406 



THE AGRICULTUKAL NEWS. 



Decemb[:r 29, 1917. 



SELECTION OF CORN FOR SEED 



Greatly increased interest has of late been shown in 

 many of the West Indian islands with regard to the 

 cultivation of maize or Indian corn; notably so in Grenada 

 and St. ViQcent. The latter island especially, as is shown 

 by recent rsports of the Superintendent of Agriculture, has 

 made great progress in this direction. During the last 

 two months, in addition to fully supplying local require- 

 ments, the crop of maize grown has been sufficient to allow 

 of the export of 85 tons of grain to the United Kingdom, 

 which is a decidedly good record f'>r this small island. It 

 would appear that owing to careful selection for seed pur- 

 poses of corn of the native varieties, the crop has been largely 

 increased. The subject .seems of sufficient importance to 

 render valuable the reproduction of the substance of an 

 article on the selection of seed maize by H. Wenholz, B.Sc, 

 Inspector of Agriculture, which appeared in the Agrkuitural 

 Gazette of Neiv South IFa^«s, August 2, 1917. The writer 

 says that from the earliest times it is probable that some 

 attention has been given to the selection of maize for seed. 

 The first method uf selection was probably that of keeping 

 the largest ears for this purpose. This crude method, though 

 still employed to some extent, does not make for much 

 impiovenient, a.s such ears may have been produced under 

 specially good conditions which may not be present the 

 following year. 



A further step in improvement by selection has since 

 taken place, viz., the choosing of a certain type which is 

 supposed to be correlated with increased yield. When this 

 type represents the majority in a well acclimatized variety, 

 it is probable that some improvement in yield is effected. 

 There are, however, certain fundamental points in the 

 selection of seed ears of any variety of maize, the observance 

 of which makes for continuous improvement. The chief of 

 these points are weight of ear and percentage of grain per 

 ear, shape, length and circumference of ear, filling of tips 

 and rounding of butts, uniformity, depth, and shape of grain, 

 and space between the rows and grains. Combined with 

 greater attention to field characters, and to uniformity in 

 the main characters which define a variety of maize (period 

 of maturity, colour of grain and core, size of grain and 

 character of dent,) it is possible to effect fairly rapid improve- 

 ment, especially by the estaUishment of special seed plots m 

 which cross-fertilization takes place only between these more 

 desirable types. 



If the conditions during a particular season have been 

 such that the standard ear length of the variety grown is 

 not reached, it is u.sually thought that the crop is not good 

 enough for seed, and the general practice is to introduce 

 fresh seed from an outside source. This practice is to be 

 strongly condemned. Owing to its not being acclimatized, 

 the introduced seed cannot put forth its maximum production, 

 and loss of yield results until the new strain becomes thor- 

 oughly adapted to its new environment of climate and soil. 

 (Jne of the most important points in the .selection of 

 seed ears is to choose those of average size, which, when dry, 

 are heavy in proportion to their size. 



A common practice in selecting seed ears is to get deep 

 grain, with a small cob, but by following this idea too rigidly 

 some' decidedly wrong results will be obtained. In the first 

 place, a small cob usually means fewer rows and less grain 

 than on a cob of mod. rale size. Secondly, under good rain- 

 fall conditions there is a tendency for the cob to become 

 larger. In this case the selection of ears with a small cob is 

 simply going in the contrary direction to the influences of 

 the environment to which the type is being adapted. 



As a general rule, the cylindrical ear Is the more desir- 

 able type for selection than the tapering, pecause it carries 

 more grain. A cylindrical ear will alsoJ contain grain of 

 uniform size, shape, and depth, almost riht up to the tip. 

 Selection for straightne.=s of rosvs and regularity of gram is 

 also desirable. Ears with twisted rows,] or with irregular 

 grain will not only increase the number pf such ears in the 

 crop, but will also render the irregularitj more pronounced. 

 Selection for depth or leuiith of grlin has been given, 

 perhaps, more attention than any other maracfcer, and there 

 is no doubt as to the value of selecting [or this character in 

 order to increase the yield. One poii/t, however, that is 

 often overlooked in selecting for deenf grain, is the faidy 

 general rule that ears with a rough denied grain have deeper 

 grain than those with a smooth dent. 



In the selection of seed ears more atJention should be paid 

 to uniformity in the appearance of thaear.s, and also in the 

 size and shape of the grain than is usiklly done Ears that 

 are uniform in size, shape, appearance,land character of denl 

 indicate greater purity of strain. Th s moans greater uni- 

 formity in maturing, and also more niforinity in time of 

 tlowering, which is very important. 'hose plants in a field 

 of maize which flower much later that their neighbours have 

 little chance of being properly fertiliiid. 



Uniformity in colour of cob is at important point. The 

 inclusion of a seed ear with a red c b among others with 

 white cobs, leads to the productio; of an objectionable 

 admixture of variou.sly coloured grail. Uniformity in the 

 colour of grain in the selected ear s also a point to be 

 remembered. 



Different general types will be fc ind suited to different 

 conditions of soil and climate, and )uie bred varieties of 

 maize, which are adapte.l to the condi ions under which they 

 are grown, give not only a higher jield, but also one of 

 better quality than those of unsuitabe or mixed type. 



Ears which have their butt eiis well rounded and 

 filled with grain will be found to shel a good percentage of 

 grain. Well rounded butts are usual f indicative of a good 

 strain. The filling of the tips of tie ears with graiu is 

 perhaps not so important. The be t type of tips is one 

 which is oval or rounded, and fairly lell filled with grain of 

 uniform regular size. 



In .selecting corn for seed purposls special care should 

 be taken only to select such ears thatlare free from fungus 

 disease, or are undamaged by insect pelts, or by weather. All 

 ears showing any trace of mould, dry mt, or splitting of the 

 grain, or any sign of weevil attack, shluld be avoided. 



Bearing in mind the advisabilitjlof keeping the seed 

 acclimatized by continuing to select sad ears grown on the 

 farm, even though below stmdard size If the crop is poorer 

 than usual, it will most likely be found that it is impossible 

 to get many ears with all the charioters perfect in an 

 unfavourable season. In fact, manylperfect ears cannot 

 usually be obtained even when selectiife from a good crop, 

 but a good foundation can be laid foramproving maize in 

 these characters by the establishment ijf special seed plots 

 of about an acre in area. Cross-fertili/.itinn is thus effected 

 between the best types each year, and tangible improvement 

 can be seen after a few seasons 



.\ summary of the chief points to bl observed in select- 

 ing miize in the barn is given in the folowing ten rules: ^ 



( 1 ) Select ears which are heavy in proportion to their 

 size when dry. 



(2) Select ears which are cylindrical |n shape or nearly 

 so, and avoid very tapering ears 



(3) Select ears with straight rows, relular from butt to 

 tip. 



