May, 1909.] 



Edible Products. 



In former days cultivators scarcely 

 manured their lands for paddy cultiva- 

 tion, and, although they do now, the 

 quantity is scarcely sufficient. The 

 manure should either be applied as 

 soon as a previous crop has been reaped 

 or kept in composts, and applied_wheu 

 ploughing in quantities of from 175 to 

 200 baskets per acre of farm-yard 

 manure. The held should be ploughed 

 deeply in the manner laid down in the 

 chapter regarding operations. 



If the ground has been throughly 

 manured and properly tilled no insects 

 are likely to injure the plants ; insects 

 only attack plants when the plants are 

 not healthy owing to bad cultivation 

 or to the exhaustion of some particular 

 plant-food in the soil. 



There are three kiuds of insects 

 known to injure the paddy crop 

 from the first stage after seedlings are 

 transplanted until the whole crop 

 has been damaged, and no cultivators 

 appear to have done anything towards 

 their prevention :— 



(1) Palanbyu (a variety of saw-fly) is 

 the size of half a grain of rice, 

 blackish in colour, with two wings 

 on each side, four legs, and a small 

 horn. They generally come from 

 elsewhere just after the seedlings 

 are transplanted and suck away 

 the leaves until the leaves become 

 white and die away. 



(2) Nga-myaung-yang (also a variety 

 of saw-fly) is dark in colour, as 

 big as a grain of lice, with 12 logs, 

 They generally form from the 

 plant jus-t when the plants begin 

 to grow well, and just at the time 

 the particular plant-food required 

 is exhausted. 



(3) Sitpo fa variety of grub) is the 

 size of an oi'dinary louse, and is 

 white in colour. They also form 

 from the roots in the same way as 

 uga-myaungdaung. When crops 

 are damaged by any or all of 

 them the cultivator is recommend- 

 ed to dust with lime while the 

 corn is still young and the insect 

 spread on it. Soot would prob- 

 ably do good, it being a fertilizer 

 as well as disagreeable to the 

 insects. 



RIPENING OP TROPICAL PRUITS. 



Some interesting investigations by 

 Mr. H. C, Prinsen Geerligs, dealing with 

 the chemical changes that take place 

 during the ripening of some tropical 

 fruits of Java, are reported upon in a 



paper lately published in the Interna- 

 tional Sugar Journal. The fruits dealt 

 with included the banana, mango, tama- 

 rind, and sapodilla. 



Bunches of bananas, as is well known, 

 are generally cut from the tree in an im- 

 mature state, and when the fruit is hard, 

 tasteless, and unfit for food. After a few 

 days the edible matter becomes tender, 

 sweet, and well-flavoured, but againa few 

 days later the fruit is unpalatable, owing 

 to over-ripeness and decay. Some of the 

 changes that go on in these stages were 

 investigated by Mr. Geerligs. 



A notable feature was the loss of 

 weight that takes place during ripening. 

 Twenty green bananas, kept in a cool 

 place, were found to have lost an 

 average weight of 8 grammes each at the 

 end of seven days. In another case, ten 

 green bananas of a smaller variety, 

 weighing originally 502 5 grammes, lost 

 15 5 grammes in four days, and by suit- 

 able means it was shown that of this 

 loss, 2-3 grammes were given off as car- 

 bon dioxide. 



From a bunch of bananas, cut in the 

 immature state, a single fruit was ana- 

 lysed daily for a week, so that the 

 changes in progress might be observed. 

 At the end of the week the remaining 

 bananas were in a stage of over-ripeness. 



The most prominent feature of the 

 ripening process in the case of the 

 banana was the rapid transformation of 

 starch into sucrose or cane-sugar. At 

 the first analysis of the unripe fruit, the 

 percentage of starch in the banana pulp 

 was 30'98, and of sucrose 0'8(3 per cent. 

 Two days later, the starch had decreased 

 to 2P98 per cent., while the sucrose 

 present was 443 per cent. On the fifth 

 day from the first analysis, the banana 

 (almost ripe) contained 13'89 per cent, of 

 starch, and 10 5 of sucrose, while on the 

 following day there were present in the 

 fully ripe fruit only 9-59 per cent, of 

 starch, but 13 - 68 per cent, of sucrose. 

 The percentages of glucose and fructose 

 also increase during ripening, and in 

 the fully ripe fruit. In the over-ripe 

 bananas, the proportion of sucrose 

 shows a falling off (l0 - 30 percent.), which 

 is explained by the fact that inversion 

 of the sucrose into glucose and fructose 

 takes place. The latter two products 

 also undergo further breaking up, which 

 probably accounts in part for the large 

 amount of carbon dioxide formed in 

 after-ripening. 



Mangoes also are usually picked when 

 unripe. At that time they are hard, acid, 

 and flavourless, but the after-ripening 

 process renders them tender and full- 

 flavoured in a few days, 



