Presentation: Predicting Relative Maturity in Barley Using Spikes

Abstract

Relative physiological maturity in barley is an important trait especially in regions where barley growing is influenced by the number of frost-free days. The objective of the study was to find the effect of genotype, environment and genotype-by-environment interactions on maturity. A range of barley genotypes was grown in non-replicated field tests in multiple locations in Alberta, Canada for three years 1998, 1999 and 2000. Harvested spikes were used to determine relative maturity of each genotype. Results showed relative spike maturity trends in genotypes were similar among years although the magnitude differed from year to year. There was significant (P< 0.05) location x year interaction. Sampling barley spikes could predict relative maturity of barley genotypes.

Introduction

Differences in days to maturity exist among barley varieties. Understanding these differences is important for barley production and research. Crop managers and researchers should be able to recognize growth stages that could be sensitive to production inputs such as chemical fertilizers, pesticides, growth regulators and harvest management.

The stage of barley maturity at harvest can affect yield, protein and fiber content. This can in turn affect the nutritional qualities.

Materials and Methods

• Three groups of barley comprising ten two-row hulled, six six-row hulled and seven hulless (3 six-row and 4 two-row) varieties were tested in six locations.
• Harrington a two-row hulled barley was used as a check in all three groups of barley varieties.
• Intact spikes of each variety were harvested on four consecutive dates, with an interval between each date of at least four days.
• Moisture content of intact spikes was determined at each harvest date and used to calculate the expected days to maturity (30% moisture) based on the rate of drying. Using moisture dry down, linear equations were developed for each variety.
• Data from each barley group were analyzed separately using SASŪ (SAS Institute, Cary, NC).

• The two-row varieties were statistically separated into three groups: late, medium and early maturing. Seebe had the highest number of days to maturity, CDC Dolly had medium, and CDC Kendall had the least number of days to maturity (Fig. 1).

• In the six-row barley group Niska had the highest days to maturity and Kasota had the lowest number of days to maturity (Fig. 2).

• In the hulless barley group, CDC McGwire had the highest number of days to maturity and Peregrine had the lowest (Fig. 3).

• There were significant (P<0.05) location (Table 1), year (Fig. 4), genotype, and location x year interactions effects (not shown), however, no significant location x genotype and year x genotype interactions were determined.

Discussion

• The number of days to maturity for the three groups of barley was relatively high in Beaverlodge, Irricana and Lacombe compared to Carstairs, Trochu, Stettler and Vegreville (Table 1). This indicates environment plays a significant role in determining barley maturity.
• The study indicates that barley varieties tend to maintain their relative days to maturity regardless of the location.
• Days to maturity could depend on the weather conditions in a particular year as shown in Fig. 4.
• Our study show that intact spikes harvested on different consecutive dates, at intervals of at least four days, could be used to determine the number of days to maturity (30% moisture) using linear dry down curves determined for each location and year (Fig. 5).

Conclusion

• Intact barley spikes sampled randomly from the field at different dates during the maturation period can be used to develop dry down curves for determining the number of days to maturity (Fig. 5)
• This study determined there were no significant location x genotype and year x genotype interactions. This confirmed that genotypes tend to maintain their relative days to maturity from year-to-year and from location-to-location.
• Days to maturity can change depending on weather conditions prevailing in a given year.

• This study was funded in part by the Alberta Agriculture, Food and Rural Development and Alberta Barley Commission.
• The authors wish to thank all technical staff at the Field Crop Development Centre for providing excellent technical support, and many research cooperators who provided help.