212 



THE AGRICULTURAL NEWS. 



July 5, 1913. 



FRUITS AND FRUIT TREES. 



GRAPES WITHOUT PIPS. 



The point of view followed in the investigation with 

 which this article deals, was the possibility of devising 

 methods for increasing the number of pipless grapes on 

 a normal bunch, not at the expense of the grapes witli pips, 

 but from flowers which, in the ordinary way, fall without 

 producing fruit of any kind. An alternative and more novel 

 asjject of producing table grapes without seed — as has been 

 done in the case of the orange and other fruits — does not 

 receive attention in the investigation, inasmuch as its achieve- 

 ment would appear to be physiologically almost impossible. 



The results of the work referred to, carried out mainly 

 in Italy, are abstracted in the Monthly Bulletin oj Ac/rkul- 

 tiiral Intellii/ence and nf Plant Diseases for April 1913. 



Dealing first veith the causal factors entering into the 

 production of seedless grapes, it is stated that these had I leen 

 shown by previous investigations to be as follows; (l)the 

 presence on the bunch of relatively few fertilized flowers; 

 (2) possibly the stimulus of the growth of the pollen tube 

 without actual fertilization; (3) presence in the stock of 

 a high content of organic nutrients, a condition which is 

 produced by ringing. 



A repetition, in Italy, of experiments similar to those 

 which led to the above conclusions gave the following 

 results. The relative number of grapes with and without 

 pips was not found to be constant, and it was noticeable 

 that, in bunches where any of the grapes are pipless, the 

 grapes of both kinds (with and without pips) are relatively 

 large; the reverse is the case where the pipless grapes are 

 few in numlier or completely wanting. Hinging was found 

 to have the etlect of largely increasing the number of pipless 

 grapes, and the average weight of the grape, with or without 

 pip.s, is also usually greater in the case of the ringed vines. 



The formation of pipless grapes in the place of normal 

 ones greatly diminishes the production on account of the 

 considerable difference in weight e.xistirg between the two, 

 which is shown by the following figures: — 



2,641 pipless grapes, average weight, 0187 gramme 



3,240 grapes with pips, „ „ 2130 grammes 



The loss which must ensue is therefore very evident. 

 To prevent it, every effort should be made, especially where 

 ringing is done, to promote pollination — particularly cross- 

 pollination — by the following means: — 



(1) Grow in the same row, varieties which cross- 

 pollinate readily; (2) in the glass house, or in garden cultiva- 



tion, artificial pollination is often of great assistance; 

 (3) flowers should be prevented from falling by repeatedly 

 dusting them with flowers of sulphur. 



The adoption of these methods should cause a 

 maximum number of large grapes with [lips lo lie produced 

 per bunch, and the development of flowers which would 

 normally fall, into moderately large pipless fruits. 



It is always advantageous to have a small percentage of 

 pipless grapes on the bunch, in spite of the fact that they 

 do not contain much sugar. 



COST OF SPRAYING CACAO IN TRINIDAD. 



At a recent meeting of the Trinidad Board of Agricul- 

 ture, the Mycologist (Mr. J. B. Borer, A.B., M.A.) presented 

 a report on the actual cost of spraying cacao derived from 

 trials made by himself and by different planters. 



It is pointed out first that the cost of spraying may be 

 divided into three classes.- (1) capital account, which includes 

 all apparatus and machinery; (2) cost of labour used in 

 mixing and applying the spray; (3) cost of the necessary 

 materials. 



The folldwing figures are next given in regard to the 

 actual cost of carrying oui the operations. It is stated that 

 a barrel outfit costing about §50 will spray under favour- 

 able conditions about 500 trees per day. A set of com- 

 pressed air knapsack sprayers costing about §100 will do the 

 same work, so if it is necessary to spray at the rate of 1,000 

 trees per day, from ■'5100 to ■'?200 must be invested in 

 apparatus. 



In regard to labour, one man should be able to spray at 

 least seventy- five trees per day. Practically speaking, a safe 

 figure appears to be fifteen men for the spraying of 1,000 

 trees per day. 



The cost of the spraying mixture depends upon circum- 

 stances. Bordeaux mixture generally costs about .^S per 

 1,000 gallons. P.ordeaux mixture with 8 lb of arsenate of 

 lead to the 100 gallons costs SIC per 1,000 gallons. Xicotine- 

 sulphate solution costs about •'JIO; kerosene emulsion is still 

 more expensive. On an average, the spray-mixture will be 

 applied at the rate of about ,' -gallon per tree to that 1,000 

 gallons of mixture will cover about 1,300 trees. 



Taking the figures given above as a basis for calculation, 

 it is inferreil in the report, that thorough spraying will co.st 

 about 515 per 1,000 trees per application. This is believed 



