Fresh market tomato growers in northern Victoria have new tools to reduce insect damage in their crops and improve the nutrition on their crops, as a result of a project recently completed by scientists at DPI Tatura. The project, funded by Horticulture Australia Limited, DPI Victoria and the Northern Victorian Fresh Tomato Industry Development Committee, identified that the current calendar spray based programs missed peak egg lays for the major insect pest, Helicoverpa moths.

The project team developed a sampling protocol to allow growers to accurately and quickly monitor moth egg populations. They also monitored pesticide resistance levels and determined the source of moths. Up to 30% of the moths had migrated from NSW or QLD.

A resistance management strategy was developed, taking consideration of the need to control other pests in the crop, insecticide use by other crops in the Goulburn Valley region and the likely use of pesticides in alternate crops in NSW or Qld.

In recent years, the fresh tomato industry in northern Victoria has moved to a new production system using indeterminate varieties. These varieties require trellising and more intensive management, and are sensitive to nutrient application. The lack of local information on agronomic practices such as crop nutrition has led to variation in approaches to maximise crop yield and fruit quality. The result has been some inefficient practices that may impact on crop performance and potentially also on the environment.

Sap nutrient levels were monitored in a number of trellis and ground tomato crops in the Goulburn Valley Region over the last three seasons, and were related to measures of crop productivity. Analysis of the fertiliser program used by growers indicated that improvements could be made in both the timing and quantity of applications to better meet plant requirements. Results of the study have been used to develop benchmarks for efficient fertiliser application to fresh tomatoes, as well as introducing local growers to the benefits of nutrient monitoring by sap analysis. Developed under local conditions and management practices, these benchmarks will allow Victorian growers to maximise their productivity by matching their fertiliser applications with crop requirements, as well as to minimise leakage of nutrients to the surrounding environment.

The improved fertiliser program, the egg-monitoring program, and the resistance strategy have been distributed to growers in time for the 2005/2006 season.