Introduction. Leaf area is often related to plant growth, development, physiology and yield. Many non-destructive models have been proposed for leaf area estimation of several plant genotypes, demonstrating that leaf length, leaf width and leaf area are closely correlated. Thus, the objective of our study was to develop a reliable model for leaf area estimation from linear measurements of leaf dimensions for citrus genotypes. Materials and methods. Leaves of citrus genotypes were harvested, and their dimensions (length, width and area) were measured. Values of leaf area were regressed against length, width, the square of length, the square of width and the product (length × width). The most accurate equations, either linear or second-order polynomial, were regressed again with a new data set; then the most reliable equation was defined. Results and discussion. The first analysis showed that the variables length, width and the square of length gave better results in second-order polynomial equations, while the linear equations were more suitable and accurate when the width and the product (length × width) were used. When these equations were regressed with the new data set, the coefficient of determination (R2) and the agreement index ‘d’ were higher for the one that used the variable product (length × width), while the Mean Absolute Percentage Error was lower. Conclusion. The product of the simple leaf dimensions (length × width) can provide a reliable and simple non-destructive model for leaf area estimation across citrus genotypes.

Introduction. Alternative propagation techniques must be developed in order to reduce the time required to evaluate germplasm in citrus breeding programs. Our study investigated the rooting capacity and initial plant development of different citrus somatic hybrids that have potential for use as rootstocks. Materials and methods. Eleven different hybrids were tested. Cuttings of these plants were placed in trays inside an intermittent mist chamber. After 100 days, the percentage of cuttings with callous and with roots, average number of roots, and root length were recorded. The cuttings were then transferred to plastic bags and kept in the greenhouse. The flush length was recorded monthly. After 7 months, the percentage of plants suitable for grafting and the average scion and root dry mass were calculated. Results and discussion. [Caipira sweet orange + Cleopatra mandarin], [Caipira sweet orange + Volkamer lemon], [Rangpur lime + Sunki mandarin] and [Rohde Red Valencia sweet orange + Volkamer lemon] hybrids developed many roots, while [Caipira sweet orange + Volkamer lemon] and [Rohde Red Valencia sweet orange + Volkamer lemon] hybrids showed the best development after the transplant.