30 THE RICE WORM (tYLENCHUS ANGUSTUs) AND ITS CONTROL 



lowest land, both because jute does not give good fibre if too early submerged 

 and also because paddy cannot be transplanted if there is too much water. 

 It is true that jute is often grown in land so low that there may be several 

 feet of standing water at harvest time. In this case, however, no transplanted 

 rice can be grown. Still, the moderately low land on which broadcasted aus 

 can be grown is sometimes double-cropped with jute and paddy. The long 

 period after the harvest of the previous crop, especially since the fields are 

 flooded for probably a couple of months before the paddy is put in, is evidently 

 enough to kill the worms. Wherever jute can be grown on land liable to ufra, 

 its cultivation should be recommended once every few years. 



Mr. Hector has found that it is more profitable, in some of the areas in 

 Dacca District where broadcasted aus and aman are grown as a mixed crop, 

 to replace the mixture with a pure crop of broadcasted aus followed by trans- 

 planted aman. In Noakhali and Backergunge, where both the constituents 

 of the mixed crop get ufra, this practice would not be likely to reduce the 

 disease : the transplanted aman would be infected from the aus. But in 

 Dacca, where the aus escapes, the replacement of the broadcasted aman by a 

 transplanted crop, put out several months later, should appreciably reduce 

 the damage. 



It has been amply demonstrated that the stubble from a diseased crop 

 is exceedingly infective if allowed to lie on the soil until the sowing time 

 approaches. In the greater part of the infected area little use is made of the 

 stubble of deep-water paddy. The crop is harvested leaving all but the top 

 foot or so behind, and what is left is not regarded as good fodder and is 

 rarely gathered for the purpose. In the majority of the fields it is left to 

 rot on the ground, and a thin crop of grass comes up through it and is grazed 

 by the cattle. The result is that the stubble is trodden into a matted mass 

 which keeps the surface of the soil moist in the early part of the year. In this 

 condition it resists decay for a considerable time. Even when the fields are 

 ploughed — often not till February— long wisps of half-buried stubble can be 

 found in them. In some places the stubble is sold to the potters for fuel 

 and ash, and the field may, in such cases, be fairly well cleared in December. 

 In other parts a certain amount is removed and burnt in the fields or more 

 usually as fuel in the villages. But in most of the really severely diseased 

 areas little is done to clean up the lowest fields after harvest. 



Experiment and observation alike show that if a field can be reasonably 

 well cleared of stubble and then ploughed and kept dry for two or three months 

 the worms can be killed out. Complete destruction of the stubble as in 

 Experiments VII to IX is scarcely practicable under field conditions, but it is 



