A vegetable farmer asked that from the outer leaves of the celery, the brown stripes along the outside surface of the petiole developed along the longitudinal veins or transverse cracks, and the cracked areas turned brown. What is going on in the end?
This is a physiological deficiency of boron. It can be sprayed with borax 0.1% aqueous solution, applied about 7 days, and sprayed continuously for 3 to 5 times. Borax can be used in combination with pesticides to select sunny afternoon medication, but pay attention to borax can not be mixed with lime, urea, etc., in order to avoid phytotoxicity.