118 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



the Celery-leaf Blight. The past season (summer of 1886) I cultivated two separate 

 plats of 10,000 plants each. 



(1) After radishes. — On tliis plat fifty loads of stable manure had been appUed the 

 fall previous, and in the spring fertilizers were applied at the rate of one ton per acre. 

 After the crop the gi-ound was again plowed and hai'rowed and furrows opened 6 

 inches deep, in which night soil (privy manure and marsh mud) was applied heavily. 

 This was slightly covered and the celery plants set 6 inches apart in the rows, 

 July 16. The state of the weather was so favorable that during the next month the 

 celery naade a sti'ong and vigorous growth. So rapid was the growth that " hand- 

 ling " was commenced, the first operation previous to blanching. No change oc- 

 curred until September 20, when, after several hot and muggy days, the small 

 pale spots, or blotches, appeared, and these in the space of a few dsay enlarged so 

 as to embrace the entire leaf, which consequently turned brown and appeared now 

 to be covered with a white or powdery mildew. The stems and leaf stalks turned 

 yellow, after which they slxriveled away, and they also turned brown to black above 

 ground, the portion under ground remaining yellow, and showing brown streaks in 

 the cells of the stems extending to the junction of the stem and crown of the plant. 

 These stems and leaves were pulled off and cleared away as fast as time would 

 permit, but the same conditions continued. Stem after stem succumbed, following 

 in quick succession, leaving nothing but the heart of the plants. I now despaired 

 of my crop, but about the middle of October cooler weather set in, with more rain, 

 and the plants began to revive, and I again commenced to cultivate and to hope. 

 The result was a fair crop at harvesting; short, though particularly crisp and tender 

 from quick growth. 



(2) After early cabbage. — This plot had received 25 loads of stable manure broad- 

 cast, and 100 bushels of ashes per acre the year previous, and to which 35 bushels 

 of lime were added in the spring and all plowed under together; then there was 

 applied, broadcast, 1 ton of fertilizer, which was harrowed in. After the crop of 

 cabbages was removed, in July, the ground was again plowed and prepared, fur- 

 rows were opened 6 inches deep and a liberal dressing of hen manure applied in the 

 furrows. The celery plants were set July 21, and an uninterrupted growth contin- 

 ued until September 29, when the Blight made its first showing in the pale and 

 brown spots and blotches on the leaves. I commenced at once to remove all such 

 stems by pulling off and taking out of the patch. I had no further trouble from 

 the Blight, but whether this treatment produced the result, or whetlier it was due 

 to a change in atmospheric conditions, I cannot say. Plat No. 3 resisted the attack 

 longer than No. 1, and recovered without material damage. The heart and roots 

 do not seem to be affected by the BHght, and where the soil is strong and rich in 

 plant food> and the weather cool and moist, the plants may possibly outgrow an 

 early attack and mature a fair crop. 



The past season was the first that I have noticed the pale spots on the leaves, or 

 the powdery appearance upon the upper surface. I am inclined to believe from the 

 season's experience that manure in the rows, as in Plat 1, is conducive to the devel- 

 opment of the Blight. 



The variety known as the " White Plume," was the first to be attacked, and suf- 

 fered most; the " Half Dwarf" variety resisted the attack longest and suffered least. 

 The "White Plume," however, recovered soonest from the disease, and developed 

 the largest and fullest heart. 



This disease is quite distinct from any general yellowing, or what 

 might be properly termed "blight" of the leaves, which may arise 

 from some injury to the roots, to the lack of proper food-elements in 

 the soil, or from an excess of rain or drought, and is undoubtedly 

 due to the direct action of the fungus. The result of this action is 

 the partial or complete destruction of the leaves, which are at once 

 the lungs and digestive organs of the plant, and it is needless to speak 

 of the gravity of any cause which may effect injury to organs of such 

 vital importance. The period when the fungus is most active is from 

 early in July to the latter part of August, but I have found upon 

 celery in the markets during the latter part of October leaves that 

 were strongly infested with the disease. 



External characters.— Th.Q first evidence of the Celery-leaf Blight 

 is the appearance upon both sides of the leaf of pale yellowish-green 

 spots, irregular or somewhat rounded in outline, anS varying from 

 one-sixteenth to one-fourth of an inch in diameter. These spots soon 



