Tree-ring history of Swiss needle cast impact on Douglas-fir growth in Western Oregon: correlations with climatic variables

The fungal pathogen, Nothophaeocryptopus gaeumannii, occurs wherever Douglas-fir is found but disease damage is believed to be limited to the Coast Range and is of no concern outside the coastal fog zone (Shaw, et al., 2011). However, knowledge remains limited on the history and spatial distribution of Swiss Needle Cast (SNC) impacts in the Pacific Northwest (PNW). We reconstructed the history of SNC impacts on mature Douglas-fir trees based on tree ringwidth chronologies from the west slope of the Coast Range to the high Cascades of Oregon. Our findings show that SNC impacts on growth occur wherever Douglas-fir is found in western Oregon and is not limited to the coastal fog zone. The spatiotemporal patterns of growth impact from SNC disease were synchronous across the region, displayed periodicities of 25-30 years, strongly correlated with winter and summer temperatures and summer precipitation, and matched the patterns of enriched cellulosic stable carbon isotope indicative of physiological stress. While winter and summer temperature and summer precipitation influenced pathogen dynamics at all sites, the primary climatic factor of these three limiting factors varied spatially by location, topography, and elevation. In the 20th century, SNC impacts at low- to mid-elevations were least severe during the warm phase of the Pacific Decadal Oscillation (PDO, 1924-1945) and most severe in 1984-1986, following the cool phase of the PDO (1945-1977). At high elevations on the west slope of the Cascade Mountains, SNC impacts were the greatest in the 1990s and 2000s, a period of warmer winter temperatures associated with climate change. Warmer winters will likely continue to increase SNC severity at higher elevations, north along the coast from northern Oregon to British Columbia, and inland where low winter temperatures currently limit growth of the pathogen. Surprisingly, tree-ring records of ancient Douglas-fir logs dated ~53K radioactive years B.P. from Eddyville, OR displayed 7.5- and 20-year periodicities of low growth, similar to those found in modern day coastal Douglas-fir tree-ring records which we interpret as being due to cyclic fluctuations in SNC severity. Our findings indicate that SNC has persisted for as long as its host, and as a result of changing climate, may become a significant forest health problem in areas of the PNW beyond the coastal fog zone.

Intensive fruit orchards cultivation

The main purpose of a High-intensity cultivation system is to maximize the yield crop per area unit through planting more trees, exploiting efficient use of different resources. There are different factors that affect high-intensity cultivation that include Land-cost, planting spaces, tree size, Rootstock, and Practice management. Meanwhile, the adoption of High-intensity cultivation to control canopy size, by using modern management practices is very crucial to get more yields in the early stages of the orchard besides simplicity in its management and increase the farmers’ net profit. In addition, High-density cultivation use in different fruit crops like olive, mango, orange, mandarin, Apple, and cherry. Numerous benefits of intensive fruit cultivation include increase fruit yield per unit area, improving use efficiency of natural resources e.g. soil, light, water, and nutrients, enhancing fruit quality, improving soil properties and rising levels of organic carbon and nutrients in plant tissues …etc. In addition, it is very effective in acid lime soil and achieves high income for the farmers.

Effect of chitosan and silicon oxide treatments on postharvest Valencia Late (Citrus × sinensis) fruits

The efficacy of chitosan and silicon oxide to prevent postharvest weight loss and fungi infection in 'Valencia Late' oranges was tested. Three silicon oxide concentrations (0.1%, 0.2%, 1%) were applied as preharvest treatments. Chitosan treatments were performed at the same concentrations in postharvest fruit. Preharvest applications were carried out by tractor spraying, while fruit were submerged for 30 seconds in baths with the chitosan concentrations in the postharvest applications. In both cases, a positive control (water treatment) and negative control (fungicide) were included. Treated fruit were stored in a chamber to simulate commercial storage conditions (4 ºC, 90% RH) for 9 weeks. After this time, the weight loss and damage caused by fungi due to natural infection were evaluated. Both silicon oxide and chitosan applications were effective in controlling natural infection by Penicillium species but had no positive effect on weight loss.

Strobilurins: New group of fungicides

Strobilurin is a group of natural products and their synthetic analogs have been widely used to control and prevent fungal diseases. Strobilurins were firstly isolated in 1977 from the mycelium of Strobilurus tenacellus, a saprobic Basidiomycete fungus causing wood-rotting on forest trees. This group of pesticides was designed to manage fungal pathogens classes such as Ascomycetes, Basidiomycetes, and Oomycetes. Also, Strobilurin commercialized included derivatives such as are azoxystrobin, kresoxim-methyl, picoxystrobin, fluoxastrobin, oryzastrobin, dimoxystrobin, pyraclostrobin and trifloxystrobin. This group is a part of the larger group of QoI inhibitors, which act to inhibit the respiratory chain at the level of Complex III. Strobilurins group control an unusually wide array of fungal diseases, included water molds, downy mildews, powdery mildews, leaf spotting and rusts. This group are used on cereals, field crops, fruits, tree nuts, vegetables, turfgrasses and ornamentals. Also, Strobilurins found to enhance the plant growth in some cases.

MALDI-MSI method for the detection of large biomolecules in plant leaf tissue

In this study we describe a method for the detection of biomolecules (in the polypeptide m/z range) directly from the surface of plant leaves by using Mass Spectrometry Imaging. The plant-pathogen interaction between Arabidopsis thaliana and the bacterium Xanthomonas campestris pv. campestris was analyzed by comparing infected and non-infected leaf discs submitted to mass spectrometry. The total surface area of ion distribution was calculated for both samples, revealing 23 ions, out of which 3 showed statistical significance. Although these ions were not identified, the results showed that this approach can be successfully applied for the detection of potential polypeptide biomarkers directly on leaf tissue, which is a major challenge in MALDI-Imaging studies.

Current challenges in plant breeding to achieve zero hunger and overcome biotic and abiotic stresses induced by the global climate changes: A review

According Sustainable Development goals until 2030 we should have zero hunger and undernourished people in the world. But to achieve this goal plant breeders must improve plants in order to produce at least the double than is produced now. This is not a easy pathway because we have only few years, but considering that plant breeding programs normally take several years to produce improved genotypes, also the further improved plants should face with pest, disease and other abiotic factors that are increasing with the current climate changes. In this review we will discuss the situation of hunger in the world and the remaining available land to increase food production, point out effects of biotic and abiotic factors on the food production and present some ways that can be used to fastening plant breeding.

Ion transporters and their molecular regulation mechanism in plants

With the global population predicted to grow by at least 25% by 2050, the need for sustainable production of nutritious foods is important for human and environmental health. Recent progress demonstrate that membrane transporters can be used to improve yields of staple crops, increase nutrient content and resistance to key stresses, including salinity, which in turn could expand available arable land. Exposure to salt stress affects plant water relations and creates ionic stress in the form of the cellular accumulation of Na+ and Cl- ions. However, salt stress also impacts heavily on the homeostasis of other ions such as Ca2+, K+, and NO3- and therefore requires insights into how transport and compartmentation of these nutrients are altered during salinity stress. Since Na+ interferes with K+ homeostasis, maintaining a balanced cytosolic Na+/K+ ratio has become a key salinity tolerance mechanism. Achieving this homeostatic balance requires the activity of Na+ and K+ transporters and/or channels. The aim of this review is to seek answers to this question by examining the role of major ions transporters and channels in ions uptake, translocation and intracellular homeostasis in plants.

Silicon rates and beneficial microorganism on blast suppression and productivity of upland rice

One of the primary constraints in upland rice cultivation is the disease blast (Magnaporthe oryzae), which can provide reduction up to 100% of the grain yield The use of silicon with beneficial microorganisms (bioagents) can be an alternative for the control of this disease and to provide an increase in the productivity of the rice grain. The objective of this work was to study the effect of rates of silicon with bioagents in blast suppression and grain yield of upland rice. The methodology used was tests carried out in field conditions, in two different areas: Capivara and Palmital farms, during the growing season 2015/2016. The experimental design was in a split-plot scheme with four replications. In the main plots were the silicon fertilization rates (0, 2, 4 and 8 ton ha-1) and in the subplots was the bioagents (1-without bioagents, 2-Pseudomonas fluorescens, 3-Burkholderia pyrrocinia, 4-Trichoderma asperellum, 5-a mixture of the three bioagents). The results showed that the use of 2 ton ha-1 of silicon with a mixture of bioagents was the best treatment to control leaf blast. Besides, from rates, 2 to 6 ton ha-1 of silicon in Capivara Farm and up to 8 ton ha-1 of silicon in Palmital Farm provided the highest grain yield. A mixture of bioagents provided the highest grain yield. In this sense, it was concluded that the best recommendation to connect blast control, grain yield and reduced amount of silicon was the use of 2 ton ha-1 of silicon with the mixture of bioagents.

An experimental study on effects of fluoridated water on Abelmoschus esculentus var. Soh-198 (Lady Finger)

An experimental study of fluoride (F) accumulation in Abelmoschus esculentus var. Soh-198 and its effect on the growth and crop yield was conducted in a pot experiment. Eight different concentrations of F in the water were used for irrigation ranging from 2 to 14 ppm with distilled water as the control. Potentiometric determinations of the F content in different parts of the plant were made 45, 60, and 120 days after sowing the seeds (first, second, and third harvest, respectively). At the third harvest the highest mean plant part concentrations of F were recorded with 14 ppm F in the irrigation water: 9.0638 mg/kg in the roots, 5.6896 mg/kg in shoot, 4.5348 mg/kg in leaf and 3.563 mg/kg in fruit.

Fluorinated nematicides: Novel classes in the way

The demand on non- fumigant nematicides was strongly increased in the last few years, and this interesting in nematicides are due to farmers are needed for safer pesticides and increasing of the regulatory pressure on many of the traditional nematicides. The control of plant parasitic nematodes with synthetic nematicides is the most widespread and preferred method, but not always effective enough. The most of synthetic nematicides especially non-fumigants are high toxic to non-target organisms. Thus, Novel non-fumigant nematicides were appeared as alternatives. The group of trifluoromethyl contains both fluensulfone and fluopyram which are different in mode of action than traditional nematicides as organophosphate and carbamate. Meanwhile, results indicated that fluensulfone and fluopyram are promising nematicides. These new nematicides are very different from traditional nematicides; they are more selective, less toxic and safer to use.