52 SOUTHEEX FIELD CHOPS 



52. "When to sow wheat. — The kind of wheat grown in 

 the South should be sown in the faU. In the Gulf States 

 some wheat is sown as late as the first part of December, 

 This is too late for the maximum j'ield, even in the central 

 or southern parts of the Gulf States. 



The best date for sowing wheat depends on the following 

 considerations : — 



(1) The average date when killing frost occurs in each 

 locality. 



(2) The latitude and altitude. 



(3) The fertility of the soil. 



53. The date as determined by killing frost. — In 

 North Carolina and the other parts of the cotton-belt in 

 which the Hessian fly, or " wheat-fly " occurs, sowing is 

 postponed, if practicable, as late as necessary' to insure that 

 the young wheat plants do not come up until after a killing 

 frost has occurred. This is because a killing frost stops 

 the laying of eggs by the Hessian fly, and because if young 

 wheat plants should appear alcove the ground before that 

 time, the eggs would be deposited on them and the crop 

 subsequently injured by the insects developing from the 

 eggs. It was found that in the northern part of Georgia 

 (Ga. Bd. Entomology, Circ. 7), wheat sown during the last 

 10 days in October practically escaped injury. 



Average dates of first killing frost. — The a\erage dates of first 

 killing frosts for typical southern localities, as determined by the 

 Weather Bureau, are as follows : — 



Blacksburg, Virginia, Sept. 30. Ashe\-ilU', Xorth Carolina, 

 Lynchburg, Virginia, X, IV. 1. Oct. 20. 



Kno.xville, Tennessee, Oct. 27. ("liarlotte, North Carolina, 

 Nash^dlle, Tennessc^o, Oct. 24. Nov. 4. 



