CalledAlternaria spp.by science , this fungous contagion is the nemesis of tomato and cole crop raiser everywhere . There are three species of Alternaria blight :
Alternaria foliage spot for tomato – Alternaria stem pestilence ( A. alternata)Alternaria leaf spot for cole crops – Alternaria blight ( A. brassicaorA. brassicicola)Leaf blight of carrot – mordant putrefaction of cultivated carrot ( A. dauciorA. radicina )
Host Plants
Alternaria potetially impress all potpourri of tomato , carrots , crucifers , beans , and less often other herbaceous plant . It assault at all growth level , though it is most common during the flowering and fruiting stage .
Symptoms of Alternaria
Alternaria fungus is seed borne , so it is transferred through taint seeds to the regard plant life and spread to nearby plants as well . Most commercial-grade semen houses screen out for contagion before dispersion , but do not always catch the problem .
Plants that are infect will show initially as soften - off and scrawny seedlings , but because contagion develops so slowly , a sick plant may not show many signs until well into growth . In fact , it ’s seldom catch up with before transplantation and fruiting begin – in this way often infect all nearby plants in the process .
Most often , gardeners will discover the blight when it start appearing on leaves as spots that range in sizing from tiny to the width of your thumb . They are commonly yellow or brown and once they appear , they propagate chop-chop in homocentric rings of darken color . spotlight normally transfer or get down appearing on fruit and seed pod at about the time they appear on leaves .
Life Cycle
Alternaria has a long - term life cps compared to most fungus kingdom . Its life begins as a spore embedded onto the app of a seed , often wait through the wintertime and give just as the seed will . It then spreads easy , attaching to other plants the septic master of ceremonies might do in contact with and even having the ability to “ blow ” spore across short distances to other plant . It can also live on some dirt materials , though conditions must be perfect .
Once the fungus has set about to show on the plant , it ’s likely that it is nearing its spore stage . It will taint the fruit of the plant and then often kill the horde at about the meter the fruit throw to begin the cycle anew .
How This Plant Disease Impacts the Plant
On most plants , it will stunt production and infected fruits are not take eatable . It ’s dangerous to feed infected fruits to animals as this is suspect to have gastro - enteric trouble ( usually diarrhea ) in some stock . Tomatoes will show sluggish production and modest than intermediate yield while cultivated carrot will wilt in the ground without growing to potential . Beans and coles will be stunted and lucre head may never develop properly . In all plants , a rush to flower and ejaculate ( “ bolting ” ) is almost always the first symptom noticed .
How to Prevent Alternaria
Prevention is about come selection and the segregation and plants surmise of being taint . Quarantined plant ( usually enclosed in charge plate ) may be watch out for star sign of contagion . Most growers will just take away and destroy suspect plants as a matter of course . septic plant should never be compost , feed to livestock , or otherwise consume .
Wider spacing , clear weed , and plant gage to allow air flow are more ways of preventing blight .
Alternaria Treatment
Once it ’s there , Alternaria can not be remove easy . Most gardener slay and ruin the whole plant life . fungous treatments can help , but are not a guarantee and with the peril of infect all other plants in the domain , most growers take the trusted route of destruction of polish off the plant .
If your plants are isolate or you ’re unwilling to perpetrate and destroy , essay first an constituent fungicide . A good one to try is GreenCure . It ’s an economical foliar organic antimycotic that can be used for treatment and prevention on flowers , trees , turf , houseplant , and garden . To use GreenCure as a bar method to Alternaria Blight , simply tot 1 tablespoonful per gallon of H2O every one to two calendar week .
resourcefulness : http://www.ag.ndsu.edu / procrop / saf / safatb08.htmhttp://www.ipm.ucdavis.edu / PMG / GARDEN / FLOWERS / DISEASE / alternariablight.html
