Absorption and transport of boron in citrus

Abstract

Boron (B) is a micronutrient that limits the production of citrus in Brazil by the low levels in the soil parent material and the interactions that occur on the colloidal matrix. The distribution and concentration of this element in plant leaves varies depending on rootstock varieties, given probably characteristics of roots and water transport in the plant. Furthermore, the increased supply of B to citrus can lead to increased absorption of potassium (K) by the roots, which would explain observed differences on the nutritional status of plants in the field. The objective of the present proposal is to evaluate the effects of the availability of B to plants on the development of anatomic structures of young Orange trees on two rootstocks and correlate absorption and partition of 10B with plant developing and estimates of the water transpired by plants. Also, assess whether a correlation exists between B and K absorption and activity of ATPase in the roots of two rootstocks. Three experiments will be developed under controlled conditions of greenhouses. The results of this project will assist in the characterization of citrus varietal differences for the absorption, use of B, and nutritional status of plants, and consequently for the establishment of nutrient management recommendations of the citrus orchards. (AU)