Cereal Rye Cover Crop for Control of Onion Grasses (Allium spp.)

Cereal Rye Cover Crop for Control of Onion Grasses (Allium spp.)

Summary

Biological control of wild onion and wild garlic pests improves sale prices, increases crop yields and reduces chemical dependency.

Objectives: 1) To introduce a cover crop into the standard corn-soybean rotation that will improve our crop management without impacting farm operations or reducing profit, 2) to test the competitive and allelepathic effect of cereal rye, at two different seed rates, on wild onion and wild garlic grasses, and 3) to monitor soil nutrient levels before, during and after the cover crop.

The producer broadcasted three one-and-one-half acre plots in three locations: one plot at each location sown at the recommended seed rate of two bushels per acre, one at four bushels per acre and one left as a control. At the time, onion grass species were established in the corn stubble.

In the spring, the producer bush-hogged the rye at the flowering stage and left it to mulch for 30 days, at which time he no-tilled soybeans into the field.

Results: At the first location, overly planted rye fields decreased wild onion populations. Control plot: three to nine wild onion plants per square yard. Plot sown at the recommended rate: two to seven plants per square yard. Plot sown at four bushels per acre: zero to two plants per square yard.

At the second location, planting of rye did not have any impact on wild onion populations. Control plot: five to nine wild onion plants per square yard. Plot sown at the recommended rate: three to eight plants per square yard. Plot sown at four bushels per acre: one to eight plants per square yard.

At the third location, rye decreased wild onion populations but not at the rate of the first location. Control plot: 20 to 32 wild onion plants per square yard. Plot sown at the recommended rate: 13 to 27 plants per square yard. Plot sown at four bushels per acre: seven to 14 plants per square yard.