Plant Breeding 273 



New Jersey Expt. Sta. 



Fig. 171. Three new varieties of squashes produced by crossing a white scallop summer 

 squash {P, at the left side of picture) with a warty, yellow-colored summer crookneck {P, 

 at right side). The photograph shows three new varieties that have been produced. The 

 upper row shows a type of short-necked "jug" fruit of medium size with a smooth, cream- 

 colored surface. The middle row shows a longer-necked type of "jug" fruit, somewhat 

 like the crookneck in shape, but greens iriped and not warty. In the lower row the fruits 

 are very thin-fleshed, nearly spherical, cream-colored, and not warty. After the first cross- 

 ing, the plants were selected and self-bred for five generations, after which some of the new 

 kinds would breed true enough to make new varieties. 



value. Plant breeding is actively carried on at the State Agri- 

 cultural Experiment Stations, by the United States Department 

 of Agriculture, by experimenters at several of the larger univer- 

 sities, by seedsmen, and by breeders of nursery stock. The activi- 

 ties of plant breeders are being directed toward four principal 

 objectives : (i) the breeding of plants with more desirable prod- 

 ucts, as flowers, fruits, leaves, and fibers ; (2) the breeding of new 

 varieties which will increase the yield per acre ; (3) the securing 

 of varieties better fitted to particular cHmates and soils; and 

 (4) the producing of varieties capable of greater resistance to 

 diseases. 



Breeding for more desirable products. The first object of 

 plant breeding may be illustrated by recent improvements of the 

 pecan. Among the hundreds of thousands of pecan trees scat- 

 tered through the Southern states, a few trees have been dis- 

 covered that produce nuts of large size and good flavor and with 

 thin shells. Breeders have found that these types may be pre- 

 served by budding pecan seedlings with buds from the most 

 desirable trees. The best paper-shell pecans on the market are 



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