| Winter sprouting broccoli was grown in a two-year study in unheated high tunnels in Durham, NH. Eleven cultivars were grown in a 9.1 m by 18.2 m unheated high tunnel and evaluated for yield, duration of harvest, and number of days from seed to harvest. Secondary rowcover applications were also evaluated for effects on yield, duration of harvest, number of days from seed to harvest, and for their effects on air temperature at plant height. All cultivars were harvested between March and May of 2008 and 2009. Yields ranged from 0.6 to 1.4 kilograms per meter squared. While mortality was observed in uncovered plants, plants under secondary rowcover in unheated high tunnels survived outdoor temperatures as low as -28°C. Preliminary experiments were conducted to evaluate the effect of planting dates and to study low tunnel environments as alternatives to unheated high tunnels over winter. |
