Skip to main content
ARS Home » Research » Publications at this Location » Publication #157940
Title: RESPONSE OF YOUNG CITRUS TREES ON SELECTED ROOTSTOCKS TO NITROGEN, PHOSPHORUS, AND POTASSIUM FERTILIZATION

Author
item MATTOS, JR, D - IAC, BRAZIL
item QUAGGIO, J - IAC, BRAZIL
item CANTARELLA, H - IAC, BRAZIL
item Alva, Ashok
item GRAETZ, D - UNIV FLORIDA,GAINESVILLE

Submitted to: Journal of Plant Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2005
Publication Date: 6/1/2006
Citation: Mattos, Jr, D., Quaggio, J.A., Cantarella, H., Alva, A.K., Graetz, D.A. 2006. Response of young citrus trees on selected rootstocks to nitrogen, phosphorus, and potassium fertilization. Journal of Plant Nutrition. 29: 1371-1385, 2006.

Interpretive Summary: Rangpur lime was the major rootstock in the Brazilian citrus industry in the past, however, recently other rootstocks have gained increased prominence. This study was conducted to evaluate the response to N, P, and K fertilization by citrus trees grafted on Rangpur lime (RL), Swingelo citrumelo (SC), and Cleopatra mandarin (CM) rootstocks. The response was evaluated based on tree growth, leaf nutrient status, as well as fruit yield of early bearing years. The results showed that the nutrient uptake efficiency was greater for the trees on RL rootstock compared to those on either SC or CM rootstocks. Fruit yield levels (during the early bearing years) were greater for the trees on CM or SC rootstock as compared to those on RL rootstock. Maximum fruit yields of the trees on the former rootstocks were obtained at rates of nutrients much greater than those currently recomended. Thus, the results suggested the need to modify the current nutrient recommendatioin in order to optimize the yield goals and to maximize the nutrient uptake efficiency.

Technical Abstract: The majority of the citriculture in Brazil is located in the state of Sao Paulo with a total production area of 700 thousand ha. Trees are mostly grafted on 'Rangpur lime' (RL; Citrus limonia Osb.) rootstock. Despite its good horticultural performance, use of other rootstock has increased with search for disease tolerant varieties to improve grove productivity and longevity. Furthermore, there is a lack of information on young tree response to fertilization, and optimal nutrient requirement of different scion/rootstock combinations for maximum fruit yield. A network of field experiments was conducted to study the differential response of young sweet orange trees on selected rootstocks to N, P, and K fertilization. The application of soil and leaf analyses to develop optimal fertilizer recommendations was evaluated. Experiments were conducted in three locations using fractional factorial design of 1/2 (4x4x4) type with four rates of N, P, or K calculated to be applied for five years after tree planting. Fruit yield response was evaluated during the last two years and correlated with soil and leaf analyses data. The trees on RL rootstock demonstrated increased efficiency of nutrient uptake compared to those on 'Cleopatra' mandarin (CL; C. reshni hort. ex Tanaka) or 'Swingelo' citrumelo [SW;Poncirus trifoliata (L.) Raf.xC. xparadisi Macf.] rootstocks. The trees on SW rootstock appeared to require greater N and K rates than those on RL rootstock. Phosphorus requirement was greater for 'Natal' or 'Valencia' trees on SW than on RL rootstock. These results will become the basis to revise current fertilizer recommendation guidelines for young trees in Brazil.