Tomato Diseases To Lookout For
Entomology together with Plant Pathology, Oklahoma State University 127 Noble Research Center, Stillwater, OK 74078 405.744.5527 Vol. 17, No. xix http://entoplp.okstate.edu/pddl/pdidl 6/22/2018
Tomato Disease Update
John Damicone, OSU Extension Plant Pathologist
Department of Entomology together with Plant Pathology Oklahoma State University
See https://apps.dasnr.okstate.edu/SSL/entoplp.okstate.edu/pddl/2018/PA%2017-19.pdf
Tomato diseases are rearing their ugly heads every bit fruit are ready together with approximately rainfall together with a lot of humid weather condition has returned. After visiting approximately marketplace position farms final calendar week together with putting approximately other string on plants inwards my garden, this is what I saw: Bacterial spot together with speck These diseases are real similar inwards that they displace defoliation of plants from the bottom upwards together with displace fruit spotting. They are hard to course of teaching inwards the plain every bit their symptoms are real similar together with may plough over off together. They are likewise hard to course of teaching from Septoria leafage spot, a fungal disease.
Entomology together with Plant Pathology, Oklahoma State University 127 Noble Research Center, Stillwa
See https://apps.dasnr.okstate.edu/SSL/entoplp.okstate.edu/pddl/2018/PA%2017-19.pdf
Symptoms laid out every bit dark, mostly circular, greasy appearing, water-soaked spots on lower leaves (Fig. 1). Spots rarely top most 1/8 inch inwards diameter. Leaf spots caused past times bacterial spot together with speck are smaller than early on blight, approximately other fungal illness together with lack the concentric rings associated amongst early on blight. Spots may or may non live surrounded past times a yellowish halo, which is to a greater extent than typical of bacterial speck. When spots learn numerous, leaves may develop varying levels of yellowing, shrivel, together with die. The diseases progresses from the bottom of the found upward. Fruit spots caused past times bacterial spot together with speck are dissimilar together with their symptoms are useful for differentiating the ii diseases.
Fruit spots caused past times bacterial speck are to a greater extent than often than non pivot caput size (Fig. 2) piece fruit spots caused past times bacterial spot are larger, reaching upwards to ¼ inch inwards diameter together with a scabby appearance (Fig. 3). In my observations, fruit spots to a greater extent than often than non plough over off infrequently inwards our climate together with the most impairment from these diseases are from the found defoliation which reduces found productivity together with longevity. Bacterial spot together with speck are mutual where crop rotation is express past times infinite constraints. This is a mutual occupation inwards residential gardens together with pocket-size marketplace position farms. Generally 3-year rotations away from tomatoes together with peppers are necessary to impact levels of the diseases. Other practices are administration of infested crop residuum together with command of volunteer tomatoes because the illness is seed borne. Ultimately because at that topographic point are no resistant varieties, spray programs amongst copper- based fungicides are required to minimize bacterial spot together with speck.
In situations where at that topographic point is dubiety inwards whether tomato plant diseases are fungal or bacterial, it is best to apply a tank mixture of a copper together with chlorothalonil (e.g. Bravo, Daconil, or Ortho Garden Disease Control).
Consult the OSU Extension Agent’s Handbook (Circular E-832) for to a greater extent than data together with a listing of registered domicile together with commercial formulations of copper together with chlorothalonil.
Figure 1: Foliar symptoms of bacterial spot and/or speck
Figure 2: Bacterial spot on tomato
Bacterial canker Bacterial canker is typically a occupation inwards commercial plain together with greenhouse tomato plant production. It’s a real destructive illness because it tin give the sack kill entire plants. Symptoms initially seem every bit a foliar leafage scorch commencement at the leafage edges. The leading edges of the scorch seem page greenish inwards coloring (Fig. 4).
Petioles of affected leaves develop pocket-size blister-like cankers from which the illness gets its cite (Fig. 5).
Fruit on affected plants develop white “bird’s midpoint spots” which are highly feature of the illness (Fig. 6). Control of bacterial canker should focus on excluding the pathogen from tomato plant operations together with sanitation mensurate to boundary its carryover from twelvemonth to year. The pathogen survives on crop residue, tomato plant stakes, transplant containers, together with greenhouse surfaces. It is of import to eliminate its carryover from twelvemonth to year. Bleach solutions (10%) are effective inwards cleaning upwards canker infestations on stakes together with surfaces.
Figure 4: Bacterial canker on tomato plant foliage. F Figure 5: Blisters or cankers on petioles caused past times bacterial canker.
Figure 6: Fruit spots caused past times bacterial canker. Tomato Spotted Wilt Virus Tomato Spotted Wilt Virus (TWSV) has been a sporadic occupation on peanuts together with tomatoes inwards Oklahoma for many years. It has never achieve severe levels hither compared to due south Texas or the Southeastern the U.S. of A. We’ve had a tomato plant sample exam positive for this illness inwards the Plant Disease together with Insect Diagnostic laboratory this twelvemonth together with I receive got an infected found inwards my garden. This is non a major outbreak past times whatsoever agency simply operate on an midpoint out for it.
Symptoms on tomatoes seem every bit bronzing or stippling on the upper leaves together with petioles (Fig. 7). Occasionally band spots are visible inwards the leaves. Symptoms seem on private branches or entire plants.
Eventually end shoots of affected plants plough yellowish or dark-brown together with eventually wilt together with operate (Fig. 8).
TSWV is spread past times thrips feeding on infected plants every bit juveniles. The thrips learn infective when they molt into adults. Current query indicates that thrips transmit the virus inwards the belatedly autumn together with wintertime to weedy hosts which thus serve every bit local sources of the virus for thrips the next spring. Planting tomato plant varieties amongst resistance to the illness inwards the best administration strategy. It’s likely best to cull out infected plants before long later symptoms seem thus that they don’t serve every bit sources of the virus for thrips.
Figure 7: Bronzing of tomato plant foliage caused past times tomato plant spotted wilt virus. Figure 8: Wilt together with decease of tomato plant foliage caused tomato plant spotted wilt virus