Nematodes are microscopic animals found in the soil, within plant tissue and within water. Some nematodes are damaging to plants, but there are also beneficial nematodes found within organic matter that parasitise destructive nematodes. Nematodes that attack plant roots are the most common. They cause root galls and excessive root branching. This affects the plant’s ability to take in water and nutrients, wilting and stunted growth. Sandy soils are particularly prone to nematode infestation. Control can be achieved by incorporating organic material into the soil, growing nematode resistant varieties, crop rotation and paying attention to hygiene procedures. For severe infestations you can treat vegetable growing areas with a mix of molasses (2 tablespoons per litre of water). This should only be used on areas that will grow nematode susceptible crops (tomatoes, potatoes and capsicum). Do not use across the entire vegetable garden as this mix has the potential to kill worms.
Scale insects and their associated sooty mould are common pests of many plants including citrus, gardenias, lillypilly hedges and other native plants. Conventional oil based controls, see [Do It Yourself Controls - Oil Spray] can be used, but should be diluted to half strength on fine leaf natives or plants with hairs on the leaves. Avoid using oil based products on plants with grey foliage. Commercial oil sprays include Eco-Oil. Soap sprays are also effective, but must be used on a regular basis. Pyrethrum based products can also be used.
This disease affects Tahitian limes and occurs where fruit is left to over ripen on the tree. The base of the fruit develops a soft rot and fruit fall to the ground. The internal flesh also shows deterioration when cut. Fruit should be harvested while still green in colour prevent this occurring.