148 



SCIENTIFIC AGRICULTURE 



April, 1921. 



cipitatioii of from 15 to 20 inches, good seed" crops are 

 frequent. But in the centre and eastern parts of 

 Kansas, where the precipitation ranges from 20 up to 

 45 inches per year, "profitable crops of alfalfa seed 

 are secured only in such seasons when a corn crop 

 fails on accomit of drouth." 



Native, and Natural Home Conditions. 



Despite the world wide recognition of alfalfa as a 

 food for live stock and as an improver of soils, and 

 although for many years there has been a decided de- 

 mand for good alfalfa seed, the greater part of seed 

 production for export has been limited to Turkestan, 

 Persia, Hungary, Spain, and Algeria. All of these 

 countries have climates vt'hich, in important respects, 

 are very similar to those of the Western Plains and 

 Plateau-regions of this continent. Turkestan and Per- 

 sia, for instance, which have been and are rather strong 

 and reliable producers of alfalfa seed, present table 

 laiuis whose vegetation is deprived of precipitation by 

 surrounding mountain ranges during the summer, i.e., 

 during the flowering season, and whose medium lati- 

 tudes guarantee warm weat^ier at thisi tame. These re- 

 gions have only moderately severe winters and toler- 

 ably hot summers, with temperatures ranging from 

 10 deg. to 10 deg.P. in the winter, and with a summer 

 temperature rising to 95 deg. or even to 105 deg.F. 

 The altitude varies from 1000' up to .3000' and more. 

 Optimum Temperature for Seed Formation. 



Although freezing temperatures do not readily kill 

 alfalfa, they retard its development and damage the 

 foliage considerably. The seasons of growth and of 

 harvest, therefore, must be entirely frost free, as the 

 growing alfalfa plant is sensitive in this respect dur- 

 ing the whole period of development. At the critical 

 time of blossoming, monthly mean temperatures, some- 

 where around 70 deg. F., seem to be favourable to the 

 plant. Ripening and harvesting of the seed may follow 

 in a month or period that is either warmer or cooler 

 than the blossoming time. Good seed yields have been 

 obtained, and are constantly realized, in either case. 



Moifture Conditions. 



One may normally expect satisfactory seed yields in 

 such localities where the soil moisture is sufficient for 

 a strong development of the first crop, and where low 

 rail fall prevails during the seed setting of the second 

 crop. With alfalfa, as for instance with strawberries, 

 we want a well developed root system, which will pro- 

 vide the necessarj' physical vigour to the plnnts which 

 have to produce the subsequent seed crop. 



We also need sufficient reserve moisture, so that the 

 second crop may be able to push ahead immediately 

 the first crop has been removed. But we do not want 

 excessive rain during the blossoming period, because 

 moisture in abundance at that time tends to promote 

 vegetative growth rather than to favour blossoming 

 and fruit setting. Under irrigation conditions, where 

 it is possible to regulate the moisture satisfactorily, 

 we have consequently an ideal situation as far as this 

 factor is concerned. Excessive rain or excessive irrig- 

 ation, after the seed has set, promotes the gi-owth of 

 new shoots, which affect the seed yield in an unfavor- 

 able direction. 



This, of course, does not mean that rain might not be 

 desirable for the second crop under any condition, or 

 that irrigation water should never be applied after the 

 seed has set. Where the ground is very dry, the plants 

 will naturally benefit from a moderate rain fall or 

 from a suitable application of water. 



Sunshine. 



For seed setting a maximum amount of sunshine does 

 not appear to be the best. It is naturally difficult to 

 estimate exactly what amount should be considered as 

 optimum — and it would be still more difficult to regu- 

 late the quantity. From a study of meteorological 

 data for districts and years noted for a high produc- 

 tion of alfalfa seed, it would seem that an average 

 cloudiness of 30-35 per cent would be desirable. In- 

 terpreted in sunshine-hours this means that our B. C. 

 averages of around 300 hours of bright sunshine in the 

 months of July and August are quite satisfactory. 

 Someone might perhaps feel inclined to deduce from 

 this statement that direct shading or dense growth, 

 which would partly amount to the same thing, might 

 be favourable under very bright weather conditions. 

 Such, however, is not the case. In crowded stands, as 

 with unpruned and much shaded fruit trees, the best 

 flowering and fruiting, that is seed setting, take place 

 only on the outer and upper branches where pollena- 

 tion fertilization, development and ripening are more 

 certain to be affected in a favourable direction than 

 where shade or half shade prevail. Tliis is the reason 

 why planting of alfalfa in rows has given so much 

 better seed returns than the broad-castmg method. 

 Planting in rows also facilitates irrigation and sub- 

 sequent cultivation. 



Tripping: and Fertilization. 



The tripping or releasing of the trigger mechanism, 

 which controls the fertilizing organ, is due to a touch 

 or a movement; by wind, pelting rain or visiting insects. 

 Bees are evidently the most aggressive, if not the most 

 important agents in opening the flowers and scatter- 

 ing the pollen. They, as we all know, are always less 

 active during damp rainy weather than they are on 

 dry sunny days. On the other hand, if the alfalfa plant 

 is undergoing heavy transpiration, on account of ex- 

 cessive dry and hot weather or wind, the trigger me- 

 chanisms of the flowers operate more tardily, and a 

 smaller number of pistils and stamina are released. 



If the flower dries up and remains on the stem we 

 may be certain that fertilization has taken place, where- 

 as dropping flowers are an indication of failing fertil- 

 ization. Thus we may .judge at a comparatively early 

 .stage whether the seed has set or net, and can act 

 accordingly. 



Time Required for Maturity. 



Speaking generally the seed crop requires about 

 twice the time needed by a hay crop, or somewhere 

 around 80 days. Early cutting of the first crop, for 

 hay, soiling or silage, is t)ierefore necessary in order 

 that the seed crop may have time to develop in a pro- 

 pitious season. Supposing the first crop is cut about 

 •Tune 15th, the plants will be in full bloom by July 

 30th, and the seed should normally be mature by about 

 September 5th, and should thus escape killing frosts 

 in favourable localities. 



. . Economy. 



Can we afford to grow alfalfa seed in B. C? The 

 answer to that question depends of course on the price 

 of land, the yield of seed, and on the price of the seed 

 that we produce. The average yield for all seed pro- 

 ducing states to the south of the line is 3.5 bus., or 210 

 lbs. per acre. A wholesale price of 25c per pound 

 would then secure us $52.50 in addition to the value of 

 the first hay crop. From this sum, whatever it be, 

 rent, interest and labour must be deducted. Like most 



