254 AGRICULTURE OF MAINE. 



Repeated attempts in our laboratory to isolate a bacterial or 

 fungous parasite from tubers affected with net-necrosis have 

 only resulted in failure. We do not know its cause, and did 

 not know its effects, other than that it made the tuber unsalable 

 for table use. Numerous inquiries have been received, asking 

 if it was advisable to use for seed purposes tubers so affected. 

 On general principles we have advised against it, for experi- 

 ence has indicated that it is unsafe to plant any abnormal tuber. 

 However, for the past two years we have been asking these 

 and other questions relative to net-necrosis of the tubers them- 

 selves, both in the greenhouse and in the field at Highmoor 

 Farm. 



This work, although it must be regarded as still in the pre- 

 liminary stages, strongly indicates that the man who plants 

 potatoes affected with net-necrosis may safely increase his 

 acreage materially, without taking the trouble to provide addi- 

 tional storage for his prospective crop. If he does not know 

 what spindling sprout is, let him plant tubers affected with net- 

 necrosis and learn to his entire satisfaction what it looks like. 

 Please note that no claim is made that net-necrosis of the 

 tuber is the sole cause of spindling sprout in the plant. The 

 fact remains, however, that in our experience so far, one fol- 

 lows the other with great regularity. 



Two lots of tubers, practically all of wdiich showed net- 

 necrosis, were planted at Highmoor last spring. Part of the 

 seed pieces failed to germinate. In one case, of the hills that 

 did come, 183 out of 204 showed characteristic spindling 

 sprout, and there were few normal ones among the remainder. 

 In the other, not a single healthy plant was produced and 86 

 out of 119 were classed as typical cases of spindling sprout. 



The yield of the first lot was at the rate of 100 bushels per 

 acre, and of the second, 38 bushels. The poorest plants and 

 the lowest yield w^as obtained from the tubers which showed 

 the greatest amount of net-necrosis at planting time. One lot 

 of healthy Green Mountain seed tubers and another of Rural 

 New Yorker on the same field, in adjoining rows, under as 

 nearly as possible identical conditions, each produced at the 

 rate of over 325 bushels per acre. 



