74 



MUSTARD AS A CATCHCROP FOR RUBBER. 



A correspondent writes to the local papers under the initials 

 S. W. H. to recommend the planting of mustard as an idea! not 

 remunerative crop among rubber as giving that nitrogen to the soi] in 

 which it is so rich and abundant. It also, ihe says, is " a vermicide 

 and has weed killing properties." The ordinary mustard plants 

 cultivated in cold or dry climates naturally will not grow in our wet 

 and hot one. The Chinese, it is true, grow a variety of which the 

 leaves are eaten, but it is hardly worth while to recommend this plant 

 which requires heavy manuring here. What does he mean by its 

 nitragenous qualities ? Not being a leguminous plant it is not pro- 

 vided with the well known nitragenous galls that Tephrosia, Clitoria, 

 etc., have, and is of no use in that direction. What is meant by its 

 weed killing properties.'' Does not a mustard plot require as much 

 weeding as any other plant and is it itself not a weed.? 



Its vermicidal properties would seem to be an allusion to the 

 practice of evicting earth worms from flower pots by the use of 

 powdered mustard seed, as often practised in Europe. The plant 

 itself has no such effect, and if it did it would be a good argument 

 against its use, as one of the greatest defects in the soils of this region 

 is the absence of the earth-worms which if abundant would immensely 

 improve the soil. 



It is really regrettable that people should publish such nonsense 

 as this recommendation. We have had a number of such pieces of 

 advice given by people really not at all qualified to give any, recom- 

 mending the use of quite unsuitable and us.L ss plants for cultivation 

 in strong language. Such plants in late years we Comhretuni sundai- 

 ciim, the so called anti-opium drug, Ocimiiiii viridc, the anti-mosquito 

 plant Coninielina imdi flora, Lucerne, Comfrey as weed killers or 

 valuable forage plants, the Manicoba rubbers which have proved com- 

 plete failure etc. 



These recommendations reprinted in all kinds of papers mislead 

 people into investing money and wasting time in attempting to grow 

 them only to discover they are useless and that the adviser had not 

 experimented with them and was only guessing that they might prove 

 useful. — Ed. 



SPAN8LE-SCALE ON SOURSOP. 



A correspondent from Ipoh sends some leaves of sour-sop, Anona 

 inuricata bearing the pretty silver spangle scale known as Lecaminm 

 expansnm var meialliciim. This scale is common on Nutmeg trees in 

 Singapore and Penang. I have not previously seen it on Sour-sops, 

 and the correspondent says he has not seen it on any other trees of 

 the garden. The insect is never so far as I have seen abundant as 

 many scale insects are, one sees but one or two on a leaf. It is in tlie 



