One way to reduce mineral fertilizers is to use alternative fertilizers instead, such as the byproducts from the food industry. In the present study we evaluated the effects of sugarcane bagasse ash on the physiology, growth, and development of sunflowers (Helianthus annuus L.). We conducted an experiment in a greenhouse using a completely randomized design with two sunflower cultivars (Multissol and Catissol), five sugarcane bagasse ash doses (0.0, 3.125, 4.687, 6.25, and 7.812 mg ha-1), and 5 replicates. At 85 days after planting we determined the plant height; leaf number; stem diameter; internal and external diameter of the flower chapter; leaf area index; shoot dry weight; net assimilation rate; dry mass production rate; relative and absolute growth rate; extravasation of electrolytes; relative water content; photosynthetic pigments (chlorophyll a, b, carotenoids, and the chlorophyll a/b ratio); and soluble carbohydrates, proteins, and proline. The height, number of leaves, and shoot dry mass increased due to the availability of nutrients contained in the ash. The incorporation of ash into the soil increased the photosynthetic activity (chlorophyll a and b) of both sunflower cultivars. The diameter of the stem, leaf area index, and relative growth rate of both sunflower cultivars increased with increasing ash dose. Therefore, the ash can be used as an alternative fertilizer, complementing or replacing mineral fertilizers.

Grafting is an effective method for pathogen control in various crops and improved several plant and fruit characteristics. This technique has been successfully adopted in melon cultivation, particularly using rootstocks resistant to multiple diseases. The objective of this study was to evaluate the compatibility of melon scions with rootstocks resistant to Stagonosporopsis cucurbitacearum, Meloidogyne incognita, M. javanica, and M. enterolobii, and to assess the effects of grafting on rootstock biometry, fruit yield, and fruit quality. The experiment was conducted in a randomized block design with four replications, 16 treatments, and seven plants per plot. Production, quality, and biometric parameters were assessed. Grafting increased epicarp and mesocarp firmness, fruit shape index, and vitamin C content, while reducing fruit length, fruit width, and locule length. Compatibility analysis revealed variability in the effects on measured traits, based on the general combining ability observed for scions JAB20-11 and 'Olimpic Express'. Grafting did not affect the total number of fruits or total fruit weight, while rootstock PI482398 exhibited the most favorable general combining ability for fruit length.

The selection of genotypes with greater tolerance to water scarcity during the early stages of growth can be a promising strategy for genetic improvement, as it enables early screening and may accelerate the identification and selection of tolerant genotypes under field conditions. Therefore, the objective of this study was to evaluate initial seedling growth, metabolic responses, and the selection of melon genotypes under water-deficit conditions. For this purpose, seeds from twenty genotypes were subjected to two osmotic potentials induced by PEG 6000 (0.0 and −0.25 MPa), with four replicates in a completely randomized design. The variables analyzed were germination percentage, germination speed index, shoot and root length, shoot and root dry mass, total dry mass, drought tolerance coefficient, and concentrations of amino acids, total sugars, and proline. Univariate and multivariate analyses of variance were performed, and genotypes were grouped using the Scott–Knott method. Genotype classification was based on the estimated drought tolerance coefficient, which was also evaluated using the membership function value. A water deficit of −0.25 MPa negatively affected germination speed and percentage, root length, and shoot dry mass, whereas metabolites exhibited the opposite behavior. Genotypes I-136 and PI234607 were classified as drought-tolerant, genotypes A-50 and A-52 as susceptible, and genotypes A-08 and A-09 as highly susceptible.

Studies on plant root system architecture may yield valuable data for genetic improvement programs for developing cultivars that acquire water and nutrients more efficiently. This study used morphological descriptors to characterize the root system and evaluate genetic diversity among 30 melon accessions. A completely randomized experiment was conducted with 30 treatments and 5 replications. The plot consisted of one seedling. After seed germination, five seedlings were fixed in a dried growth medium for 12 days. Then, they were scanned and measured for primary root length and primary root neck diameter. Root hairs were visually evaluated. Finally, basal root angles were measured. The accessions diverged genetically regarding the root system morphological characteristics. The primary root neck diameter contributed the most to the dissimilarity between the accessions (43.06%). The A-50 accession stood out for the highest mean for morphological characteristics. It may represent a reference in genetic improvement programs to develop cultivars that acquire water and nutrients more efficiently.

The objective of this study was to evaluate the effect of foliar and soil application of molybdenum (Mo) fertilizer on the biological efficiency, competitive ability, and nutrient uptake of the sorghum–cowpea intercropping system. The experimental design was a randomized complete block design with four replications and nine cropping systems: sorghum–cowpea intercropping with foliar Mo application; sorghum–cowpea intercropping with soil Mo application; sorghum–cowpea intercropping without Mo application; sole sorghum with foliar Mo application; sole sorghum with soil Mo application; sole sorghum without Mo application; sole cowpea with foliar Mo application; sole cowpea with soil Mo application; and sole cowpea without Mo application. Overall, molybdenum (Mo) application did not affect most indices of biological efficiency and competitive ability of the intercropping system, with effects observed only on the current loss or gain in sorghum yield, the partial land equivalent ratio of sorghum, and the area-time equivalent ratio. Regarding Na⁺ and K⁺ concentrations, the treatments affected these nutrients only during the second cropping cycle. On the other hand, no effect of the treatments was observed on Cl⁻ concentration in the sorghum shoot. Therefore, molybdenum fertilization did not alter the overall biological efficiency or competitive ability of the intercropping system. The changes in Na⁺ and K⁺ concentrations were localized and dependent on the cropping cycle, without causing changes in Cl⁻ accumulation in the sorghum shoot.

Melon (Cucumis melo L.) production in Brazil is concentrated in the semi-arid Northeast region, where environmental variability hinders the selection of stable, high-yielding genotypes. This study evaluated the adaptability and phenotypic stability of experimental hybrids of yellow melon, cantaloupe melon, and Galia melon under contrasting environmental conditions, using Toler’s bi-segmented and simple linear models under frequentist and Bayesian approaches. The experiments were conducted in the Brazilian semi-arid region, comprising 8 environments for the first Yellow melon group, 12 for the second Yellow melon group, 9 for Cantaloupe, and 12 for Galia. Bayesian inference was implemented using nested sampling with the UltraNest package to estimate the intercept ($\alpha$)and regression coefficients (${\beta }_1$ and ${\beta }_2$) of the bi-segmented model, as well as the common regression coefficient (${\beta }_{\mathrm{common}}$) of the simple linear model, together with their posterior uncertainty. The Bayesian analysis provided 95% highest-density intervals (HDIs) for these parameters, with convergence assessed using trace and corner plots. The frequentist and Bayesian approaches showed consistent classifications for 37 of the 38 genotypes (97.37%), with an isolated difference observed for AM-12. Based on the Bayesian analysis, Group A genotypes were identified among the Yellow melon and Cantaloupe materials, whereas the Galia genotypes were classified into Groups C and E. Group A genotypes exhibited a convex and doubly desirable response pattern, characterized by low sensitivity in unfavorable environments and high responsiveness under favorable conditions; Group C represented broad adaptability, whereas Group E represented a concave and doubly undesirable response. The results indicate that Bayesian inference provides complementary information to traditional analyses by explicitly quantifying parameter uncertainty, supporting the interpretation of genotype adaptability and phenotypic stability in melon breeding under semi-arid conditions.