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Diet affects pesticide resistance in honey bees

Feeding honey bees a natural diet of pollen makes them significantly more resistant to pesticides than feeding them an artificial diet, according to a team of researchers, who also found that pesticide exposure causes changes in expression of genes that are sensitive to diet and nutrition.

“Honey bees are exposed to hundreds of pesticides, while they are foraging on flowers and also when beekeepers apply chemicals to control bee pests,” said Christina Grozinger, professor of entomology and director of the Center for Pollinator Research, Penn State. “Our study demonstrates that exposure to non-lethal doses of at least two of these pesticides causes large changes in the expression of genes involved in detoxification, immunity and nutrition-sensing. This is consistent with results from previous studies that have found that pesticide exposure compromises bees’ immune systems. Furthermore, our study reveals a strong link, at the molecular level, between nutrition, diet and pesticide exposure.”

Exploring this link further, the researchers found that diet significantly impacts how long bees can survive when given lethal doses of a pesticide.

“This interaction between pesticide exposure and nutrition is likely what’s at play in our finding that feeding bees a complex diet of pollen — their natural diet — makes them significantly more resistant to lethal doses of a pesticide than feeding them a more simple, artificial diet,” said Daniel Schmehl, postdoctoral researcher, University of Florida.

To determine the impact of pesticide exposure on gene expression patterns in honey bees, the scientists first fed one of two miticides — coumaphos or fluvalinate, the two most abundant and frequently detected pesticides in the hive — to bees for a period of seven days. On the seventh day, the researchers extracted RNA from the bees, attached a fluorescent marker to the RNA and examined differences in gene expression patterns — indicated by changes in patterns of fluorescence — between the pesticide-treated bees and the control bees.

“We found significant changes in 1,118 transcripts — or pieces of RNA — among the bees that were fed either of the two miticides compared to the control group,” said Schmehl. “These transcripts included genes involved in detoxification, immunity and nutrition.”

Based upon the results, the team performed several subsequent analyses aimed at understanding the impact of pesticides on honey bee physiology. One of these subsequent analyses examined the susceptibility of bees to pesticide stress after consuming a pollen diet or an artificial diet — either a soy protein or no protein diet. The team fed the bees these diets while simultaneously feeding them a lethal dose of the pesticide chlorpyrifos, an insecticide that is frequently used to control pests in agricultural crops and commonly detected in honey bee hives. They then recorded bee mortality daily for each of the treatment groups for a period of 16 days.

The researchers found that the bees that were fed a pollen-based diet exhibited reduced sensitivity to chlorpyrifos compared to the bees that were fed an artificial diet.

The results appear in the online issue of the Journal of Insect Physiology.

“This is the first time such a strong link between pesticide exposure and diet has been demonstrated at the molecular level, and the first time the effects of artificial versus natural diets have been explored in terms of resistance to pesticides,” said Grozinger. “Diet and nutrition can greatly impact the ability of bees to resist pesticides, and likely other stressors. However, agriculture and urbanization have reduced the amounts and diversity of flowering plants available to bees, which likely nutritionally stresses them and makes them more sensitive to these other stressors. If we can figure out which diets and which flowering plants are nutritionally optimal for honey bees, we can help bees help themselves.”

Story Source:

The above story is based on materials provided by Penn State. The original article was written by Sara LaJeunesse. Note: Materials may be edited for content and length.

Agriculture and Food News — ScienceDaily

Mexico: Oil spill affects 10,000 tons of orange in Nuevo Leon

Mexico: Oil spill affects 10,000 tons of orange in Nuevo Leon

Producers from the Township of Cadereyta Jiménez estimated that at least 10,000 tons of oranges had been lost because of the lack of irrigation caused by the oil spill into the San Juan River that a clandestine outlet on Pemex’s pipeline caused. 

The producers presented their estimates at a meeting with deputies of the Special Investigative Committee of the oil spill in the San Juan River.  According to Francisco Javier Limon Guzman, deputy of Santa Isabel’s common land, the orange trees haven’t been irrigated since August 16, when the clandestine outlet on kilometre 463.5 of the Madero-Cadereyta pipeline was detected. 

“There are two or three early orange varieties, one is cut at the beginning of the month, and, in fact we already lost that one. Then there is the late orange, which we can start cutting from December 15. We are talking about 20,000 tons in all the area,” he said. 

Half of that amount, he said, would result in beeing affected by the ecological contingency in the San Juan River, so we would need to bring citrus from other areas of the country to supply local demand. Limón Guzmán noted that the authorities are aware of the issue and have been waiting for Pemex to perform actions to clean up the affected area. 

Within this process, he said, the landowners have presented documents that show which plots have been affected and are expecting compensation from Pemex. 

“We need to water the trees so that the fruit can develop and so that the trees can bloom next year. Hence, this is affecting us,” he said in an interview. 

“Yes we will be affected. One of our production is its developmental stage and the other is about to be cut, but when the tree lacks water it feeds from itself so the oranges become loose and start lacking juice,” he said. 

It was agreed, at the meeting with local representatives, that the needs of the affected population would be monitored in order to try the ecological problem more quickly. 

Source: 20minutos.com.mx

Publication date: 9/15/2014


FreshPlaza.com

US (CA): Heat throws off tomato picking, affects volumes

Warm weather in some of California’s tomato-growing regions has sped up harvesting of the tomato crop there. With accelerated maturation throwing off growers’ planning, the spurts and gaps in production have affected pricing.

“We had a good start to the season, and then the heat came along,” said Todd Giardina of The Dimare Company in Newman, California. “As conditions got hotter, the tomatoes grew faster.” Accelerated maturation threw off the timing of many growers, who typically harvest their tomatoes on a 90-day cycle. But warm weather brought on more supplies sooner than expected and could cause gaps in production later in the season. Giardina noted that the past three weeks have seen low prices, in the range of $ 3 to $ 5 per 25-pound case, which is lower than the $ 7 to $ 10 per case growers were seeing this time last year.

“The reason for the prices is that there’s too much product,” said Giardina. “The harvest has been pushed up, so there will be gaps and swings in production.”

For more information:

Todd Giardina

The DiMare Company

+1 209 862 2872

FreshPlaza.com

US (CA): Heat affects Central Valley grapes

Several weeks of high temperatures in California’s Central San Joaquin Valley have affected table grapes in the region. The heat has had an effect on the sugar content, maturation and colouring.

High temperatures in the valley have reached or topped 100 degrees for most of the month of July, and that intense heat has sped up fruit maturation. The lack of water the state’s growers have had to deal with has also compounded the situation. As Nick Dulcich, of Sunlight International, explained, the drought means there’s less water for vineyards, and dry conditions in the fields have augmented the heat’s effects.

“We usually run water down the furrow in the middle of the rows and get grass growing in between,” said Dulcich. “But because we have less water due to the drought, the soil is dry in the field and there’s no absorption of that heat, so it’s just pure heat on that dirt. It’s stopped the colour, it’s advancing the sugars and some varieties are coming abnormally early.” He pointed to the Princess variety as an example of the effects of the heat. While that variety doesn’t usually come on until August, this year Sunlight will be done with the Princess by July 22 – a full two weeks before it’s usually available. In addition to speeding up maturity, the heat has also been upping sugars.

“Brix for Summer Royal grapes are usually around 18 or 19,” noted Dulcich, “but we’ve measured them at 27 this year, which is unheard of.” While sugars may be up, the timing to get good colouring on the grapes has been thrown off.

“We’ve got fruit that’s got 15 percent colour and 19 brix, and if the fruit doesn’t get the right colour it doesn’t make it to market,” said Dulcich. “We’re worried because, if you look at Scarlet Royals, they have 60 percent colour and a lot more sugar than you’d think. It’s a timing thing, and the heat hit at a time when it affects colour.”

For more information:

Nick Dulcich

Sunlight International

+1 661 792 6360

FreshPlaza.com

US (CA): Heat affects Central Valley grapes

Several weeks of high temperatures in California’s Central San Joaquin Valley have affected table grapes in the region. The heat has had an effect on the sugar content, maturation and colouring.

High temperatures in the valley have reached or topped 100 degrees for most of the month of July, and that intense heat has sped up fruit maturation. The lack of water the state’s growers have had to deal with has also compounded the situation. As Nick Dulcich, of Sunlight International, explained, the drought means there’s less water for vineyards, and dry conditions in the fields have augmented the heat’s effects.

“We usually run water down the furrow in the middle of the rows and get grass growing in between,” said Dulcich. “But because we have less water due to the drought, the soil is dry in the field and there’s no absorption of that heat, so it’s just pure heat on that dirt. It’s stopped the colour, it’s advancing the sugars and some varieties are coming abnormally early.” He pointed to the Princess variety as an example of the effects of the heat. While that variety doesn’t usually come on until August, this year Sunlight will be done with the Princess by July 22 – a full two weeks before it’s usually available. In addition to speeding up maturity, the heat has also been upping sugars.

“Brix for Summer Royal grapes are usually around 18 or 19,” noted Dulcich, “but we’ve measured them at 27 this year, which is unheard of.” While sugars may be up, the timing to get good colouring on the grapes has been thrown off.

“We’ve got fruit that’s got 15 percent colour and 19 brix, and if the fruit doesn’t get the right colour it doesn’t make it to market,” said Dulcich. “We’re worried because, if you look at Scarlet Royals, they have 60 percent colour and a lot more sugar than you’d think. It’s a timing thing, and the heat hit at a time when it affects colour.”

For more information:

Nick Dulcich

Sunlight International

+1 661 792 6360

FreshPlaza.com

Italy: Weather affects strawberry campaign

Secondulfo PO
Italy: Weather affects strawberry campaign

“The weather deeply affected the campaign, so much so that nothing developed at the usual times,” explains Salvatore Secondulfo, owner of OP Secondulfo, 


Strawberries developed more during the winter months, “therefore we expect lower yields towards the end of the season. Unfortunately, there were less nutrients in the plants during their most productive period.”


According to the owner, there are many factors that influence the campaign. “Due to the change in climate, Germany, as well as other Central and Northern European countries, is now cultivating more fruit, so it can satisfy internal demand and import less produce. In addition, the produce in exporting countries ripened earlier than usual, thus reducing their commercial period.”


“Despite this, we feel the strawberry campaign was good, especially in February, March and April 2014. We are confident we have done a good job, nonetheless, we are open to improvements. Basilicata for example adopted a number of different commercial strategies and achieved good results.”

OP Secondulfo covers around 400 hectares of kiwis, grapes, peaches, strawberries, apricots and nectarines. Produce is sold under the KiwiPiù and MissDolcezza brands.


Contatti:
Annarita Secondulfo
OP Secondulfo
Via Antico Cilento
84091 Battipaglia (SA)
Tel.: +39 (0)828 547515
Fax: +39 (0)828 547519
Email: [email protected]
Web: www.secondulfo.com

Publication date: 5/23/2014


FreshPlaza.com

Italy: Weather affects strawberry campaign

Secondulfo PO
Italy: Weather affects strawberry campaign

“The weather deeply affected the campaign, so much so that nothing developed at the usual times,” explains Salvatore Secondulfo, owner of OP Secondulfo, 


Strawberries developed more during the winter months, “therefore we expect lower yields towards the end of the season. Unfortunately, there were less nutrients in the plants during their most productive period.”


According to the owner, there are many factors that influence the campaign. “Due to the change in climate, Germany, as well as other Central and Northern European countries, is now cultivating more fruit, so it can satisfy internal demand and import less produce. In addition, the produce in exporting countries ripened earlier than usual, thus reducing their commercial period.”


“Despite this, we feel the strawberry campaign was good, especially in February, March and April 2014. We are confident we have done a good job, nonetheless, we are open to improvements. Basilicata for example adopted a number of different commercial strategies and achieved good results.”

OP Secondulfo covers around 400 hectares of kiwis, grapes, peaches, strawberries, apricots and nectarines. Produce is sold under the KiwiPiù and MissDolcezza brands.


Contatti:
Annarita Secondulfo
OP Secondulfo
Via Antico Cilento
84091 Battipaglia (SA)
Tel.: +39 (0)828 547515
Fax: +39 (0)828 547519
Email: [email protected]
Web: www.secondulfo.com

Publication date: 5/23/2014


FreshPlaza.com

Citrus greening affects roots before leaves

Although citrus greening enters trees through their leaves, University of Florida researchers have discovered that the deadly disease attacks roots long before the leaves show signs of damage — a finding that may help growers better care for trees while scientists work to find a cure.

“The role of root infection by insect-carried bacterial pathogens has been greatly underestimated,” said Evan Johnson, a research assistant scientist with UF’s Institute of Food and Agricultural Sciences.

Hundreds of researchers throughout the world are rushing to find a viable treatment for citrus greening, which is devastating Florida’s $ 9 billion citrus industry and has affected citrus production throughout North America.

Johnson was the lead author of a scientific paper outlining the research published in the April issue of the journal Plant Pathology. He and his fellow team members — Jian Wu, a graduate student in soil and water science, researcher Diane Bright and Jim Graham, a professor of soil microbiology — are based at the UF/IFAS Citrus Research and Education Center in Lake Alfred.

Citrus greening first enters the tree via a tiny insect, the Asian citrus psyllid, which sucks on leaf sap and leaves behind bacteria that spread through the tree. Johnson said the bacteria travel quickly to the roots, where they replicate, damage the root system and spread to the rest of the host tree’s canopy. The disease starves the tree of nutrients, leaving fruits that are green and misshapen, unsuitable for sale as fresh fruit or juice. Most infected trees die within a few years.

It was originally thought that the leaves and fruit were affected first, but the team’s research found that greening causes a loss of 30 to 50 percent of trees’ fibrous roots before symptoms are visible above ground.

“This early root loss means that the health of a citrus tree is severely compromised before the grower even knows it is infected,” Johnson said.

Experts say this research is significant in the fight against greening.

“Based on the work of Dr. Johnson and his colleagues, we now know how important roots are in the development of greening disease,” said Jackie Burns, director of the CREC. “We hope further investigations on the role of roots in this disease will lead to future management solutions that help growers remain productive until a permanent solution can be found.”

To battle greening, UF/IFAS researchers have attempted everything from trying to eradicate the psyllid to breeding trees that show better greening resistance. While Johnson’s research is not a cure, it may help more trees survive as scientists continue their search.

“We are still trying to determine how the bacteria are killing the roots,” Johnson said. “This finding suggests that growers should focus more effort on maintaining the health of the root system in relation to other soilborne pests and overall soil quality to maintain as much of the root system as possible.”

Johnson suggested that growers increase the acidity levels of irrigation water and soil to match the optimum pH for the rootstock (preliminary results show that this improves root density compared to untreated groves) and water more frequently for shorter periods. Those treatments are being studied by UF researchers in Lake Alfred and at the Southwest Florida Research and Education Center in Immokalee.

He added that while psyllid control is essential, growers should make careful decisions on how many resources to devote to any management strategy for greening-infected trees, based on their economic means, until field trials have been completed.

Story Source:

The above story is based on materials provided by University of Florida Institute of Food and Agricultural Sciences. The original article was written by Kimberly Moore Wilmoth. Note: Materials may be edited for content and length.

Agriculture and Food News — ScienceDaily

Citrus greening affects roots before leaves

Although citrus greening enters trees through their leaves, University of Florida researchers have discovered that the deadly disease attacks roots long before the leaves show signs of damage — a finding that may help growers better care for trees while scientists work to find a cure.

“The role of root infection by insect-carried bacterial pathogens has been greatly underestimated,” said Evan Johnson, a research assistant scientist with UF’s Institute of Food and Agricultural Sciences.

Hundreds of researchers throughout the world are rushing to find a viable treatment for citrus greening, which is devastating Florida’s $ 9 billion citrus industry and has affected citrus production throughout North America.

Johnson was the lead author of a scientific paper outlining the research published in the April issue of the journal Plant Pathology. He and his fellow team members — Jian Wu, a graduate student in soil and water science, researcher Diane Bright and Jim Graham, a professor of soil microbiology — are based at the UF/IFAS Citrus Research and Education Center in Lake Alfred.

Citrus greening first enters the tree via a tiny insect, the Asian citrus psyllid, which sucks on leaf sap and leaves behind bacteria that spread through the tree. Johnson said the bacteria travel quickly to the roots, where they replicate, damage the root system and spread to the rest of the host tree’s canopy. The disease starves the tree of nutrients, leaving fruits that are green and misshapen, unsuitable for sale as fresh fruit or juice. Most infected trees die within a few years.

It was originally thought that the leaves and fruit were affected first, but the team’s research found that greening causes a loss of 30 to 50 percent of trees’ fibrous roots before symptoms are visible above ground.

“This early root loss means that the health of a citrus tree is severely compromised before the grower even knows it is infected,” Johnson said.

Experts say this research is significant in the fight against greening.

“Based on the work of Dr. Johnson and his colleagues, we now know how important roots are in the development of greening disease,” said Jackie Burns, director of the CREC. “We hope further investigations on the role of roots in this disease will lead to future management solutions that help growers remain productive until a permanent solution can be found.”

To battle greening, UF/IFAS researchers have attempted everything from trying to eradicate the psyllid to breeding trees that show better greening resistance. While Johnson’s research is not a cure, it may help more trees survive as scientists continue their search.

“We are still trying to determine how the bacteria are killing the roots,” Johnson said. “This finding suggests that growers should focus more effort on maintaining the health of the root system in relation to other soilborne pests and overall soil quality to maintain as much of the root system as possible.”

Johnson suggested that growers increase the acidity levels of irrigation water and soil to match the optimum pH for the rootstock (preliminary results show that this improves root density compared to untreated groves) and water more frequently for shorter periods. Those treatments are being studied by UF researchers in Lake Alfred and at the Southwest Florida Research and Education Center in Immokalee.

He added that while psyllid control is essential, growers should make careful decisions on how many resources to devote to any management strategy for greening-infected trees, based on their economic means, until field trials have been completed.

Story Source:

The above story is based on materials provided by University of Florida Institute of Food and Agricultural Sciences. The original article was written by Kimberly Moore Wilmoth. Note: Materials may be edited for content and length.

Agriculture and Food News — ScienceDaily

Citrus greening affects roots before leaves

Although citrus greening enters trees through their leaves, University of Florida researchers have discovered that the deadly disease attacks roots long before the leaves show signs of damage — a finding that may help growers better care for trees while scientists work to find a cure.

“The role of root infection by insect-carried bacterial pathogens has been greatly underestimated,” said Evan Johnson, a research assistant scientist with UF’s Institute of Food and Agricultural Sciences.

Hundreds of researchers throughout the world are rushing to find a viable treatment for citrus greening, which is devastating Florida’s $ 9 billion citrus industry and has affected citrus production throughout North America.

Johnson was the lead author of a scientific paper outlining the research published in the April issue of the journal Plant Pathology. He and his fellow team members — Jian Wu, a graduate student in soil and water science, researcher Diane Bright and Jim Graham, a professor of soil microbiology — are based at the UF/IFAS Citrus Research and Education Center in Lake Alfred.

Citrus greening first enters the tree via a tiny insect, the Asian citrus psyllid, which sucks on leaf sap and leaves behind bacteria that spread through the tree. Johnson said the bacteria travel quickly to the roots, where they replicate, damage the root system and spread to the rest of the host tree’s canopy. The disease starves the tree of nutrients, leaving fruits that are green and misshapen, unsuitable for sale as fresh fruit or juice. Most infected trees die within a few years.

It was originally thought that the leaves and fruit were affected first, but the team’s research found that greening causes a loss of 30 to 50 percent of trees’ fibrous roots before symptoms are visible above ground.

“This early root loss means that the health of a citrus tree is severely compromised before the grower even knows it is infected,” Johnson said.

Experts say this research is significant in the fight against greening.

“Based on the work of Dr. Johnson and his colleagues, we now know how important roots are in the development of greening disease,” said Jackie Burns, director of the CREC. “We hope further investigations on the role of roots in this disease will lead to future management solutions that help growers remain productive until a permanent solution can be found.”

To battle greening, UF/IFAS researchers have attempted everything from trying to eradicate the psyllid to breeding trees that show better greening resistance. While Johnson’s research is not a cure, it may help more trees survive as scientists continue their search.

“We are still trying to determine how the bacteria are killing the roots,” Johnson said. “This finding suggests that growers should focus more effort on maintaining the health of the root system in relation to other soilborne pests and overall soil quality to maintain as much of the root system as possible.”

Johnson suggested that growers increase the acidity levels of irrigation water and soil to match the optimum pH for the rootstock (preliminary results show that this improves root density compared to untreated groves) and water more frequently for shorter periods. Those treatments are being studied by UF researchers in Lake Alfred and at the Southwest Florida Research and Education Center in Immokalee.

He added that while psyllid control is essential, growers should make careful decisions on how many resources to devote to any management strategy for greening-infected trees, based on their economic means, until field trials have been completed.

Story Source:

The above story is based on materials provided by University of Florida Institute of Food and Agricultural Sciences. The original article was written by Kimberly Moore Wilmoth. Note: Materials may be edited for content and length.

Agriculture and Food News — ScienceDaily

Citrus greening affects roots before leaves

Although citrus greening enters trees through their leaves, University of Florida researchers have discovered that the deadly disease attacks roots long before the leaves show signs of damage — a finding that may help growers better care for trees while scientists work to find a cure.

“The role of root infection by insect-carried bacterial pathogens has been greatly underestimated,” said Evan Johnson, a research assistant scientist with UF’s Institute of Food and Agricultural Sciences.

Hundreds of researchers throughout the world are rushing to find a viable treatment for citrus greening, which is devastating Florida’s $ 9 billion citrus industry and has affected citrus production throughout North America.

Johnson was the lead author of a scientific paper outlining the research published in the April issue of the journal Plant Pathology. He and his fellow team members — Jian Wu, a graduate student in soil and water science, researcher Diane Bright and Jim Graham, a professor of soil microbiology — are based at the UF/IFAS Citrus Research and Education Center in Lake Alfred.

Citrus greening first enters the tree via a tiny insect, the Asian citrus psyllid, which sucks on leaf sap and leaves behind bacteria that spread through the tree. Johnson said the bacteria travel quickly to the roots, where they replicate, damage the root system and spread to the rest of the host tree’s canopy. The disease starves the tree of nutrients, leaving fruits that are green and misshapen, unsuitable for sale as fresh fruit or juice. Most infected trees die within a few years.

It was originally thought that the leaves and fruit were affected first, but the team’s research found that greening causes a loss of 30 to 50 percent of trees’ fibrous roots before symptoms are visible above ground.

“This early root loss means that the health of a citrus tree is severely compromised before the grower even knows it is infected,” Johnson said.

Experts say this research is significant in the fight against greening.

“Based on the work of Dr. Johnson and his colleagues, we now know how important roots are in the development of greening disease,” said Jackie Burns, director of the CREC. “We hope further investigations on the role of roots in this disease will lead to future management solutions that help growers remain productive until a permanent solution can be found.”

To battle greening, UF/IFAS researchers have attempted everything from trying to eradicate the psyllid to breeding trees that show better greening resistance. While Johnson’s research is not a cure, it may help more trees survive as scientists continue their search.

“We are still trying to determine how the bacteria are killing the roots,” Johnson said. “This finding suggests that growers should focus more effort on maintaining the health of the root system in relation to other soilborne pests and overall soil quality to maintain as much of the root system as possible.”

Johnson suggested that growers increase the acidity levels of irrigation water and soil to match the optimum pH for the rootstock (preliminary results show that this improves root density compared to untreated groves) and water more frequently for shorter periods. Those treatments are being studied by UF researchers in Lake Alfred and at the Southwest Florida Research and Education Center in Immokalee.

He added that while psyllid control is essential, growers should make careful decisions on how many resources to devote to any management strategy for greening-infected trees, based on their economic means, until field trials have been completed.

Story Source:

The above story is based on materials provided by University of Florida Institute of Food and Agricultural Sciences. The original article was written by Kimberly Moore Wilmoth. Note: Materials may be edited for content and length.

Agriculture and Food News — ScienceDaily

Weather affects crop yield, especially hot days

Sep. 16, 2013 — Because Wisconsin and Ontario are similar in terms of agricultural practices, types of vegetable crops produced, climate, and latitude, researchers in Ontario looked to data from Wisconsin when comparing the long-term effects of climate on vegetable crop yield. According to researchers from the University of Guelph (Ontario, Canada), the length of the growing season is similar in the two locations, so growing conditions and yields could also be similar. Michael Tesfaendrias, Mary Ruth McDonald, and Jon Warland published the results of their extensive study in the July 2013 issue of HortScience.

“To study the effects of weather, we examined yield data of the major vegetable crops by county and county weather data for a 55-year period from Wisconsin,” explained the study’s lead author Michael Tesfaendrias. The study was designed to determine the associations between long-term weather and yield of 11 horticultural crops and one field crop in Wisconsin, and to determine if the relationships between weather and yields identified in Ontario were similar for vegetable crops in Wisconsin. The team used yield data obtained from the U.S. Department of Agriculture, National Agricultural Statistics Service (NASS) in Wisconsin for beet, cabbage, carrot, cucumber, green pea, onion, potato, snap bean, sweet corn, and grain corn.

The data revealed several similarities between the long-term weather in Wisconsin and Ontario. The number of days with rainfall and the mean season temperatures showed the strongest relationships. “Among the weather parameters that were examined to determine their impact on vegetable crop yield in Wisconsin, the number of hot days during the growing season was the most important factor,” the scientists reported. Yields of most of the crops evaluated were affected by the number of hot days in June, July, and August.

When the team looked at rainfall data, they determined that the number of days with rainfall was more important than the total monthly rainfall. With the exception of beets, the yield of crops in the study was unaffected by the total number of days with rain during the growing season. The yields of beets in Wisconsin and green pea in both Wisconsin and Ontario increased with increasing total growing season rainfall.

“The number of days with hot temperatures, especially during July and August, emerged as the most important environmental factor that should be measured to estimate yields of vegetable crops,” the researchers said. Noting that high temperatures can be challenging to modify, the authors recommended that growers could reduce the irrigation interval during hot days to prevent heat stress. “This study emphasizes the importance of breeding vegetable crops for heat tolerance,” they said.

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Story Source:

The above story is based on materials provided by American Society for Horticultural Science.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Michael T. Tesfaendrias, Mary Ruth Mcdonald, and Jon Warland. Long-term Yield of Horticultural Crops in Wisconsin in Relation to Seasonal Climate in Comparison with Southern Ontario, Canada. HortScience, July 2013

Note: If no author is given, the source is cited instead.

ScienceDaily: Agriculture and Food News