Alfalfa Variety Trial in Graham County Arizona, 1997

L.J. Clark and E.W. Carpenter

Abstract

Twenty four alfalfa varieties with fall dormancy ratings of 8 or 9 were tested in a replicated small plot trial on a heavy clay loam soil on the Safford Agricultural Center. This was the second year of a new study. UC 331 had the highest yield for the year but CUF 101 had the highest average yield. Heat units with thresholds of 77° F and 40° F are included for each cutting in the study.

Introduction

This is the second year of a new study which includes the better varieties from the previous trial along with several new varieties that seem promising. This is the 22nd year of continuous alfalfa variety testing in Graham county.

Materials and Methods

Twenty four alfalfa varieties with fall dormancy ratings ranging from 8 to 10 are included in this test. Plots were planted by hand using a Precision Garden Seeder Model 1001A from Earthway Products. Four rows on six inch spacings were planted 20 feet long with twelve inch spacings between varieties. Replicates were placed in a 2 by 2 arrangement to reduce errors due to soil variation.

Crop History:

Location: Safford Agricultural Center, Graham County
Elevation: 2950 feet above sea level
Soil type: Grabe clay loam
Planting date: 26 September, 1995 Rate: 25 lbs/acre
Herbicide: None
Fertilizer: 300 lbs/ac 16-20-0 at planting
Insecticide: Treatment to control alfalfa weevil
Irrigation: Border, 9 irrigations (ca. 53 acre inches)
Harvest strategy: Cut around 10% bloom to optimize quantity and stand longevity.
Plot size: 2.5 feet by 20 feet
Replicates: Four

Plots were cut by hand using a Troy mower and raked and weighed immediately to prevent loss of moisture. Weights were converted to dry weight at 0% moisture for reporting purposes.

Results

The results of the study are recorded in tables below. Table 1 provides the yields per cutting in the current year and Table 2 gives a summary of the two years of the study.