126 STATE POMOLOGICAL SOCIETY. 



• 

 also planted four thousand Clarner, two thousand Franklin, and four hundred 

 Clinton. TJiis gentleman states as the result of his experience that moderate 

 manuring and culture diminished the rot of the grape. The Concord grapes 

 of this vineyard rotted more than any of the other varieties. 



Messrs. Gruuer and Behus planted one-quarter of an acre with Ives' vines, 

 one year old. On the third year three thousand pounds of grapes were ob- 

 tained ; the fourtli, five thousand five hundred pounds, and the sixth year, 

 which was 1877, about one-quarter of the crop rotted. Tiiis firm had a Con- 

 cord vine eleven years old which, in former years produced bountifully, but iu 

 1877 its grapes rotted badly. One hundred Martha vines one year old were 

 planted, and gave the third year one thousand and fifty pounds of grapes; 

 loss by grape rot, one-third of the crop. 



G. A. Frendenthal has three acres of vines consisting of Ives', Martha, Vir- 

 ginia Seedling, Clarner, and Taylors Bullet, planted in lioles about two feet 

 square for each vine, and about ten feet apart. Of tliese varieties the Concord 

 and Martlia rotted most, and the Concord more than the Martha. The latter 

 is a white seedlins: of the former. Mr. Frendentlial states that the Concord 

 grape did not rot as much on the yellow sand as on the sandy loam. 



The soil at Egg Ilarbor is mostly gravel or coarse sand, while at Vineland it 

 consisted mostly of sandy loam. Sometimes the grape growers of New Jersey 

 discover at various depths from the surface of the soil a layer of what is 

 known as 'Miard pan," composed ,of carbonate of iron and sand, which is 

 imjiervious to water; it is frequently found necessary to cut through this iron 

 layer to allow the water to drain off from the surface. When water accumu- 

 lates in hollow, gravelly places after heavy rains, it indicated the presence of a 

 '^ hard pan" bottom or other impervious substances, the character of which 

 should be ascertained, and if possible a remedy applied. This precaution is 

 particularly necessary with plants of extended root growth such as the grape 

 vine. Ivoots penetrating standing water will surely ferment and the fruit of 

 the plant will fail to ripen. 



From the preceding investigation it will appear evident that the Concord 

 grape suffered more from rot than any of the other varieties mentioned. The 

 cause of this at first sight does not appear evident. While making these inves- 

 tigations I observed in some cases the green grapes of the Concord crack open 

 while hanging on the vine. AVhen such a condition occurs in. the absence of 

 mildew and after heavy rains, it would seem reasonable to suppose that the 

 cracking is caused by an abnormal and rapid absorption of moisture, probably 

 by the roots, although late investigations indicate that leaves also do absorb 

 moisture, not functionally, perhaps, as through their stomata or breathing 

 pores, but after the fashion of exosmose and endosniose. All membranes, 

 even those made of rubber, when very thin will under suitable conditions allow 

 "water to pass through them, and as the cellular tissue of the leaves of plants is 

 more porous than rubber, I deem it quite probable that moisture from dews 

 and rains will pass through the epidermal cells, although in a much smaller 

 ratio than by the roots. 



If it can be shown by any mode that the Concord grape vine absorbs more 

 moisture during excessively wet seasons than any of the other varieties men- 

 tioned, the rotting of the grapes under such conditions may be easily accounted 

 for, all other conditions being equal. In grape culture it is not so important 

 to consider the amount of rainfalls during the year as the special time they 

 occur. 



A vine which is affected year by year by the fungus known as Perouospora 



