#Beloved crape myrtle in nurseries now susceptible to bacterial leaf spotit's enough to send gardeners into conniptions.
Crape myrtle a tree adored for its bright flowers that scream summer carefree maintenance and even its colorful bark now has a disease problem--although so far only in the commercial nursery setting.
or overhead irrigation and some crape myrtle varieties are more susceptible than others. I've been working with crape myrtles for a long time
and they've been such a disease-resistant plant for such a long time so it's pretty significant
The U s. crape myrtle crop had a value of nearly $43 million in 2010 and Florida is its second-biggest producer behind Texas. Florida has more companies producing crape myrtle
however with 130 compared with 72 in Texas. In the June issue of the journal Plant disease the UF/IFAS team outlined the first report of the disease
They believe it is the first report of the bacterium causing leaf spot in crape myrtle.
The researchers say for now the disease affects only crape myrtle commercial producers and is spread by factors such as overhead irrigation systems
I think you can safely say that nearly every crape myrtle producer would have the disease at this point Knox said.
Crape myrtle is so close to Southern gardeners'hearts that they endlessly debate such topics as how to spell its name (variants include crepe myrtle crape myrtle
The scientists were able to establish that the pesticide induced an average risk of loss that rose from 3%to 26
and percent cover of grasses rose from 1 to 3 percent. Tree seedlings jumped from about 2 percent to about 13 percent of total plant cover a finding that suggests
which includes some 1500 species of mostly poisonous plants including nightshades but also three economically important global food crops:
The Solanaceae family including the Genus solanum is known as the nightshade family and many of the plants are toxic hallucinogenic
Weedy but Not a Weeds. cordicitum and the varieties that are elevated newly to species belong to section Androceras
The most widespread Androceras species is S. rostratum known as buffalo bur prickly nightshade and Kansas thistle.
While S. cordicitum belongs to a weedy group within the spiny solanums technically it isn't a weed
because weeds are more common and spread easily Bohs says. Like other plants in Androceras the new species and its five-petaled flowers are bilaterally symmetrical (like a mirror image down a vertical line)
It is a concept for producing edible plants during long-term missions to destinations such as Mars. Heather Hava who is working on a doctorate in aerospace engineering sciences explains that the goal is to have robots do much of the monotonous tasks saving time
#Earth-Kind roses analyzed for salt toleranceearth-Kindâ roses are favorites with gardeners and landscapers.
and pests as well as their outstanding performance in landscapes Earth-Kindâ roses can thrive in most environments even with limited care.
and growers researchers at Texas A&m University evaluated 18 popular varieties of Earth-Kindâ roses for salt tolerance.
Their findings were published in Hortscience (May 2014. The rose cultivars were tested in greenhouses in College Station and El paso Texas in response to two salinity levels at electrical conductivity:
Identifying and using salt-tolerant garden roses is important in landscapes where soil salinity is high
Because cover crops can provide weed and erosion control determining the best method for establishing a uniform and dense cover crop stand as soon as possible after planting is a critical first step.
and reduce light penetration to weeds should be a primary focus. Eric Brennan and Jim Leap from the U s. Department of agriculture Agricultural research service (ARS) coauthored the study published in the April 2014 issue of Hortscience.
and weed-suppressive cover crops on beds the authors said. Both drilling and broadcasting methods are used commonly to plant cover crops.
and faster emergence characteristics that would likely increase their ability to suppress weeds that emerge with the cover crop.
Moth attacks in sparse woods cause extensive changes in ground vegetation--the dwarf shrub heath disappears
Fauna changes as wellwhen the ground vegetation changes from heath to grass there are impacts on the animal life.
or impalas devouring dozens of its fruits at a time the shrub easily conquers the landscape. Just as the governments of nations such as Kenya prepare to pour millions into eradicating the plant the findings present a method for controlling the Sodom apple that is cost-effective for humans
because they belong to a class of herbivores known as browsers that subsist on woody plants and shrubs many species
While elephants ate an enormous amount of Solanum seeds they also often destroyed the entire plant ripping it out of the ground and stuffing the whole bush into their mouths.
LMU biologist Professor Susanne Renner and her research group have looked now at the effects of this warming trend on the timing of leaf emergence (leaf-out in a broad range of shrubs and trees.
and shrubs says Renner. As Director of Munich's Botanic Garden she was in a position to remedy this situation.
and Renner and her doctoral student Constantin Zohner have taken advantage of this unique resource to monitor the timing of leaf-out in nearly 500 different species of woody plants.
which signal is used actually in a given species. The results of the new study show that in many woody plants that thrive in warmer southern climes day-length acts as a safety barrier
#Surprising spread of spring leaf-out timesdespite conventional wisdom among gardeners foresters and botanists that woody plants all leaf out at about the same time each spring a new study organized by a Boston
Significantly observations the past two springs of 1597 woody plants in eight botanical gardens in the U s. Canada Germany and China suggest that species differences in leaf-out times could impact the length of the growing season
At the Arnold Arboretum in Boston some gooseberry and honeysuckle shrubs start leafing out Mid-march
and early April and evergreen rhododendrons and pine trees don't start leafing out until two to three months later in late May or even June.
The study showed that shrubs leafed out on average 10 days before trees and deciduous plants leafed out on average 17 days before evergreens.
And certain groups of plants--such as honeysuckles willows lilacs and apples--tended to leaf out early while other groups--such as oak beeches honey locusts and grapes--tended to
In a recent study scientists used ARID to predict crop yields by quantifying water loss for cotton soybeans corn
When it comes to controlling hay fever-triggering ragweed plants on Detroit vacant lots occasional mowing is worse than no mowing at all
Those are the findings of a new University of Michigan study that surveyed vacant lots in several Detroit neighborhoods for ragweed counting the number of ragweed plants
The researchers found that ragweed was significantly more likely to be present in vacant lots mowed once a year or once every two years--a common practice in Detroit
which ragweed plants thrive. Katz's co-authors on the vegetation study are SNRE's Benjamin Connor Barrie and Tiffany Carey of the U-M Program in the Environment.
Woody plants are establishing in vacant lots and reclaiming large chunks of Detroit Katz said. Regardless of whether people think that reforestation of vacant lots is a good
The U-M studies found that vacant lots are the main habitat for ragweed in Detroit:
Ragweed densities were six times higher in vacant lots than at locations around occupied homes in the city.
Vacant lots contained up to 42 ragweed plants per square meter. When you consider that the tiny drab flowers of a single ragweed plant can produce up to a billion pollen grains annually it's clear that Detroit vacant lots are pollen factories churning out a noxious product that afflicts thousands of city residents.
The vegetation survey looked at 62 vacant lots in several neighborhoods including Mexicantown Kettering and Core City.
They found that 28 percent of the unmowed lots contained ragweed plants while 63 percent of the annually mowed lots
and 70 percent of the biennially mowed lots contained the weed. Vacant lots mowed at least once a month during the growing season had no ragweed plants.
When these lots are left alone completely other plants rapidly outcompete ragweed Katz said. When the lots are left unmowed the common perennial plants that replace ragweed include goldenrod milkweed Kentucky bluegrass chicory and aster.
When a vacant lot is mowed not for several years the young trees that can encroach include the Norway maple silver maple box elder cottonwood and tree of heaven.
To determine whether ragweed populations are associated with a particular land-use type in Detroit Katz and Carey documented the amount of ragweed found in vacant lots around occupied residences and in city parks.
They also set up pollen collectors at 34 sites and analyzed the concentration of ragweed pollen grains collected at each location.
They found that the amount of ragweed pollen in the air at a collection site was determined both by the abundance of ragweed plants within 10 meters (33 feet) of the collector and by the number of vacant lots within 1 kilometer (0. 62 miles) of the site.
That result drives home the point that pollen is mainly a local and neighborhood-level problem even though public health officials have treated for decades it as a regional problem Katz said.
and cassava a tuber that is the third-largest source of carbohydrates in the tropics.
Already some sections have been reduced to grassland littered with shrubs he noted. Story Source: The above story is provided based on materials by South dakota State university.
John Jelesko an associate professor of plant pathology physiology and weed science began studying the plant after experiencing a nasty poison ivy rash himself
and adaptation in woody plants suitable for biomass production said Myburg. Our comparative analysis of the complex traits associated with the Eucalyptus genome
Our analysis provides a much more comprehensive understanding of the genetic control of carbon allocation towards cell wall biopolymers in woody plants--a crucial step toward the development of future biomass crops.
Examples for such a combination of two genomes called allopolyploidy are found abundantly in both wild plants and crops like wheat rapeseed and cotton.
During the last 15 years expansion of agriculture in the state has helped Brazil become one of the world's top producers of soy corn cotton and other staple crops.
Some sites may have been burned more frequently she noted to control weeds. We've got a sneak peek of
Jasmine Saros associate director of the Climate Change Institute at UMAINE and professor in UMAINE's School of Biology & Ecology;
The drones also may be deployed in the battle against Palmer amaranth an invasive weed that is spreading across the Midwest
Before the soybean rows close or if we get a different spectrum response from some of these weeds as they break through the canopy we may see some of those weeds show up in the imagery as well to identify where there are hot spots
researchers reportan invasive weed that has put some southern cotton farmers out of business is now finding its way across the Midwest
and grows faster than other weeds and is seed a prolific producer Hager said. It can tolerate drought
As a seedling Palmer amaranth looks a lot like waterhemp another problematic weed that is difficult to control.
In other parts of the U s. this species has devastated cotton production and in many areas especially in Georgia it was not uncommon to see cotton fields literally mowed down to prevent this weed from producing seed Hager said.
Some growers who failed to recognize the threat lost their farms as a result he said.
In 2010 for example Southeast Farm Press reported that the cost of weed control efforts on Georgia farms had risen from $25 per acre to $60 to $100 an acre in response to Palmer amaranth invasions.
The state spent at least $11 million in 2009 to manually remove Palmer amaranth from 1 million acres of cotton something not normally done the magazine reported.
--or failing to properly fight--this weed Hager said. If you think about the value of agronomic row crops in this state that's why we're very very concerned about how devastating this could be to us he said.
In about half of those counties the weed is already resistant to glyphosate the most commonly used herbicide on Midwest farms Hager said.
Many farmers think they can use the same techniques that tend to work against other common weeds--a onetime application of glyphosate herbicide for example--to control Palmer amaranth Hager said.
And if the weed gains a foothold in planted fields corn and soybean growers in Illinois should take a tip from Georgia cotton farmers
and do everything possible to remove the plants he said. Not a single plant should be tolerated.
It's hard to imagine another weed species that would be more injurious to crop production than
which produced tubers but were thought more often of as a weed than a vegetable crop.
New nasty weeds sometimes evolve directly from natural crosses between domesticated species and their wild relatives.
Surely these couldn't be fathers from outside of our wild radish populations--hundreds of meters away?
They account for up to 25 percent of the woody plants in a typical tropical forest but only a few percent of its carbon.
#Genetic basis of pest resistance to biotech cotton discoveredan international team led by scientists at the University of Arizona
what happens on a molecular basis in insects that evolved resistance to genetically engineered cotton plants.
Their findings reported in the May 19 issue of the journal PLOS ONE shed light on how the global caterpillar pest called pink bollworm overcomes biotech cotton
Scientists from the UA and the U s. Department of agriculture worked closely with cotton growers in Arizona to develop
and implement resistance management strategies such as providing refuges of standard cotton plants that do not produce Bt proteins and releasing sterile pink bollworm moths.
As a result pink bollworm has been eradicated all but in the southwestern U s. Suppression of this pest with Bt cotton is the cornerstone of an integrated pest management program that has allowed Arizona cotton growers to reduce broad spectrum insecticide use by 80
which grows the most Bt cotton of any country in the world. Crops genetically engineered to produce proteins from the bacterium Bacillus thuringiensis
The team studied the long-term effects of five'Fuji'strains('Autumn Rose''Desert rose''Myra''September Wonder'and'Top Export'on RN 29 rootstock) on fruit yield and harvest time quality.
while'September Wonder'and'Desert rose'had more red color. The authors deemed'Desert rose'a good choice for a late-maturing'Fuji'strain based on the apple's excellent color great storability and shape.'
'Myra'was particularly desirable for its attractive pink color resembling bagged'Fuji'without the expensive cost of labor associated with bagging Fallahi said.
The authors recommend against planting'Autumn Rose 'because the strain produces muddy colored fruit under growing conditions like those in the study.
#Weeds grow bigger among corn; Weeds influence gene expression, growth in cornthe axiom growing like a weed takes on new meaning in light of changes in gene expression that occur
when weeds interact with the crops they infest according to plant scientist Sharon Clay. Using sophisticated genetic-mapping techniques the South dakota State university professor
and her research team are documenting how corn and weeds influence one another. Weeds grow like weeds
when they grow with corn says Clay. They grow bigger and taller in corn than by themselves.
And inversely corn grows less among weeds. Over the last 20 years Clay has been studying weed management in range
and cropping systems weed physiology and interactions among herbicides soil and crops. The weed scientist was the first woman to serve as president of the American Society of Agronomy.
She has received two awards from the Weed Science Society of America for outstanding papers published in Weed Science--one in 2007 and another in 2012.
Both articles were written in collaboration with David Horvath a research plant physiologist for the Agricultural research service at the U s. Department of agriculture in Fargo N d. Growing better among cornto figure out how corn
and weeds affect each other's gene response Clay and a team of two research associates and a soils expert planted plots of velvetleaf alone corn with velvetleaf and corn kept weed-free.
The researchers saw an entirely different response when velvetleaf was grown by itself versus among corn plants.
The velvetleaf alone was shorter and stouter Clay explains. In addition specific genes that influenced photosynthesis
and other important plant responses differed in expression. Another study compared the corn's growth and yield in response to weeds lack of nitrogen or shade.
In all cases Clay and Horvath found that genes were expressed differentially compared with nonstressed plants.
However each stress resulted in very different expression patterns. Traditionally weeds have been thought to reduce crop growth and yield due to competition for water nutrients and light.
This study however indicates that weed-crop interactions are much more complex than researchers have thought.
When grown with weeds genes that control the major facets of the corn plant's metabolism were decreased
or down-regulated according to Clay. These included its response to light stimulus the amount of chlorophyll it produces
and its ability to convert raw materials into energy. In short these changes in gene expression adversely affect the plant's ability to grow
Having long-term impactwhen the researchers started taking weeds out of the corn at early points such as
when compared to corn without weeds. However Clay points out the amount of biomass--the stem
The genes never recovered says Clay even after the weeds were removed. The impact is long term she adds
which further builds the case for controlling weeds early. These changes in gene expression can help explain instances in which the yield is unaffected
In one indication of the swiftness by which the devices have been embraced in the U s. youth ever use of the devices rose from 3. 3 percent in 2011 to 6. 8 percent the following year;
in Korea youth ever use of e-cigarettes rose from. 5 percent in 2008 to 9. 4 percent in 2011.
To reduce the corn's height the researchers borrowed a trick used by the greenhouse industry to dwarf Christmas poinsettias.
These bugs have been documented to feed on many of our important agricultural crops including apples peaches grapes soybean peppers tomatoes corn and cotton.
and grow like weeds. These will cover an area fast so be aware of that.
Save threatened species by giving them treated cotton for nestswhen University of Utah biologists set out cotton balls treated with a mild pesticide wild finches in the Galapagos islands used the cotton to help build their nests killing parasitic
if treated cotton is placed only in the habitats of endangered finches not others. Knutie and Clayton conducted the study with University of Utah doctoral students Sabrina Mcnew and Andrew Bartlow and with Daniela Vargas now of the Autonomous University of Barcelona in Spain.
and Clayton say their method might help the endangered mangrove finches with only 60 cotton dispensers needed to cover the less than half a square mile inhabited by the birds on Isabela Island.
if mangrove finches will collect cotton balls from dispensers. There are other species of birds that are hurt by parasites
and so if the birds can be encouraged to incorporate fumigated cotton into their nests then they may be able to lessen the effects of the parasites Knutie says.
Knutie says permethrin-treated cotton has been used in the Northeast to get mice to incorporate it in their nests to kill Lyme disease-carrying ticks.
if finches could be encouraged to pick up treated cotton to fumigate their own nests located in tree cacti and acacia trees.
The biologists built wire-mesh dispensers for the cotton. They tried processed cotton balls treated with 1 percent permethrin solution
and as a control unprocessed cotton balls treated with water. Processed and unprocessed cotton balls appear slightly different so researchers could distinguish treated or untreated cotton in nests.
In a preliminary experiment Knutie showed the birds had no preference for collecting treated versus untreated cotton or for processed or unprocessed cotton.
In another preliminary test the researchers showed that the finches which are territorial travel no more than 55 feet from their nests to collect nest-building material.
Collecting Cotton Balls and Killing Maggotsduring the key experiment Knutie and colleagues set up two lines of 15 cotton dispensers--one line on each side of a road
in arid scrub woodland. In each line dispensers alternated between treated and untreated cotton and dispensers were 130 feet apart--more than twice 55 feet making it likely each nesting finch had a favorite dispenser.
That was confirmed: none of the nests were found to have both types of cotton. The researchers searched for active finch nests weekly within 65 feet of each dispenser using a camera on a pole to check each nest
and confirm breeding activity. They found cotton balls were collected by at least four species of Darwin's finches:
the medium ground finch (Geospiza fortis) small ground finch (Geospiza fuliginosa) small tree finch (Camarhynchus parvulus) and vegetarian finch (Platyspiza crassirostris.
and separated all the nest materials including cotton. The Utah biologists found 26 active nests of which 22 (85 percent) contained cotton:
13 nests had treated permethrin cotton nine had untreated cotton and four had no cotton. Regardless of treatment the amount of cotton in nests and the percent of the nest made of cotton didn't vary significantly.
The researchers write that their study found self-fumigation had a significant negative effect on parasites killing at least half the fly maggots.
The 13 nests with treated cotton averaged 15 maggots give or take 10. Nests with untreated cotton averaged 30 maggots give or take eight.
The amount of untreated cotton in a nest was unrelated to the number of maggots; but the more treated cotton the fewer the parasites.
Of eight nests with at least 1 gram of cotton (one 28th of an ounce) seven had no maggots
and one nest had four. If the birds insert a gram or more of treated cotton--about a thimbleful--it kills 100 percent of the fly larvae Clayton says.
A separate follow-up experiment--and earlier studies by others--showed killing the parasites with sprayed permethrin increases baby bird survival.
The researchers did not study survival of offspring in nests with cotton balls because that requires repeatedly climbing to nests
so birds can be weighed and banded which might disrupt the birds from self-fumigating their nests with cotton balls.
Story Source: The above story is provided based on materials by University of Utah. Note: Materials may be edited for content and length.
Journal Reference e
#Tomato turf wars: Benign bug beats salmonella; tomato eaters winscientists from the U s. Food and Drug Administration (FDA) have identified a benign bacterium that shows promise in blocking Salmonella from colonizing raw tomatoes.
Their research is published ahead of print in the journal Applied and Environmental Microbiology. When applied to Salmonella-contaminated tomato plants in a field study the bacterium known as Paenibacillus alvei significantly reduced the concentration of the pathogen compared to controls.
Each subject performed 10 common gardening tasks in a high tunnel and in a nearby grassy area with a vegetable garden and weeds.
This ratio proved to be a robust marker for prognosis said MD Anderson co-author Anil Sood professor of gynecologic oncology and reproductive medicine and co-director of the Center for RNA Interference and Non-Coding RNA.
Although their research has been performed in a weed called'Arabidopsis thaliana'the work horse of plant geneticists the team is confident that their discovery can be used for the protection of crops from their enemies.
Producers will need to know how fruit of the other color groups compare with red raspberries with regard to the many postharvest qualities noted the University of Maryland's Julia Harshman corresponding author of the study published in Hortscience
although there is abundant information in the literature regarding red raspberry production in regard to gray mold very little research has been conducted on postharvest physiology of black yellow or purple raspberries.
Red raspberries in comparison with the other three colors analyzed during the study had the highest titratable acids (TA) and the lowest ratio of soluble solids to TA
Their TA was lower than red raspberries but their ratio of soluble solids to TA was the second highest.
Black raspberries resisted leakage the least of all of the colors particularly after rainy humid overcast days. The authors observed that this quality will make it challenging to move black raspberries into the wholesale fresh market.
Purple raspberries--a hybrid between red and black raspberries--had the third highest anthocyanin and phenolic content
and their flavor was intermediate between black and yellow raspberries. Similar to black raspberries their ability to resist juice leakage was poor and cool weather tended to exacerbate this the authors said.
We have shown for the first time that when significant differences between ethylene rates and decay incidence coincide; the berries that produced the highest ethylene rates rotted the most quickly Harshman said.
#Impact of pelargonic acid for weed control in yellow squashgrowers who produce squash for market are interested increasingly in using more natural herbicides that are also effective in providing season-long weed control
but the options for controlling annual broadleaf weeds in summer squash are limited currently. The authors of a new study say that both organic
and conventional producers will benefit from the identification of natural herbicides that effectively provide postemergent weed control.
and animals and is found in many foods--on weed control efficacy crop injury and squash yields of yellow squash.
The experiments included an untreated weedy control and an untreated weed-free control. Pelargonic acid was applied in Mid-july
Results of the experiments revealed that maximum smooth crabgrass control broadleaf weed control and yellow nutsedge control occurred with the 15-lb/acre PA treatment at 9 days after initial spray treatment and 1 day after the sequential treatment.
Pelargonic acid was less effective at controlling yellow nutsedge than smooth crabgrass and broadleaf weeds. Analyses showed that increasing the PA application rate increased the crop injury rating at 1 and 3 days after each application;
-or 15-lb/acre rates and yields and fruit number equivalent to the hand-weeded weed-free treatment.
This research determined that a sequential postdirected application of pelargonic acid at 10-lb/acre in 40-gal/acre can consistently produce satisfactory weed control with low crop injury to produce weed-free
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