48 EXPERIMENT STATION EECOED. 



floodiug, and moving water diminishes the amount. Mineral salts had no effect 

 on tlie disease, nor did the addition of ground limestone, aside from the general 

 effect it had on the growth of rice through improved biological conditions. 



From the results of the experiments, the author suggests that the disease 

 may be controlled by the preparation of the soil and the seeding of the rice 

 when the soil is in goocl condition to work. Rice should be flooded for the 

 first time when it Is about 8 in. high, barely covering the land with water for 

 G or 7 weeks. At the time the head is forming in the "boot " the water should 

 be drained off and the soil aerated for 2 or 3 weeks, after which the fields are 

 again to be flooded to a depth of about 3 in. for 4 or 5 weeks. The water 

 should be gradually drained off until time to dry for harvest. 



Preliminary study of the red rot of sugar cane in the Bombay Presidency, 

 G. S. KuLKARNi {Dept. Agr. Bombay Bid. J/Jf, 1911, pp. 8, pis. 3). — The red rot 

 disease due to CoUetotrichum falcatum has become a serious trouble in some of 

 the cane-growing regions of India. The distribution of the disease and symp- 

 toms are described. 



From the author's observations it api>ears that the infection is most com- 

 monly through the use of diseased cane for planting. For the prevention of 

 the disease it is urged that the sets be carefully examined and only those that 

 show white pith at the cut ends be selected for planting. Any that show the 

 slightest reddening should be destroyed. 



The life history of the plum rust in England, F. T. Bkooks {'Neio Pliytol., 

 10 {1911), ISO. 5-6, pp. 207, 208; Gard. Chron., 3. ser., 50 {1911), No. 1295, i). 

 292; ahs. in Internat. Inst. Agr. [Rome], Bui. Bur. Agr. Intel, and Plant Dis- 

 eases, 2 {1911), No. 11-12, pp. 2603, 260 J/). — A severe epidemic of plum rust 

 {Puccinia prunl) is said to have prevailed in fruit plantations of Cambridge- 

 shire, England, the trees often being prematurely defoliated. There has been 

 some doubt as to how the fungus survives the winter. Both uredospores and 

 teleutospores are produced on plum leaves, but experimental proof is lacking 

 that they can survive the winter and infect the leaves of the plum the following 

 season. 



Experiments by the author, in which a?cidiospores of Jicidium punctatum 

 from Anemone coronaria when placed on plum leaves produced the disease, 

 confirm the claim of the hetercecism of P. pruni. The mycelium is perennial 

 in Anemone and gives rise to crops of uredospores year after year, so that a 

 few plants attacketl by the a?cidium are sufficient to account for the recurrence 

 of the plum rust. After the first crop of uredospores has been produced on the 

 plum leaves the fungus spreads rapidly on that host. Plants of Anemone 

 affected by the fungus are said to have more fleshy leaves and to flower very 

 rarely. 



The eradication of plants of A. coronaria affected by the fecidium is sug- 

 gested as a means of controlling this disease. 



Experiments on the control of chlorosis of fruit trees, G. Riviere and G. 

 Bailiiaciie (Prog. Agr. ct Tit. {Ed. VEst-Centre), 33 {1912), No. 11, pp. S'/O- 

 S'/Jf). — Experiments are reported on the treatment of pear trees for chlorosis. 



The trees were fed a solution of pyrophosphate of iron with ammonium citrate 

 through holes near the base of their trunks. Inserted in the holes were tubes 

 connected with vessels holding the solutions of the chemical. The solution, it 

 is said, did not precipitate tannin and close the vessels of the wood, as is the 

 case when some other iron compounds are used. Ten-year-old pear trees took 

 up more than 14 liters of the solution, corresponding to 0.716G gm. of the 

 pyrophosphate of iron, in S7 days of the experiment. The chlorotic appearance 

 of the trees was changed to a healthy one. 



