Abstract
To clarify the influence of phosphorus application and available phosphorus concentration in soil on phosphorus concentration in head or occurrence of head rot in Broccoli, phosphorus application test in the same nitrogen application rate and field research on plant and soil nutritional state were conducted. Besides of it, to investigate influence of nitrogen and phosphorus concentration on calcium concentration in head, we measured contents of these elements in foliage, stalk or head every week in nitrogen application test. The results are as follows: 1. Phosphorus application increased phosphorus contents in Broccoli, but had no consequence on phosphorus concentration in head and head weight. Similarly available phosphorus concentration in soil less than 450mg-P_2O_5kg^<-1> had no consequence on each of them. 2. In field research, there was no relation between available phosphorus concentration in soil and the occurrence of head rot or calcium concentration in head of Broccoli. 3. In head growing period, phosphorus and nitrogen probably translocated from leaves to head simultaneously. Nitrogen application increased phosphorus and calcium contents in head. The increasing ratio was lower in calcium than phosphorus. 4. In field research, phosphorus absorption affected neither calcium uptake nor calcium translocation to head. 5. It was concluded that phosphorus application rate, available phosphorus concentration in soil less than 450mg-P_2O_5kg^<-1> and phosphorus uptake amount have little influence on calcium concentration in head or occurrence of head rot. Nitrogen application decrease calcium concentration in head and enhance head rot.
