On-Farm Versus Agricultural Experiment Station Evaluation and Improvement of Intrinsic Characteristics of Landrace Common Bean Cultivars for Sustainable Farming Systems in the Twenty-First Century
Evaluation of 16 common bean landraces and improved cultivars in four on-farm (high-input organic, low-input organic, low-soil fertility stressed, and conventional farming) and three Research Center (continual bean cropping, drought stressed, and irrigated farming) cropping systems indicated that low-input organic cropping had the lowest mean yield followed by drought stressed, conventional, and continual bean cropping systems. High-input organic farming resulted in the highest yields, especially for late maturing, prostrate, and semi-climbing cultivars that competed well with weeds. Common Red Mexican landrace yielded higher under drought-stressed and irrigated farming systems. Early maturing cultivars yielded lower across cropping systems.
By seeking farmer participation and on-farm evaluation and selection from early segregating generations, this proposal focuses on identification, genetic improvement, and promotion of the most appropriate common bean cultivars for low-input sustainable and organic farming systems for Idaho in particular and the Western U.S. at large for the 21st century. The specific objectives are to:
1. Compare the most popular landrace and modern cultivars developed over the last 75 years of major market classes on-farm (LOF and OSF) and at AES. Identify and promote adoption of the most promising cultivars.
2. Evaluate and select on-farm (LOF and OSF) and at AES from multiple-parent interracial populations involving landrace cultivars and donors of complementary desirable traits high yielding high quality cultivars suitable for low-input, sustainable, and organic farming systems.
3. Promote adoption of promising and new cultivars through field days, farmer outreach, farmer conferences, bean school, news media, bulletins, and electronic means.
Experiment # 1. Identification of intrinsic characteristics of common bean landraces associated with low-input sustainable farming systems.
Ten genotypes evaluated in 2002 and six additional genotypes were included in Experiment # 1 in 2003. These 16 genotypes represented landraces that had been popular for centuries in the Western United States and improved cultivars of great northern, pink, pinto, and red market classes of dry beans released between 1932 and 1998. The trial was conducted on-farm in four cropping systems: high-input organic (HIO, at Mulberry's farm), low-input organic (LIO, at Parrott's farm), low-soil fertility stress (LSF, at Smith's farm), and conventional farming system (CFS, at Fullmer's farm). It was also conducted in three cropping systems, namely 53 years of continual bean cropping (CBE), drought stress (DSE), and irrigated farming systems (IFE) at the University of Idaho-Kimberly Research and Extension Center. All sites were located in the Magic Valley, in southern Idaho in the heart of the largest bean production region. A randomized complete block design with four replicates was used. The plot size varied from 4 to 8 rows, each 25 to 50 ft long, depending upon the land availability. The spacing between rows was 22 inches. Pre-plant soil samples were taken. In addition, soil moisture and compactness was measured, and plant samples during late pod fill were taken for nutrient analyses. However, complete data from these analyses are not yet available. The LIO did not receive any fertilizer, and was not irrigated after July 14 (i.e., the middle of cropping season), thus totaling only three irrigations, including the pre-plant. Moreover, LIO and HIO fields were heavily infested with several weed species from early on.
Effects of cropping systems (environments), genotypes, and their interaction were large and highly significant (P<0.01) for seed yield, 100-seed weight, and number of days to maturity. The LIO had the lowest mean yield (271 kg ha-1). Mean seed yield on CBE was also relatively low (747 kg ha-1) compared to LSF (2371 kg ha-1) and HIO (3097 kg ha-1). Despite a severe attack from an unknown virus, large differences were similarly found among the three environments at Kimberly R & E Center. The mean seed yield was the lowest under DSE (688 kg ha-1), followed by CBE (1026 kg ha-1), and IFE (1800 kg ha-1). The DSE caused 62%, and CBE caused 43%, reduction in mean seed yield. Additionally, maturity was delayed and seed weight was reduced in DSE and CBE environments.
Significant cropping system x genotype interaction for the three traits suggested that the rank order of genotypes changed markedly from cropping system to cropping system, and that in order to develop high yielding cultivars, selection and evaluation must be carried out across cropping systems. Moreover, for the highest yielding cultivars specific to cropping system, selection may need to be carried out in that particular cropping system.
Late maturing, prostrate, and semi-climbing cultivars such as Mesa, Bill Z, and Buster yielded higher under high fertility heavily weed infested organic farming system. The landrace Common Red Mexican continued to be among the highest yielding under drought-stressed and irrigated farming system at Kimberly R & E Center. Early maturing cultivars such as Topaz, Le Baron, UI 320, US 1140, and Common Pinto were among the lowest yielding across cropping systems including DSE and LIO. The noteworthy exception was cultivar Othello, which ranked fifth across seven environments.
When environments were grouped using the mean seed yield of 16 genotypes, LIO, DSE, CBE, and CFS grouped in one cluster, and HIO, LSF, and IFE in another cluster. Common Red Mexican landrace, Othello, and Matterhorn expressed below average stability and high yield in stressful environments. On the other hand Buster, NW 63, UI 239, Mesa, and Bill Z did well in relatively more favorable high yielding environments. Currently, 16 genotypes are being screened in greenhouse for anthracnose, bean common mosaic virus, common bacterial blight, halo blight, rust, and white mold. Field trials across the seven environments will be repeated in 2004 to obtain more reliable estimates for seed yield, and to determine stability of performance.
Experiment # 2. Breeding strategies for nutrient and water use efficiency, and resistance to soil compaction and weed competition.
The F2 and F3 families from populations Topaz///Matterhorn/Mesa//Buster/Common Red Mexican and LeBaron///VAX 3/Common Red Mexican//Matterhorn/NW 63 made in 2002 were grown in the greenhouse during the fall (2002) and spring (2003), respectively. Thus, 236 F2 derived F4 families from the former, and 246 families from the latter population were available for Experiment # 2. The F4 seed from each family was divided into three equal parts. One set of all families and their parents were grown in each of the IFE, CFS, and HIO farming systems in the summer of 2003. Each plot consisted of a single row, 10 ft long without replication. Data were recorded for growth habit, maturity, and general adaptation. All plants within plot were harvested in bulk. A representative sample of each family is currently being grown in the greenhouse at Kimberly R & E Center. They will be multiplied in the field in Arizona in the spring of 2004 for subsequent evaluation in replicated trials in their respective cropping systems to identify the most promising families from which then to develop breeding lines for further evaluation and selection.
Singh, S.P. 2003. Early maturity among common bean landraces of the Western United States. Annu. Rpt. Bean Improv. Coop. 46: 229-230.
Impacts and Contributions/Outcomes
All participating farmers and a few of their invited colleagues visited both experiments in all cropping systems and environments near physiological maturity. The ongoing work at each site and tentative work plan for 2004 were discussed. Another meeting of all participating farmers will be held at a convenient date in early spring to discuss 2003 data and to formulate the work plan for 2004. An integrated genetic improvement for multiple agronomic traits simultaneously for each important cropping system will be sought by emphasizing overall plant performance.