CITEUS DISEASES. 57 



viewi)oint.. the requireiuents heiug a machine that will ^ve satisfac- 

 tory, sustained service. To avoid delays, spare parts for engine, and 

 hose and nozzle equipment, should be at hand. Special men should 

 be trained to manipulate the spray leads, and to operate them cor- 

 rectly without waste of material, ])ut in such way as to cover each 

 tree thoroughly. Watch must be kept to maintain sufficient .pressure. 

 Material applied in large drops is valueless if not harmful, a fine 

 mist, uniformly applied, being the desired aim. The requisites then 

 for a successful spraying campaign are adequate equipment, and the 

 proper material applied at the proper time, and in thorough manner. 



SPECIFIC DISEASES. 



DISEASES OF THE SEED-BED. 

 DAMPING OFF. 



Considerable losses are sustained by fung-us attack in the seed- 

 bed, by what is commonly known as damping oif, since delicate seed- 

 lings are peculiarly subject to infection. Several fungi are doubtless 

 involved, acting either independently or together, but the symptoms 

 are practically identical. Infection occurs most commonly near the 

 ground level, and is first noticed as watersoaked areas on the stems, 

 that soon become brown and sunken. Following infection the seed- 

 lings fall over and death ensues. Isolated plants are first attacked, 

 but small patches are soon involved, which enlarge and unite if 

 prompt measures are not taken to check the trouble. 



Control lies in careful management of the seed beds. The im- 

 portant point in this connection is to provide for thorough drainage. 

 Excessive shading should be avoided. An inch of dry sand applied 

 over the bed at the first appearance of the disease often checks its 

 spread. The greatest possible cai-*' nuist be exercised in artificial 

 watering. Thorough applications at as long intervals as possible are 

 preferabh' to frequent sprinklings, which wet only the surface of the 

 soil, and so aid the fungus. Since infection takes place at or near 

 the crown of the plant on tlie ground level, care should be taken to 

 keep this region as dry as i)ossible to inhibit fungus action. 



In selecting new areas for seed-beds, land should be taken which 

 has not been used previously for this purpose, or land on which at 

 least, damping oflC luis not occurred. If this is not obtainable, the 

 soil should be sterilized, either by steam applied under pressure for 



