Black polyethylene tunnel covers affect plant production and quality of sweetpotato transplants

The influence of a black polyethylene tunnel cover (BTC) was evaluated for its effect on quantity and quality of sweetpotato [Ipomoea batatas (L.) Lam .] transplants in plant beds In Louisiana and North Carolina. Use of ETC in creased production of 'Beauregard' transplants from 63% to 553% in comparis on with the bare ground control, 'Jewel' was less responsive; ETC treatment s increased transplant production by at least 48% in Louisiana over the bar e ground control, but no increase was observed in North Carolina. Individua l transplant weight was at least 34% less in ETC treatments than in the con trol. The first harvest of cuttings in ETC beds was at least 14 days prior to that in control beds. Transplant quality was assessed as yield of storag e roots in repeated trials that extended throughout the normal growing seas on. Yield of storage roots was not affected by ETC in early season planting s, but was frequently lower for ETC treatment transplants in middle and lat e season plantings. We therefore do not recommend this method as a means of increasing sweetpotato plant production front bedded roots.