A simple and selective method for the measurement of azadirachtin and related azadirachtoid levels in fruits and vegetables using liquid chromatography electrospray ionization tandem mass spectrometry

Neem-based insecticides containing azadirachtin and related azadirachtoids are widely used in agriculture. Here, we report an analytical method for the rapid and accurate quantification of the insecticide azadirachtin A and B and other azadirachtoids such as salannin, nimbin, and their deacetylated analogues on tomatoes and peaches. Azadirachtoids were extracted from fruits and vegetables with acetonitrile. Using high-performance liquid chromatography/electrospray ionization tandem mass spectrometer, azadirachtoids were selectively detected monitoring the multiple reaction transitions of sodium adduct precursor ions. For azadirachtin A, calibration was linear over a working range of 1-1000 microg/L with r > 0.996. The limit of detection and limit of quantification for azadirachtin A were 0.4 and 0.8 microg/kg, respectively. The presence of interfering compounds in the peach and tomato extracts was evaluated and found to be minimal. Because of the linear behavior, it was concluded that the multiple reaction transitions of sodium adduct ions can be used for analytical purposes, that is, for the identification and quantification of azadirachtin A and B and related azadirachtoids in fruit and vegetable extracts at trace levels.     

Effects of starvation and water quality on the purging process of farmed Murray cod (Maccullochella peelii peelii)

The aim of this study was to determine the effects of starvation and water quality during the purging process on the biometric parameters, fatty acids, and flavor volatiles of Murray cod farmed in a recirculation system. Market size Murray cod, at the end of the grow-out stage, were divided into eight treatments. The treatments were either fed/starved (F or S) and kept in clean water (CW: CWF2, CWS2, CWF4, and CWS4) or fed/starved and kept in recycled water (RW: RWF2, RWS2, RWF4, and RWS4) for either 2 or 4 weeks. Fish were sampled at 0, 2, and 4 week intervals. Food deprivation was responsible for a significant (P < 0.05) weight loss compared to that of fed treatments. The same was observed for the condition factor (K), hepatosomatic index (HSI), and dress-out percentage (DP). No significant changes were, however, observed in the visceral fat index (VFI). Saturated fatty acids (SFA) were highest in RWF4 and lowest in CWS4 (P < 0.05), while monounsaturated fatty acids (MUFA) were lowest in CWF4 (P < 0.05). Starvation did not affect the flavor volatile compounds, which were mainly affected by changes in water quality. Specifically, total aldehyde (% w/w) content was significantly (P < 0.05) affected by water quality, but the time of purging was not responsible for any noteworthy differences. This study was able to separate the effects of starvation and water quality, in the purging process, on the final eating quality of farmed market size Murray cod. It is concluded that because of the inevitable weight loss during starvation, Murray cod should be fed during the purging stage but kept in clean water and deprived of food only for the time necessary to empty the gastro-intestinal tract.     

A novel type of seaweed extract as a natural alternative to the use of iron chelates in strawberry production

The new generation of seaweed extracts, such as Actiwave^®, may represent a promising strategy to reduce the use of phytochemicals in agriculture. Actiwave^® is a metabolic enhancer derived by the algae Ascophillum nodosum, but differently from some older seaweed extracts, it has a constant and balanced formulation containing kahydrin, alginic acid and betaines which synergistically contribute to the efficacy of the product. Actiwave^® has been proposed to increase the mineral nutrient uptake and the abiotic stress tolerance. The aim of this work was to evaluate, under a multidisciplinary approach, the effect of the biostimulant on the vegetative and productive performances of strawberry plants grown on a lime inducing iron chlorosis substrate. This biostimulant increased the vegetative growth (10%), the leaf chlorophyll content (11%), the stomata density (6.5%), the photosynthetic rate and the fruit production (27%) and berry weight. The most significant result was the increase of the plant biomass: the shoot dry matter was increased up to 27% and root dry matter up to 76%. Finally, preliminary experiments showed that Actiwave^® positively influenced also the root-associated microbial biocoenosis. These results are discussed in relation to the physiological and ecological mechanisms proposed to explain the beneficial effects of this seaweed extract. Finally, the effects of Actiwave^® and sequestrene were significantly similar, thus showing that this biostimulant may represent an environmental-friendly substitute of the iron chelates.     

Radiation interception and biomass and nitrogen accumulation in different cereal and grain legume species

The increasing interest in the sustainability of agricultural systems has emphasised the importance of incorporating legumes into cereal production, in spite of their lower and less reliable grain yields. The basis of the poor performance of legumes has been analyzed in a 2-year comparison between varieties of pea, faba bean, durum wheat and triticale, in terms of resource capture and use. The cereals developed a full canopy 350 °Cd earlier than did the grain legumes, and the triticale more rapidly than the durum wheat. This difference, and the 11-day longer duration of the growing cycle of cereals allowed them to intercept more photosynthetically active radiation (PAR) than grain legumes. This, combined with their higher radiation use efficiency (2.35 ± 0.07 vs 2.10 ± 0.05 g MJ⁻¹), resulted in a biomass greater, on average, by about 500 g m⁻². Within the cereals, triticale accumulated 34% more biomass than durum wheat. Radiation interception and nitrogen uptake are closely tied in both cereals and grain legumes. There was no difference between cereals and legumes in the relationship between the amount of nitrogen assimilated and the fraction of intercepted PAR (FIPAR), but there were differences in the form and in the parameters of the relationship between nitrogen assimilated and PAR intercepted. Below a FIPAR of 0.8, the relationship between FIPAR and N uptake is crop independent, underlining the influence of FIPAR on N uptake. The significance of this FIPAR level is that by the time it has been achieved, the plants will have accumulated most of the N present in their biomass at maturity.     

Spatial distribution of roots and cracks in soils cultivated with sunflower

The aim of this research was to investigate the spatial distribution of roots and cracks in two clay soils cropped with sunflower under different inter-row spacing in order to identify the optimal management. A latin square experimental design was applied to compare bare soil and soil cropped with sunflower, with three plant densities, obtained by keeping constant the number of plants on the row (3 plants m^?1) and varying the row spacing (0.4, 0.6, 0.8 m). The presence of the crop and the different distance between rows influenced soil moisture content as well as the root spatial distribution and thus the structural features of cracks. Increasingly lower values of moisture were found in both soils as the distance between rows decreased; an opposite trend was observed for both root density and crack size. The volume of cracks in the soil grown with sunflower at 0.4 m row spacing was 201.4 m³ ha^?1, thus 8 times higher than the value on the bare soil and 2.5 times higher compared to the one grown at 0.8 m between rows. Optimal results in terms of root density, soil moisture and crack size were obtained with an inter-row spacing of 0.6 m.     

Sea fennel (<Emphasis Type="Italic">Crithmum maritimum</Emphasis> L.): from underutilized crop to new dried product for food use

Sea fennel (Crithmum maritimum L.) is a perennial halophyte species typical of coastal ecosystems, used fresh in traditional cuisine and folk medicine due to its sensory properties and a good content of healthy compounds. Although considered as a promising biosaline crop, this halophyte is underutilized for commercial cultivation possibly due to a shortage of its consumer demand. For promoting a full exploitation of this species, a new food product was obtained by drying sea fennel using different treatments (air-drying, microwave-drying, microwave-assisted air-drying and freeze-drying). Water activity, essential oil content, chlorophylls, surface colour, colouring power and sensory evaluation were analyzed. All drying treatments allow to obtain a good water activity but significantly reduced the content of essential oils and chlorophylls. Freeze-drying and microwaving preserved the surface colour parameters more than other drying treatments, while freeze-drying gave the product the best colouring power. Based on sensory analysis, microwave-drying, microwave-assisted air-drying and freeze-drying showed the highest scores among the drying methods. Taken together the results indicate that microwaving and freeze-drying are optimal for preserving qualitative traits, including organoleptic properties, in dried sea fennel for food use. Furthermore, dried sea fennel can be usefully exploited in human food not only for its aromatic traits but also for its food colouring power like other plant derived natural colorants. It could be concluded that this underutilized crop could play a better role for making up a sustainable food production system.     

Identification of candidate genes for paratuberculosis resistance in the native Italian Garfagnina goat breed

Paratuberculosis disease is a chronic bacterial disease infection of ruminants of global relevance, caused by MAP (Mycobacterium avium subsp. paratuberculosis). The present study was conducted on the Garfagnina goat breed that is an Italian native goat population registered on the Tuscan regional repertory of genetic resources at risk of extinction. Forty-eight adult goats (27 serologically positive to MAP-positive and 21 serologically negative to MAP-negative) belonging to a single flock that had experienced annual mortalities due to MAP infection were identified and genotyped with the Illumina GoatSNP60 BeadChip. Diagnosis was achieved by serological tests, as well as post-mortem examination of affected animals. A genome-wide scan was then performed on the individual marker genotypes, in an attempt to identify genomic regions associated with MAP infection disease. Nine significant markers were highlighted and they were located within, or nearby, annotated genes. Two genes found in this study encode are linked to protein kinases that are among the most important enzymes involved in the immune response to Johne’s disease, and four genes are involved in the functions of the Golgi complex.     

Rhyzopertha dominica (F., 1792) (Coleoptera: Bostrichidae): a stored grain pest on olive trees in Sicily

In October 2014 samples were collected from olive trees growing in South‐Eastern Sicily (Italy) that were showing wilting symptoms. In the field, clear signs of flagging appeared on young twigs and lateral shoots, and many leaves had fallen to the ground. Initial laboratory examinations of attacked twigs revealed the presence of a large number of adults of Rhyzopertha dominica (F., 1792). Sampling was repeated during the following 2 years, and while an outbreak of the pest did not occur, continuous damage was observed. In 2016, exclusively using pheromone‐baited traps in olive trees, a large number of adults were captured. The main local climatic parameters were monitored from 2014 to 2016 and compared with the population levels. The incidence of damage and survival of R. dominica in an environment different from its usual one (stored grain) deserves attention, especially considering that climate change could greatly affect pest demographics and put olive trees in this area and further afield at risk of increased damage.