CORRELATION BETWEEN GENOTYPE DIFFERENCES IN YIELD AND CANOPY TEMPERATURES IN WYOMING DRY BEAN

INTRODUCTION Breeders and physiologists continue to seek phenotypic and genetic markers that are easy to measure and help predict yield. METHODS In 2015, 49 dry bean genotypes from varying market classes were sown on 19 June 2015 on a Haverson and McCook loam at Lingle (WY). Experimental design was a split-plot with irrigation level the main plot and genotypes (one row only, 6 m, 76-cm spacing) assigned to subplots. Irrigation levels were “unstressed” (for the season) vs. “partial drought.” Partial drought consisted of full irrigation pre-bloom but was followed by approximately irrigation at 50% potential evapotranspiration post-bloom. There were two replicates per genotype per water regime. The fully irrigated plot received 6.09 inches of supplemental water while the limited plot received 2.38 inches of supplemental water (irrigation was performed weekly). Other details of the methods are provided in Heitholt and Baumgartner (2016). Canopy temperatures were recorded on 9 August with a Spectrum Technologies IR Temp Meter. A second and similar study was sown on 27 May 2016 at Lingle (WY) with 23 genotypes on a Haverson, McCook loam and a Heldt silty clay. Plots (four rows) were 5 m long with 76-cm rows. Differential watering (0.75 inches vs. 0.50 inches) was employed at each irrigation post-bloom with a split-plot arrangement (three replicates per genotype per irrigation regime). Canopy temperature was recorded mid-morning and mid-afternoon on 23 July with an Apogee MI-2H0 infrared thermometer several days after a differential watering. Other methodological details for this second study are provided in Heitholt et al. (2017). A hail storm on 27 July terminated the crop and no yield data was collected

Genetic and environmental effects on crop development determining adaptation and yield

Slafer, Gustavo Ariel. ICREA - AGROTECNIO - Spain.Kantolic, Adriana Graciela. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.Appendino, María Laura. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.Tranquilli, Gabriela Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Recursos Naturales. Instituto de Recursos Biológicos. Buenos Aires, Argentina.Miralles, Daniel Julio. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.Savin, Roxana. ICREA - AGROTECNIO - Spain.Crop development is a sequence of phenological events controlled by the genetic background and influenced by external factors, which determines changes in the morphology and/or function of organs (Landsberg, 1977). Although development is a continuous process, the ontogeny of a crop is frequently divided into discrete periods, for instance ‘vegetative’, ‘reproductive’ and ‘grain - filling’ phases (Slafer, 2012). Patterns of phenological development largely determine the adaptation of a crop to a certain range of environments. For example, genetic improvement in grain yield of wheat has been associated with shorter time from sowing to anthesis in Mediterranean environments of western Australia (Siddique et al., 1989), whereas no consistent trends in phenology were found where drought is present but not necessarily terminal, including environments of Argentina, Canada and the USA (Slafer and Andrade, 1989, 1993; Slafer et al., 1994a) (Fig. 12.1). Even in agricultural lands of the Mediterranean Basin where wheat has been grown for many centuries, breeding during the last century did not clearly change phenological patterns (Acreche et al., 2008). This chapter focuses on two major morphologically and hysiologically contrasting grain crops: wheat and soybean. For both species, we have an advanced understanding of development and physiology in general. Wheat is a determinate, long-day grass of temperate origin, which is responsive to vernalization. Soybean is a typically indeterminate (but with determinate intermediate variants), short-day grain legume of tropical origin, which is insensitive to vernalization. Comparisons with other species are used to highlight the similarities and differences. The aims of this chapter are to outline the developmental characteristics of grain crops and the links between phenology and yield, to revise the mechanisms of environmental and genetic control of development and to explore the possibilities of improving crop adaptation and yield potential through the fine-tuning of developmental patterns

DIFFERENTIAL RESPONSE OF FIFTEEN PINTO BEAN CULTIVARS TO TWO NITROGEN RATES

INTRODUCTION - Dry bean (Phaseolus vulgaris L.) is the main source of protein (20 to 25%) for most people in the world; protein from soybean is higher but is primarily use for livestock. Dry bean yield is often lower than 1000 kg ha-1 in most dry bean producing regions except the US. Besides drought, low soil fertility and ineffective nitrogen (N) management strategies are the most important yield-limiting factors for dry bean production worldwide (Fageria et al., 2013). Use of N-efficient dry bean genotypes, optimal timing of N application(s), and identifying a costeffective N rate are good strategies to optimize dry bean profitability. Therefore, the aim of this study was to evaluate fifteen pinto bean cultivars grown in the greenhouse with two rates of nitrogen fertilizer for physiological/growth traits and their tolerance to low N. MATERIAL AND METHODS - Seed of (Bill Z, Centennial, CO46348, COSD-25, COSD-35,Croissant, El Dorado, ISB1231-1, La Paz, Lariat, Long’s Peak, ND307, Othello, Poncho, and UIP-40) were sown in 11.3 L pots (8 kg of soil) in the greenhouse (four pots per cultivars) on 20 September 2016 in Laramie WY (2200 m elevation). Seed were inoculated with a commercial inoculant at planting. The soil mix was 33% sand, 33% soil amendment, and 33% native soil. Seedlings were thinned to three per pot at two weeks. Aqueous fertilizer treatments (NH4NO3) were applied at (25, 32, 39, and 46 days after planting, dap) in two rates (0 and 67 kg N ha-1 seasonal equivalent). A randomized complete block design was used with two replicates. Leaf chlorophyll (CHYL) was measured on the third uppermost fully-expanded leaf by using a chlorophyll meter (SPAD-502) at (26, 33, 40, 47, and 54 dap). The height, root mass, and stalk mass was determined at maturity. Seed yield, pod harvest index (PHI), and nitrogen susceptibility index (NSI) were also determined at maturity. Pod harvest index equaled seed weight divided by the sum of pod wall plus seed weight; NSI was calculated as the cultivar’s percentage reduction in yield due to zero N divided by the average yield reduction due to zero N