Aster Yellows – Aster yellows phytoplasma (AYP)

Aster yellows Common name Aster yellows Causal agent It is caused by the phytoplasma bacterium Scientific name Aster yellows phytoplasma (AYP) Symptoms & Signs It affects broad-leafed plants, especially members of the Asteraceae family. Chlorosis of leaves and stem occurs along with stunted growth. The thin and weak stems start growing in close bunches. The flowers are also malnourished and often fail to grow and develop color. Transmission It is transferred through the aster leafhopper, Macrosteles quadrilineatus, which feeds on the phloem of the plants. The disease is transmitted to other plants when the grasshopper feeds on the infected plant first and moves to a healthy plant. When subjected to hot conditions between 38 to 42 °C (100 to 108 °F), the phytoplasma is destroyed both on plants and in grasshoppers. Time of concern Early spring to late summer Common hosts Garlic Carrot Thistle Dandelion Onion Cereal