Red Pitaya: How to Grow the Red-Fleshed Dragon Fruit Cactus

Scale insects are small sap-sucking pests that appear as brown, shell-like bumps on plant stems and leaves. There are over 25 species, divided into armored (hard) and unarmored (soft) scales. They feed by piercing plant tissue and extracting sap, which weakens the plant and can lead to yellowing, stunted growth, and even death if left untreated. They also excrete honeydew, which attracts ants and promotes sooty mold growth.

Fusarium is a soil-borne fungus that primarily attacks the roots and vascular tissues of plants. It enters through small wounds or stressed roots, is favored by warm temperatures and waterlogging, and then obstructs the flow of sap. Symptoms include yellowing, often on only one side of the plant, wilting even with moist soil, stunted growth, and, when cutting the stem, internal brown streaks. It frequently affects tomatoes, peppers, eggplants, basil, cucumbers, and zucchini, as well as ornamentals like carnations and cyclamen. In potted plants, it can manifest as root rot with a darkened crown.

Sunburn or sun scorch is an environmental condition that occurs when plants are exposed to intense, direct sunlight beyond their tolerance level. This causes the breakdown of chlorophyll in the leaves, resulting in bleached, dried, and damaged foliage. The damage can happen rapidly, sometimes within just a few hours of exposure.