liS.S ,)(iiK.\Ai. oi' liiK Dkj'aki .\ii;m Oh A(.i{u I i/iUKK. — Aug., l\)22. 



Lime Unnecessary for Maize and Potatoes. 



Standei-ton. — Please send me instructions liow to take a soil 

 sample which I wish anah'sed. I think my soil is sour, and I want 

 to know how mucli lime to put on my mealie and potato lands. 



Tlie Research Chemist, Fotchefstrootn, replies: It is not necessary 

 to lime land for these crops, so it will not be necessTiry to do a soil 

 analysis. If you think your soil is deficient in somiethino-, it is no 

 doubt phosphates. Try superphosphate at the rate of 200 lb. per acre 

 for your mealies and 400 lb. per acre for potatoes. Give the potatoes, 

 in addition, plenty of kraal manure, and you mio'ht also try the addi- 

 tion of 100 lb. of sulphate of potash. Lime does not pay for all crops. 

 Read the article appearing in the Denartment's Journal for February, 

 1922, entitled " The Ijime He(|uirement of Soil antl Plant," by 

 Thos. T). Hall. 



Seed of Kikuyu Crass. 



Albanij, Cape. — Can you tell me where I can procure seed of 

 kikuyu? I have a small plot of the grafss on my farm, but, though 

 it has been well established for about three years, it has never 

 flowered. I wish to put down a couple of acres to it, and should be 

 glad if you could let me know where I < an procure seed for the 

 ])uipose. 



J he Chief, /)ir,.<ioii of Botanjj, replies: Kikuyu grass usually 

 flowers very regularly, but the inflorescences are short and hidden 

 between the leaf sheaths and the culms (hence its botanical name 

 I'ennisetuvi clandestinum), and only the feathery stigmas are exserted, 

 which close examination of the plant will reveal. Kikuyu, however, 

 never (as far as we know) sets seed; even in its native habitat ol 

 Kiisi Afiica i( r(>lies for i)r.)])agation entirely on its inimeis. 



Grown Call. 



.Johauneshiirjj. — I shall be glad if you will kindly inform me of 

 the nature of the peculiar growth (specimen enclosed) which is 

 attacking willow trees. It is ;loing considerable harm to these very 

 graceful trees. 



/At' Chief, Division of Botanij, replies: The willow twig sub- 

 mitted is infected with crown gall, due to the organism Bacterium 

 tumefaciens. Willow trees are very susceptible to crown gall ami 

 form a fruitful source of infection for fruit trees in their neighbour- 

 hood. Infected willow trees near an orchard of stone fruit trees have 

 been known to cause a serious infestation with crown gall. Read the 

 aiticle on crown gall which appeared in the Journal for July, 1921. 



