Crop Production Lab 8 Soybeans

VE

emergence

V1

first trifoliate

R1/R2

beginning/full flower

R3/R4

Beginning/Full Pod

R5/R6

Beginning/Full Seed Development

R7/R8

Beginning/Full Maturity

Intermediate Varieties

Vegetative growth continues even after reproductive flowers form. We grow this type in the North to maximize GDD. 

Determinate Varieties

Stop vegetative growth after flowering.

Maturity groups

categories based on duration of time from planting to physiological maturity. lower/early maturity groups are planted in Northern Climates (00,0,1,2’s). Southern climates plant later, higher maturity groups. 

What color are healthy nodules

Healthy are pink; white, green, and gray are unhealthy.

aphid

grasshopper

how do aphids eat?

they use piercing/sucking mouthparts to suck the plant sap. Leaves a stippling pattern on the leaves.

How do grasshoppers eat?

round/ragged holes in the leaf caused by chewing.

what conditions cause soybeans to grow slowly?

cold soil temp, pH outside 5.5-8.8 range, low moisture, extremely high soil temperature, nutrient deficiencies

Soybean flower development is greatly influenced by?

Day length/photoperiodism, soybeans flower once day length decreases.