INSTITUTE AND COLLEGE, PUSA, FOR 1913-14. 45 



is six to eight. The great saving of water possible by tha 

 use of a surface mulch in the case of a wheat crop is there- 

 fore obvious. 



The growth of Persian clover (shaftful) as a green 

 manure at Quetta continues to give excellent results. When 

 sown in August, this crop gives three cuts of green fodder 

 weighing about 60,000 lbs. per acre before the end of the 

 following May. In addition, the last cut is either ploughed 

 in as green manure or a crop of seed is raised. A marked 

 improvement in the water holding capacity and tilth of the 

 soil follows this treatment. A small amount of seed was 

 distributed during the year and arrangements are being 

 made to raise a large quantity this summer. 



The investigations, referred to in the previous report, 

 on the yellowing of peach trees have resulted in the 

 discovery of the cause and of an easy method of prevention. 

 In the vegetable gardens in the Civil Station of Quetta the 

 peach trees have, as a rule, very yellow foliage, often accom- 

 panied by excessive gumming. Such trees die very quickly 

 and do not bear a large crop once the unhealthy symptoms 

 are well marked. The early symptoms appear to be iden- 

 tical with the disease in the Eastern United States known 

 as " Peach yellows." The later symptoms of the disease, 

 namely, premature reddening and ripening of the fruit, are 

 however not developed. The yellow condition is not pro- 

 pagated by buds taken from affected trees and thus the 

 disease is not the " Peach yellows " of the United States. 

 Applications of soluble nitrogenous manures, such as nitrate 

 of soda or sulphate of ammonia, gave negative results, so 

 that want of available nitrogen is not connected with the 

 trouble. It was found that if shaftal is grown round the 

 affected trees the disease slowly disappears and the trees 

 produce healthy growth. This result suggested that the 

 yellowing of the foliage is due to want of air in the subsoil 

 which follows the system of surface irrigation without any 

 subsequent cultivation now in use at Quetta. During the 

 present year this opinion has been confirmed. Some of the 

 peach trees at the Fruit Experiment Station were over-irri- 



