Weed & Crop Emergence & Mngement in Strip Tillge Frnk Forcell, Don Reicosky, & Kurt Spoks USDA Agriculturl Reserch Service Morris, MN 320-589-3411 x 127 Frnk.Forcell@rs.usd.gov
Two-yer study ner Morris Comprison of 5 tillge systems NT, no-till SS, strip-till shllow SD, strip-till deep CP, chisel plow MP, moldbord plow Crop stnd & emergence rtes Weed density & emergence rtes, wheel trck, nd interrow sites Implictions for mngement
Herbicide recommendtions http://ppliedweeds.cofes.umn.edu/pubsweedbull.html
Averge Crop Stnds Sunflower 30,000 / A Soyben 98,000 / A Corn 25,000 / A
1.0 0.8 0.6 0.4 0.2 0.0 Sunflower NT SS SD CP MP Reltive Stnd Density
1.0 0.8 0.6 0.4 0.2 0.0 Soyben NT SS SD CP MP Reltive Stnd Density
1.0 0.8 0.6 0.4 0.2 0.0 Corn b b bc c NT SS SD CP MP Reltive Stnd Density
Summry of crop stnds Bsiclly, good crop vrieties don t cre much bout tillge. The exception is corn. It s stnds cn be reduced in no-till. Possible solution: Plnt 10 to 20% more seeds in no-till.
Crop Emergence Rtes 15 Dys to 50% Emergence 10 5 0 Sunflower Soyben Corn
Dys to 50% Emergence 15 10 5 Sunflower Emergence (Less is better; = consistently worse thn best) * * 0 NT SS SD CP MP
15 Soyben Emergence (Less is better; = consistently worse thn best) * * Differences mong tillge tretments re minor. Dys to 50% Emergence 10 5 0 NT SS SD CP MP
Dys to 50% Emergence 15 10 5 * Corn Emergence (Less is better; = consistently worse thn best) * 0 NT SS SD CP MP
Summry of crop emergence rtes No-till cuses delys in emergence of ll crops. Strip-till, especilly deep strip-till, never differs from best tretment. Differences for soyben probbly re not importnt, but my be so for other crops.
Weed Densities Foxtil (Pigeon grss) Common lmbsqurters Wild mustrd
600 500 400 300 200 100 0 Foxtil Densities NT NT NT SS SS SS SD SD SD CP CP CP MP MP MP Foxtil Density (10 sq ft)
140 120 100 80 60 40 20 0 Lmbsqurters Densities NT NT NT SS SS SS SD SD SD CP CP CP MP MP MP Lmbsqrtrs Desnity (10 sq ft)
14 12 10 8 6 4 2 0 Wild Mustrd Densities NT NT NT SS SS SS SD SD SD CP CP CP MP MP MP Stnd Desnity (10 sq ft)
Summry of weed densities Foxtil is n ll-purpose weed. It hndles ll tillge systems well. Prefers rows in reduced tillge system. Lmbsqurters clerly prefers plowed soils, but lso cn be bundnt in reduced tillge. Wild mustrd is restricted to plowed soils.
Compring weed emergence 100 No Till - - Foxtil 75 Rel Emrg 50 Sunflower 25 Soyben Corn 0 28-My 7-Jun 17-Jun 27-Jun 7-Jul 17-Jul 100 Chisel Plow - - Foxtil 75 Rel Emrg 50 Sunflower 25 Soyben Corn 0 28-My 7-Jun 17-Jun 27-Jun 7-Jul 17-Jul
Foxtil Emergence (Unlike in crops, high is better. Weeds tht emerge slowly compete poorly with crops.) 30 Dys to 50% Emergence 25 20 15 10 5 b b bc c 0 NT SS SD CP MP
Lmbsqurters Emergence (Unlike in crops, high is better. Weeds tht emerge slowly compete poorly with crops.) 20 Dys to 50% Emergence 15 10 5 b b b c 0 NT SS SD CP MP
Weed Emergence (Unlike in crops, high is better. Weeds tht emerge slowly compete poorly with crops.) 25 Dys to 50% Emergence 20 15 b x Foxtil Lmbsqtrs y b y 10
Durtion 25-75% Emergence (dys) 14 12 10 8 6 4 2 0 Weed emergence durtion (Time between 25% & 75% emergence) b c d b Foxtil Lmbsqtrs NT SS SD CP MP b b c bc c c
Summry of weed emergence rtes Reduced tillge cuses delys in weed emergence. Delys lso seen in wheel-trck nd interrow res. Delyed weed emergence reduces cropweed competition. Short-durtion of weed emergence mkes weed control esier, but hrder if it is prolonged (foxtil in strip-till).
Overll Summry for Strip Till Strip-till effects on crop densities & emergence rtes re not unique. Strip-till impcts foxtil little, limits lmbsqurters, & elimintes mustrd. Strip-till delys & prolongs emergence of foxtil. Strip-till delys & shortens emergence of lmbsqurters. PRE grss herbicides re dvisble (e.g., Dul, Hrness/Surpss) fb POST herbicides, even in RR crops. ($10-$15 / A)