\oi.. I. No. 



THE AGRICULTUJIAI. NE\V8. 



45 



RECENT REPORTS. 



Notf-i on [user! I'l-.^tx, lUOt. A Ripart m' Ih • Soutli- 

 luixtern Ai/riculfnriil Volleije, ir>/f», KihiIiiikI. Hi/ /•'. I'. 



Th'-oMil, M.A., F.E.S. 



Tlii.s lieiKU-t ileitis with ]H«t.s dlisiiAud in Kiij^lainl, 

 eHpeciiilly in the southiTii rountit's, ami i-oiitaiiis iiiui'h inter 

 eating matter. In diseussini; leniedies tor seale insects, the 

 author phues reliance on three methods : spraying witli 

 fiustie alkali wash, with resin wash, and fumigating with 

 liydrocyanie acid gas. Mr. Theobald's caustic alkili wash is 

 ■A powerful liciiiid, to be applied to (loniianf trees in winter. 

 I'lifortunately a liquid of such iMitency cannot he u.setl in 

 the West Indies where most j)lants are in more or le.ss active 

 •{rowth through the whole year. The resin wash is similar 

 lo that recommended l>y the Department (see HVs/ Indian 

 jtnllelin. Vol. II., p. 180, and Ginfiuil Tri'dlmcnt of Insccl 

 fi-xla, 2nd. edition, p. 12) with the substitution of soft soap 

 for whale oil. It is curious that whale oil ami whale oil soap 

 <Io not app ar to be used in Englan I to the extent they are 

 in America and tli'- West Indies, s ift soaj) being fie(|nently 

 .substituted. 



With regard to fumigation, ^Ir. Theoliald especially 

 recominemls it for green-houses. Fumigation is probably 

 not jiracticable on a large scale in the \Ve.st Indies at the 

 present time. It has been trieil in Mont.serrat in [last years 

 and there i.s no doubt that the ]>n)ce« is fatal to scale insects. 

 For the j)resent, however, we mu.st depend on the spraying 

 machine, and we agree with Mr. Theubalcl in placing 

 reliance on got)d washes. 



Another section of the report, of interest in the West 

 Indies, is that on the 'Introduction of foreign Ladybirds.' 

 The ladybirds are a familiar group of small beetles that eat 

 plant lice and scab' insects : hence their importance to agri- 

 «-ultnre. Mr. Theobald wishes to sujudement the native 

 English ladybirds by the introduction of more voracious 

 foreign ones that would keep jdant lice in better cheek, and 

 to this end he obtained three consiginnents from Tasmania. 

 He has hopes that one of the.se may check the Apfiit: that is 

 .such a pest to hop-growers. We trust the experiment will 

 meet with success. .\s a rule, such introductions do not 

 .s.-em to be successful ; the beetles travel well and many arrive 

 alive ; but they do not ajijiear to thrive in new localities 

 Several unsuccessful attempts have been mad • in the West 

 indies. A number were imjiorted some years ago to 

 Montserrat to eat the 'scale' on the lime trees, but they 

 a|>|iear to have had no lasting eft'ect. In a more recent 

 trial, the lizards enjoye*! the beetles that were lil>erated. 

 fn /Vmerica there have besn .some striking succes.ses and 

 numerous failures, and the general balance of o]iiuion inclines 

 to the unsuccessful nature of these attempts (.see Wixt Indian 

 tinlletin, Vol. II, p. '.VM). Plant lice (Aphiih'^) are kept 

 in check in the West Indies by that most voracious little 

 beetle Cydoni'dn Miniinincn, the <ommon red la<lyliird. Plant 

 lice never get really abundant here, proliably from the 

 ftfective work of this l)eetlo and other eiieuiies. 



liritixli (liiiiinii. lioiii'd of Ayilcidturi'. Report by 

 Mr. Word, Instriii-tiir In Agrlrnlliiri', on a ]'lslt to Trinidad, 



Mr. Ward in <'(inipany witli l'r<ifes-:or .1. }'. Harrison 



visited Trinidad, in returning from the Agricultural Confer- 

 ence at I'arbado.s, for the purjio.se of obtaining some 

 knowledge of the cultivation of cacao and other products as 

 carried on in that i.sland. En route, vi.sits were paid to the 

 Hotanic Stations at St. Vincent and Grenada. The Hotanic 

 (■aniens and St. ("lair Experiment Station at Trinidad are 

 shortly described. A visit to a district mainly cultivated by 

 small settlers revealed an un.satisfactory condition of things. 

 The trees were loaded with (!piphytic growths, dead wood 

 and broken blanches, whilst on the ground decaj ing empty 

 cacao |>ods were lying. Such conditions are very favourable 

 to the .s])read of fungoiil diseases. In plea.sant contrast is the 

 account of a visit to Ortinola estate, under the control of 

 Mr. .1. P. Bain. Ortinola is .situated high u\> in the Maraea* 

 .Mountains and is well .sheltered, drained and watered. The 

 methods ])racticed there of training cacao trees are described. 

 The cptestion of shade trees for cacao is discu.s.sed at some 

 length. .Mr. Ward is of ojiinion that the .shade tree commonly 

 employed in British (Juiana, the ' Oronoipie' tree ( Ery- 

 t/irlna (ilaiwa ) gives too ilen.se a .shade, if l)lanted at the 

 distiince apart found most suitable for its near relative the 

 ' Ijois Immortelle' of Trinidad. He recommends that in 

 British (iuiana the OrinoipU' tree, if used for sliade, should 

 be ]>laced from 80 to 90 feet apart, diagonally. The report 

 concludes with some interesting information relative to the 

 po^isible establishment of a trade in ])lantains between 

 British (iuiana iind Trinidad. 



Triijiiciil 'I'iiid'tr and tlifli rinf/x <f ffronjih, hy lle.rJiert 

 Wrofhl, A.I'.C.S., Srientlfic AsgUtant, Royal Botanic Gar- 

 den.i, C\>/I"ii. Indian (lanli'nhn) and Planting of August '2:'' 

 /nO!. 



The annu il rings s I eh iracteristic of the wood of trees 

 fiom t 'mperate regions enable the age of trees to be readily 

 determined as, on account of the definite sea.sons, each ring 

 represents a year's growth. Such rings are particularly well 

 s_'en in the wmxl of confers, .such as pine, etc. In the 

 tropics where many of th • trees are evergreen and the seasons 

 are by no means well marked, th? time represented by each 

 ring of growth is not ne -e-isirily one j'ear. 



The problem of interpr.'ting the rings of growth in trojii- 

 cal trees is coniplii-itjd by the fact tint, in the tropics every 

 gradation exists between tives which are evergreen and tho.se 

 like ' Immortelles' which drop their leaves and remain leafless 

 for several weeks or months each year. The drojjjiing of the 

 leaves before or during the dry .sea.son is evidently an 

 adaptation on the |mrt of the tree to jirevent drying up. 

 There are however some e\c 'ptions to this rule in Ceylon and 

 elsewhere, where tre.'s drop their leaves in the wet months 

 and burst into leaf during the dry season. The author 

 suggests that this is du3 to the migration of species to 

 localities where the climate doo.s not correspond with that 

 from which they came. 



In discussing the influence of climate on trees an 

 Interesting cise is quoted from Dr. Watt's writings. Plants 

 of an Acacin, native of New South Wales, where it flowered 

 in October were introduced to the Nilgiris in Imlia in I84."i. 

 Here they flow ere 1 in October uj) to 18.50, but in I860 they 

 were observed to Hower in September, in 1870 in August, and 

 finally in 1882 in .(une, this being the 'spring' month in the 

 Nilgiris corresponding with October in New South Wales. 

 It therefore took nearjy forty years for this species to I'egain 

 it.s habit of flowering in the spring. I.e., to become perfectly 

 acclimatised. 



