TUTORIAL The agricultural activity, in a globalized and competitive market, demands for an effective permanence of the producer in such a huge field the use of all the tools which are available to obtain rewarding harvests, reducing costs, risks of contamination of the environment and the product s final quality. In order to achieve these goals it is necessary to know the factors that limit the development and yield. In this context, the knowledge of nutritional factors which are limiting the productivity, obtained by plant s foliar analysis, allows the establishment of rational fertilization programs, an agricultural practice which is a significant percentage of the production costs. Numerous fertilization experiments have been conducted in several agrosystems in order to establish the optimum doses of nutrients to be applied in the crops, using the analysis of the soil. Therefore, when the fertilizer recommendation is made in a given situation, it s considered that other factors responsible for the productivity are present at sufficient and non-excessive levels. However, as the relations between the various components of an agroecosystem are complex, particularly the interactions between soil and plant, the hypothesis that nutritional factors all become non-limiting after fertilization may prove to be optimistic. An economical and effective way to assess the nutritional status of the crops is to employ chemical analysis of plant tissue, comparing the results with pre-established standards from the productive plots. This is the objective of the programs "CND-Goiaba" and "CND-Manga", using the
concept CND (Compositional Nutrient Diagnosis), in other words, the diagnosis of the nutritional composition. The CND concept expresses the mineral composition of the plant tissues in the form of nutrient content or relative values, which is the basic numerical information to establish the diagnosis of nutritional status of the plants. The method employs the compositional analysis and principal component analysis of the data, and thus greater potential to improve the sensitivity of diagnosis of the analyzed culture. In order to facilitate the implementation of mathematical calculations and interpretation of results, it s been elaborated programs as "CND- Goiaba" and "CND-Manga", which received assistance from the Foundation for Research Support of the State of São Paulo - FAPESP, which may be used for both fruit. As an example for this tutorial it s been chosen CND-Goiaba, whose steps are as follows: 1 - The Software is best viewed in browsers "Google Chrome"; Mozilla Firefox ; Opera e Safari. 2 - Having in hands the chemical analysis of the leaves, transcribe the nutrient content in the corresponding fields. 3 - After filling in all fields, click on "CALCULAR".
If you want to correct the value of some field just click on "ALTERAR" and make the correction. After completing this analysis it is possible to perform a new analysis by clicking on "NOVO". 4 - After clicking on "CALCULAR" as shown in the hypothetical example of the image above, the balance index for each nutrient appears, and it s shown as well the CND-r², which represents the sample s nutritional imbalance index The graphics in form of radar / polar (left) and bars (right) represent the ratios calculated for each nutrient. In this example, may be interpreted that in relation to the population of high productivity, all in green color indexes are in 'excess', as phosphorus (P), Magnesium (Mg), and so on, and that every index which is in the red is 'disabled', such as nitrogen (N), Potassium (K), et cetera. On the other hand, it may be considered "suitable" that indexes tend to zero, such as calcium (Ca) and boron (B).
5 - After viewing the graphs the user is able to click on FORMULÁRIO, and fill in all fields deemed relevant to establish the history of the orchard, whose details are described in the image below. 6 Then it s possible to click on "RECEITA", to generate a diagnosis of nutritional composition, as indicated: 7 - The quote authored of the program is displayed in the footnote.
References CND-Goiaba Universidade Estadual Paulista Júlio de Mesquita Filho (São Paulo, Brasil); Université Laval (Ville de Québec, Canadá). Danilo Eduardo Rozane; William Natale; Léon Etienne Parent; Serge-Étienne Parent; Eduardo Maciel Haitzmann dos Santos. CND-Goiaba. BR5120130003792. 18 abr. 2013. CND-Manga Universidade Estadual Paulista Júlio de Mesquita Filho (São Paulo, Brasil); Université Laval (Ville de Québec, Canadá). Danilo Eduardo Rozane; William Natale; Léon Etienne Parent; Serge-Étienne Parent; Eduardo Maciel Haitzmann dos Santos. CND-Manga. BR5120130003806. 18 abr. 2013.