CEREALS J 3 



At this point one of the very latest scientific discoveries 

 comes in. The native usually allows his land to remain 

 unploughed for a considerable time after the wheat has 

 been removed, but it was noted at Pusa that if the soil 

 were ploughed soon after harvest and exposed to the sun 

 and wind during the intensely dry, hot weather of April, 

 May, and June an astonishing effect was produced on the 

 succeeding wheat crop, which appeared to have been 

 manured with some nitrogenous fertilizer. The key to 

 this riddle was subsequently supplied by Rothamsted. 

 Apparently the sun in India supplies sufficient heat to kill 

 off or diminish harmful soil organisms, and in that way 

 adds to the supply of available nitrogen. One wonders 

 to what extent the growers and consumers of wheat can 

 benefit by this application of modern science in other 

 words, to what extent can sunshine replace the dung cart 

 in hot countries. Does it provide one explanation for the 

 benefits of fallowing in temperate climes ? Be that as it 

 may, the variation of native practice as to the time of 

 ploughing led at Pusa to a notable increase in the follow- 

 ing crops. 



In India, and especially tropical India, the rust problem 

 is of the greatest importance. In 1896 Watt estimated 

 the annual loss from rust in India at upwards of 10 per 

 cent. It varies from season to season, and is much 

 greater in some districts than in others. For instance, 

 " the damage done in the great wheat-growing tracts of 

 the North- West is generally slight, while in Bombay, the 

 Central Provinces, and in parts of the United Provinces 

 and Bengal the crop may be reduced 50 per cent, or even 

 more." Nor is the prevalence of rust a modern occur- 

 rence, for in 1839 Sleeman, referring to rust in the 

 tropical Central Provinces, wrote: "I have seen rich 

 sheets of uninterrupted wheat cultivation for twenty miles 

 by ten in the valley of the Narbada so entirely destroyed 

 by this disease that the people would not go to the cost 

 of gathering one field in four," and further: " I believe 

 that the total amount of the wheat gathered in the harvest 

 of 1827 in the district of Jubbulpore was not equal to the 

 total quantity of seed that had been sown." 



I need not go on piling up evidence of the harm done 



