Sweetcorn
These guidelines are based on those developed by R.V. Hazzard, J.C. Howell, A.R. Bonanno, D.N. Ferro & C.S. Hollingsworth, published in C.S. Hollingsworth & W.M. Coli (eds). 1999. Massachusetts Integrated Pest Management Guidelines: Crop Specific Definitions. University of Massachusetts Extension Publication IP-IPMA.
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Soil Nutrient Management and Cultural Practices
- Crop rotation is practiced, as follows:
a. At least 50% of sweet corn acreage was not planted to corn the previous year.
OR
b. At least 25% of sweet corn acreage was not planted to corn the previous year.
15 pts - Fields have been evaluated with an appropriate soil test for nutrient status and pH for the current year. 10 pts
- Organic matter status has been tested within three years 10 pts
- 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
- 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
- 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
- A pre-sidedress nitrate test is taken. Nitrogen applied at side-dress conforms to test results. 10 pts
- This year's crop was preceded by a winter cover crop. 10 pts
- 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
- If compost or manure is applied, its nitrogen contribution is calculated, and fertilizer application reduced accordingly. 5 pts
- Crop is planted into previous cover crop residue without tillage (no-till or strip till). 10 pts
- Corn transplants are used to avoid seed and seedling pests and to improve stand establishment 10 pts
Category Total 120 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. Win-PST analysis is conducted for all pesticides considered for use on the farm.
- Pesticides with a LOW or VERY LOW environmental hazard (Win-PST) are used for one or more key pests 20 pts
- Spray equipment, including hoses, nozzles and pumps, is inspected at least once per season and replaced as needed. Equipment is calibrated at the start of the season and the procedure is recorded. 10 pts
- Calibration is checked at least once during the season and equipment is recalibrated as needed. 5 pts
- A boom sprayer with double drop nozzles is used where coverage of the ear zone is desirable. 5 pts
OR
A boom sprayer without drop nozzles is used
OR
If mist blower is used for coverage of the ear zone, blocks are not greater than 12 rows wide. 5 pts - Records of planting date, harvest date, and cultivars in each block are maintained and organized. 5 pts
- 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 65 pts
Adjusted Total ______ pts
Insect Management
- ECB populations are reduced by disking after harvest, planting a fall cover crop and spring plowing. 10 pts
- 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
- Application of insecticides for CEW correspond to state-specified thresholds and spray intervals, based upon pheromone trap counts. 15 pts
- 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
- 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
- Fields are monitored for infestation with ECB at the appropriate crop stage and when traps indicate flight activity, by examining 50-100 plants for larvae. Application of insecticides corresponds to state-specified thresholds. 15 pts
- Fields are monitored for infestation with FAW, at the appropriate crop stage and when traps indicate flight activity, by examining 50-100 plants for larvae. Application of insecticides corresponds to state-specified thresholds. 15 pts
- 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
- Floating row covers are used in early corn to reduce ECB infestations. 10 pts
- Insect pests are kept below economic injury levels using biologically based or other non- chemical methods, such as microbial insecticides in at least 10% of the sweet corn acreage *10 pts
- Beneficial insects are released for suppression of a key pest (e.g. Trichogramma ostrinia for ECB). 10 pts
- 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 145 pts
Adjusted Total ______ pts
Disease Management
The two major diseases are maize dwarf mosaic virus, which is vectored by aphids, and Stewart's wilt, vectored by flea beetle. Disease incidence can be reduced by selecting well-drained fields, minimizing mechanical injury, avoiding excessive nitrogen and by controlling insect vectors.
- If there is a field history of maize dwarf mosaic virus (MDMV), disease
resistant
cultivars are planted in late plantings. *5 pts - If plants are observed with MDMV symptoms, they are submitted for confirmation. *5 pts
- 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 - 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
- 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 - Weed management includes one of the following:
- Weeds are controlled by cultivation, with no herbicide applied. 20 pts
- Herbicide rates are reduced through banding of herbicides and cultivation. 15 pts
- Herbicide use is reduced through delayed application of reduced
rates
of herbicide. 15 pts - Herbicide is supplemented with at least one cultivation or hand weeding. 5 pts
- Weeds in field, alleys and roadways are prevented from going to seed. 10 pts
- 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 - Outbreaks of new or problem weed species are controlled, using chemical
or
non-chemical means, to prevent spreading or seed production. 10 pts - 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
- Manager subscribes to the UMass Extension Vegetable Notes & IPM Message. 5 pts
Category Total 5 pts
Adjusted Total ______ pts
Grand Total 430 pts
Adjusted Grand Total ______ pts
Percentage of adjusted total %
