The. CULTIVATION' of Buchu. 2^7 



For export purposes the bucliu sliould not contain more than 

 10 per cent, of the small green twigs and none of the larger cres. 



The produce is usually marketed in wool packs, and is mainly 

 exported to England, Australia, and America. 



To secure a crop of seed from cut-backs it is necessary to allow 

 the bushes to develop unchecked and uncut for two years, or three 

 years if a good crop is desired. AVlien the seed is ripe the capsule 

 bursts and the seed is thrown some distance. In gathering this stage 

 must be anticipated a little, and the capsules dried iii the sun on trays 

 or sheets, with light hessian laid over to prevent loss by the explosions. 



The climate of the " winter rain belt" is naturally suited to the 

 requirements of buchu, and generally throughout the western and 

 south-western districts it will thrive with a minimum of attention. 

 Un the Karroo or other arid regions it is doubtful if the plant would 

 thrive, though here irrigation may ensure success. It is a moot point 

 as to whether or how much frost it will withstand. In districts with 

 good summer rains there is a possibility of its doing well if not allowed 

 to dry out during the winter. Jiut just what amount of success can 

 be attained can only be learned from actual trials. It is hoped to 

 obtain reports of the results from seeds distributed to districts through- 

 out all tlie Provinces of the Union. 



The future prospects of buchu as a field crop are bright in that the 

 demand for the herb and oil is increasing rapidly throughout the 

 world. The supply of seed is very limited, so that the acreage cannot 

 rapidly increase, as propagation is limited to this means up to the 

 present. 



The dried leaves of Barosnia hetulijia are official in the British 

 Pharmacopoeia under the name of Buchu Folia. Admixture with 

 other species depreciates the market value of the herb. In the United 

 States there is also a good sale for Barosma creivulata. Barosma 

 serratifolia is the only other species of commercial value at present, 

 the value of the three species being in the order named. 



Under distillation buchu yields a resin and also a volatile oil. 

 0. J. S. Thompson gives the following yields for the three commercial 

 varieties, calculated as peicentages of the weight of dried leaves: — 



Pusin. Oil. 



B. hetulina 4.25 1.45 



B. crenulata 3.75 1.6 



B. serratifolia 3.45 1.0 



Pluckiger gives the percentage of volatile oil derived from dried 

 B. hetulina as 1.56 per cent. — the higher yield being doubtless due to 

 more careful drying. 



The oil can be obtained from green leaves as well as from the 

 dried herb, and Mr. P. M. Williams states that the yield of oil from 

 green B. hetulina leaves is about 1 per cent. Moreover, the green 

 twigs give a yield of about 0.5 per cent. As the herb loses about half 

 its weight in drying it is clear that a considerable waste of oil takes 

 place in this process; and this is evident from the dtrong scent of a 

 heap of drying branches as compared with the almost imperceptible 

 scent of the growing plant. The most economical way of extracting 

 the oil, therefore, would be by distillation of the green shoots shortly 

 after cutting, and this could best be done as one of the operations in 

 an essential oil industry in South Africa. 



