Which action of theodore roosevelt had the most negative reaction?

Probably when he invited booker T. Washington, a black man to dinner with his family in 1901. This was especially shocking because segregation was law in the early 1900's. 

The changes to agriculture in the united states since 1900 is that increased mechanization has increased food production, thereby increasing the need for labor. there has been an increased need for higher speeds of food production due the fact that the population in the united states continues to rise.