Fat plants

Yellow spots


Question: yellow spots


hi, I have for many years now a "mother-in-law's pillow" I have noticed for some time that yellow spots have formed on the coasts and in the middle, in the "folds" it is drying and holes are forming. thank you very much :)

Answer: yellow spots


Dear Tora,
the mother-in-law's pillow is a cactacea of ​​the species echinocactus grusonii; in nature it lives in arid climate zones of South and Central America, where it can enjoy a warm climate, direct sun, and very aerated locations. Unfortunately it often happens that even very old specimens of this beautiful plant will be irreparably damaged after years of life in the apartment. In fact, by keeping the plant in the house for many months, with a "spring" and dry climate, plants become easy prey for various parasites.
If the spots are yellow, and the surface of the spots tends to become translucent, as if it were plastic, it could be small insect bites, through whose saliva a virus or bacterium has been inoculated into the plant, which they have ruined. the plant. If the spots remain stationary, you can simply try to prevent others from being created. Generally this type of disease develops above all in the presence of scale insects; these insects nest in a particular way on plants that are always kept in the dry heat (they are very common in greenhouses). To eradicate the cochineal it is necessary to place the plant where it enjoys greater ventilation, water it correctly during the warm months, expose it to direct sunlight for at least a few hours a day, and treat it with white oil, in order to kill the parasites still present on of it.
If the spots, after having turned yellow, are tending to become brown, it could instead be a rottenness of the collar or of the roots, which has extended to the stem of the plant. In this case the only way we can save the plant is to remove the areas affected by the disease, up to the healthy pulp; work with a cutter or a very sharp and clean knife, and remove the stains until you find the underlying healthy tissue. If the plant has been affected in many areas, with large spots, the whole healthy apex is removed (if any) and placed on a vase with fresh soil, hoping it will take root (in essence a cutting is produced). In both cases, the plant is destined to remain marked by the spots, because the fabric is now dead in those areas, and therefore it is not possible to restore the green and healthy color.