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

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

Soil-Applied Nitrogen and Composted Manure Effects on Soybean Hay Quality and Grain Yield

Grain yield in many soybean experiments fails to respond to fertilizer nitrogen (N). A few positive responses have been reported when soybean were grown in the southern U.S., when N was applied near flowering and when biosolids were added. In a previous study, low N concentrations of soybean forage in north Texas on a high pH calcareous soil were reported and thus, we suspected a N nutrition problem. Consequently, we initiated this study to determine whether selected preplant N sources broadcast and incorporated into a Houston Black clay (fine, smectitic, thermic Udic Haplusterts) might increase forage N concentration, forage yield, or soybean grain yield. In 2003, N was applied as ammonium nitrate (NH4NO3, AN) up to 112 kg N ha−1 and dairy manure compost (DMC) was applied at rates of 4.9, 9.9, 15.0, and 19.9 Mg ha−1. The DMC contained 5.9, 2.6, and 6.7 g kg−1 of total N, P, and K, respectively; thus DMC added 29 to 116 kg N ha−1. In 2004, AN was applied at rates of 112 and 224 kg N ha−1 and DMC was applied at 28 and 57 Mg ha−1; thus, DMC added 168 to 335 kg N ha−1. In another 2004 test, biosolids, a biosolids/municipal yard waste compost mixture (BYWC), and AN were compared. The biosolids contained 31, 18, and 2.9 g kg−1 total N, P, and K, respectively. The BYWC mixture contained 8.8, 6.1, and 3.4 g kg−1 of total N, P, and K, respectively. Biosolids were applied at 10 Mg ha−1 (310 kg N ha−1), BYWC was applied at 58 Mg ha−1 (510 kg N ha−1), and AN up to 224 kg N ha−1. None of the soil treatments increased soybean grain yield or forage yield although AN slightly increased forage N concentration in 2003