One of the biggest miss-conceptions that I have found in my years in the Hunter olive industry is the belief that olives are a low maintenance crop
It is probably true that olives require less maintenance than some other crops, and being the Hunter Valley, wine grapes are an obvious example. Whereas wine grapes are prone to 3 or 4 major fungal diseases (downy mildew, powdery mildew, botrytis, ripe-rot to name 4 that come to mind) olives are a lot less prone to this sort of attack and require less fungicide spraying.
However, olives are prone to attack from 2 insects, Olive Lace Bug & Black Scale, neither of which attack grapes to any large degree. We do get ripe-rot (known in the olive world as anthracnose) and Peacock Spot as our two main fungal diseases, but generally speaking the attacks of fungal diseases on olives are not as severe as the attacks of fungal diseases on wine grapes, and over 12 months there is less chemical spraying usually required for an olive grove.
What are the secrets?
1. Monitoring. Take the time to walk through the grove at least every two weeks. Look at the foliage and trunk of every tree. If there are suckers popping out where you don't want them, cut them off before they start to take over. If there are signs of Olive Lace Bug or Black Scale, do something about it before it becomes a major problem.
2. Early Intervention. Do something right away, before it gets to be a major problem. There are recommended and approved chemicals to kill the various insects, and fungicides for the fungi. A knapsack spray, set of overalls, chemical face mask, protective glasses and pair of gloves should cost you about $200. One mature tree standing 4m high is probably worth $200. Olive Lace bug could kill a tree in a couple of months if left unchecked.
3. Monitor the soil moisture and irrigate according to your soil type. Setting the irrigation to come on for 2 hours twice a week might work fine for the lawn, but is probably wrong for olives, certainly on a heavy clay soil this sort of automatic watering will do more harm than good. The NSW Department of Agriculture run water and soil courses.
4. Soil & leaf tests. Most of the agricultural supply companies and many others can offer a soil testing and leaf testing service. This should cost about $300 or so a year for both tests, and is usually the best way of telling what is going on under the ground. In my opinion, the top of the line service is offered by Sydney Environmental & Soil Laboratories in Thornleigh, Sydney.
5. Patience. This is agriculture, not the foreign exchange market. Everything will take longer than you think, except for Olive Lace Bug and Black Scale.
6. A good irrigation supplier. If your grove is irrigated, and I strongly recommend that all groves in the Hunter at least consider irrigation due to our predominant rainfall pattern, then a reliable irrigation supplier is well work while.
7. If in doubt, call in some help. It is much easier to fix little problems, so if there is something not quite right, give be a ring (0419 244785) or an e-mail and I'll pop out and have a look (within the Hunter!). If I can't make it I probably know somebody who can.