460 MINNESOTA STATE HORTICULTURAL SOCIETY. 



onions are earlier than globe-shaped onions of the same strain ; 

 late maturity may mean a larger crop, but a poorer keeping 

 quality. Always avoid thick necks in saving for seed, for they 

 represent a reversion toward the ancestral, or primitive, onion. 



Onions selected for seed growing are stored over winter 

 and planted out in the early spring in rows wide enough for 

 horse cultivation. From 125 to 150 bushels are needed for an 

 acre. An upland soil or a fertile loam soil should be selected 

 rather than muck soil. The heads are gathered just before the 

 earliest maturing seed pods shatter when handled. About three 

 inches of stem is usually left with the head. Curing on a tight 

 floor of a dry, airy room should be thorough. After threshing 

 out, the light seed and waste particles should be taken out with 

 a fanning mill or by washing in a tub, saving only the seed that 

 sink to the bottom. A yield of 400 to 500 pounds per acre is a 

 good crop of seed. Good seed from a selected strain has every 

 chance to produce a crop above the average. Five pounds of seed, 

 testing eighty per cent, or better, is enough to sow an acre. 



With all the cultivated crops, the onion has its insects and 

 diseases that may reduce the yield to a point where it ceases to 

 be profitable. The onion maggot, thrips and the blight are the 

 three chief pests of the onion crop. The onion maggot belongs 

 to the order diptera, or flies, and is known wherever the onion 

 has been grown for any length of time. The true onion maggot 

 is the larvae of a fly and when full grown is one-fourth inch long. 

 The adult may pass the winter in sheltered places or pupate in 

 the ground. The adult emerges in the spring and lays her eggs, 

 two to six, on the young plant near the surface of the ground. In 

 about ten days the eggs hatch, and the larvae begin eating im- 

 mediately, feeding within the epidermal tissue of the plant. In 

 two weeks from hatching the maggots are ready to pupate, and 

 the adult fly will appear in another two weeks. Two or three 

 broods often appear during a season. The black onion fly, and 

 the barred winged onion fly, also often attack the onion. The 

 life histories of these is nearly the same as for the onion maggot, 

 except that the maggots appear in storage. Fumigation with 

 bisulphide of carbon, one pound to each 200 cubic feet of storage 

 will check these insects. 



Control measures for the onion maggot must of necessity 

 be largely preventative measures. Practice clean culture, clean 

 up all crop remnants and do not grow onions on land infested the 



