IPM Guidelines for Sweet Corn
by Ruth V. Hazzard, John C. Howell, A. Richard Bonanno, David N. Ferro,
and Craig S. Hollingsworth
Soil Nutrient Management and Cultural Practices
Cultural practices may be of value in management of nutrients, weeds, diseases, and/or insects. The goal of a sound fertility program is to supply adequate nutrients with optimum timing for maximum economical crop yield, while avoiding excesses that can degrade water quality or adversely affect crop or soil quality.
1. All corn stalks are turned under or harrowed promptly after harvest. 15 pts
2. Crop rotation is practiced, as follows:
a. At least 25 % of sweet corn acreage was not planted to corn the previous year. 5 pts
OR
b. At least 50 % of sweet corn acreage was not planted to corn the previous year. 10 pts
3. Fields have been evaluated with an appropriate soil test for nutrient status and pH for the current year. 10 pts
4. Organic matter status has been tested within three years. 10 pts
5. Fertilizer is applied in accordance with current soil test results and expected uptake of nutrients and expected crop yield, giving credit for nitrogen supplied by organic matter, compost, manure and cover crops. Expected nutrient uptake is determined from the New England Vegetable Management Guide. 15 pts
6. Nitrogen fertilizer is applied by split application. Twenty to 40 lb/acre is applied in a band at planting, and some as a side dress, as needed. 15 pts
7. If fertilizer is applied at planting, the total of nitrogen plus potassium in the band does not exceed 80-100 lb/acre to avoid crop burning. *5 pts
8. A pre-sidedress nitrate test is taken. Nitrogen applied at side-dress conforms to test results. 10 pts
9. This year's crop was preceded by a winter cover crop. 10 pts
10. If the cover crop was a legume or legume/grass mix, its nitrogen contribution is calculated and fertilizer for this year's crop is adjusted appropriately. *10 pts
11. If compost or manure is applied, its nitrogen contribution is calculated, and fertilizer application reduced accordingly. *5 pts
12. A trial plot is maintained to test organic sources of nutrients (e.g., compost, legume cover crops, or soil organic matter), reduced rates of fertilizer, or use of the pre-sidedress nitrate test to determine rates of sidedressed N. The methods and results are recorded. Bonus: 10 pts
Category Total 115 pts
Adjusted Total ______ pts
Pesticides Application and Records
Only pesticides approved and registered for sweet corn in the state are used. Records of pesticide applications are maintained, including date, field and block, target pest, crop stage pesticide name and EPA number, formulation, rate and number of acres treated. Pesticide drift is minimized. Re-entry and pre-harvest intervals are adhered to.
1. Pesticide application equipment is calibrated at the start of the season and the procedure is recorded. 10 pts
2. Calibration is checked at least once during the season and equipment is re-calibrated as needed. 5 pts
3. A boom sprayer with double drop nozzles is used where coverage of the ear zone is desirable. 15 pts
OR
If mist blower is used for coverage of the ear zone, blocks are not greater than 12 rows wide. 10 pts
4. Records of planting date, harvest date, and cultivars in each block are maintained and organized. 5 pts
5. Pesticide coverage of tassel and ear zone has been field tested across all rows in the block with water sensitive spray cards within the past five years, using the current spray equipment. 10 pts
Category Total 45 pts
Adjusted Total ______ pts
Insect Management
1. Pheromone traps are used to monitor corn earworm (CEW) flight, as specified in state sweet corn IPM publication. Moth counts are recorded at least weekly. 20 pts
2. Two pheromone traps/farm are used to monitor European corn borer (ECB) flight, as specified in state sweet corn IPM publication. Moth counts are recorded weekly. 10 pts
3. Pheromone traps are used to monitor fall armyworm (FAW) flight, as specified in state sweet corn IPM publication. Moth counts are recorded weekly. 10 pts
4. Fields are monitored for infestation with ECB or FAW, at the appropriate crop stage and when traps indicate flight activity, by examining 50-100 plants for larvae. 15 pts
5. Application of insecticides for ECB and FAW correspond to state-specified thresholds (15% of plants infested with ECB and/or FAW). 15 pts
6. Application of insecticides for CEW correspond to state-specified thresholds and spray intervals, based upon pheromone trap counts. 15 pts
7. Occasional pests for which thresholds are not available (e.g., aphids, sap beetles, flea beetles), are treated only after scouting. Scouting results are recorded. 10 pts
8. Floating row covers are used in early corn to reduce ECB infestations. Bonus: 10 pts
9. Insect pests are kept below economic injury level using biologically based or other non-chemical methods, such as microbial insecticides or beneficial insects, in at least 10% of the sweet corn acreage. 10 pts
10. If transgenic-Bt sweet corn is used, at least 25% of acreage is planted to non-transgenic corn, to reduce risk of resistance to Bt. *10 pts
Category Total 115 pts
Adjusted Total ______ pts
Disease Management
The two major diseases are maize dwarf mosaic virus and Stewart's wilt, which is vectored by flea beetle.
1. If there is a field history of maize dwarf mosaic virus (MDMV), disease resistant cultivars are planted in late plantings. *5 pts
2. If plants are observed with MDMV symptoms, they are submitted for confirmation. *5 pts
3. If there is a history of Stewart's wilt disease on the farm, and mild winter conditions should allow high survival of flea beetles, tolerant cultivars are planted in early plantings. *10 pts
4. If there is a history of Stewart's will disease on the farm and susceptible cultivars are grown, flea beetles are monitored and insecticide applications made only after numbers reach state-specified thresholds. *5 pts
Category Total 25 pts
Adjusted Total ______ pts
Weed Management
1. This year's fields were scouted for weeds last year at mid- to late season. Weeds present were identified, and field locations recorded. This information was used in the current weed management program. 10 pts
2. Weed management includes one of the following:
a. Weeds are controlled by cultivation, with no herbicide applied. 20 pts
OR
b. Herbicide rates are reduced through banding of herbicides and cultivation. 15 pts
OR
c. Herbicide use is reduced through delayed application of reduced rates
of herbicide. 15 pts
OR
d. Herbicide is supplemented with at least one cultivation or hand weeding. 5 pts
3. Weeds in field, alleys and roadways are prevented from going to seed. 10 pts
4. Fields are scouted in midseason for weeds. Location and species of uncontrolled weeds are mapped and the information is used in planning for next year. 10 pts
5. Outbreaks of new or problem weed species are controlled, using chemical or non-chemical means, to prevent spreading or seed production. 10 pts
6. A trial plot is maintained to test a different weed management technique. The methods and results are recorded. Bonus: 10 pts
Category Total 60 pts
Adjusted Total ______ pts
Education
1. Manager possesses a copy of the current New England Vegetable Management Guide. 5 pts
2. Manager attends one or more state, regional or national Extension vegetable workshops during the current year. 5 pts
3. Manager subscribes to the UMass Extension Vegetable Notes & IPM Message. 5 pts
Category Total 15 ptsPoints
Adjusted Total ______ pts
Grand Total 375 pts
Adjusted Grand Total ______ pts
Percentage of adjusted total %
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