Growing Fall Cucumbers

Transcription

1 Growing Fall Cucumbers Efficacy and economics of downy mildew resistant varieties 2018 CCE ENYCHP Winter Conference February 21, 2018 Susan B. Scheufele UMass Extension Vegetable Program September 26, 2017

2 Many pests have been building up

3 Suddenly, plants appear scorched

4 Cucurbit downy mildew Cucumber

5 Cucurbit downy mildew Acorn squash Butternut Photos from cdm-ipm-pipe.org

6 Cucurbit downy mildew Melon Watermelon Photos from cdm-ipm-pipe.org

7 Cucurbit downy mildew 5 strains infect different host crops + Highly compatible host interaction incompatible or very slightly compatible host interaction

8 Cucurbit downy mildew Oomycete Produces many sporangia Wind dispersed great distances Living host to survive Does NOT overwinter

9 Where does it come from? cdm.ipm-pipe.org Blows up from FL each year Usually arrives in mid-august (MA)

10 Control of Downy Mildew Need to spray every 5-7 days once disease present and conditions favorable!! Broad spectrum: Bravo, Copper, Mancozeb + Oomycete-specific: e.g. Tanos, Ranman, Forum, Gavel, Previcur Flex, Zampro Organic: Copper, Oxidate, Biofungicides??

11 So, what s the problem? Market for cucumbers all year round but So much time and $$ spraying Bravo is harmful to bees Affects fungal gut symbiont More susceptible to fungal parasite Nosema Organic spraying effective? Need new resistant varieties Photo by K. Keatley Garvey, UCANR

12 Reduce need for fungicides Save time Save money Work for organic and conventional alike Durable solution Role of Resistant Varieties New varieties coming on the market X

13 How effective are new resistant varieties? Can we extend the cuke season? More profitable than spraying? Research Questions More profitable to plant resistant variety AND spray? X

14 Resistant Variety Trials Cultivar Straight Eight (Susceptible control) X X SV4719CS X X Green Bowl X X Bristol X X DMR401 X X NY264 X X Diamondback Python X X

15 Straight 8 Susceptible to EVERYthing!! PROS Heirloom variety High yielding CONS Susceptible to everything Monoecious

16 SV4719CS New standard of DM resistance PROS Good resistance to DM, PM, other leaf spots, viruses Widely available CONS Not very vigorous plants, brittle Attractive to beetles and so bacterial wilt

17 Green Bowl Great DM resistance, poor yields PROS Strong resistance to DM, PM CONS Very poor yield Off flavor Will not be marketed

18 Bristol Great DM resistance, good yields PROS Strong resistance to DM, PM, fungal diseases and viruses Vigorous, high yields Good looking and tasting CONS Susceptible to anthracnose

19 DMR401 Great DM resistance, some off shapes PROS Strong resistance to DM, PM, leaf spots, virus Vigorous Good looking and tasting CONS Misshapen fruit--tapered, hooked, broken ends Not widely available: CommonWealth Seeds

20 NY264 Best DM resistance, short fruit PROS Strongest resistance to DM, PM, virus Vigorous. Plants are huge, many flowers Good looking and tasting CONS Not widely available Longer DTH (75) Unconventional shape, color

21 Diamondback Strong DM resistance PROS Good resistance to DM, PM Strong yields Good looking and tasting CONS Susceptible to anthracnose

22 Python Strong DM resistance PROS Good resistance to DM, PM Strong yields Good looking and tasting CONS Susceptible to anthracnose

23 2016 Season Hot Dry, drought Unfavorable conditions Disease came Aug 17 Low DM pressure Virus affected control plots 2017 Season Cool Wet Favorable conditions Disease came early Aug 2 Very high DM pressure **use white mulch when planting in July!!

24 Downy Mildew over Time (AUDPC) a b bc c d e p <

25 3,000 2, Downy Mildew over Time (AUDPC) a P < ,000 1,500 b b b b 1, c c c

26 2016 Marketable Yield (lb/a) 60,000 50,000 40,000 30,000 20,000 d c cd ab bc a p = ,000 0

27 2017 Marketable Yield (lb/a) 30,000 25,000 20,000 15,000 10,000 5,000 cd abc d ab a ab p = bcd abc 0

28 Last Harvest Date 2016 Python Diamondback NY Sep DMR401 Bristol Green Bowl SV4719CS Straight Eight 9-Sep 9-Sep 9-Sep 9-Sep 2-Sep 24-Jul 3-Aug 13-Aug 23-Aug 2-Sep 12-Sep 22-Sep 2-Oct

29 Last Harvest Date 2017 Python Diamondback 4-Sep 1-Sep NY Sep DMR401 Bristol 4-Sep 4-Sep Green Bowl SV4719CS Straight Eight 22-Aug 22-Aug 29-Aug 24-Jul 3-Aug 13-Aug 23-Aug 2-Sep 12-Sep 22-Sep

30 Variety Trial Conclusions NY264 Susceptible NY264 (Commonwealth Seeds) Bristol (Seminis) DMR401 (Commonwealth Seeds)

31 Next Questions Does it help to spray the resistant varieties? Can we extend the season further? What is the most profitable approach? $$$

32 Fungicide Efficacy and Economics Study Susceptible (Straight 8) Resistant (SV4719CS) No Spray Conventional Spray Organic Spray

33 Fungicide Efficacy and Economics Study 2016 Season Hot Dry, drought Unfavorable conditions Disease came Aug 17 Low DM pressure Virus affected control plots 6 sprays 2017 Season Cool Wet Favorable conditions Disease came early (Aug 2) Very high DM pressure 9 sprays

34 a 2016 DM over Time (AUDPC) b b p = c d cd 0 Unsprayed Conv Org Unsprayed Conv Org

35 a Unsprayed 2017 DM over Time (AUDPC) d Conv ab Org bc Unsprayed d Conv p = c Org

36 2016 Marketable Yield/A 30,000 25,000 p = a a a 20,000 15,000 b b b 10,000 5,000 0 Unsprayed Conv Org Unsprayed Conv Org

37 2016 Marketable Yield/A 30,000 25,000 p = a a a 20,000 15,000 b b b 10,000 5,000 0 Unsprayed Conv Org Unsprayed Conv Org

38 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 0 c Unsprayed 2017 Marketable Yield/A a Conv c Org bc Unsprayed ab Conv p = b Org

39 Last Harvest Date 2016 Org Conv Unsprayed Org Conv Unsprayed 24-Jul 20-Sep 20-Sep 16-Sep 9-Sep 9-Sep 2-Sep 3-Aug 13-Aug 23-Aug 2-Sep 12-Sep 22-Sep 2-Oct

40 Last Harvest Date 2017 Org 22-Sep Conv 22-Sep Unsprayed 15-Sep Org 8-Sep Conv Unsprayed 22-Aug 2-Oct 24-Jul 3-Aug 13-Aug 23-Aug 2-Sep 12-Sep 22-Sep 2-Oct

41 Calculating Sales & Profits Cost of Materials 6 sprays in 2016 $411 (C) $37 (O) 9 sprays in 2017 $702 (C) $40 (O) Price/lb Conventional: Retail $2.00/pound Organic: Retail $2.50/pound Cost of Spraying $24/hour 1.0 hours /A to mix, spray, clean up Tractor maintenance, repair, depreciation = $20/acre (

42 2016 Marketable Yield/A 30,000 25,000 p = a a a 20,000 15,000 b b b 10,000 5,000 0 Unsprayed Conv Org Unsprayed Conv Org

43 2016 Profit/A $30,000 $25,000 $20,000 $15,000 $15,415 (C) $19,268 (O) $19,910 $25,611 $10,000 $5,000 $0 $0 Unsprayed $2,740 Conv $1,525 Org Unsprayed Conv Org

44 18,000 16,000 14,000 12,000 10,000 8,000 6,000 4,000 2,000 0 c Unsprayed 2017 Marketable Yield/A a Conv c Org bc Unsprayed ab Conv p = b Org

45 $35,000 $30,000 $25,000 $20,000 $15,000 $31, Profit/A $13,861 (C) $17,326 (O) $20,674 $22,651 $10,000 $5,000 $0 $0 Unsprayed Conv $3,629 Org Unsprayed Conv Org

46 Economics Study Conclusions Conventional fungicides are very effective, if you use them choose high yielding variety Resistant varieties yield better even if lower yield potential Resistance to other diseases more reliable, consistent yield Spraying can improve yield and profitability Choose a better yielding resistant variety e.g. NY264 or Bristol and spray to get maximum benefit

47 Thanks!!! Thanks to my colleagues in the UMass Extension Vegetable Program: Katie Campbell-Nelson Lisa McKeag Genevieve Higgins Michele Meder Ben Jankowski Farm Crew: Neal Woodard and Zack Zenk Sue s Contact Info: sscheufele@umext.umass.edu This project was supported by the Specialty Crop Block Grant Program at the U.S. Department of Agriculture