Studies on the effects of seed inoculation With Rhizobium on leguminous trees. A test on the seeds of Acacia mollissima Willd. (Preliminary report)

The author studied on the inoculation of root nodule bacteria to Acacia mollissima Willd., together with fertilization test. The experiment was made at theShuri experimental site in Demonstration Forest of University of the Ryukyus, using 40 pots (about 20 cm in diameter) in total. As shown in Table 3 and Figure 1-8, the inoculated seedlings had greater height, diameter on ground, weight of the top, total weight, length of main root, length of lateral roots, dry-weight of the top, number of root nodules, etc. than the uninoculated ones in average, in both unfertilized and fertilized sections (the quantity of soil per pot was 2 kg collected from the experimental site, 20 g of the mixing fertilizer in which the ratio of nitrogen sulphate, calcium superphosphate, and potassium sulphate is 1 : 4 : 2). The seedlings inoculated are smaller in the index of slenderness than the one uninoculated. And the results showed that the growth of inoculated seedlings was superior, especially those of fertilized and inoculated section were best than the other three sections in average. Judging from the results of this experiment, Acacia rhizobium seems to be dificient in the soil, so it is essential to inoculate the seeds with Rhizobium when they are sown in these area