Alternaria brassicicola / brassicae
Two coinage of the fungusAlternaria , A. brassicicolaandA. brassicae , can cause leaf spot on turnips .
You will know that you have Alternaria leaf spots on your turnip or rutubaga leaves when they train yellow to black leaf spots with concentric band like a target .
This disease is mostly cosmetic and will not destroy your turnip . However , if you seek to sell them , consumer and retail merchant will probably avert buying from you if they have these symptoms .
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Your choice for control this disease depart depending on what part of the country you live in . commonwealth vary in the number and type of antifungal agent that you may use to control Alternaria leafage berth on crucifers .
However , there are a number of ethnical controls that you may use and two microbic antimycotic agent that can suppress this disease .
understand on for more info about Alternaria leafage spot of turnip and control method .
What You Will Learn
Alternaria Leaf Spot Symptoms
The most common symptom is circular folio spots on the Brassica rapa leaves . The spots start out jaundiced and then can become tan or black . They have concentric rings like a mark .
The centers of the wound can descend out , and the spots can blend together to take shape large regions of stagnant tissue .
The Brassica rapa plants can also prepare lesions on the pod , prime , blossom pedicels , stems , and leafstalk .
Life Cycle
Alternaria survive outside of the plant – typically on debris from pathologic crop . This fungus is potential to spread when the weather is warm ( 60 - 78 F ) and moist , for exercise , 90 % relative humidity for at least 12 hours .
The fungi produce a tremendous number of spores , which can be go around by spatter water , jazz , people , or equipment .
The most vernacular way to originate Alternaria on your Brassica rapa is by planting infected seed .
Cultural Control Methods
Using disease - innocent seed will considerably bring down the likelihood of your turnips contract Alternaria leaf spot .
you’re able to also treat your seeded player with live water ( 122 F ) to kill the fungus , although the seeds of cruciferous plant ( like turnips ) are often less likely to germinate if they have been subjected to this character of treatment . The Ohio State University offers instructionson how to treat your seed .
You should avoid other type of crucifers as much as you may , since they can harbor the disease . extinguish any cruciferous pot like fantastic mustard that are near your flora . Also rotate with non - cruciferous crops for 1 - 3 years to abridge the levels of spores remaining in infected debris .
Do your best to keep the leafage of your turnip dry . If you water , do so in the morning to give the parting time to dry out . Plant your rows so that they are orient with the prevailing fart and reduce the density of your planting .
After you glean your turnips , incorporate all the debris into the territory , so it will decay and not be a generator of spores to infect your next crop .
Fungicide Control Methods
Biofungicides
The New England Vegetable Management Guideproduced by the University of Massachusetts Amherst urge two biofungicides that can be used to treat Alternaria folio blot . Both of these microbes are okay for organic yield .
One isBacillus amyloliquefaciensstrain D737 . While these bacterium will not heal an exist contagion , they can preclude the disease from occurring . The Double Nickleformulation can be used as a foliar spraying at 0.25 to 3.0 Cypriot pound per acre .
The otherbiofungicide isBacillus subtilis , sell as CEASE , available at Arbico Organics .
Copper Sprays
Another option is to spray with Kocide ( copper hydroxide ) .
check that that you spray in a solution with a pH higher than 6.5 . you may not use this atomizer on rutabaga .
Synthetic Fungicides
Several synthetical antifungal are available to care for Alternaria leaf spot on turnips . Two Group 11 fungicide include :
Do not go around with other fungicides in this group .
extra fungicides that can treat Alternaria leaf spots admit penthiopyrad ( Fontelis ) and cyprodinil plus fludioxonil ( Switch 6.25 WG ) .
Prevention is Your Best Bet
Although Alternaria leaf spotlight is a cosmetic disease and wo n’t kill your plants , people will not want to grease one’s palms your turnips if they have this hideous contagion on the leave of absence .
Since the most common way of life to cut this disease is to plant infect seed , you should buy Brassica rapa seed that is certified free of Alternaria . Another option is to treat your seeds with raging water to stamp out the fungus .
Get rid of any mustard or other cruciferous weed that are near your plant life and do your good to keep your Brassica rapa plants dry .
There are microbic and synthetic fungicides useable to treat your turnips , and liquid cop is another option .
Vigilance will help extinguish this disease from your garden .
Andread on for more information on disease on turnipsincluding :
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About
Helga George , PhD
