Prediction of Genetic Gain in Sweet Corn using Selection Indexes

Journal of Crop Science and Biotechnology - The cultivation of sweet corn is expanding in Brazil, but there are serious constraints about the availability of commercial cultivars. The selection of...     

Integrated sustainability assessment of cropping systems with agro-ecological and economic indicators in northern Italy

The sustainability of agricultural systems is frequently evaluated with indicators, which are synthetic variables describing complex systems. Each indicator deals with one aspect of sustainability (e.g. nutrients, pesticides, energy), and therefore the result of a complete assessment usually includes several indicator values. These values are frequently presented separately, while an integrated evaluation could benefit from the calculation of a single sustainability index. The aim of this work was to integrate 15 economic and environmental indicator values into a global sustainability index (S_g) ranging from 0 to 1.To calculate the indicators, we used a large data set of cropping systems management for 131 fields cultivated with arable crops in northern Italy, obtained through periodic interviews with farmers over a 2-year period. The fields were chosen to represent the main cropping systems in the area (cereals and forages, on animal and cereal farms). The 15 indicators describe a large variety of sustainability aspects, i.e. the economic performance and the management of energy, nutrients, soil, and pesticides.The indicator values were first converted into a sustainability score (S_i; 0–1) applying continuous non-linear sustainability functions that use thresholds defining what is sustainable, unsustainable, or intermediate. We obtained 15 values of S_i per each field, which we aggregated into S_g using indicator-specific weights provided by different stakeholders. This procedure permits not only the single indicators evaluation, but also to combine indicators for an assessment of cropping systems at field level.Permanent meadows, due to good management of soil, pesticides and nutrients, obtained the highest S_g, even when different weights were used. Continuous rice obtained the lowest S_g (due to unsatisfactory soil management, low energy production, and high pest and weed pressure, which involved a large use of pesticides), while maize was intermediate, with good economic and energetic performance.The methodology allows a transparent, repeatable, sound, and quantitative evaluation of sustainability of agricultural systems. It can be easily expanded by adding other indicators, and can be tailored by changing the thresholds used to calculate S_i and the weights assigned by stakeholder groups.     

Phenolic acids composition,total polyphenols content and antioxidant activity of Triticum monococcum, Triticum turgidum and Triticum aestivum: A two-years evaluation

Wheat is a good source of polyphenols, plant metabolytes with beneficial effects on human health. However, little information is available on phenolic acid composition and concentration in different Triticum species, as well as on possible environmental effects. To shed some light on this issue, thirty-nine wheat accessions cropped for two years and belonging to different Triticum species (Triticum monococcum, Triticum turgidum ssp. dicoccum, turanicum and durum, Triticum aestivum ssp. spelta and aestivum) were assessed for phenolic acids (ferulic, p-coumaric, vanillic, syringic, p-hydroxybenzoic, caffeic acids and syringaldehyde), total polyphenols and antioxidant activity in soluble conjugated and insoluble bound extracts. Ferulic acid was the most abundant compound in both extracts. Insoluble bound phenolic acids represented >90% of total phenolic acids. Einkorn showed the maximum concentration of conjugated phenolic acids (50.5 mg/kg DM), while durum and bread wheats presented the highest content of bound phenolic acids (651.8 and 629.2 mg/kg DM, respectively). Cropping year influenced the concentration of conjugated but not of bound phenolic acids. A survey of phenolic acid distribution in the kernel showed that they are rare in endosperm, but abundant in germ and bran. Total polyphenols and antioxidant activity were highly correlated to phenolic acid content.     

Arbuscular mycorrhizal fungi communities improve the phytochemical quality of strawberry

The application of arbuscular mycorrhizal fungi (AMF) in strawberry cultivation can improve its growth and development. The objective of this study was to evaluate if strawberry plants in the absence and presence of inoculation with AMF communities, obtained from soils collected in reference-sites in the cultivation of this species, differ in their morpho-horticultural performance. Two experiments were carried out: in experiment I (frequency of AMF communities species) the treatments were eight soils containing AMF communities, collected from natural and agricultural ecosystems in reference-sites of strawberry cultivation in southern Brazil, with nine samples per treatment; in experiment II (use of AMF communities in strawberry) the treatments were eight AMF communities and one control (non-mycorrhizal plants), arranged in a completely randomised design, with three replicates. The species Claroideoglomus aff. luteum, C. claroideum, C. etunicatum, Funneliformis mosseae and Glomus sp2 were the most frequent in the studied sites and the morpho-horticultural performance of strawberry plants was improved when plants inoculated with AMF communities. Strawberry plants inoculated with mycorrhizae develop a more profuse root system and fruit anthocyanin content is increased.     

Soil Fertility,Nutrition and Early Growth of Physic Nut as Affected by Nitrogen Fertilization

The initial growth and mineral nutrition of the physic nut (Jatropha curcas L.) as a function of nitrogen (N) fertilization was investigated. The transplanting of seedlings was carried out in plastic pots filled with 50 dm³ of a Rhodic Hapludox, under a plastic greenhouse. In addition to a control treatment, the dosages of 0, 40, 80, 120, and 160 mg dm^?3 N were tested. The results demonstrated that N fertilization for the cultivation of physic nut could be added as top dressing from 60 days after planting with a dosage of 65 mg dm^?3. A SPAD index of 46 can be used as a nutritional reference to its initial development. Furthermore, the results suggested that the order of nutrient accumulation by the physic nut plants is as follows: potassium (K) > N > magnesium (Mg) > calcium (Ca) > phosphorus (P) > sulfur (S) > iron (Fe) > manganese (Mn) > boron (B) > zinc (Zn) > copper (Cu).     

Arterial blood gas analysis in 53 racehorses with a diagnosis of Small Airway Inflammatory Disease (SAID)

In 53 racehorses with a mean age of 4.5 years old presented for poor performance, Small Airway Inflammatory Disease (SAID) was diagnosed by bronchoalveolar lavage (BAL). Thirty of these horses (58.5%) had arterial pCO₂ above normal range (> 46 mmHg), while pO₂ was within normal range (> 80 mmHg) in both hypercapnic (group A) and normocapnic (group B) horses although pO₂ was significantly lower in group A horses. The horses were subsequently subdivided into two groups according to the duration of symptoms (group 1: less than 4 weeks; group 2: longer than 4 weeks). Horses from group 2 had significantly higher values of pCO₂ (p < 0.01) , HCO₃- (p < 0.01) and TCO₂ (p < 0.05) when compared to horses from group 1. It was concluded that the duration of the inflammatory process may play a role in the alteration of blood/alveolar gas exchanges and acid-base status in SAID affected racehorses.     

Nitrogen budget in a soil-plant system after brachiaria grass desiccation

Abstract

Brachiaria spp. have been grown in a variety of cropping systems and are often terminated with herbicides, which may cause nitrogen (N) loss from the soil-plant system. In this study ammonia (NH₃-N) loss by shoots and N balance in a soil-plant system were determined after desiccation of palisade grass (Brachiaria brizantha (Hochst. ex A. Rich) Stapf, cv. Marandu), signalgrass (Brachiaria decumbens Stapf), humidicola (Brachiaria humidicola (Rendle) Schweick) and Congo grass (Brachiaria ruziziensis Germain et Evrard). The grasses were grown in pots filled with an Oxisol in a greenhouse. Sixty days after planting, the plants were desiccated with glyphosate. Analyses were performed on plant and soil at desiccation and then at 7, 14, 21 and 28 days after desiccation in order to assess NH₃-N losses by shoots and to estimate the N balance in the system. Total nitrogen (Total-N) concentration in shoots and roots of brachiarias decreased after desiccation, thereby reducing the amount of N in plants of the four brachiaria species. However, as most of the N lost by plants was released into the soil, N losses from the soil-plant system were small compared with the total N in the system: 1.2, 0.5, 0.4 and 1.4% for palisade grass, signalgrass, humidicola and Congo grass, respectively. N losses as NH₃ from the soil-plant system after desiccation with glyphosate varied among brachiaria species, ranging from 0.8 to 2.0 g m^?2 kg^?1, and accounted for 30–80% of total loss.     

Chemical management of weeds in corn hybrids

Corn stands out among the cultivars because of its high importance in food, animal feed and raw materials for energy production. The quantity and quality of the harvested grain can be reduced, mainly due to inadequate weed management. Nowadays, weed control is accomplished with the use of herbicides as pre‐emergence and postemergence, applied alone or in a tank mix. This study aimed to evaluate the efficiency of the control of weeds and phytotoxicity of the herbicides that were applied in tank mix or isolated in the corn hybrids, Formula TL® and SYN 7B28 . Two experiments were conducted: in the 2012/2013 season (Formula TL®) and 2013/2014 season (SYN 7B28). There was a low initial phytotoxicity of all the tested herbicides in the initial evaluation; however, from 14 days after treatment, it was minimal. The weed control of Ipomoea indivisa, Urochloa plantaginea and Euphorbia heterophylla in both experiments was better, in general, when using the tank mixtures of atrazine + simazine + tembotrione and atrazine + simazine + mesotrione, respectively. The application of atrazine + simazine + tembotrione in the SYN 7B28 hybrids provided, with the exception of the thousand‐grain weight, the best expression of grain yield components, combining a low phytotoxicity and best control of the weeds. The Formula TL® hybrid presented the highest mass of a thousand grains and yield with the application of nicosulfuron + tembotrione. The yield average difference of the herbicide treatments and the unweeded control showed an increase of 27.66 and 34.59% in the grain yield of the corn hybrids, Formula TL® and SYN 7B28, respectively.