STATE OF MONTANA 9 



CHEMICAL CONTROL OF WEEDS IN MONTANA WHEAT— 1949 



In 1949 approximately two and three-fourths million acres or 47 per cent of 

 the total wheat acreage in Montana v/as sprayed with chemicals for the control 

 of weeds. Two-thirds of the winter wheat was sprayed and a little more than 

 one-third of the spring wheat received weed killing chemicals. A larger area 

 may have been treated had not winter kill and the early drought inflicted heavy 

 abandonment of the seeded acreage. 



It is difficult to measure the effect that chemical weed sprays have upon 

 wheat yields because there are many other factors responsible for yield differ- 

 entials. The choice that the farmer has cf spraying weeds in fields with the 

 better prospects rather than those with the poorest prospects may show an un- 

 realistically higher yield in favor of the sprayed acreage. The differences, 

 therefore shown in yields of unsprayed and sprayed wheat may include many 

 other factors. An analysis of the data shows the unsprayed planted winter 

 wheat acreage returned an average yield of 14.9 bushels per acre in 1949, com- 

 pared with 17.8 bushels for the acreage sprayed. Unsprayed spring wheat 

 yielded 8.7 bushels against 11.7 on that where the weeds were controlled. 

 These calculations were based upon summer fallowed and continuously 

 cropped dry land wheat and excluded the irrigated and volunteer acreage. 



WHEAT ACREAGE SPRAYED FOR WEEDS BY CROPPING PRACTICES— 1949 



By Cropping Practices 



Total 



DISTRICT 



Seeded 

 Acres 



Sprayed 

 Pet. Acres 



Irrigated Summer rallo\jv 



Other 

 Dry Land 



W. of Divide 128,100 34 



N. Central 2,157,000 55 



N. East 1,949,000 33 



Central 700,600 63 



S. West 146,600 31 



S. Central . 421,800 58 



S. East 402,900 41 



TOTAL 5,906,000 47 



W. of Divide - 72,900 40 



N. Central 707,400 71 



N. East 14,300 74 



Central ..._ 430,000 76 



S. West 83,000 32 



S. Central 327,100 65 



S. East ._ 41,300 72 



TOTAL 1,676,000 68 



W. of Divide _ 55,200 28 



N. Central 1,449,600 47 



N. East 1,934,700 33 



Central _. 270,600 42 



S. West 63,600 29 



S. Central 94,700 31 



S. East „ 361,600 38 



TOTAL 4,230,000 39 



'Less than 50 acres sprayed. 



Pet. Acres Pet. Acres 



ALL WHEAT 



44,200 

 ,184,900 

 641,400 

 441,500 



45,000 

 243,000 

 165,500 



30 

 47 

 17 

 44 

 38 

 24 

 22 



9,100 

 37,000 



2,900 



5,300 

 14,400 

 12,400 



1,000 



38 

 56 

 40 

 69 

 28 

 65 

 36 



26,100 



,099,800 



483,800 



381,200 



28,200 

 207,200 



53,300 



Pet. 



31 

 40 

 21 

 36 

 34 

 43 

 44 



Acres 



9,000 



46,100 



154,600 



50,700 



2,400 



21,800 



111,000 



2,765,500 35 82,100 52 

 WINTER WHEAT 



28,900 26 



,600 42 



499,900 

 10,600 



327,200 

 26,600 



213,900 

 29,900 



62 8,500 



62 

 34 

 27 

 35 



900 



4,700 



2,500 



(*) 



71 

 75 

 77 

 32 

 67 

 92 



25,500 



472,900 



5,900 



299,500 



21,500 

 196,100 



25,300 



28 

 62 



71 

 54 

 30 

 55 

 32 



1,800 

 16,500 



4,600 



22,500 



400 



13,700 



4,400 



1,137,000 41 18,200 69 1,046,700 53 



SPRING WHEAT 



15,300 

 685,000 

 630,800 

 114,300 

 18,400 

 29,100 

 135,600 



30 

 44 

 17 

 42 

 40 

 24 

 23 



7,500 

 28,500 

 2,900 

 4,400 

 9,700 

 9,900 

 1,000 



7 

 48 

 40 

 50 

 20 

 41 

 24 



600 



626,900 



477,900 



81,700 



6,700 



1 1,100 



28,000 



32 

 33 

 21 

 29 

 36 

 31 

 45 



1,628,500 34 63,900 44 1,232,900 28 331,700 



Volunteer 

 Pet. Acres 



54 2,000 

 60 100 

 70 4,300 



73 

 40 



73 

 40 



63,900 65 



7,200 



29,600 



150,000 



28,200 



2,000 



8,100 



106,600 



,600 

 200 



2,279,600 30 395,600 65 8,200 



54 2,000 

 60 100 

 70 4,300 



1,600 

 200 



8,200 



