58 U.S. DEPT. OF AGRICULTURE MISC. PUB. 93 9 



sorus at maturity, promycelium external, four- celled ; basidiospores 

 round to elliptical. 



It is widespread in teak forests in India. Damage is severe in young 

 plantations, especially in nurseries where young plants are retarded 

 in growth due to premature defoliation. Opening the canopy is help- 

 ful in controlling the disease. 



Teak is indigenous in India, east Pakistan, Burma, Siam, and Java. 

 It is raised as an exotic in Central America, Sudan, and elsewhere. 

 Importation of living plant material other than seeds should be for- 

 bidden. 



Hosts : Verbenaceae — Tectona grandis L. 



Literature: Thirumalachar, M. J. Telia of the leaf -rust of teak. 

 Current Science 18 : 175-177. 1949. 



Shisham Wilt 



Fusarium solani (Martius) Appel and Wollenw., forma dalbergiae 

 Gordon. A fungus causing wilt of shisham {Dalbergia sissoo Roxb.) 

 in north India and Pakistan. The disease is systemic. Early symp- 

 toms are drooping leaves and leaflets which lose the normal green 

 color, gradually turn yellow, become dry and are shed early, render- 

 ing the branches increasingly bare. Diseased trees die within 4 to 6 

 months. The affected roots gradually become devoid of finer branches 

 and rootlets, on which nodules are scarce or absent. The outer living 

 wood of roots shows a pink stain which may progress up the stem 

 a short distance in advanced stages of the disease. The pathogenicity 

 of the fungus is established by inoculation of healthy plants in which 

 symptoms are reproduced. 



Fusarium solani forma dalberqiae is a soil inhabiting fungus. In- 

 fection occurs through roots. Trees of all ages are attacked though 

 seedlings and saplings are less susceptible. A definite correlation 

 exists between soil texture and incidence of the disease. The disease 

 is absent in shisham occurring naturally on sandy soils such as river 

 beds, where the species is one of the early colonizers. The disease 

 is also rare in plantations where soil is loose and sandy. In natural 

 forests and also in plantations where the soil is stiff and clayey, the 

 disease incidence is high. Freedom from the disease can thus be 

 secured if shisham plantations are raised in soils containing a high 

 proportion of sand and less of silt and clay. Irrigation with good 

 soil drainage is known to maintain healthy stands. 



A species indigenous to India and west Pakistan and that is being 

 tried as an exotic in the Middle East countries like Sudan, where 

 care should be taken to see that the disease does not appear. 



Hosts : Leguminosae — Dalbergia sissoo Roxb. 



Literature : Bakshi, B. K., et al. Wilt disease of shisham. I. Indian 



Forester 80: 316-322. 1954; II. Ibid. 81: 276-281. 1955: IV. 



Ibid. 83 : 505-511. 1957 ; V. Ibid. 83 : 555-558. 1957. 



Casuarina Wilt 



Trichosporium. vesiculosum Butler. A stem and root parasite of 

 Casuarina equisetifolia Forst. in plantations in south India. Ap- 

 pears on Casuarina bark as blisters, which rupture and expose a thick 



