Baby Yoda Grow

That size for 4 weeks of vegetative growth is not normal not even for an auto flowering plant! (which can possibly out-perform photoperiod plants). It's quite hard to tell which toxicity your plant is suffering from but she definitely has one! at this small size and at young age the plants are very fragile and sensitive to overfeeding. Try lowering your overall fertilizing to about 1/4 of the recommended dosage and hold the Calcium/Iron fertilizer you're using until the plant actually shows a deficiency (those are micro-nutrients needed in small amounts). A better picture of the whole plant with the damaged parts would help a lot to identify exactly what the problem is. Hope this helps! Good luck and happy growing :)