This work was conducted in order to evaluate the procedures for analysis of nodule development through non-destructive and destructive methods in the same plant set. A greenhouse experiment was carried out with cowpea grain legume. Plants were weekly measured, from seven days old to physiological maturity, for evaluation of plant height and leaf area, and to obtain digitized images of all the visible part of the rooting systems. Weekly, a plant was also collected from each block for destructive determination of plant and nodule development.Nodules area, length and diameter were measured for those hand-separated from the root system and for those visible on the vessels side. For area, length and diameter of the nodules, initially a escriptive analysis was conducted in each point and next it was determined the average, median, maximum, minimum and the sum for each variable. Both variables, leaf area and plant height, were studied by regression analysis being considered as dependent variables and plant age as independent variable. Independent regressions were conducted for data obtained through the traditional destructive methods. Results have indicated a general concordance for development curves obtained by destructive and non-destructive methods, especially regarding nodule appearing and age in which the maximum value for each variable was found.

The objective of this work was to evaluate the effect of four nitrogen sources (ammonium sulfate, calcium nitrate, urea and monoammonium phosphate) at 80 kg ha-1, applied 2, 3, 4 and 5 times through drip irrigation on the production and characteristics of the melon, under field conditions, at the Cajazeiras Agricultural Farm, located in Tibau, RN, Brazil. The experiment was carried out in a completely randomized block design, in a 4 x 4 factorial scheme, with four replications. The melon yield was measured considering total number and weight of the fruits, the number of marketable fruits per hectare and size of the fruits. Generally speaking, the results showed that melon plants presented similar response to all used nitrogen sources, notably to the MAP applied three times; that the number of nitrogen applications did not affected the evaluated parameters regarding production and quality of fruits; and that the used nitrogen sources and the application number of the fertilizers resulted in higher amount of types 6, 7 and 8 fruits (fruits with average size).