The combination of plant density, fungicide, and levels of genotype resistance to white mold (WM) has not been studied for the role played in affecting performance of common bean with type III growth habit under WM pressure. We established four sprinkler-irrigated trials in the fall-winter season in Brazil, combining density (8, 14, 20 or 26 plants/m2), genotype (susceptible or partially resistant to WM), and fungicide to manage WM (two fluazinam applications or without fluazinam) at 0.5 m row spacing in fields infested with sclerotia. One trial was established in a warm region, aiming to obtain low WM pressure. For three trials, the linear mixed model was used. WM pressure in the trials ranged from low to high. Genotype × density × fungicide and genotype × density interactions were not significant for incidence, severity, and yield for all trials. In the three trials, severity was 29% lower at 8 than at 26 plants/m2, and yield at 14 plants/m2 (3,294 kg/ha) was 14% higher than yield at 8 plants/m2 (P = 0.035) where fluazinam was applied. However, without fluazinam, density did not affect yield. In conclusion, plant density for type III bean cultivars does not need to take into account their resistance levels to WM in the fall-winter season. However, fungicide treatment to manage WM affects the decision on density, with 8 to 12 plants/m2 recommended if fungicide is not an option to manage WM (as in organic systems), and 10 to 14 plants/m2 recommended if fungicide applications are likely.

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Development of common bean cultivars with partial white mould resistance through breeding techniques has been a challenge in Brazil. As yet, lines/cultivars from breeding programmes have not been investigated for resistance; therefore, this study screened 107 lines/cultivars for their reactions to white mould in 14 preliminary trials conducted under irrigation. Thirteen resistant lines/cultivars (three of Andean origin) and six Mesoamerican cultivars (three intermediately resistant and three susceptible) were selected for further investigation. These lines/cultivars and the resistant control A195 were evaluated in six advanced trials and two straw tests to assess the effectiveness of the screening procedure. In 11 preliminary trials, screenings were performed under moderate/high or higher disease pressure. These pressures occurred in two advanced trials in which, when yields were averaged across moderate/high and high pressures, 10 Mesoamerican lines/cultivars selected for resistance yielded 14%, 23%, and 38% more than intermediately resistant cultivars, A195, and susceptible cultivars, with median disease ratings (1–9 scale) of 4.5, 5.7, 5.7, and 6.7, respectively. In the straw test, three Andean lines/cultivars (A195 included) and two susceptible cultivars in the field were among those with the highest levels of physiological resistance. Thus, field rating under high disease pressure and greenhouse rating did not correlate significantly, suggesting that field trials are critical to evaluating resistance and to identifying high‐yielding beans. Therefore, lines/cultivars from breeding programmes assessed in field trials may provide a low cost and fast way to identify high‐yielding bean cultivars with partial resistance to white mould in the subtropical southern hemisphere.

BRSMG Camaleão' is a mungbean cultivar with large, shiny, green seeds released for the state of Minas Gerais, Brazil. It was developed by the Asian Vegetable Research and Development Center as line VC 6148-B-16. In seven trials established in the Zona da Mata region, it had an average yield of 1493 kg ha -1 and 1000-seed weight of 68-78 g.

Common bean (Phaseolus vulgaris L.) plants sprayed with molybdenum (Mo) fertilizer produce Mo‐enriched seeds, which may increase yield in Mo‐poor soils. The challenge has been to produce Mo‐enriched seeds with less fertilizer. Split applications of Mo increase seed Mo content (SMoC), but the number of splits that maximize SMoC has not been studied sufficiently. In three sprinkler‐irrigated field trials, we evaluated the effects of split‐applied Mo fertilizer on SMoC and seed physiological quality. All treatments received NPK fertilizer at sowing. In two treatments, 69 kg ha−1 of urea‐N was top‐dressed or not applied. In six treatments, Na2MoO4·2H2O was foliar‐sprayed once at either 90 or 600 g ha−1 of Mo at the 4th trifoliolate leaf (V4) growth stage, or 600 g ha−1 was split equally at V4 and bud initiation (R5); V4, R5, and full flowering (R6); V4, R5, R6, and early pod formation (R7); or V4, R5, R6, and early and late R7 growth stages. Seed yield for each trial ranged from 3723 to 4621 kg ha−1. Site‐treatment interaction was significant for SMoC and seed germination (p < 0.001). SMoC ranged from 0.11 to 0.23 (only NPK‐fertilized), 1.81 to 3.31 (600 g ha−1, no split), and 5.22 to 6.29 μg (four splits). Four and five splits did not differ significantly for any variable. In two trials, seeds from 600 g ha−1 of Mo had a 3.9% higher germination than seeds from 90 g ha−1. In conclusion, SMoC increases as the number of splits increase up to four times. Additionally, Mo applied at 600 g ha−1 may improve seed germination rate.

Improving integrated management of white mold by using partial resistant genotype and adequate plant population in common bean. Adviser: José Eustáquio de Souza Carneiro. Co-adviser: Rogério Faria Vieira. The white mold (WM), caused by the soil fungus Sclerotinia sclerotiorum, is the main disease of common bean in the dry season in the Southeastern and Mid-western regions of Brazil. The integrated management by using partially resistant genotypes with adequate plant population may keep WM infection at low damage levels, thereby increasing yield. Studies showed that plant population for beans of type II growth habit could be higher than that currently recommended, but concerns with the possibility of increasing disease, especially WM, lead researchers to limit the plant population recommended. However, as partial resistant genotype of bean may be released soon, the use of high plant population could improve seed yield without a great increase on WM incidence and severity. We conducted two studies. In the first, we reevaluated the strategy of field selections/evaluations in obtaining high-yield genotypes with partial resistance to WM. In the second, we evaluated to the performance of type II bean partially resistant to WM in the field using high plant population in areas infested with sclerotia of S. sclerotiorum. In the first study, we assessed four groups (G) of Mesoamerican genotypes and a group of early maturing Andean genotypes (resistant control): G1 = seven genotypes with resistance; G2 = four elite lines with putative resistance; G3 = A195, G122, Cornell 605, and Ouro Branco (Andean), G4 = two cultivars with intermediate resistance, and G5 = three susceptible cultivars. Genotypes of G2 were screened in the 2013- 2014 VCU trials; the others, in the 2008-2011 VCU trials. A linear mixed model was used. To evaluate the performance of the type II bean with partial resistant to WM under high plant population, we combined between-row spacing levels (0.25 or 0.50 m) with in-row plant density levels (7, 10, 13 or 16 plants m -1 ). The effects of these factors on WM infection and yield were assessed using the carioca line CNFC 10720, which has partial resistance to WM. In the first study, the contrast G1,G2 vs. G3 was non-significant for WM incidence and severity index, indicating that genotypes selected for partial resistant were as resistant as the control group. Additionally, G1,G2 yielded 43% more (p < 0.001) and produced 33% less sclerotia (p = 0.001) than G3. In the second study, yield at 0.25 m was 28% higher than yield at 0.50 m (p < 0.001). The use of 13 plants m -1 provided the higher yield for both 0.25 and 0.50 m. In conclusion, the first study supports the previous findings and add new evidencethat support the effectiveness of the strategy proposed to identify resistance for WM associated with high yield for the dry season in Brazil. The results related to the type II bean with partially resistant to WM indicate that plant population higher than that currently recommended may improve seed yield. However, further studies of plant population are needed under condition of diseases pressure, especially WM, before a conclusion can be reached. Keywords: Sclerotinia sclerotiorum. Phaseolus vulgaris. Genetic resistance. Plant population. Dry bean. Escape mechanisms.

In‐row plant densities have not been studied for common beans with type II growth habit and contrasting reactions to white mould. Advanced breeding lines with partial resistance or susceptibility to white mould were combined with 4, 7, 10 or 13 plants m−1 and with or without fungicide at a constant between‐row spacing of 0.5 m in five sprinkler‐irrigated field trials conducted during the autumn–winter season in Brazil. White mould pressures in the trials covered the whole range from zero to moderate/high (46–60% of white mould severity index). In all trials, means of white mould incidence, severity and yield did not vary significantly between 7 and 13 plants m−1 for the partially resistant line, regardless of the fungicide levels. For the susceptible line, 13 plants m−1 increased white mould incidence and severity under moderate disease, regardless of the fungicide levels, and decreased yield compared with 10 plants m−1 when fungicide was applied twice under moderate/high disease pressure. For the susceptible line, 7 or 10 plants m−1 maximized yield in all trials, with or without fungicide applications. The results suggest that the current recommendation of 11–13 plants m−1 could be used for type II beans with partial resistance to white mould in either a conventional or organic system. For susceptible genotypes, 7–10 plants m−1 seems to be the most appropriate in‐row plant density. This study may improve the recommendation of in‐row plant density for type II beans cultivated under white mould pressure.