470 XXIII. LEGUMINOSAE 



Albizzia Lebbek : rate of growth of seedlings in experimental plots. 



Irrigated plots. 

 Weeded. Unweeded. Weeded. 



Height at end of first season. 



(1) 1 ft. 2 in.-8 ft. 4 in. Maximum 1 ft. 5 in.^^ Maximum 2 ft, 



(nursery plants ; seed 

 sown Feb. and early 

 start obtained) 



(2) Maximum 2 ft. in.i 



Height at end of 2nd season. 



(1) Maximum 14 ft, 4 in. Maximum 4 ft. 5 in.^ Maximum 6 ft. 



(2) 6 ft. 8 in.i 



Height at end of 3rd season. 



(1) Abandoned Maximum 11 ft. in. Maximum 14 ft. 9 in. (1) Maximum 4 ft. 10 in. 



(2) Maximum 13 ft. in. (dominant plants (2) 4 ft. Sin. 



(dominant plants vigorous) 



vigorous) 



^ Growth of seedlings retarded by attacks of Oxyrhachis taratidus, Fabr., a hemipterous insect 

 of the family Membracidae which infests seedlings and saplings of this and other species of Albizzia 

 as well as certain other leguminous species (to some extent Acacia Catechu), doing much damage 

 by sucking the young shoots and causing them to wither ; the leading shoots are often destroyed in 

 this way and the growth of the plants is seriously interfered with. 



All the plots noted in the above statement were in fuU sunlight : the 

 unirri gated unweeded plots may be taken to represent the development under 

 natural conditions. Nursery-raised plants, regularly weeded and watered, 

 show rapid growth from the commencement, and may attain a height of 

 nearly 4 ft. in four months from germination. A long stout taproot is pro- 

 duced at an early stage ; this may reach a length of 2 ft. in three to four 

 months. The lateral rootlets are often covered with rather large nodules. In 

 northern India the leaves of seedlings fall from about December to March, 

 and growth ceases during the cold season ; new growth commences about 

 February. 



The seedlings are not very frost-tender, though the leaves are apt to 

 shrivel up in frosty localities before falling, and the leading shoots are some- 

 times killed back where frost is severe. Young plants are somewhat sensitive 

 to drought, especially in the first season. If early rain stimulates germination 

 and prolonged dry weather ensues, the young seedlings are killed off in quantity. 

 Under naturtv^ conditions light weed-growth and grass, though it impedes 

 development, acts as a protective against drought. The sudden removal of 

 weeds from over young seedlings is fatal ; weeding requires to be carried out 

 from the commencement. Seedlings do not stand suppression weU, and where 

 they are at all crowded the more vigorous individuals quickly suppress the 

 more weakly ones. 



SiLVicuLTURAL CHARACTERS. Youug plants are capable of standing 

 a moderate amoimt of shade, though their growth is interfered with if the 

 shade is at aU heavy. For its best development the tree requires full over- 

 head light. It is not exacting as to soil, and will grow fairly well even on 

 laterite or black cotton soil. The root-system is largely superficial, and though 

 as a rule the tree does not produce root-suckers regularly, it may do so if the 

 roots are exposed. Mr. G. M. Ryan writes : ^ " Albizzia Lebbek is not a tree 



1 Ind. Forester, xxx (1904), p. 454. 



