-watered conditions, in which seedlings were growing in half-strength Hoagland solution and 2) PEG-induced drought conditions, in which seedlings were growing in half-strength Hoagland solution plus PEG 6000 (30%; Beijing Kebaiao, Beijing, China). Water potential of
Thanks to Christina Gigliotti, Peg Pecora, and Kathy Anderson for their assistance with this project.
. Two hundred fifty milligrams of seeds of one cultivar were placed in one cell. Each plate was floated in PEG-6000 (VWR International, Batavia, IL) solutions at 0.0 MPa [0% PEG-6000 (control, nonstressed)], −0.3 MPa (15% PEG-6000), or −0.6 MPa (22
Hardiness Zone ratings. Each of the five ingredients in our spray was chosen for its specific mode of action in hypothetically improving resistance to cold in plant tissues. In animals and insects, polyols like polyethylene glycol (PEG) appear to enhance
) with 10 mL of a polyethylene glycol [PEG (PEG 8000, Sigma-Aldrich, St. Louis, MO)] solution at ψ S of −1.25 MPa and then sealed with laboratory film (parafilm M; Bemis Flexible Packaging, Neenah, WI). The PEG concentration was calculated according to
was pegged at each corner to minimize wind interference. Land preparation and maintenance practices Experimental plots were manually prepared (common practice used by growers in the region) to ≈30-cm depth with final preparation using a fine tooth rake
://water.epa.gov/aboutow/upload/71issue.pdf >. Verhagen, F.J.M. Hageman, P.E.G. Woldendorp, J.W. Laanbroek, H.J. 1994 Competition for ammonium between nitrifying bacteria and plant roots in soil pots: Effects of grazing flagellates and fertilization Soil Biol. Biochem. 26 89 96
L·h −1 ). Capillary tubing (3 mm i.d.) cut to a 48-cm length was placed onto emitters and was supported by stabilizer pegs to deliver the nutrient solution to each plant. The irrigation frequency was once every 15 to 30 min from 0600 to 1700 or 1800