762 ANNUAL REPORT OF THE Off. Doc. 



fungus, rhizoctouia, whicli attacks the roots and stems of many cul- 

 tivated jjlauts. The hist indication of its presence is found in the 

 wilting of the leaves in the buds. The edges turn inward, giving the 

 plant a lighter appearance. The wilt conlinues, and examination of 

 the stem shows discoloration. The i)resence of the fungus in the 

 stem appears to shut olf the circulation of the eap, and in bad cases 

 the vine will turn yellow quickly. In other -cases, the injury to the 

 stem may be sufficient only to dwarf the grow th of the vine. The 

 fungus may attack the stems that feed the tubers, checking their 

 growth and giving only small potatoes from large vines. In 1DU2 

 this disease again attacked a field of potatoes on the farm and gave 

 promise of most severe injury, but it was checked by some unknown 

 means — most probably by a period of cool, dry weather — and while 

 some plants were too badly atl'ected to recover, a majority did so, 

 losing the wilted appearance and giving a good yield of large tubers. 

 it is known that the germs are transmitted on the seed, and that 

 when they are in the soil it nmy remain infested for many years. 

 Station authorities advise treatment of the seed with corrosive sub- 

 limate and liming of the land. The spraying of affected vines with 

 any fungicide can not affect the disease which is lodged inside the 

 stem of the plant. 



HARVESTING AND STORING. 



Potatoes keep beet when they can be left in the ground until 

 the cool nights of September, if the season is dry. In a very wet 

 season, ripe potatoes left in the ground may make a second-growth, 

 sending up sprouts from the eyes, and there is danger also of rot. 

 But it is not easy to keep potatoes stored in quantity in very hot 

 weather, and it usually is better not to dig until earl^^ in the fall 

 unless the crop can be marketed at once. Just as soon as the nights 

 become cool, the potatoes can be stored safely in piles in the field 

 under a covering of straw, or in cellars. Aoy tubers cut by steel 

 in digging should be taken out of a lot intended for early storage 

 aei they will rot in a warm splace. This is equally true of potatoes for 

 early shipment to a distant market. 



Diggers. — Formerly the crop w'as dug largely with hoes, hooks 

 and forks, but the lack of cheap labor has brought a number of kinds 

 of good implements for harvesting the crop. In loose soils, and es- 

 pecially with shallow planting and ridge culture, some of these dig- 

 gers do nearly perfect work. The best digger is one that lifts up 

 all the soil in the row with the potatoes, sifts the soil back into 

 the furrow it makes, and leaves all the tubers lying on the surface. 

 The digger that elevates the mass of earth in the row, and gives 



