The results show that the culture of the melon in hydroponic medium using different substrates, and increasing concentration of NaCl salts, indicated that when the electrical conductivity (EC) levels increases as 2.0; 5.0; 8.0 and 11.0 dS.m -1 , the melon growth was higher by 2.88 cm per day, with EC of 2 Sm -1 . Thereafter, decreases the growth rate of melon as 2.33, 1.77 and 1.23 cm per day, when EC's goes from 5, 8 and 11 dS.m-1, respectively. In addition, the substrates sand, coconut, respectively presented a growth rate of 2.33; 1.77 and 1.23 cm per day. The increase in salt concentration in the solution negatively influenced the morphology and color of the melon leaves. The substrates washed sand, coconut powder and Basaplant presented no significant difference in the effects on the melon culture. The substrate type did not influence the effect of the salt on the melon.

The melon plant is one of the plants with agronomic potential adult among the vegetables, for presenting high productivity in a short time. In Brazil the main producing areas are located in the owed semiarid the favourable conditions of climate for the culture, however, that area presents some factors limitations, mainly as the salinity of the soil and of the water, what carts in the decrease in the productivity and in certain cases total loss of the cultivation. The objective of that work was to accomplish a growth analysis in cycles of melon plant selection developed in a saline environment. The experiment was executed from March to May of 2017 in the Federal University of Alagoas. The appraised treatments were six cycles of melon plant (C1, C2, C3, C4, C5a and C5b) selection. The used design was in randomized complete block design in subdivided portions, being the six selection cycles the portions and the six evaluations biometrics in the time the subplots, with four repetitions. The subplots were divided into two stages in agreement with the presence of the characteristic in the vegetative stage of the plant, in that were appraised vegetative and reproductive variables. Variance analysis and test were accomplished from Tukey to 5% of probability, besides the obtaining of the earnings for selection. To determine the variable of larger importance the technique of main components it was used. Among the cycles C1 and C5a there was an increase of 15,89% of the number of leaves, that is due mainly for the small ones won to each election cycle. The selection cycles accomplished in the melon plant population promoted a small reduction in the percentile of matter dries to each selection cycle, not presenting significant difference among the cycles, with averages of 13,92; 13,10; 13.05; 12,62; 11,94 and 12,28%, respectively for the cycles C1, C2, C3, C4, C5a and C5b. NL and NFB explain about 85% of the total variation found among the selection cycles. NL presented the largest importance in the vectors and it presented correlation with several characteristics, like LMS (0.99), LSS (0.90), NBFF (0.80) and % MSPA (0.91). The selection cycles presented genetic progress as the tolerance the salinity. The number of leaves is the characteristic to be selected for obtaining of tolerant superior genotypes the salinity.

The objective of this work was to evaluate the diversity between accessions of Cucurbita moschata from the Northeast of Brazil and preserved at the Universidade Federal Rural do Semi-Árido (UFERSA) in Mossoró-RN. The experiment was carried out in complete randomized blocks, with two replications and three plants per plot. The treatments consisted of 51 accessions of C. moschata Duch and a commercial cultivar of Cucurbita maximum Duch. After ripening, the fruits were harvested (one fruit per plant) and evaluated for morpho-agronomic descriptors. Univariate and multivariate variance analyzes were performed. From the dissimilarity matrices, accessions were hierarchically grouped by the UPGMA method. The relative contribution of quantitative characters to the divergence was also estimated. There was an effect of accessions (p <0.01 or p <0.05) for all characters in univariate analyzes, indicating that there is heterogeneity between the accessions evaluated. Considering the quantitative descriptors, the accessions formed eight groups and for the qualitative six groups. When considering the two sets of descriptors, the accessions were distributed in eight groups but presenting a greater distribution of accessions. The descriptors that most contributed to the discrimination of accessions were the firmness of the pulp and the length of the fruit.

The genus Cucurbita has been mentioned as a good source of carotenoids, including β-carotene, which is a precursor of vitamin A. However, the variability observed for the genus denotes the individual need to invest in the species. An experiment was carried out with the aim of evaluating the content of total carotenoids and β-carotene in C. maxima germplasm. Treatments consisted of 23 accessions and two commercial cultivars of C. maxima. The content of total carotenoids, β-carotene, and the pulp color of the accessions were evaluated. Clustering was performed, and the components of genotypic variance, mean heritability, and accuracy were calculated. The grouping led to the formation of four groups where the total carotenoid content influenced the formation the most. There was no difference in color parameters. High variability was observed for total carotenoids in the studied genotypes (22.28 µg/g to 49.58 µg/g) and β-carotene (7.81 µg/g to 13.75 µg/g). Accessions CMAX-09, CMAX-10, CMAX-12, CMAX-13, and CMAX-14 showed the highest levels of total carotenoids and β-carotene.

This work aimed at estimating the genetic divergence between luffa accessions (Luffa cylindrica (L.) M. J. Roem) by means of multivariate analysis techniques and at verifying the importance of the assessed traits for the study of genetic divergence. Two trials were carried out in the municipality of Mossoró, in the state of Rio Grande do Norte, Brazil. The trials were carried out in incomplete block design, comprising two experiments in completely randomised blocks with four regular treatments and two treatments common to both experiments, amounting to a number of ten Original Research Article

Lettuce is the hardwood vegetable that presents the greatest increase of consumption in Brazil, and therefore the most important for local horticulture. Because the intensity of cultivation, and the large area planting, some problems have worsened, especially issues related to pathogens such as nematodes of the species Meloidogyne incognita, which penetrate to the root AND CAUSING reduction in productivity. Existing cultivars on the market have more or less able to tolerate the nematodes attack, depending on growing conditions and climate conditions which are subject. In addition to these factors, the actual population of nematodes is a determining factor to harm the yield of lettuce.

The objective of this study was to evaluate genetic divergence among cowpea genotypes and to select parents for crosses aimed at the fresh pod and grain market. Two experiments were carried out during 2014, corresponding to two sowing times, in the municipality of Mossoró, State of Rio Grande do Norte. Twenty-three cowpea genotypes were evaluated in a randomized complete block design with four replicates. Fifteen descriptors were used to quantify divergence, using the Mahalanobis distance as a measure of dissimilarity, obtained from the genotypic mean predicted by the Restricted Maximum Likelihood/Best Linear Unbiased Prediction (REML/BLUP) method. The Unweighted Pair Group Method with Arithmetic Mean (UPGMA) hierarchical method was used to group genotypes and the Singh criterion to quantify the contribution of traits to genetic divergence. The genotype × environment interaction (G × E) influenced divergence, both in the contribution of traits and in the grouping of genotypes. In the experiment 1, the genotypes were distributed among four groups. In the experiment 2, less discrimination occurred and the genotypes were represented by only two groups. When joint analysis of two evaluations was carried out based on two sowing times, genotypes were represented by six groups. The G × E interaction influences the contribution of traits and the grouping of cowpea genotypes in the study of divergence. The genetic divergence of the set of cowpea genotypes evaluated is mainly due to green grain and pod yield. BRS Aracê and BRS Xiquexique cultivars are the most divergent among the genotypes studied, representing 75% of the recommended crosses.