Copper Sources in Citrus Seedlings Production.

Copper sources in citrus seedlings production

Tatiana P.A. Merlin ⁽¹⁾; Sarita Leonel ⁽¹⁾

⁽¹⁾São Paulo State University, Crop Sciences College, Dep. of Crop Science.    

             CEP 18603-970 - Botucatu, São Paulo, Brazil. trpdalmeida@hotmail.com Tel +55 14 3811 7172.

In order to detect the best supply of copper to citrus seedlings, an experiment was carried out in a commercial nursery in the city of Botucatu, SP, Brazil. Commercial substrate of coconut fiber and five treatments were used: 1-control; 2-cupric oxychloride (1,8g L^-1); 3-cuprous oxide (3 mL L^-1); 4-chelated copper (0,04 mL L^-1) and 5-copper sulphate (2,5 g L^-1). The experiment was installed in July 2006 with the sowing of ‘Rangpur’ lime (Citrus limonia Osbeck) rootstock. After eight months, the plants were grafted with 'Valencia' orange (Citrus sinensis L. Osbeck). Monthly evaluations were made for plant height (cm), diameter of rootstock (mm) and dry matter of leaves and root (g). The statistical design was randomized blocks with five treatments and six replications. Each plot consisted of twenty plants. It was observed that the parameters analyzed for the copper-based treatments were not significant but it was possible to verify that treatment 3 (cuprous oxide) gave better plant growth followed by treatment 4 (chelated copper). As to copper content in leaves, although the concentrations obtained found were higher than indicated as excessive the plants did not show any abnormal symptoms, having a normal growth.

Keywords: copper, Citrus sinensis L. Osbeck, coconut fiber substrate