Location: Chemistry ResearchTitle: The Florida citrus soil water atmosphere plant (SWAP) project: final summary of cumulative yields and tree health Author
|Allen, Leon - Retired Ars Employee|
|Calvert, David - Retired Non Ars Employee|
|Cohen, Mortimer - Retired Non Ars Employee|
|Pelosi, Robert - Retired Non Ars Employee|
|Rogers, James - Retired Ars Employee|
|Stewart, Ernest - Retired Ars Employee|
Submitted to: Proceedings of Florida State Horticultural Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2014
Publication Date: 12/31/2014
Citation: Allen, L.H., Calvert, D.V., Cohen, M., Pelosi, R.R., Rogers, J.S., Stewart, E.H. 2014. The Florida citrus soil water atmosphere plant (SWAP) project: final summary of cumulative yields and tree health. Proceedings of Florida State Horticultural Society. 127:45-52. Interpretive Summary: Citrus trees on high water table soils of the Indian River region of Florida require special drainage and soil water management. Soils are sandy with low water and nutrient holding capacity, and have restrictive layers in the profile. Subsurface drains tend to clog. Therefore, a Soil Water Atmosphere Plant (SWAP) Project study of citrus production on deep tilled soils with two types of subsurface drains was undertaken at Fort Pierce, Florida. ARS scientists in Florida and University of Florida scientists summarized 12 years of fruit yields on six rootstocks on three soil mixing conditions and two types of subsurface drains. Deep mixing and submerged-outlet drains did not increase fruit yields compared to shallow tillage and open-outlet drains. However, by year 12, cumulative yields of Pineapple orange were ranked high for rootstocks of Rough lemon, Rangpur lime, and Cleopatra mandarin, intermediate for Sour orange and Carrizo citrange, and lowest for Poncirus trifoliata. Tree health rakings by rootstock were: Cleopatra mandarin, Rangpur lime, Sour orange, Rough lemon, Carrizo citrange, and Poncirus trifoliata. Sour orange showed the most tristeza disease, Rough lemon showed the most blight, Rangpur lime showed the most foot rot, and Carrizo citrange and Poncirus trifoliata showed the most water damage.
Technical Abstract: The Florida Citrus Soil Water Atmosphere Plant (SWAP) Project at the Fort Pierce had three blocks each of soil tillage treatments of shallow tilled (ST), deep tilled (DT), and deep tilled plus lime (DTL) on a Spodosol (Oldsmar fine sandy loam). Each block had three adjacent submerged subsurface plastic drains and three adjacent open drains. Pineapple orange and Marsh grapefruit scions on six rootstocks were transplanted in November 1970. Yields are reported from 1973-74 to 1984-85 by scion, rootstock, tillage treatment, and subsurface drain type. By the last harvest, cumulative yields of Pineapple orange were greatest for rootstocks of Rough lemon, Rangpur lime, and Cleopatra mandarin, intermediate for Sour orange and Carrizo citrange, and least for Poncirus trifoliata. Ratings of tree health were made in November 1984. Major trends were: (i) the number of healthy trees continued to decrease; (ii) the number of trees with citrus blight symptoms continued to increase, especially on Rough lemon rootstock; (iii) trees on the Cleopatra mandarin rootstock continued to be the healthiest; and (iv) Carrizo citrange and Poncirus trifoliata rootstocks showed the most water damage.