Aphids and whiteflies are primary insect pests. White raised growths on top of leaves is an edema like disorder, not a disease. If liners are not already pinched, pinch them at time of planting. Drench with a broad-spectrum fungicide at planting. 500 ppm two weeks apart with the first spray applied as soon as plants are established in the final container.
Warmer temperatures produce softer less desirable growth.
Multiple applications will delay flowering. Preventative foliar sprays for botrytis are recommended. Cooler nights produce sturdy plants but lengthens crop cycle. Pinch once, 1-2 weeks after planting. Wilting blasts flower buds and yellows foliage.