156 



grain. The endosperm is only scantily filled with starch ; the grains slender 

 and light. 



A second injurious efifect is the shortness of the straw. This appears 

 especially in summer oats, which on light soils have red stalks and grow- 

 scarcely a foot high, maturing only a few small heads instead of the full 

 ones. Barley shows less injury, wheat comes next and finally rye, the most 

 resistent. If the dry period makes itself felt as early as seeding time, the 

 plants come up late and unequally. This leads to a double growth, i. e., to 

 a very irregular maturing of the grain. At the time of harvest many green 

 blades are found among the ripened ones. The former come from the seeds 

 which were left on top at the time of sowing, and which at first did not start, 

 while those more deeply placed found moisture enough for a speedy germi- 

 nation. 



In this, limited local conditions often become effective. Thus, for ex- 

 ample, one early crop may have drawn more water from the soil than an- 

 other, or a potassium fertiliser is irregularly distributed and keeps the soil 

 more moist in the spots where it has accumulated. The whole development 

 of the plant is also changed by this. I found under otherwise equal conditions 

 that the root shortened when the concentration of the nutrient solution in- 

 creased and the plant's need for water became less. This is of great signifi- 

 cance in soils imperilled by drought. 



In the cultivation of sugar beets and all vegetables, grown as seedlings 

 in small spaces and then planted out in the field, the dryness of the soil 

 makes itself felt most of all by preventing the growth of the seedlings since 

 no new roots can be formed in dry soil. Next under consideration is the 

 drying of the foliage, which stops the development of the beets. Experience 

 teaches^ that, as with grain, ivell fertilised fields survive drought better. 

 Varieties also show differences in this regard. It has been observed that 

 varieties of sugar beets with outspread leaves wilt more easily than do those 

 with erect petioles. 



The influence of long continued drought on potatoes shows more in its 

 effect on the maturing of the tubers than upon their setting. The tubers 

 remain small and ripen prematurely. As a rule, this premature ripening 

 of early potatoes is of less consequence economically because they are 

 adapted by nature to a shorter vegetative period and because, in the second 

 place, they are rapidly consumed. Only the premature ripening of the later 

 varieties is disasterous, because the tuber has a small content of starch and 

 its keeping quality is much impaired. 



Leguminoseae suffer greatly from continued drought when they are 

 grown for fodder. Clover and alfalfa burn out in spots or the second crop 

 fails. The most frequent results with fruit trees are the premature ripening 

 and poor keeping quality of the fruit and premature defoliation. 



1 Jahresberichte d. Sonderausschusses fiir Pflanzenschutz. Deutsche Landw. 

 Ges, 1904, 



