Pesticide knowledge and practice among horticultural workers in the Lâm Đồng region, Vietnam: A case study of chrysanthemum and strawberries.

Background: In Vietnam, large amounts of pesticides are being used in agriculture. Next to benefits for agriculture, pesticides impose a huge threat to the environment when they are used in the wrong way. The objective of this work was to determine the level of knowledge and awareness of the smallholder farmers towards the use of pesticides in Vietnam, Dà Lat region.

Primary metabolism plays a central role in moulding silicon-inducible brown spot resistance in rice.

Over recent decades, a multitude of studies have shown the ability of silicon (Si) to protect various plants against a range of microbial pathogens exhibiting different lifestyles and infection strategies. Despite this relative wealth of knowledge, an understanding of the action mechanism of Si is still in its infancy, which hinders its widespread application for agricultural purposes. In an attempt to further elucidate the molecular underpinnings of Si-induced disease resistance, we studied the transcriptome of control and Si-treated rice plants infected with the necrotrophic brown spot fungus Cochliobolus miyabeanus.

Fate of xylem-transported 11C- and 13C-labeled CO2 in leaves of poplar.

In recent studies, assimilation of xylem-transported CO2 has gained considerable attention as a means of recycling respired CO2 in trees. However, we still lack a clear and detailed picture on the magnitude of xylem-transported CO2 assimilation, in particular within leaf tissues. To this end, detached poplar leaves (Populus × canadensis Moench 'Robusta') were allowed to take up a dissolved (13)CO2 label serving as a proxy of xylem-transported CO2 entering the leaf from the branch.

Responses of tree species to heat waves and extreme heat events.

The number and intensity of heat waves has increased, and this trend is likely to continue throughout the 21st century. Often, heat waves are accompanied by drought conditions. It is projected that the global land area experiencing heat waves will double by 2020, and quadruple by 2040.

Phloem transport: a review of mechanisms and controls.

It is generally believed that an osmotically generated pressure gradient drives the phloem mass flow. So far, this widely accepted Münch theory has required remarkably few adaptations, but the debate on alternative and additional hypotheses is still ongoing. Recently, a possible shortcoming of the Münch theory has been pointed out, suggesting that the Münch pressure flow is more suitable for herbs than for trees.

The effect of heat waves, elevated [CO2 ] and low soil water availability on northern red oak (Quercus rubra L.) seedlings.

The frequency and intensity of heat waves are predicted to increase. This study investigates whether heat waves would have the same impact as a constant increase in temperature with the same heat sum, and whether there would be any interactive effects of elevated [CO2 ] and soil moisture content. We grew Quercus rubra seedlings in treatment chambers maintained at either ambient or elevated [CO2 ] (380 or 700 μmol CO2 mol(-1) ) with temperature treatments of ambient, ambient +3 °C, moderate heat wave (+6 °C every other week) or severe heat wave (+12 °C every fourth week) temperatures.

The effect of induced heat waves on Pinus taeda and Quercus rubra seedlings in ambient and elevated CO2 atmospheres.

Here, we investigated the effect of different heat-wave intensities applied at two atmospheric CO2 concentrations ([CO2]) on seedlings of two tree species, loblolly pine (Pinus taeda) and northern red oak (Quercus rubra). Seedlings were assigned to treatment combinations of two levels of [CO2] (380 or 700 μmol mol(-1)) and four levels of air temperature (ambient, ambient +3°C, or 7-d heat waves consisting of a biweekly +6°C heat wave, or a monthly +12°C heat wave). Treatments were maintained throughout the growing season, thus receiving equal heat sums.