20 EGYPTIAN AGRICULTURE. 



to exist under thickly planted crops. Seed crops should 

 be sown thinly so as to allow of the fullest formation of 

 the seed. 



Light breezes are usually conducive to health and 

 vigour of life. Through shaking the leaves of plants, the 

 breeze ensures a fresh supply of air from which the plant 

 can abstract its food materials. By ventilation or the 

 gentle circulation of air, animals are enabled to live in 

 closed houses without suffering from the carbon dioxide 

 which they exhale. Wind is also serviceable in bringing 

 about the fertilisation of plants. Unfortunately it also 

 fertilises and spreads the seeds of weeds. Further, it 

 distributes the " seeds" of plant diseases. Hot, dry winds, 

 causing excessive evaporation, are exhausting to both 

 animals and plants. Strong winds do more or less 

 damage in detaching the seeds from the plants and thereby 

 decreasing the yield of the crop. When strong winds 

 are blowing, great care is necessary in the watering of the 

 cereal and maize crops ; the water loosens the soil and 

 plant roots and the wind "lays" the crop. The sand 

 carried by strong winds injures the plants by cutting into 

 their tissues damaging the plant and allowing of the easy 

 entrance of disease germs. 



