(1) specific reason: the lack of these two elements may make the leaves yellow, but the parts are different. If iron is deficient, the mesophyll will turn yellow; if nitrogen is deficient, its veins will turn yellow. Therefore, according to different symptoms, we can determine which element should be added.
(2) solution: observe the yellowing part of the leaves and supplement the corresponding elements.
(1) specific reason: this kind of situation is more frequent when flowering. At this time, we need more nutrition. If we don't pay attention to supplement, it may cause the leaves to turn yellow.
(2) solution: it is necessary to spray some fertilizer, such as potassium dihydrogen phosphate solution. It contains not only basic elements such as nitrogen, phosphorus and potassium, but also some trace elements. Spray the blade once every half a month.
(1) specific reasons: if the root rots, it may also make the leaves yellow. The most likely cause of root rot is too much standing water or too much fertilizer.
(2) solution: the rotten part and a small part around should be scraped off with a knife, and some tobujin should be applied. Wait until the cut is completely restored before covering. After that, we also need to pay attention to not too much watering, nor too high concentration of fertilizer
(1) specific reason: after the birth of pests, it may also endanger the leaves and make them yellow.
(2) solution: if the quantity is small, the pest can be removed manually. If the quantity is large, spray the corresponding agent.
