240 EXPEEIMENT STATION EECOED. 



Blackwood (Dalbergia latifolia), E. Benskin {[Indian] Forest Bui. 27 

 (1915), pp. 12, pi. 1). — A note similar to the above on Bombay blackwood or 

 rosewood of southern India. 



Note on sundri timber (Heritiera minor), R. S. Peabsox ( [Indian] Forest 

 Bid. 29 {1915), pp. 8, pi. 1). — This comprises a note similar to the above on 

 sundri timber. 



Seasonal variations in the storage of plant food in Hevea brasiliensis and 

 their relation to resting periods, L. E. Campbell {Dept. Agr. Ceylon Bui. 22 

 {1915), pp. 18, pis. 7). — In this bulletin results are given of a comparative study 

 of untapped and tapped trees of //. brasiliensis, conducted with the view of 

 determining what relation, if any, exists between food storage and the resting 

 period of the tree. 



As briefly summarized the experiments show that there is a variation in the 

 amounts of rubber obtained which agrees with the order of variation in the 

 amounts of reserve starch in the bark and wood during the same months. The 

 results indicate that the period during which the rubber trees are rested must 

 include the period which extends from the time the new leaves are developing 

 to about the third week after the leaves have fully developed. This resting 

 period can be profitably extended by ceasing tapping when the loaves are falling 

 and commencing again one month or more after the trees have regained their 

 full foliage. 



Preservation of railway ties, H. K. "Wicksteed (Cow. Conserv. Canada Ept., 

 G {1015), pp. 76-86). — In this paper the author discusses the importance of wood 

 preservation and describes a method of artificially seasoning and waterproofing 

 ties and other timbers developed by G. W. and G. B. !McMullen. In the new 

 process the ties are placed in a kiln, here described, atid surrounded with warm 

 vapor, which softens and volatilizes the saps and resins in the wood. After 

 some hours of treatment the amount of moisture is slowly reduced until finally 

 the ties are removed with not more than 5 per cent of moisture in them. The 

 ties are then waterproofed in a hot bath of heavy asphalt and sanded to absorb 

 superfluous stickiness. 



A brief report on the above process by .T. S. Bates is also given. 



DISEASES OF PLANTS. 



[Notes from the California station on miscellaneous plant diseases] (Cali- 

 fornia Sta. Rpt. 1915, pp. 22-24, 25). — Brief accounts are given of investigations 

 which have been carried out on a number of plant diseases. 



The cause of bench root in citrus nursery stock has been found to be the 

 inability of the root to penetrate the tough, fibrous seed coat before encircling 

 the cotyledons in an effort to break through the seed coat. Seeds which had 

 the coat removed before planting showed no bench root, and soaking the seed 

 before planting was found to reduce the trouble to about 10 per cent. 



Recent investigations by Sliss E. H. Smith have shown that the so-called sour 

 sap disease, which has resulted in extensive losses in citrus nursery stock, is due 

 to the fungus which has been described as causing the brown rot of lemons 

 (E. S. R., 19, p. 658). 



In the treatment of gum diseases of lemon, and also of scaly bark of orange, 

 Bordeaux paste has given very satisfactory results. 



Investigations by the division of plant pathology have shown that the age and 

 productive capacity of many of the deciduous orchards of the State are refluced 

 by fully 50 per cent by wood-decaying funsri. This loss, it is said, can be largely 

 avoided by pruning and by disinfecting large cuts with corrosive sublimate and 

 afterwards keeping the cuts covered with asphaltum. 



