ROOT CROPS. I^'- 1 



The injury to the tuber is very similar to that done to the plant. The eye 

 of the potato is usually the spot selected by the moth to lay its eggs. The 

 larva, when hatched, channels its way through jusl beneath the skin, or 

 through the substance of the tuber. Its presence can usually be detected by 

 the castings or excrement which it throws out. Several larvie have been 

 found in the one tuber. 



Ihe battle should begin when cultivating. Where hilling is the practice 

 it should be done with care, so that all tubers should be well covered with 

 well-pulverised soil, and no clods should be permitted, as they form crevices 

 for the moth to make its way in and do its work of destruction. Where flat 

 cultivation is practised, plant deeply and keep the soil well stirred. When 

 the potatoes are dug they should be bagged without delay; if they are 

 exposed even for a .-hurt while infestation i- almost sure to follow. It will 

 be particularly noticeable in a season when showers are frequent that the 

 percentage of infected tubers when dug is considerably smaller than in a 

 comparatively dry one. This is mainly owing to the rain breaking down 

 the clods and compacting the soil, effectually closing any crevices, thus 

 preventing the moth from gaining an entrance to the tubers. 



Many growers, after filling the bags, and before sewing them up, cover 

 the mouth of the bag with stalks and leaves, probably to shade them from 

 the sun. This practice cannot be too strongly condemned, as the moth is 

 generally lurking in the haulms, and will immediately leave them to attack 

 the potatoes. All stalks and foliage should be removed and effectually 

 destroyed as soon as possible. The bags should be sewn up immediately 

 after filling and l'emoved without delay to suitable storage. If it is not 

 convenient to remove them for some time they should be placed in stacks 

 and closely covered with some cloth or tarpaulin. Extreme care and watch- 

 fulness all along the line are necessary, particularly in storage. The 

 majority of growers think that there the tubers are immune from attack. 

 Far from it ; more damage is done while in store than elsewhere. But if 

 suitable storage is provided, the ravages of the moth can be better controlled 

 than in the field. 



Frequently potatoes are stacked in the open shed on the farm, and no pre- 

 cautions taken in the way of securely covering them. To prevent infestation 

 hey should he stacked in a tight room. On top of the stack place a sliallcw 

 - essel, and into this pour some bi-sulphide of carbon, and close the door 

 tightly. This liquid becomes a gas when exposed to the air, and being 

 heavier than air the fumes diffuse among the potatoes and destroy any moths 

 and larvae. This should be repeated every ten to fourteen days, in order to 

 kill any larva? or moths that might emerge from the egg stage. Four or five 

 charges should be sufficient. About 5 lb. of liquid bi-sulphide of 

 carbon to every 1,000 cubic feet of space should be used. As the gas is 

 highly inflammable, the greatest care should be exercised. No lights of any 

 kind should be near, or disastrous results will follow. 



Of course it is recognised that many growers may not, perhaps, be in a 

 position to provide themselves with a suitably-closed room, but every effort 

 should he made to do so. and to adopt the treatment recommended. Tt will 

 be found that the potatoes, being free from infestation, will realise better 

 prices, and the trouble and expense will be warranted. In the absence of 

 such a store-room, the potatoes should'be drawn into a heap, a saucer 

 containinc- carbon bi-sulphide placed on top. ami the whole covered closely 

 with a cloth. 



Covering with grass from some place remote from the potatocrop, or hay, 



and occasionally sprinkling with water, i- a primitive method, but is found 

 to keep the attack in check. 



