AvoJect are specialised avocado injecting syringes designed for the application of HiPK for the control of phytophthora. HiPK is a systemic fungicide soluble concentrate containing 400g/litre phosphorus acid as mono- and di-potassium salts.
The phosphonates in HiPK are injected into the tree's trunk tissue and are carried by the xylem stream directly to the leaves and then translocated to the roots to protect against the invasion of the root rot pathogen.
“For effective phytophthora control, there should be around an eight-week gap to inject HiPK into avocados trees once the flush is hardened off, and before the end of May,” says Aongatete Avocados managing director Tony Bradley.
“This will vary from season to season. We inject before the winter months to protect against the invasion of phytophthora through the wetter winter period when there is an increased risk of phytophthora invasion.”
At the end of winter, the avocado tree appears to be dormant, but before flowering, the tree has a period of root development.
Tony says This period of root development before flowering allows a small window of two to three weeks for injecting HiPK, usually at the end of August and into early September.
“Once flowering begins, the phosphate in HiPK is drawn to the flowers and any sizing fruit because those parts of the tree are growing more actively than the roots.”