270 



THE AGRICULTURAL NEWS. 



Ai 'i 5T 14, 1915. 



FUNGUS NOTES. 



LIME AS A FACTOR IN RESISTANCE 



TO DISEASE. 



interest in tiheii 

 question of resistance to plan I di i raised in a papei 



by Mr, J. K. Ramsbot toi i a in the • the 



I: i i ! U , Vol. XI, p. 481. The subjei 



the leaf blotch d une species oi I id by the 



fungus //- ( 



The affection on the young leaves and 



attains serious prop md autumn. The 



prematun leaves weakens the plants as a whole, 



a ; 1 1 if unchecked the may bring about their death. 



Mr. F. J. Chittenden reports as follows on the effects of 

 treatments ipplied ai the Royal Borticultural Socii 



lens at \\ 

 in the d ■ bul it broke 



out with equal virulence in the g year. Spraying 



weeks wa to, but * I i < I not 



In the following winter a different method 

 ipted. After the dead foliage had been removed, 

 the was heavilj dressed with slaked lime. The 



ri 'lit surpassed expectations. The growth came away 

 clrau and healthy in the spring, and remained so through 

 out the season. An occasional winter dressing of lime has 

 been given, and extremely little of the fungus has 1 . t ■ « • ? i seen 

 since. 



The idea underlying the application ol lime was the 

 Usual one, namely, that it would encourage the oxidation of 

 ■ ■ _ in! mattet in the soil upon which the fungus conceivably 

 maintained Itself through the winter, and that by neutralizing 

 soil aridity it would render the conditions less favourable for 

 the growth of the fungus. 



Some notes by Mr. W. II. Dykes, the well-known 

 authority on the genus his, suggest another interpretation oi 

 the result obtained. Certain groups of Iris prefer a limestone 

 soil, others a soil free from lime. According to his 

 observations the disease does noj occur on the lime-hating 

 species, and only on the lime loving species when grown on 

 a -<>il which is deficient in that substance. 



As tin- author of the paper suggests, the facts are too few 

 I." bear the weight of any theory as to their significance, but 

 they indicate the possibility of obtaining definite information 

 oi a kind that is much needed for -the progress of economic 

 mycology. It is to l" 1 hoped that the matter will In- pressed 

 to a conclusion. 



SUCCESSFUL SPRAYING OF PALM 



TREES IN INDIA. 



A disease ol areca palm- known as koleroga and caused 



,//,.,),; ornni i ora has been 



M) sore fbi some years. An account of 



an investij . Dr L.C.Coleman appeared in the 



i Vol. V p. In the 



Af/ricnlturaUourti ' I ; ■ i i 1 1915 (Vol. \ p. 129), 



extent to 



'"lit i .1 i . kdo] '--nit - 



I lark with regard to India 



which might with justice 1» given •■ wider ippl 



of plant ili.-ra carried out methodically 



fully, and -till mi ire tstrely ha- it been taken up t" any 

 iderable extent by the igriculturists themselves. 1 Henci 

 the interest ol the account under review. 



'flu' principal area in which the diseas icurs i- a strij 



at 100 miles long, and from 20 to 30 miles broad al 



tie' i ti i western edge i the Mysoi Pra allj 



tie ly import mt crops are p nut. Thi 



rdens in which the pall cultivated occupy thesii 



• if the valleys and the higher portions of their troughs, 

 frequently extend for miles in a practically 

 'I'lir L nd cultivated by Brahmins, 



wlai an- sufficiently educated hable by means ■■! 



printed matter. The return from a well cultivated i 



i ■ .' : - i" 600 rupees per acre. 



The method <>t treatment recommended i- tie' spra; 

 of the I. ij nuts with Bordeaux mixture before the 



disease appear-. The chief difficulties t" !»• faced 



heavy rainfall of the monsoon, reaching in -nine plaei- t 



20 inches in day and II" inches in one month; tin 



remoteness of the gardens from the main mad-, and thi 

 physical difficulties oi spraying the tops oi slendei I 

 tn 80 feet high. Xiie author is probably justified in thin! 

 that in ie. ..tin i' p.nt of tlie world has the scientific control 

 a disease been attempted where the initial difficulties h 



Tie- washing awaj of the sprayed deposit by the 

 torrential rains was prevented l>y using Bordeaux mixture 

 of double strength, to which was added a resin - 

 made by heating together resin and soda in water. In 

 most ease- one application was found to In- sufficient 

 to protect the nuts during the critical period. The 

 method of application first tried involved the use of a line 

 of hose carried up the tree by a climber, the fluid being 

 pumped up from a barrel on the ground. This was found 

 to be both awkward and dangerous, and the solution of the 

 difficulty was found in the use of compressed air sprayers, 

 holding rather less than a gallon, and capable of being easily- 

 carried up a tree. Such machines have withstood six years 

 of rough usage. 



After three year- of experimental demonstrations carried 

 out at the expense of the Government it was decided to offer 

 sprayers for sale. In tin 1 three years 1912-14, the numbers 

 disposed of were 31, 36, and 110, respectively, showing that 

 the •extremely sceptical garden owners 1 were favourably 

 impressed by the results obtained. The Agricultural 

 Department has placed stocks of the ingredients used in 

 preparing the spray mixturefor -ale at convenient centres, and 

 the demand has Ween such, that during the past year over 

 HI, tons of material has been -tucked. Over 100 owners are 

 carrying out spraying quite independently of any assistance 

 from the Department, and not fat from 600 acres must have 



I n sprayed during the past year, as against less than 200 



icres the previous year and about '. icre six years ago. One 



leading garden owner estimates that the spraying of his 

 den of 1 1' acres has during three years saved him 

 I. mm rupi 



There is some hope of stamping out the disease entirely, 



or at 1 from isolated tracts, it p thi 



owners can be secured, and experiments to fun whatjustifi- 



to I i- for such hope are in progress. I hi' 



lii- been kept entirely free ! I will now be 



left alone -o a o i i i tain whether the disease will reapp 

 The report is a valuable rca ird ol difficultii - fai 



