Ignorance is not bliss. I moved to a house in the southwest that had what appeared to be a dwarf navel orange tree. At t he onset of winter I noted a serious curly-leaf problem. I watched as it got worse. I sprayed with neem oil. I checked the leaves for spider mites or some sort of fungal infection. After much cogitation I have decided that the leaves curled because they did not like the unusually cold winter. I may be wrong, but if so I would like for someone to set me straight.
Citrus trees may be affected adversely by pests, diseases, environmental conditions and/or cultural practices. There are four major reasons for leaf curl in orange trees: pests, disease, water stress and weather. Sometimes it’s a combination of all four.
Read more at Gardening Know How: Leaf Curl In Orange Trees: Why Are My Orange Tree Leaves Curling https://www.gardeningknowhow.com/edible/fruits/oranges/leaf-curl-in-orange-trees.htm