

THE AGRICULTURAL NEWS. 



Octobeb 23, 1915. 



PLANT DISEASES. 



SPRAYING OF GROUND NUTS FOR 



LEAF RUST. 



Mr. W. I the Botanic Statioi . M 



port on the results he h 

 in the current year from a comparison of sprayed and 

 unspra; ad outs. Tl" 



the amount of 



yield t> from the of the 



rust : Lag., 1>\ i I lordeauj 



I IX'. 



Mr. 11 carried cut 



in 1914 was pub! si d h : ; I Vol. XIII, p. 380. 



The plot, which was situated at '• S ition, was 



April 1- with the Virginia Running variety 



each way. The ground has 



d the eastern half was 



i ionally chosen foi for the reason that the 



lowei (western) exti i sucB plots usually gii 



available as to 

 this particular plot. The sprayed and unsprayed sections 

 were eai b ' n area, and each was again divided for 



the purpose of theyieldsoi sub-sections thinned 



out to one plant to the hole and others left with two. An 

 additional, more legitimate complication was introduced by 

 the variation of the number of times the sub sections of the 

 treated portion were sprayed. The accompanying diagram 

 will make the explanations easier to follow: — 



East 



West 



A represents the sprayed section, B the unsprayed. A"J 



and B2 were left with two plaids to the hole, Al and Bl 

 with only one. Spraying was carried ont as follows: — 



Al, thrice, at 4f>, 59, and 74 days from planting. 

 A - -', twice, at 59 and 84 days from planting. 



In other words, A2 was sprayed at *! week- and again 

 in interval of .'I 1 , weeks, while Al was first sprayed at 

 <;', weeks and twice again at fortnightly intervals. 



Pustules of the rust fungus were first noticed on the 

 unsprayed portion on .Inly li.'i or just a month before the 

 nuts " ed. At the time of reaping the foliage on 



i .I. < | n .it i< m i if this unsprayed plot was withered and 

 dropping from the plants, and the remainder was much brown 

 ed, practically every developed leaf being covered with the 

 pustules of the fungus. 



v., s'ji fungu as to be seen 



, , it sect ion up to the time of reaping; onlj a Few 



scattered ild be found carrying pustules. Reap 



han in the case of the unsprayed section,, 



and even then the foliage of the pi fairly greei 



healthy. 



yield of tl ent. more than 



of the uns] : out below: — 



(The loss oi weighl in drying uoaj betaken as about 

 per cei 



In 1914 the rate of yield ol fre fa nut i rambia 



variety) was 2,496 R>. for the unsprayed, and 3,558 for the 

 spra\ nl sect ii >n, at i nt. 



The plots were kept under ion and it can 



definitely said that the rust fungus has been effectively 



I rolled by the Bordeaux mixture I" was 



carried out with a barrel pump at 80 H>. pres ore; r Mistry 



Junior nozzle was used. 



As regards the subsidiary experiment, the section A 1, 

 which had one plant to ' md was three times sprayed, 



gave 139 tt>. of fresh nuts as compared with a yield oi 197 lb. 

 from A 2, which had two plants to the hole and was twice 

 sprayed. 



The corresponding unsprayed sections 1! 1 and B 2 

 yielded 103 lb. and 160 fc. respectively. It would apj 

 that there is a very definite gain from leaving two plants as 

 against one. 



With regard to the general application of the results of 

 the spraying experiment the caution given last year may be 

 repeated. The degree of infestation of the plants by this 

 fungus depends largely on conditions of soil and climate. 

 When the conditions are favourable to the host, only the 

 leaves which are approaching senility are infested: in other 

 circumstances the fungus can be so severe as to kill the 

 plants outright. The improvement to be expected from 

 spraying must therefore vary considerably from one place to- 

 another, and from year to year. 



W.N. 



DOWN THE ISLANDS. 



ITEMS OF LOCAL INTEREST. 



ST. VINCENT. A list of the exports of the island with 

 their declared values for the years 1913 and 1!>14 appears 

 in the Government <;<i ette for September 30. The export 

 of arrowroot exceeded in value those of 1913. Cassava 

 starch shows a reduction as a result of reduced cultivation. 

 Sea I sland cotton also shows a falling off, but this must be 



attributed to delayed shipments and not to a decrease iii 



production. According to the Sentry for October I, the 



island was visited on the previous Monday by a thunder- 

 storm of considerable forqe, hut up to the present notice has 

 not been received of any fatality or noticeable damag 

 property by lightning. According to the same paper the 

 peasant ry and other land owners are responding to the ( toveni- 

 ment - enterprise in installing machinery for shelling and 



kiln drying Indian corn on a perative basis at the G 



m. 'lit central factory. The machine is capable of shelling 

 1 2 barrels of corn per hour and dries the same as 

 rapidly as the shelling appliances can supply the kiln, which 

 has a capacity for .'i tons. Thi ' Qent is paying! 



per 100 lb. for com cob or lc. per lb. for shelled corn, and at 

 the close of the season when the produce is sold, profits will 

 be distributed in tin- form of a I. nun- amongst the sellers. 



