トマトの生育とミネラル分布におよぼす過剰厩肥施用の影響

Effect of excess farmyard manure (FYM) on tomato plant was studied under green-house conditions. There were two plots one of which was applied at the rate of 50t FYM per 10 a and the other was applied at the rate of 5t FYM per 10 a. The FYM used in this study contained 2.8% nitrogen, 2.8% potassium and 2.4% calcium. There was a slight difference between the standing crops of the heavily manured plot and those of the conventionally manured plot. The difference observed was possible due to the increase of leaf area and of leaf numbers. There also was a little difference of the tomato yield between the two plots. In the first crop the rate yield of fruit was about 15 t per 10 a in the heavily manured plot and 16 t in the conventionally manured plot. But in the second crop, 19t and 18t were produced per 10 a in heavily and in conventionally manured plots respectively. The tomato plants received heavy manure bore many numbers of flowers. In the second crop the number of fruit set was about 10-12 per truss in the heavily manured plot whereas that in the 5t FYM manured plot was about 8-9 per truss. Ripening disorder in fruit was not observed, even the K/Ca me ratio in soil solution decreased to 0.25. The sugar contents of tomato had a tendency to increase in the heavily manured plot. (p<0.1) The concentration of potassium in the stem and leaf decreased with growing stage, irrespective of the leaf position. But there were significant differences in the concentration of potassium in these organs between the two plots at each growing stage. The data in Table 4 suggested that the petioles might be capable of accumulating much higher concentration of potassium. In the 50 t plot, the petioles from all the leaf positions appeared to be approaching to a saturation point of potassium, and under these conditions potassium in the petioles were amounted to about 21 per cent of the dry matter. The concentration of potassium in the leaf blades petriole and stem increased with increasing potassium in the soil solution. But the maximum concentration of potassium in fruit juice was 4 to 5 per cent, even in the plot received 50 t FYM.