Procedures for assessment of risk of Phytophthora rot pre-harvest

Orchard factor Assessment procedure Risk criteria
1. Bare ground

Inspect orchard in July

Estimate bare ground under trees, taking into account mulch and weed cover

100% bareground
= overall herbicide

= high risk

overall grass or mulch

= 0% bareground

= no risk

20% or more bare ground in

herbicide strip

= moderate/high risk

2. % crop <½ metre (knee height) from soil splash

Select 20 trees at random and assess % crop <½ metre from soil

Make assessment in July to identify at-risk orchards.

Reassess near harvest

15% or >= risk
3. Rainfall Monitor rainfall in 15 days up to harvest 20 mm or > = risk