NOV. 1900.] 



R97 



Plant Sanitation. 



successful carrying out of this important work. The application of the simple 

 instructions drawn up recently by the author on Ned wet el Assal is a proof of this. 

 Unfortunately, in so suitable a climate for the propagation of insect pests, the 

 absence of a complete resting stage, and an almost continuous succession of broods, 

 the working of insect life is such that it is not until a pest has obtained a firm 

 hold on cultivation that the evil is brought to light. 



From practical observation in the field, there is considerably more cotton 

 worm in the country than is generally supposed, and the pest having once reached 

 a certain stage, human agency can do little more than act as a check, it being 

 almost impossible to entirely exterminate it. A natural method, acting in co- 

 operation with the system at present employed, is therefore required to further the 

 success of this important work. The occurrence of insect pests on cotton can invari- 

 ably be traced to unnatural methods of cultivation, such as late and heavy sowing, 

 which produces weak plants and small crops ; overcrowding and overwatering, 

 which provide abundance of food and conditions favourable to pests, by producing 

 rank, succulent, shady growth, fatal to the lower bolls and the early first picking 

 of cotton. The deteriorating effect of fertilization by inferior varieties has also 

 to be considered. The practical agriculturist has only to look at the strong 

 useless wood and rank foliage produced by the average crop, and to consider the 

 strain on theland and the valuable time wasted in its production, to understand that 

 the application of quick acting manures under the present cultural conditions would 

 in many cases only hasten disaster by over-stimulating the plants. Moreover the folly 

 of utilizing the unique cotton-producing characteristics of this climate and soil for 

 producing useless wood and foliage, is apparent from the yield of last year crop. 



Cotton cultivated under a suitable method, by the writer, and proved by 

 a series of practical experiments, presented the following appearance :— 



Healthy, bushy plants covered with flowers. Red-ripe wood. Foliage slightly 

 yellow in colour. One and two bolls at the base of each leaf. Flowers well above 

 the terminal shoot. The lower branches on the ground with bolls. 



Sun and air to reach all parts of the plants. Instead of which, one finds 

 large areas of over- watered cotton with soft green and unripe wood, dark rank 

 foliage, few flowers, and the early bolls at the base of the plant shaded, of an 

 unhealthy yellow colour, and falling from the absence of light and air. Still larger 

 is the area of small, weak plants, caused by late planting, from which it is hopeless 

 to expect a full crop. 



Should further proof be required for the necessity of reform in the cotton 

 cultivation of Egypt, it can be found in the very large number of unripe bolls to 

 be seen on the stacks of dry cotton stalks everywhere. 



The natural methods of agricultural reform in cotton cultivation, strong 

 in their simplicity, may probably be entered into in time for next season's crop* 

 The object of the writer is merely to endeavour to show how the work of checking 

 Prodenia littoralis can be assisted by nature, rather than by reform in cultivation, 

 although they both work hand in hand. 



A NATURAL METHOD OF PREVENTION. 



Dryness prevents the deposit of the egg-nidus by the female moth. Heat and 

 dryness combined are fatal to the young cotton worms. The production of rank, 

 succulent foliage and shade by overwatering has been mentioned ; because it is not 

 only detrimental to the yield of a full crop, but also to show that it produces 

 abundance of food for cotton pest in the form of chlorophyll or sap in the cells 

 between the upper and lower epidermis or skin of the leaf. This green-coloured fluid 

 is essential to the life of the cotton worm, especially in the early stage of j the hatching 

 moreover, on such cotton foliage only are eggs deposited by the female moth 



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