APPENDIX G. 



METEOROLOGY AND THE GROWTH OF THE BEET. 

 By Marie Davy. 



[Journal d' Agriculture Pratique, 1880, 1, 539.] 



In ordinary beet-root culture there is no special phase to consider. The plant is 

 pulled before it has accomplished its preparation for blooming. The duration of 

 growth is therefore limited only by temperature. It is within these conditions that 

 we must endeavor to determine what are the climatic influences which modify the 

 yield in weight of roots and of sugar. 



With this crop as for the vine, we have but few documents bearing upon it ; but we 

 find in the Annates Agronomiques of December, 1879, a very important memoir by M. 

 Pagnonl, of Arras, which provides means for a primary examination of this great ques- 

 tion, and we must applaud the fruitful efforts of the able directors of the agricultural 

 stations of France in the scientific paths into which they have entered. The prelim- 

 inary examination we shall undertake will doubtless convince them of the necessity 

 of conducting meteorological observations alongside their agricultural work instead 

 of limiting themselves to those old practices which no longer correspond to the needs 

 of science. 



M. Pagnonl describes in his memoir the demonstrative experiment he made to de- 

 termine the influence of light upon the development and the saccharine richness of the 

 beet, and he calls attention to those of M. Corenwinder on the same subject. It is greatly 

 to be regretted that he had no means for valuation of the degree of light acting upon 

 his crops except the estimation of the proportion of sky free from clouds ; this process 

 is absolutely insufficient. We have endeavored to supply these deficiencies by actino- 

 metric data collected at Montsouris, but this is only a palliative, the clearness of the 

 sky at Arras not being always the same as at Paris. 



The documents furnished by M. Pagnoul are of two orders. One series relates to 

 successive analyses made every ten days in 1879 with samples taken from the same 

 plot uniformly planted ; the other series relate to analyses often successive crops taken 

 from the same field from 1870 to 1879 inclusive. 



A primary point seems to us to follow from this great work. Beets sown April 5 

 came up slowly and unevenly. At Paris this month was not dry. From the 5th to 

 the 30th March we find 17 days of rain giving 2.59 inches of water. The total amount 

 falling during the month was, it is true, 1.8 inches at Arras ; but it was still above the 

 average (1.6 inches) of the past ten years. The bad germination of the seed cannot, 

 therefore, be attributed either to dryness or to an excess of humidity in themselves. 

 The month of April, 1879, was a cold one, especially from the 10th to the 30th. Its 

 average temperature was but 45°. 6 Fahr., while the average of the last ten years is 

 49°. 6 Fahr. 



Beet seed is generally sown from the 10th to the 25th of April, during which period 

 the average temperature at Paris is 50°. 36 Fahr. This period may be advance'd and 

 in the northern departments sowing is often done, in favorable years, during the last 

 fortnight of March. We believe that more inconveniences than advantages result 

 from sowing before the average temperature has passed 46 c .4. This condition occurs 

 at Paris as early as the 28th of March in average years, but it is far from common to 

 al) years. 



On the other hand the analysis of M. Pagnoul show that from the 19th to the 25th 

 of September, 1879, the weight of the roots and their contents of sugar showed no 

 marked variations other than those which may be attributed to inequalities of sam- 

 ples, whatever may be the care observed in selecting them. At the same time, the pro- 

 2e4 



