410 Journal of the Department of Agriculture. 



Ripeninf/. — Soon after the flower-head of the tuvkish tobacco 

 phuit befi'iijs to develop, the lower leaves undergo a decided change in 

 colour. This change in coh)ur and other properties constitutes the 

 pi'ocess of ripening. Garner states that " tlie young glowing leaf 

 has an intense green coh)ur, showing Ihal it is quite ricli in the 

 nitrogenous constituents wliich go to make up the living or A'ital 

 part of the leaf and which are active in l)uil(ling up ilic food su])ply 

 of the plant. This food supply, consisting of starch and other 

 similar substances, is carried from the leaf into the seed-head to 

 furnish the necessary food for the development of the seed. This 

 accomplished, the leaves have completed their full task, and they 

 now pass into a period of gradual decay. . . . The principal indica- 

 tion that the above-mentioned processes are taking place is a decided 

 change of colour. AVhen tlie reserve food supply of the mature leaf 

 is no longer required for ihe nourishment of the otlier parts of the 

 plant, it is deposited in the leaf tissue in the form of starch granules, 

 while the green coiiiUring matters are dissolved and carried to the 

 younger, growing parts. This interchange causes the appearance of 

 light-tinted flecks so characteristic of the ripe leaf. Moreover, the 

 accumulation of the starch grannies in the leaf causes it to become 

 brittle, so tliat it snaps when folded between the fingers, another 

 characteristic sign of ripeness. Now, the replacement of the complex 

 nitrogenous constituents, including the green colouring matter, by 

 starchy matter has a most important effect on the colour, flavour, 

 elasticity, and finish of the leaf. Indeed much of the success in 

 curing tobacco depends on harvesting it just at the right time, when 

 it is neither too ripe nor too green." If the leaves are harvested too 

 green, the colour will be dull and dark, because they contain too 

 much of the green colouring matters, and if they are harvested too 

 ripe the colour will be imeven, mottled, and lacking in freshness, 

 because they contain too little of the green colouring matter. For 

 these same reasons green leaves when cured are tough and leathery, 

 and over-ripe leaves strawy and lifeless to the touch. 



As the lower leaves on the jilant contain a greater percentage of 

 moisture and are less tough than the higher-placed ones, and, being- 

 nearer the ground, suffer to a greater extent from llie reflected heat 

 of the sun's rays, they have a tendency to rijjen very (juickly during 

 hot spells. Unless the grower has many extra pickers during such 

 hot spells in December and the beginning of January his loss from 

 over-ripe and shiivelled lower leaves is often considerable. To })ievent 

 this, it is advisable to commence harvesting the bottom leaves sliglitly 

 on the green side, and so be prepared for tlie second picking, i.e. the 

 middle-seconds, which also ripen all too soon. The lower leaves, even 

 it liar\ested slightly green, turn a better coloui' than the top leaves. 

 The grower, however, is cautioned not to overdo this. As a rule, 

 the bottom leaves are ripe a few days before the flowers begin to 

 open (see fig. 1). (Unlike most other tobaccos, turkish tobacco is 

 not topped.) Different ty])es of turkish tobacco differ in appearance 

 on ripening. Samsun, for instance, has a very yellowish appear- 

 ance, and the leaves seem unusually translucent, not unlike White 

 Burley, when held, even when it is still (juite green, against the light, 

 llipe Kavalla leaves show marked light-tinted flecks when fully ripe, 

 and leaves which are still latlier green are generally yellowish in 

 ajipearance. Rijje Dubek, on the other hand, seems green to the 



