Disease Management in Tomato Production

Transcription

1 Disease Management in Tomato Production Mohammad University of Illinois Vegetable Conference 9 February 2016 Major Tomato Diseases in 2015 Leaf mold Early blight Septoria leaf spot & foliar blight* Bacterial diseases Bacterial spot* Bacterial speck* Bacterial canker A fungal disease: Fulvia fulva Importance: more important in high tunnels and greenhouses Favorable conditions: high humidity Symptoms: leaf spot and foliar blight Leaf mold of tomato in a high tunnel Disease characteristics: Fungus can survive as conidia and sclerotia in plant debris, seed, and soil Sclerotia produce conidia Conidia initiate infection Conidia are dispersed by water-splash, air current, mechanical means, insects Spore germination: in water or >85% RH, at F (optimum C) Symptoms appear 10 days after infection (Management) Cultural and chemical management Cultural practices Remove and destroy plant debris Steam greenhouse at 135 F for 6 hrs Have good air circulation, maintain RH below 85% Avoid wetting leaves Keep temp above 60 F at night 1

2 (Management) Chemical control: Fungicides: Chlorothalonil (eg, Bravo), mancozeb, Maneb, Inspire Super, Quadris Top, Tanos Cover the foliage thoroughly with fungicides Early Blight of Tomato A fungal disease: Alternaria solani Affected plant parts: foliar and fruit Occurrence: worldwide Seed- and residue-borne Early Blight Early Blight of Tomato (Disease Management) Methods used for management of Septoria foliar blight are effective for management of early blight too Septoria Leaf Blight of Tomato Fungal Diseases: Septoria lycopersici Leaf infection, foliar blight Seed- and residue-borne disease Plant infection throughout the season A devastating disease in 2015 Septoria leaf spot & blight of tomato 2

3 Septoria Blight of Tomato (Disease Management) Cultural practices Plant pathogen-free seed Crop rotation: 3 years Remove debris after harvest Chemical control Quadris Alt Chlorothalonil Septoria Leaf Blight of Tomato (Disease Management) Chemical control Quadris, Quadris Opti, Quadris Top, Cabrio Reason, Scala, Gavel, Endura, Fontelis, Inspire Super Maneb, Mancozeb, Chlorothalonil, Ziram Bacterial Diseases of Tomato Bacterial canker: Clavibacter michiganense pv michiganense Bacterial spot*: Xanthomonas campestris pv vesicatoria Bacterial speck: Pseudomonas syringae pv tomato Bacterial canker Bacterial canker Bacterial spot Bird s eye 3

4 Bacterial speck Bacterial speck Bacterial Canker Bacterial Spot Bacterial Speck Bacterial Diseases of Tomato Bacterial spot: most prevalent bacterial disease of tomato in Illinois, especially in the south Bacterial speck: second most prevalent, specially in the north Management: both diseases can be managed using the same methods Bacterial spot on leaves Bacterial spot on flower stems 4

5 Bacterial spot on fruit Bacterial spot of tomato in the south Bacterial spot of tomato in the north Managing Bacterial Diseases of Tomatoes _ Plant resistant/tolerant varieties, if available Plant pathogen-free seed and seedlings Plant treated seed A 3-year crop rotation Field sanitation: remove old material Plant varieties separately Control volunteer plants and weeds Managing Bacterial Diseases of Tomatoes Use clean crates, boxes, and stakes Scout your field weekly Do not enter the field if the foliage is wet Disinfest pruning tools Avoid cull pile in the field Spray plants with copper + mancozeb Actigard, Tanos, and Quintec may suppress disease development and spread Bacterial Spot of Tomatoes-2014, Vandalia foliage Dis severity (%) Treatment # Spray Jul 17 Aug 18 Control (check) Phyton 27AG (2 lb/a) Copper Oxychloride (2 lb /A) Mettle 125ME (8 oz/a) GWN SC (32 fl oz/a) Quadris 208SC (62 fl oz/a) Affiance (10 fl oz/a) Quintec+Kocide/Dithane-M+Koc Quadris+Kocide/Bravo WS+Koc

6 Bacterial Spot of Tomatoes-2015, Vandalia Foliage Dis severity (%) Treatment # Spray 25 Jul 28 Aug Control (check) 0 5 a 50 a Phyton 27AG (40 oz/a) 8 2 bc 28 bc Torino 085SC (34 fl oz/a) 8 1 bc 26 b-d Mettle 125ME (8 fl oz/a) 8 2 bc 21 c-e Mettle/Torino 8 2 bc 23 b-e Rally (4 oz/a)/quintec (6 fl oz/a) 8 2 bc 25 b-e GWN SC (36 fl oz/a) 8 3 b 20 c-e GWN (30 fl oz/a)/quintec (6 fl oz) 8 2 bc 25 b-e Gavel 75 DF (2 lb/a) 8 3 b 18 e Bacterial Spot of Tomatoe-2015, Champaign Dis severity (%) Treatment # Spray 9 Aug 27 Aug Control (check) 0 15 a 30 a /Dithane-M(2 lb)+kocide(15 lb) 8 5 b 10 c /Bravo WS (2 pt)+kocide(15 lb) 8 5 b 6 c Phyton 27AG (40 oz/a) 8 9 b 24 b Mettle (8 fl oz)/torino (34 fl oz) 8 5 b 11 c GWN (32 fl oz/a)/quintec (6 fl oz) 8 8 b 19 b Septoria Blight of Tomatoes-2015, Champaign Dis severity (%) Treatment # Spray 22 Jul 18 Aug Control (check) 0 6 a 21 a /Dithane-M(2 lb)+kocide(15 lb) 8 2 bc 4 cd /Bravo WS (2 pt)+kocide(15 lb) 8 1 c 3 d Phyton 27AG (40 oz/a) 8 5 ab 15 ab Mettle (8 fl oz)/torino (34 fl oz) 8 2 bc 4 d GWN (32 fl oz/a)/quintec (6 fl oz) 8 2 bc 9 c Septoria Blight /Bacterial Spot of Tomatoes , Champaign Foliage blight Treatment # Spray 5 Sep (%) Control (check) 0 79 a /Dithane-M(2 lb)+kocide(15 lb) 8 /Bravo WS (2 pt)+kocide(15 lb) 8 21 d 13 d Phyton 27AG (40 oz/a) 8 60 b Mettle (8 fl oz)/torino (34 fl oz) 8 25 d GWN (32 fl oz/a)/quintec (6 fl oz) 8 40 c Tomato Disease Conclusions _ Major diseases: Septoria leaf blight and bacterial leaf spot Effective treatments at this time: Quintec (6 fl oz) + Kocide (15 lb) Alt Dithane-M(2lb)+Kocide (15lb) OR Quintec (6 fl oz) + Kocide (15 lb) Alt BravoW S(2pt)+Kocide(15lb) Questions/Comments 6