings from reduced fungicide use were weighed against the increased harvesting and grading costs and revenue losses from increased disease, there appeared to be scope to reduce fungicide use by up to 25 % before increased disease adversely affected profitability. Where disease risk was lower because of fewer infection periods, savings of up to 56% appeared to be feasible. It was concluded, however, that because fruit harvesting and grading costs are a high proportion H93069 Received 12 October 1993; accepted 11 March 1994 of total costs, because they increase with increasing disease incidence and because cost savings from reducing fungicide use are a relatively small proportion of total costs, there is at present little economic incentive for apple growers to reduce fungicide use.

This study demonstrated that natural foliage and artificial collectors range in surface wettability affecting spray adhesion retention spreading and coverage Therefore the choice of artificial collector or natural foliage depends on the scientific question If the volume of spray available to the canopy or spray accountancy is to be determined then an artificial collector that will intercept and retain all of the spray is required Careful consideration of collector is required to meet stated objectives For example water sensitive paper is an excellent aid to sprayer setup but does not distinguish differences between formulations It also provides no indication of retention or coverage on the crop surface All artificial collectors tested were poor indicators of adhesion and retention by and spreading and coverage on natural plant surfaces and should not be substituted for natural plant surfaces in field trials attempting to quantify spray retention and coverage on the crop surfaces

Tree canopy sizes and training systems can vary widely on modern apple orchards, but most growers do not have the information required to determine appropriate spray volumes and chemical rates for different canopies. Chemical rates and volumes currently used in the majority of New Zealand apple orchards are derived from an arbitrary standard application rate of 2,000 litres/ha. The Tree-Row-Volume (TRV) system for describing spray volume requirements on different canopies has been tested and widely adopted in America, but the American system appears not to work with New Zealand canopies and has not been adopted here. Development and validation of a modified TRV estimation system for use on New Zealand apples are described in this paper and potential benefits of TRV spraying are discussed.

Spray drift continues to be an important issue for commercial pipfruit growers Offtarget agrichemical movement was determined from the Hawkes Bay Focus Orchard on two occasions Canopy development had a major influence on spray drift with 25 times less drift from a fully foliated canopy compared with a dormant canopy The proximity of the sprayer relative to the edge of the sprayed block was an additional major factor influencing spray drift Results are compared with those found in previous New Zealand and overseas studies and management strategies for spray drift minimisation are discussed