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or very bad; 2, small or bad; 3, passable or mediocre; 4, fairly good; 5, good; 6, very good.

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ter in shade— Bor de Calais

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Oct. 12 29 3,079 |.......... 393 4 5 5.3 Oct. 19 31 3,389 8,963 264 5 3 4.6 Oct. 5 27 3,172 7,900 313 6 3 4.2 Oct. 19 30 3,003 8,539 299 1. 1 3.9 - Sept. 21 26 2,786 7,326 344 4 6 5.5 6 |----do - - - 24 2,791 6,552 347 5 3 4.7 1879----------------- Apr. 20 |----do - - - 22 2,359 5,815 278 1. 3 4.4 1880----------------- Mar. 2 || Oct. 11 32 3,132 8,410 280 --------|--...... ........ 1881----------------- Apr. 6 Sept. 28 25 2,520 6,309 340 |................ - - - - - - - Average ----- Mar. 26 || Oct. 4 27 * 7,484 300 --------|---------------

The climatic data given in the above table as directly applicable to the seasons of growth of the beet root illustrate what should be given for any similar study of development of any crop. But it is commonly the case that the dates of the various phenological epochs are not exactly given, and that we have to rely upon general tables of general climatic conditions month by month, such as are recommended by the International Meteorological Congress of Vienna and by that of Rome. Therefore, for the sake of comparison with other climates whose data are given on the so-called international forms, I give in the following table a part of Pagnoul's tables of average temperature Centigrade and rainfall in millimeters as observed at Arras:

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The preceding study gives a first idea as to the relation between climate and the development of the leaves, the roots, and the sugar, and offers a first step toward determining how suitable for the beetSugar industry any climate may be, and especially does it suggest to the planter how he may early in August begin to safely predict from week to week what his probable crop will be early in October. Thus, table on page 259 shows, by the samples taken August 20, that there were then in the beets 3,073 kilograms of suger per hectare, whereas on October 9 there was 5,068, or five-thirds of that present on August 20. This factor, five-thirds = 1.67, is, therefore, that by which the figures of August 20 are to be multiplied in order to obtain those of October 9. The following table gives similar factors for the successive decades for the crop of 1879, and when a succession of years has been thus treated we shall know something of the accuracy with which the harvest crop can be predicted. The regularity with which these numbers run shows that after the 1st of September the error of prediction can only be a small per cent.

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August 10-------------------------------------------------------------------------- 2.74 1,848 August 20---------------- 1.65 3,073 August 30-------------------------------------------------------------------------- 1.43 3,534 September 9----------------------------------------------------------------------- 1.17 4,320 September 19 1.09 4,655 September 29 1.08 4,691

October 9-------------------------------------------------------------------------- 1.00 5,068

Pagnoul calls attention to the fact that the roots contain a considerable portion of nitrates, although the soil in which they grow had not received during this or previous years a trace of these salts. This salt could only have come into existence by the nitrification of organic nitrogenous matter, and it is well to insist upon this fact, for we can thus remove from the minds of certain persons the idea that if the beet root contains nitrates they must have been put into the soil by the cultivator. This mistake has frequently caused unhappy contests between the farmer and the sugar manufacturer.

If the beet root had at its disposal only a proper proportion of nitrates that had been formed in the soil before sowing, these salts would be rapidly absorbed; they would by their decomposition give rise to a large and prompt development of leaves, and, consequently, to an easier elaboration of sugar, and in proportion as vegetation advances we should find smaller quantities of nitrates in the beets. This fact was proven by Marié-Davy in 1878.

If on the contrary the nitrogen is furnished by a process of nitrification that is prolonged during the whole season, then the absorption of the nitrates goes on continuously and their total weight per hectare increases steadily to the end of October, as shown in these analyses for 1879.

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Some further experiments by Pagnoul (1879, p. 486) on the beet as grown in darkness and in sunshine shows that the former were exceptionally rich in alkali, ash, and especially the nitrates. This is explained as above, viz: The nitrates will not decompose within the plant except under the influence of sunshine; if the plant is kept in darkness it stores up the nitrates within itself without having the power of utilizing its own nitrogen, so that the substances in the formation of which this nitrogen ought to be of assistance can not be formed. From this one must conclude that years that are bad for the beetsugar crop are so not only because of unfavorable temperatures and humidities but above all because of a defect in the insolation. Lively complaints have been made of the quantity of nitrates in certain harvests; now these salts that accumulate in the molasses and in the inferior products and augment the difficulty of the work occur often in beets cultivated upon a soil that has never received a trace of nitrates as a fertilizer. It is therefore not to the abuse of nitrates as a fertilizer that we ought to attribute their presence, but rather to a too cloudy sky. We know that the neighborhood of large trees is injurious to the vegetation around them. Ordinarily we attribute this injurious influence to their roots. It would perhaps be more exact to attribute it to the shade that they cast, and the more so because it has been demonstrated by Cailletet that green light has no power to bring about the decomposition of carbonic acid. In the Annuaire for 1883 Marié-Davy studies the influence of the date of sowing. In order to ascertain the best dates for sowing and trace out the various vicissitudes to which the crop is subject, whether resulting from the climate as such or from the ravages of insects or fungi, it is necessary to make a rather detailed study of the state of development of the plant under the assumption that the seeds were sown on successive dates—for instance, on a given series of successive week days. An elaborate study of this kind is given for wheat by Marié-Davy (pp. 244–285 of his Annuaire for 1883), from which the following tables have been extracted. In general the varieties of wheat cultivated in the south of Europe are more sensitive to cold than those of the north, but the studies of Marié-Davy for the latitude Montsouris, when paralleled by similar studies for localities in the United States, can but be of the greatest value both to the farmers and the statisticians of this country. The study of such tables will enable one to very closely predict the time of harvest, the quantity and quality of the crop, and the range of uncertainty. To this end it is, of course, understood that corresponding elaborate tables of meteorological conditions must be accessible, samples of which I have prepared for twenty United States stations." If we suppose some wheat to have been sown on the 22d of September, 1871, near Paris, and if we adopt the rule established by Gasparin that the vitality of the seed is actively aroused as soon as its temperature in a moist earth exceeds 5° C., and that it germinates visibly when it has received a sum total of mean daily temperatures that is equal to 85°C., and that the sprout rises above the surface of the earth in a few days after the seventh, then we obtain six days as given in the following table for the interval from sowing to germination. A similar computation for every other date of sowing, as given in the following table, shows at a glance the effect of the temperature of the soil on this phase of plant life.

I) uration, in days, from souring to germination of wrinter wheat at Montsouris, France, for the years 1872–1881.

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In studying the preceding table we recall that the duration of germination varies slightly with the condition of the soil and the depth of the grain below the surface; these two considerations will be perfectly allowed for if we observe directly the temperature of soil by a buried thermometer. Such observations are earnestly recommended to all agricultural experiment stations, as they are, evidently, more directly applicable to the growth of plants than any crude approximations derived from the observation of the temperature of the air only. If when the grain has sprouted the soil continues very dry, the nourishment having all been drawn from the seed, the young plant may droop and die. If, again, the frost penetrates to the seed while it is germinating, many of the seeds will perish, and the field will appear as if sparsely sown, but this latter mishap is generally repaired by nature if the soil is good and the springtime favorable, for the sowing is generally in excess and the extra heading will supply the loss of the seeds that have perished, but in poor soil the harvest will be notably diminished, and often it will be profitable to plow the soil for a new sowing. In any case the chances for a successful crop vary very much with the date of the sowing, as we shall see by the study of the following table, which shows that in each year the season for sowing that is favorable to the crop of that year is very much restricted by the early arrival of the winter cold. Thus in 1871 the sowing was stopped on the 20th of October by the cold weather; in 1872 it continued throughout the autumn until the 29th of December; in 1880 it occurred on the 3d of November. Sometimes heavy rains prevent the sowing, but in 1881 neither cold nor rain prevented field work until the middle of December. [In order to save space I have omitted the elaborate tables of frosts, low temperatures, and rains given by Marié-Davy for each of these years and weeks.-C. A.] The grain now arrives at the epoch of heading, at which the original stalk becomes several branches, each of which bears an immature head on which the rudimentary seed can already be counted under the microscope; the number of such seeds will not increase in the further development of the plant, but many of them may not come to maturity; therefore a careful count of these rudimentary seeds over a small area of the field would give a first estimate of the maximum possible crop. According to Gasparin the length of time that elapses from the moment when the mean daily temperature of the air in the shade is 5° C. up to the date of heading of the wheat is such that the sum total of the mean daily shade temperatures is 430° C., but as the initial date is difficult to determine we shall in our calculations adopt the rule of Hervé Mangon, according to whom the sum of the mean daily temperature in the shade, rejecting all that are below 6° C. (at which the wheat does not yegetate), is 640° C. if we count from the date of sowing, or 555°C. if we count from the date of germination. The following table is computed by counting from the former date; a parallel computation from the latter date shows that on the

a These tables are omitted in the present edition.

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