Abstract
`Green Mignonette', `Salinas', `Parris Island Cos', and `Amaral 400' lettuce (Lactuca sativa L.); `WR-55 Days' Chinese cabbage (Brassica rapa L. Pekinensis Group); Waianae Strain' green mustard cabbage [Brassica juncea (L.) Czerniak]; `Tastie Hybrid' head cabbage (Brassica oleracea L. Capitata Group); and an unnamed local selection of green bunching onions (Allium fistulosum L.) were field-grown during Fall 1987 and Spring 1988 at Waimanalo, Oahu, Hawaii, in full-sun and with four artificially produced levels of shade (30%, 47%, 63%, and 73%). Yields of cos lettuce, green mustard cabbage, and green bunching onions were irresponsive to shade or negatively affected by shade in both seasons. Yield responses of the other crops to shade varied seasonally. Optimum shading of 30% to 47% increased `Green Mignonette', `Salinas', and `Amaral 400' lettuce yields by 36% and head cabbage and Chinese cabbage yields by 23% and 21%, respectively, compared to full-sun plots in one or both seasons. Leaf areas similar to unshaded controls were maintained as shade intensity increased, while leaf dry weight decreased in all crops except `Salinas' and `Parris Island Cos' lettuce. Maximum rates of net photosynthesis (Pn) were attained at 1500 umol·s-1·m-2, which was about two-thirds of full sunlight.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the American Society for Horticultural Science
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
