Managing forage and turf‐type bahiagrass for seed production

Bahiagrass (Paspalum notatum Flüggé) is the most extensively cultivated perennial warm-season grass in the southeastern United States for pasture, utility turf, cover cropping, and soil stabilization. The University of Florida Institute of Food and Agricultural Sciences bahiagrass breeding program has recently selected several improved forage- and dwarf-turf-type tetraploid breeding lines. However, seed production andseed quality quantification is needed before proposing any of these lines for cultivar release. The objectives of this study were (a) to evaluate seed production in seven tetraploid bahiagrass breeding lines (two forage-type apomictic hybrids, and five turftype facultative apomicts) and the cultivar ?Argentine?, and (b) to determine the optimum management practices (defoliation timing [May, June] and N rate [0, 60, and 120 kg N ha−1]) to increase seed yield and quality. Six seed traits were evaluated during 2 yr (first and second production year) under a randomized complete block design in a strip-split-plot arrangement with three replications. Eight genotypes (main plot), two defoliation timings (subplot), and three N fertilization rates (sub-subplot)were tested. All breeding lines produced viable seed comparable with Argentine,although some of them exhibited very low reproductive efficiency. Nitrogen fertilization improved seed yield by increasing inflorescence density but did not affect seed quality traits. Defoliation in May produced greater seed yield, whereas defoliation in June resulted in greater seed quality, especially for turf-type genotypes. The information generated in this study will guide cultivar release(s) and will be used to develop targeted recommendation practices for seed production in the species.Fil: Rios, Esteban Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina. University of Florida; Estados UnidosFil: Zilli, Alex Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Kenworthy, Kevin E.. University of Florida; Estados UnidosFil: Mackowiak, Cheryl. University of Florida; Estados UnidosFil: Quesenberry, Kenneth. University of Florida; Estados UnidosFil: Blount, Ann. University of Florida; Estados Unido

Manutenção da qualidade de rosas cortadas cv. Vega em soluções conservantes Keeping quality of cut roses cv. Vega in holding solutions

A rosa é considerada uma das flores de corte mais tradicionais e requisitadas no mercado mundial. Entretanto, após o corte, essas flores tornam-se altamente perecíveis devido à elevada atividade metabólica que conduz aos processos de senescência. Assim, o experimento foi realizado para verificar o efeito do uso de soluções conservantes na fisiologia pós-colheita de rosas vermelhas cortadas cultivar Vega. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial composto por dois fatores: sete tratamentos pós-colheita e quatro datas de avaliação. As flores permaneceram nas seguintes soluções de manutenção: 1) Água destilada; 2) 8-hidroxiquinolina (200 mg L-1); 3) 8-hidroxiquinolina (200 mg L-1) + Sacarose (20 mg L-1); 4) Ácido cítrico (75 mg L-1); 5) Ácido cítrico (75 mg L-1) + Sacarose (20 mg L-1); 6) 6-benziladenina (60 mg L-1); 7) 6 benziladenina (60 mg L-1) + Sacarose (20 mg L-1). Foram realizadas análises qualitativas e fisiológicas ao longo do período de avaliação. O tratamento com 8-hidroxiquinolina e ácido cítrico revelaram-se mais promissores para manter a qualidade e prolongar a vida de vaso das flores, o que foi evidenciado pela menor perda de massa fresca, atividade respiratória e conteúdo relativo de água; melhor manutenção do conteúdo de carboidratos solúveis e redutores, antocianina e coloração.<br>The rose is considered one of the most traditional and required cut flowers in the world market. However, after cutting, these flowers become highly perishable, because the high metabolic activity leads to senescence processes. The experiment was accomplished to verify the effect of holding solutions on the postharvest physiology of cut red roses, cv. Vega. A randomized design in a factorial scheme composed by two factors was used: seven postharvest treatments and four evaluation dates. The flowers remained in the following holding solutions: 1) Distilled water; 2) 8-hydroxyquinoline citrate (200 mg L-1); 3) 8-hydroxyquinoline citrate (200 mg L-1) + Sucrose (20 mg L-1); 4) Citric acid (75 mg L-1); 5) Citric acid (75 mg L-1) + Sucrose (20 mg L-1); 6) 6-benzyladenine (60 mg L-1); 7) 6-benzyladenine (60 mg L-1) + Sucrose (20 mg L-1). Qualitative and physiologic analyses were carried out during the evaluation period. The treatment with 8-hydroxyquinoline citrate and citric acid were the most promising to keep the quality and extend the vase life of flowers content; better maintenance of soluble and reducing carbohydrates, anthocyanin and color