6 MASS. EXPERIMENT STATION BULLETIN 195. 



It will be noted that the season of 1916, as a whole, was very wet, with 

 excessive rainfall occurring during the first two-thirds of the growing 

 period. The season of 1915, which was so disastrous, was even more 

 wet; but a reversal of the 1916 conditions is found, most of the rainfall 

 occurring during the last two-thirds or half of the season, when the crop 

 was going through its period of greatest growth, and maturing. The 

 season of 1905, while rather dry, produced many fine crops of tobacco 

 (although they were later damaged by pole sweat), and it will be noted 

 that the rainfall was low; in fact, the precipitation was below normal in 

 many of the weeks and, as a whole, the season would be considered a 

 droughty one. The fact that the last week or two were very wet, and 

 consequently interfered somewhat with harvesting, does not in any way 

 lessen the importance of the statement that the crop was very large. 

 The quality, however, was slightly lowered. 



There is no question but that the excessive precipitation of the two 

 seasons first mentioned reduced the weight and quality of the crop; but 

 its general effect was much less in 1916, when most of the excessive rains 

 occurred in the first half of the growing season. These checked early 

 growth in the field, but a subsequent return to normal, or thereabouts, 

 in August allowed of a rapid development in the last few weeks, although, 

 in spite of the favorable conditions, the crop was late in maturing. The 

 excessive rainfalls of 1915 and 1916 have, in all probability, been an 

 important factor also in intensif3dng the effects produced on the crop by 

 the various forms of soil "sickness." 



To illustrate : It was observed that on fields kno^\m to be badly infested 

 with the root-rot fungus {Thielavia basicola Zopf.) the percentage of plants 

 infected sufficiently to check growth was much greater than usual in 1915 

 and 1916. The apparent leaching out of certain plant foods, especially 

 the more soluble forms of nitrogen, was also observable, as indicated by 

 the character of growth on some fields. Mention will be made of a few 

 interesting observations on this point later in the report. 



The theoretical benefit which might be derived from the leaching out 

 of the accumulation of soluble salines — which Haskins ^ found to be 

 excessive (as compared with soils producing normal crops) in certain spots 

 and fields producing unthrifty plants — was apparently observable in 

 some cases and not in others. It is unfortunate that determinations of 

 the change in amounts of these salines present in soils which had been 

 previously examined were not made, but lack of time prevented this. 



It is a well-recognized fact that rainfall, soil-moisture, and temperature 

 all play an important role in the making of quality of tobacco, and it is 

 also true that, as a rule, the finest quality of cigar leaf is raised on light 

 soils which carry relatively only a small percentage of moisture, say from 7 

 to 15 per cent. Aside from quality alone, in seasons with excessive rains 

 there is always a falling off in the crop, particularly as regards weight. 



A study of the rainfall, relative humidity, hours . of sunshine, and 



1 Haskins. H. D. Twenty-fourth annual report, Mass. Agr. Exp. Sta. (January, 1912), p. 35. 



