Effects of Post-anthesis Detasseling on Sweet Corn Yield

Prevention of bird damage to maturing sweet corn ears has become a major challenge for peri-urban vegetable producers in New England. The primary pests are large flocks of starlings, grackels, blackbirds, and crows. Propane cannons are the most common control method, as they are easily moved between planting blocks of sweet corn and require minimal labor. However, the cannons are extremely unpopular with non-farm neighbors, due to the incessant noise. Anecdotal reports and unreplicated on-farm trials have suggested that bird damage to maturing sweet corn ears can be reduced or eliminated if the tassels and upper leaves are removed after pollination. Sweet corn grown for processing in the Willamette Valley of Oregon is routinely detasseled after pollination to speed maturity and reduce lodging of plants following heavy rains. Detasseling does not affect yields of the standard processing cultivar, Jubilee, but it has been reported to reduce yields of other cultivars. Growers may be willing to adopt detasseling if it prevents bird damage without negative effects to sweet corn yields or quality, but they are unlikely to accept the added costs of detasseling if the practice also reduces marketable yields. The objective of this study was to determine how detasseling affects the fresh market sweet corn cultivars popular with growers in southern New England.

Sixty cultivars, blocked by market class and maturity date, were planted in four replications in the Summer of 2015 at the Gardiner Crops Research Farm in Kingston, RI. Tassels were removed from half the plants in each plot by cutting the stalk two nodes above the top ear 5 to 7 days after silking. Corn was harvested by hand from each subplot, and data were collected on yield. Detasseling significantly reduced yield. By weight yields from detasseled plants were only 85% of the control yields, and number of marketable ears was only 89% of the control. Effects were consistent across all cultivars. Detasseling also significantly increased the incidences of poor tip fill and incomplete pollination, with the supersweet cultivars being more strongly affected. Detasseling does not appear to be a viable alternative to propane cannons for preventing bird damage, as it would increase costs while decreasing yields on a crop with low profit margins.