Morphological diversity among local and introduced maize (Zea mays L.) varieties in Haiti for yield improvement

Maize, the cereal with the largest production in the world, is a staple crop in many developing countries including Haiti. Even if Haiti is the second maize consumer in the Caribbean region, its national yield is low and alleged of aflatoxin contamination. In order to increase grain yield, three introduced and two local maize varieties (these used as comparative control) were evaluated. Three field trials were carried out at Torbeck and Morne Briller (Port-Salut) during different growing seasons. Experiments were designed in a three-replicate randomized block. Each experimental plot was 3.50 m per 10.5 m with a gross area of 36.75 m2 and 40 000 plants/ha densities. The trials were carried out according to local agricultural practices. The results revealed that the introduced varieties had a smaller yield than the local ones. Moreover, all varieties showed some aflatoxin content below the European Union limit (5\u3bcg/Kg). Statistical analyses showed a strong and direct correlation between yield and ear weight and an inverse correlation between yield and male and female flowering day after sowing. The broad phenotypic diversity suggested a rich reserve of alleles to exploit in a breeding program focused to improve food security in Haiti

Evaluation of concentration of heavy metals in animal rearing system

Animal manure is one of the diffusion routes of heavy metals and metalloids into the environment, where the soil can accumulate them. Heavy metals and metalloids can then be released into groundwater sources, be absorbed by crops, and enter the food chain with negative effects for human and animal health. The aim of this study was to evaluate the concentration of heavy metals and mineral nutrients from modern animal rearing systems in order to develop effective strategies to increase the sustainability. Samples of feed (n\ubc24: n\ubc16 from swine, n\ubc8 from cattle), faeces (n\ubc120: n\ubc80 from swine, n\ubc40 from cattle) and water (n\ubc8), were collected from eight typical intensive swine and cattle farms located in northern Italy. All samples were analysed for the humidity and the principal components. The samples were also dried, mineralised, and analysed by ICP-MS to detect the following elements: Na, Mg, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, and Pb. The swine diets represented the highest amounts of Zn and Cu, with an average concentration for the finishing and weaning phases of Zn: 1737.9 \ub1 301.3; 821.7 \ub1 301.3; Cu: 133.8 \ub1 11.6; 160.1 \ub1 11.6 mg/kg as fed, respectively. The faecal content reflected the heavy metal composition from feed. The average content of cattle diets of Zn and Cu did not result higher than the maximum permitted levels. We observed that the swine manure represented the sources of Zn and Cu output into the environment. The Zn and Cu content should be monitored strictly in line with agroecology principles

Evaluation of leonardite as a feed additive on lipid metabolism and growth of weaned piglets

We evaluated the effects of leonardite supplementation, mainly composed of humic acids (HAs), as a functional feed additive in weaned piglets. One hundred and twenty piglets (Large Withe 7 Landrace) were weaned at 28\ub12 days, and randomly divided into two groups (6 pens per group, 10 piglets per pen). After one week of adaptation, for 40 days groups were fed a control diet (CTRL) and an HA enriched diet (0.25% of leonardite; HAG). Body weight (BW), average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR) were measured throughout the experimental period. On the last day of the trial four piglets per pen were randomly selected and the blood was collected to evaluate the serum metabolic profile and diamine oxidase content. Chemical analyses showed that leonardite was characterized by a high content of ash 23.27% (as-fed basis), polyphenolic content of 35.18\ub13.91 mg TAEq/g, and an antioxidant capacity of 73.31\ub18.22 \u3bcmol TroloxEq/g. The HAG group showed an increase in BW, ADG and ADFI (P<0.01) compared to the CTRL group during the experimental period. In terms of the serum metabolic profile, the HAG group showed a significant increase in total protein content (P<0.001), albumin (P<0.001), albumin/globulin ratio (P<0.01), phosphatase alkaline (P<0.01), calcium, phosphorus and magnesium (P<0.05) compared to the CTRL group. A modulation in the serum lipid profile was recorded. The HAG group showed a decrease in total triglycerides (P<0.05) with higher total cholesterol (P<0.05), however only high-density lipoprotein showed a significant increase (P<0.001) compared to the CTRL group. No significant differences in the amount of diamine oxidase were found between groups. In conclusion, leonardite inclusion in the diet at 0.25% was shown to have a positive effect on the serum lipid profile and animal growth. This thus suggests that leonardite can be considered as a new feed additive, which improves the health and performance of weaned piglets

Regulation of branching during inflorescence development in monocots

The structure of the plant inflorescence is an important agronomic and ornamental trait studied for its potential economic applications: the capacity to modify inflorescence architecture has always been a breeder's goal. The shape of flowering plants is determined by the forms of the flower-bearing branch system, named inflorescences, and their position in the overall structure of the plant. Branching patterns and branches are produced by the shoot apical meristem; thus, inflorescence structure reflects the number, size and activity of the meristems. The genetic and molecular control of inflorescence and flower development has been extensively studied in model dicotyledonous plants such as Arabidopsis. However, not all the genes controlling inflorescence architecture in grasses are orthologous of Arabidopsis genes and thus grass inflorescence genes could not have been identified by simple extrapolation from Arabidopsis. Among plants, rice and maize in particular are the best genetic models for studying inflorescences: the maize inflorescence is a useful model for developmental and evolutionary studies, because several mutants have been isolated that taken together dissect every step of the inflorescence development. Because of the sequencing of the rice genome, positional information can be used to clone genes in maize, wheat and related grasses. In recent years, several master genes involved in inflorescence development have been cloned, providing considerable insights into the genetic control of the plant inflorescence

La canna comune e il mais : simulazione di un impianto reale di digestione anaerobica

La canna comune o Arundo donax L. \ue8 una pianta erbacea largamente diffusa a livello nazionale che ben si adatta a diverse condizioni pedoclimatiche; infatti le sue pi\uf9 evidenti peculiarit\ue0 sono la forte rusticit\ue0 e l\u2019adattabilit\ue0. Poich\ue9 il mondo agricolo \ue8 sempre pi\uf9 interessato alla produzione di energia e all\u2019integrazione del proprio reddito mediante nuove filiere bioenergetiche, la canna comune assume un\u2019importanza sempre maggiore per i processi di digestione anaerobica. La coltura di Arundo si caratterizza per l\u2019entit\ue0 dei costi molto contenuti grazie al fatto che \ue8 poliennale (12-15 anni), ha delle rese molto elevate se confrontate con le altre specie coltivate, necessita di pochi input agronomici (interventi irrigui, concimazioni, fitofarmaci\u2026), pu\uf2 essere impiegata su suoli marginali, resiste bene agli stress biotici (malattie, virus, insetti\u2026) ed abiotici (carenze idriche, carenze di nutrienti\u2026). Per valutare la possibilit\ue0 di impiegare Arundo donax L. per la produzione di biogas, sono state condotte prove di insilamento ed \ue8 stata studiata la sua attitudine ad essere impiegata durante i processi di digestione anaerobica. I risultati mostrano che la biomassa della canna comune pu\uf2 essere insilata mediante le stesse tecniche impiegate per ottenere l\u2019insilato di mais. Le analisi condotte hanno dimostrato che la biomassa \ue8 in grado di conservarsi per lunghi periodi di tempo mantenendo pressoch\ue9 inalterata la propria qualit\ue0 e dotazione di acidi grassi. La prova di digestione anaerobica \ue8 stata eseguita confrontando direttamente le biomasse di insilato di canna e di mais, per evidenziarne le principali differenze in un sistema che simula un impianto CSTR. A parit\ue0 di sostanza secca immessa nel digestore simulato, si \ue8 notato che la produzione di biogas da Arundo \ue8 quasi il 70% di quello ottenuta da mais. La caratterizzazione chimica dei digestati e l\u2019analisi del gas, hanno mostrato che non ci sono delle differenze particolarmente evidenti tra le due tipologie di biomassa. La minore quantit\ue0 di biogas prodotto da insilato di Arundo rispetto al mais trova giustificazione per la mancata presenza in tale biomassa di una componente amidacea e di una buona dotazione di zuccheri, substrati importanti per il processo di metanogenesi. Considerando le produzioni medie di biomassa secca raccolta, pari a 20 t ha-1 per il mais e 45 t ha-1 per Arundo, \ue8 possibile stimare che la produzione di metano per unit\ue0 di superficie sia superiore con la canna comune. Quest\u2019ultima \ue8 in grado di produrre pi\uf9 del 30% di metano all\u2019ettaro rispetto al mais; infatti, la resa in termini di biomassa di Arundo \ue8 in grado di sopperire alla sua pi\uf9 ridotta produzione di biogas durante la digestione anaerobica