82 REPORT OF THE AGRICULTURAL RESEARCH 



isolated from diseased plants in the field was found to be 

 insufficiently strong to attack healthy plants, although by 

 passage through several individuals or by artificial culture 

 on Potato it could be raised to a high degree of virulence. 

 For this reason the practice of leaving the plants in the 

 ground for a second cutting should be avoided in infected 

 areas. 



A bacterial disease of wheat in the Punjab, locally 

 known as " Tannan " or " Tandu," was investigated; this 

 was found to be due to the attack of a bacillus closely resem- 

 bling Ps. Hyacinthi which invests the opening ear with a 

 sticky growth causing deformation and stunting and pre- 

 venting ripening of the grain. The attack is confined to 

 small badly drained areas and can probably be avoided by 

 proper cultivation; its distribution is limited and it is pro- 

 bably of no economic importance. 



5. Programme of work for 1912-13. 



Work on influence of soil conditions upon nitrification 

 will be continued. 



A new line of enquiry will be commenced this year with 

 the object of determining the conditions under which nitro- 

 gen fixation by so-called non-symbiotic organisms may 

 balance losses of nitrogen due to various causes under agri- 

 cultural conditions. 



The green manuring experiments will be continued in 

 collaboration with the Imperial Agriculturist. 



Should time permit an attempt will be made to obtain 

 more precise data as to the effect of variations in tempera- 

 ture, moisture, and aeration upon nitrification in soils with 

 special reference to field conditions and agricultural prac- 

 tice. The apparent inhibitory action of various crops will 

 be taken into account, and the effect of different systems of 

 cultivation upon aeration and moisture content of soil. 



Work on formation of soil toxins and their influence 

 upon bacterial action will be continued. It is hoped that 

 this may be done in collaboration with Mr. Meggitt. 



