Efficacy of Rinskor™ (florpyrauxifen-benzyl ester) on Herbicide Resistant Barnyardgrass (<Emphasis Type="Italic">Echinochloa crus-galli</Emphasis>) in Rice Fields of Mekong Delta,Vietnam

Barnyardgrass (Echinochloa crus-galli) seed samples were collected in rice fields in different locations at Mekong delta in Vietnam for herbicide resistance tests. The ALS-resistant and synthetic auxin-resistant E. crus-galli were confirmed at several locations in the Mekong Delta. The average LD₉₀ value of bispyribac, penoxsulam and quinclorac for assessed weed populations was 33.1, 15.1 and 550.2 g a.i.ha^?1 respectively. There were cross resistant barnyardgrass populations to bispyribac and penoxsulam, the LD₉₀ value of the two ALS inhibitors for E. crus-galli was positively correlated at R²=0.39, the cross resistant population was 33.3% of total sample. The correlation analysis was not useful to evaluate the multiple resistance between quinclorac and the two ALS inhibitors, the R² value was lower than 0.05, however, the percentage of multiple resistance weed was 36.2% of population. There was no cross resistance or multiple resistance among the 3 tested herbicides and the new synthetic auxin herbicide Rinskor?. All tested weed samples, including quinclorac-resistant populations, were effectively controlled by Rinskor?. There was no difference between control from Rinskor? in the different herbicide resistant populations. Average LD₉₀ value of Rinskor? in all tested barnyardgrass was 17.1 g a.i ha^?1.     

Dietary supplementation with autochthonous Bacillus cereus improves growth performance and survival in tambaqui Colossoma macropomum

The aim of this study was to evaluate the effect of dietary supplementation with the autochthonous probiotic bacteria Bacillus cereus on growth performance, haematological parameters and survival of tambaqui (Colossoma macropomum). Tambaqui fingerlings (0.94 ± 0.02 g) were fed for 120 days the following diets: basal (without probiotic) and three supplemented diets (4.2 × 10⁴, 3.9 × 10⁶ and 3.3 × 10⁸ CFU/g). Growth performance and haematological parameters were evaluated every 30 days. Thereafter, fish were challenged against Aeromonas hydrophila and survival was evaluated. Probiotic B. cereus improved weight and length gains (p < 0.05), and increased neutrophils and thrombocyte counts (p < 0.05) in tambaqui supplemented with 3.9 × 10⁶ CFU/g diet. Challenged fish fed unsupplemented diet presented the lowest survival rate (33.4%) while fish fed diets supplemented at 4.2 × 10⁴, 3.9 × 10⁶ and 3.3 × 10⁸ CFU/g B. cereus had 88.8%, 80.5% and 80.5% relative per cent survival respectively. These results demonstrated that B. cereus supplemented as probiotics to C. macropomum for 120 days improved physiological and haematological responses, leading to enhanced survival in this fish species.     

Exploring ethyl methanesulfonate (EMS) treated cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L.) to improve drought tolerance

The Texas High Plains often has extended periods between rainfall events, which can lead to a reduction in the yield and fiber quality of cotton (Gossypium hirsutum L.). It is known that cultivated cotton suffers from low levels of genetic diversity due to the over-use in breeding of similar gene pools, which may hinder breeding for drought tolerance. In this study, for the first time the novel variability or genetic diversity of morphological and agronomic traits possibly created by the chemical mutagen ethyl methanesulfonate (EMS) was evaluated to improve drought tolerance in cotton by traits’ response to different irrigation regimes. EMS is a chemical mutagen that has been shown to cause point mutations in the DNA of many model plants and crop species. Three EMS treated lines were advanced from the M₁ to M₄ generation as bulk-harvested populations. A diverse selection scheme was applied to capture most of the genetic trait-variability or diversity and superior lines in these populations. In 2014–2016 the diversity of these populations was evaluated based on four agronomic and thirteen morphological traits to determine differences in response to multiple irrigation rates. Analyses of these traits showed statistically significant (p?≤?0.05) differences between and within populations when compared to the original non-treated EMS source, with most of the variability being observed in the high irrigation rate. However, none of the EMS treated populations had significantly (p?≤?0.05) better lint yield than the commercial cultivar (control) in 2016. EMS yield performance was possibly constrained by the applied diverse selection scheme of this study. Traits such as total number of bolls, bolls retained at node 7 and below, and those retained between nodes 8 and 12, and bolls retained at node of first fruiting branch may be predictors to improve cotton production (yield) in water limiting environments.     

Are standing dead trees (snags) suitable as climate proxies? A case study from the central Scandinavian Mountains

Standing dead trees (snags) play important roles in forest ecology by storing carbon as well as providing habitats for many species. Moreover, snags preserved for hundreds of years can provide useful data to extend tree-ring chronologies used for climatological and ecological studies beyond the lifespans of living trees. Here we examined the growth patterns of Scots pine snags from the central Scandinavian Mountains, in relation to still living trees. Using changes point analyses, we showed that a majority (74%) of the snags displayed significant negative growth changes prior (on average 17 years) to death. Change points around the same years were also seen in living trees, but they recovered their growth. The average growth reduction of snags showing negative growth changes before death was 46%. In most cases the final growth change points coincided with very cold summers, or to a lesser degree to period of cool summers. It was suggested that pines ending up as snags were less resilient than the trees which continued living, and thus not able to recover after cold summer events. Since the snag growth reductions prior to death were partly unrelated to climate, care should be taken when using such data in dendroclimatological studies.     

Unusual behavior of oviposition and development of <Emphasis Type="Italic">Sitophilus zeamais</Emphasis> (Coleoptera: Curculionidae) in peach and apple fruits

The maize weevil Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae) is a worldwide pest on stored products, as maize, wheat and rice grains. However, in South Brazil, these weevils have been found attacking fruits in field conditions. It was reported that adults attack fruits to feeding, but there was no information of oviposition and larval development on these hosts. Furthermore, due to monitoring apple orchards, was observed that some fruits showed distinct kind of punctures, suggesting a oviposition by these weevils. The present study reports first record an unusual behavior of S. zeamais by oviposition and larval development in peach and apple fruits. The study was conducted in laboratory conditions (temperature: 25?±?1 °C, RH: 70?±?10% and photophase of 14 h). Peach and apple fruits were offered to S. zeamais females. The oviposition and duration of immature stages in peach were measured in fruits and in corn grains, used as control observation. The oviposition and larval development occurred in peach and apple fruits, with a development until to adult. The average of egg-to-adult was 47.4 d in peach and and 45.1 d apple fruits, respectively, while in corn grains, its natural host, the duration was 38.2 d. These results show that the damage caused by S. zeamais in peach and apple fruits may be due to oviposition and the development of immature stages. So, the novelty is in demonstrating that the maize weevil does not just feed as an adult opportunistically on the fruits, but can complete a full life cycle using fresh fruits.     

Phenotyping of Urochloa humidicola grass hybrids for agronomic and environmental performance in the Piedmont region of the Orinoquian savannas of Colombia

In the low fertility acid soils of the Orinoquian savannas of Colombia, Urochloa humidicola cv. Tully or Humidicola is one of the most widely planted tropical forage grasses for improving livestock productivity. Low nutritional quality of this grass limits sustainable livestock production in this region. In this study, we conducted a phenotypic evaluation under field and greenhouse conditions of one of the first hybrid populations of U. humidicola generated from the forage breeding program of CIAT. Our objective was to identify a set of new hybrids of U. humidicola that combine improved productivity and nutritional quality plus the biological nitrification inhibition (BNI) trait/ability to reduce nitrogen (N) losses via leaching and nitrous oxide (N₂O) emissions. To this end, we tested 118 hybrids (planted in pots) in the greenhouse for over 6 months and measured potential nitrification rates (NR) using soil microcosm incubation. NR values observed ranged from 0.27 to 5.75 mg N-NO₃⁻ kg soil⁻¹ day⁻¹. Later, 12 hybrids with different levels of NR were selected and field-tested in the Orinoquia region over a 4 years period (2013–2017) for dry matter production, nutrition quality (crude protein, in vitro digestibility and fibres content) and NR in each year. In the rainy season of 2018, two hybrids with superior agronomic performance and contrasting field level NR (Uh08/1149 and 0450) were subjected to analysis of soil-borne N₂O emissions after fertilization during 13 days. The NR values recorded were not directly correlated with the forage quality parameters evaluated, however, the two grasses with the lowest NR values were among those with the highest biomass production, crude protein content, and N uptake. The grass hybrid Uh08/1149 and the germplasm accession CIAT 16888 were found as materials with superior forage value, with production of 14.1 and 14.6 tons dry matter ha⁻¹ year⁻¹ (up to 8% higher than the cv. Tully), crude protein of 11.5 and 9.1% per cut (up to 20% higher than the cv. Tully), and N uptake of 31.6 and 25.7 kg N ha⁻¹ cut⁻¹ (up to 30% higher than the cv. Tully). Additionally, these two grasses are likely to exhibit high-BNI ability, with potential to improve N use efficiency in managed pastures.     

Mangroves enhance local fisheries catches: a global meta‐analysis

Mangroves are among the most productive ecosystems in tropical and subtropical regions. Historically, mangroves are assumed to support artisanal fisheries, leading decision‐makers to protect mangroves based on this premise. However, this relationship remains unclear, despite positive correlations obtained in different geographical regions. Here, we provide the first meta‐analysis of the mangroves–fisheries linkage at a global level. After conducting a systematic review, 23 publications containing 51 studies estimating the mangrove–fishery linkage were obtained. A random effect model was used to estimate the effect size (Pearson's correlation coefficient) of each individual study as well as the overall effect size. We found strong evidence for the mangrove–fishery linkage with an overall effect size of r = 0.72 (95% CI: 0.61–0.81), and substantial heterogeneity was observed (Q = 143.88, df = 50, P < 0.01). The countries where the studies were carried out were the only significant moderator (Q_M = 26.07, P < 0.01), while fisheries types (i.e. crab, fish, shellfish, prawn and total) and global regions were not good predictors of the relationship. Our results show that mangrove area is a good predictor of fishery catches overall, confirming the importance of conserving such habitats.