Uhhh, without any description of your setup my first three guesses are, in order of most likely to least... A: Heat Stress, anything over 80f will stress the plant out B: Over-watering, the plant looks droopy and sad. over watering will also cause root rot which leads to nutrient def. which can in-turn affect new growth and old. C: PH problem: too high or too low PH will lockout certain nutrients making them unavailable to the plant and the new growth. D: Under-Watering, plant is sad and droopy dry soil wont transport the nutrients to the roots and cause nutrient def.