SO SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



in the upper soil quickly get wilt. In all cases of wilted 

 plants, nodules have been found to be absent and new roots 

 very few. 



As a result of Mr. Howard's investigations, five types 

 of root- development have been recorded — 



(a) Early bush type, with all laterals at right angles 



and near the surface. 



(b) Early vertical type, with all laterals near the sur- 



face but pointing down. 



(c) Late bush type, with laterals at right angles, both 



near the surface and extending to some depth. 



(d) A similar type to (c), but with laterals pointing 



downwards. 



(e) No side branches, but tap root only. 



Type (a) has been found much less subject to wilt than 

 the others, and in the 1919 root examinations every case 

 of wilt examined was found associated with deep-rooting. 



Seed selection. As mentioned in previous reports, Java 

 indigo is not uniform, but consists of a mass of heterozy- 

 gotes differing widely in habit and character. This is due 

 to the cross-pollination which takes place, owing to which 

 selection by pure lines is not possible, as plants do not set 

 seed under bag, and a system of mass-selection has there- 

 fore to be resorted to. Some types are deep-rooted with 

 long tap roots, others shallow-rooted with surface roots. 

 The habits above ground differ in similar ways, some being 

 much more branched than others. There are also differences 

 in the maturity of plants. The object of-the selection is to 

 obtain early, surface-rooting, freely-branching plants, 

 which will give good yields of both seed and leaf. A con- 

 siderable amount of selection work has already been done, 

 and some types are already being tested on an estate scale. 

 Further selection work was started in 1917-18 and is still 

 in progress. In that year plants were selected for their 

 free-branching habit and high yield of seed and leaf, 

 together with other desirable qualities, such as earliness and 

 surface-rooting. Seed of these selected plants was sown in 

 August 1918 in separate lines. From these, 100 desirable 



