Drought is a worldwide constraint to dry bean (Phaseolus vulgaris L.) production. The objective of this research was to determine the response of three dry bean landraces and 13 cultivars evaluated under non-stressed (NS) and intermittent drought-stressed (DS) environments at Kimberly, Idaho in 2003 and 2004. The NS received seven irrigations in 2003 and five in 2004, and DS only four in 2003 and two in 2004. Most water use occurred within the top 0.5 m soil in both the NS and DS. Drought reduced biomass and seed yield, harvest index, and seed weight. Maturity was delayed in severe drought, but was similar or shortened by 1 to 6 d under moderate drought. Mean seed yield was reduced by 62% in 2003 and by 27% in 2004. Common Red Mexican and CO 46348 had high seed yield in both NS and DS environments, whereas 'Matterhorn' and 'Othello' yielded comparatively high under DS but moderately in NS environment. Drought resistance was inadvertently reduced from Common Red Mexican landrace to intermediate levels in 'NW-63' and 'UI 239' released in 1979 and 1993, respectively, and more recently released 'LeBaron ' (1999) and 'UI 259' (1996) were susceptible. Conversely, drought resistance was increased in newer pinto (Othello 1986; CO 46348) and great northern (Matterhorn 1998) releases compared to the landraces and older cultivars tested for those market classes. Seed yield in NS and DS was positively correlated. Seed yield was also correlated with harvest index in DS and NS. All early maturing cultivars except Othello (e.g., UI 59, US 1140, Common Pinto, Topaz, UI 320, and LeBaron) were susceptible. Common Red Mexican did not have any reduction in seed weight due to drought stress. Drought resistant genotypes should be used for determining irrigation frequency, amount of water to be applied, and mechanisms of resistance and for identifying, mapping, and pyramiding favorable genes for dryland and irrigation-assisted sustainable production systems.

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High‐yielding cultivars adapted to stressed and nonstressed production systems (PS) would maximize efficiency of soil water and nutrient usage, compete well with weeds, resist diseases and insect pests, and reduce dependence on water, fertilizer, and pesticide. The objectives of this study were to (i) determine the performance of dry bean (Phaseolus vulgaris L.) landraces and cultivars across seven stressed and nonstressed PS, (ii) identify high‐yielding cultivars within and across PS, and (iii) determine associations among PS. Three landraces and 13 cultivars were evaluated for days to maturity, 100‐seed weight, and yield in 2003 and 2004. The PS and genotype effects and their interactions with years were significant (P < 0.01). The mean yield (740 kg ha−1), 100‐seed weight (28 g), and days to maturity (81 d) were least in the on‐farm organic low input (OFOL) PS. The greatest mean yield (2740 kg ha−1) was obtained in the on‐station conventional (OSCN) PS, while the greatest 100‐seed weight (35 g) and days to maturity (95) were obtained in the on‐farm low soil fertility (OFLF) PS. Red genotypes yielded more across all PS. ‘Bill Z’ in OSCN and on‐farm organic high‐input (OFOH) PS, ‘UI 239’ in on‐station continual bean production (OSCB), CO46348 in on‐station drought‐stressed production (OSDS), ‘Matterhorn’ in on‐farm conventional (OFCN), ‘NW 63’ in OFLF, and ‘Buster’ in OFOL had high yield. CO46348, UI 239, NW 63, and Bill Z had high yields across PS. Positive associations for yield in the OFCN occurred with yield across all PS except OFOL. The latter was not correlated with other PS. Thus, testing in the OFCN PS would be pivotal for development of high‐yielding cultivars for diverse PS, while testing at OFOL would need to be done for cultivars developed for use in that PS.

Terminal drought is a worldwide constraint to common bean production and its negative effects will be increased by climate change. The objective of this research was to characterize phenotypically advanced lines and commercial cultivars of common bean for their resistance to terminal drought stress. Field trials were conducted during 2012 and 2013 at Centro Internacional de Agricultura Tropical (CIAT), Palmira, Colombia. A 4x4 partially balanced lattice design with four replicates was used and, evaluated under irrigation and terminal drought. To achieve the terminal drought condition, irrigation was suspended at 22-23 days after planting. Terminal drought reduced mean grain yield by 68%. Lines SEN 56, BFS 29, NCB 226 and SER 16 showed high grain yield in both irrigated (3617-3836 kg/ ha) and terminal drought (1232-1447 kg/ha) conditions, while RCB 593 and G 40001 showed high grain yield in drought (>1270 kg/ha) and similar to checks in irrigated condition. The most resistant lines showed lower drought susceptibility index (0,88 - 1,00), earlier maturity (56 - 60 dds), superior geometric mean (1931 - 2311 kg/ha), and higher number of grains/m2, (673 - 1250). Drought resistant lines produced at least 15% and 50% more grain yield than EAP 9510-77, commercial check for Central America, in irrigated and drought condition, respectively. In addition, they were also superior to other commercial checks such as DOR 390 and Bribri.

En este estudio se evaluó el efecto del agua tratada magnéticamente (ATM) en parámetros fisiológicos de ají Tabasco, rábano rojo y maíz amarillo. La mitad de las plantas de las tres especies se regaron con agua normal del acueducto, y la otra con agua tratada a través de un dispositivo magnético. Se midieron la fotosíntesis, la biomasa y el contenido mineral (este último solo en frutos de ají Tabasco). Todas las especies cultivadas con ATM aumentaron su tasa fotosintética y su conductancia estomática. Los parámetros de fluorescencia, como la fluorescencia variable (Fv /Fm) y la extinción no fotoquímica, permanecieron sin cambios en las especies evaluadas. En el ají Tabasco, el agua con tratamiento favoreció un mayor rendimiento, en parámetros como biomasa aérea, frutos por planta y área foliar, incrementándose también el contenido de nitrógeno y cationes divalentes en frutos. Además, hubo una relación parcialmente positiva entre el área foliar y el rendimiento de frutos por planta (r2=0,52 en el control y 0,30 con ATM). En contraste, en las plantas de maíz solo hubo un aumento en el peso y en los granos por mazorca, mientras que las de rábano mostraron una pérdida no significativa en la biomasa total. La mayor acumulación de biomasa observada en las plantas de ají Tabasco y maíz se atribuye a una mayor área foliar o a la asimilación de carbono. Debido a que la fluorescencia de la clorofila no se alteró, se propone que el ATM no provoca ningún cambio en el complejo de oxidación del agua del fotosistema II. Por otra parte, la falta de respuesta de algunas variables en las tres especies mostró que el ATM puede tener efectos interespecíficos. A pesar de lo anterior, esta tecnología puede ser una alternativa para mejorar el rendimiento de los cultivos, en particular en del ají Tabasco.