ABSTRACT The response of shallot plants to potassium differs substantially depending on the cultivar, organic matter, soil conditions, and weather in the cultivation area. This research aimed to determine some of the growth characteristics of a Tinombo variety of shallot following treatment with an organic fertilizer comprising manure and potassium in the area of Palu, Central Sulawesi. This research took the form of a greenhouse experiment with planting in pots arranged in a completely randomized factorial pattern. The first factor was the application of chicken manure at 0 and 10 tons.ha-1, while the second factor was the dose of KCl fertilizer: 0 kg.ha-1; 30 kg.ha-1; 60 kg.ha-1 and 90 kg K2O.ha-1. Each treatment was replicated three times. The application of potassium and manure significantly affected the accumulation of dry matter and the linear growth rate of shallot var. Tinombo. Manure applied at 10 tons.ha-1 increased the leaf area index when combined with 0 to 60 kg K2O.ha-1. However, the addition of manure increased the net assimilation rate at all doses of potassium fertilizer. The number of bulbs and harvest index were affected by the amount of manure and potassium fertilizer applied, but there was no significant interaction between these two factors. Applying manure and K2O fertilizer resulted in a significantly higher number of bulbs and a better harvest index than in those cases where the two types of fertilizer were not applied.

ABSTRACT Morphoagronomic characterization is a basic requirement to identify a phenotypic profile of a population. The quantification of variability allows efficient selection of superior and divergent genotypes. Thus, this study aimed to estimate the variability among 490 genotypes and seven strains, from an F2 population of Ricinus communis L., in 35 morphoagronomic traits and 12 agronomic traits. For qualitative descriptors, the entropy technique was used in the percentage frequencies of each category, computing its level using the coefficient of Rényi (1961). Quantitative descriptors were subjected to analysis of variance by the F test, and Tukey test was performed at 1% probability level. Of the morphoagronomic traits used, 13 were related to plants, nine were related to inflorescence, six were related to fruits and seven were linked to seeds, in addition to 12 agronomic traits. The material was arranged in the field with families (strains of five families) interspersed with their respective parents (controls). Stem color, shape and number of racemes collected, main color, type of secondary color and hundred-seed weight have high variability in the population, with formation of 68 groups as a function of genetic similarity. The possibility of selection as to the number of racemes harvested is clear, so it is possible to identify genotypes with higher number, aiming to enhance crop yield.

ABSTRACT One of the major ecosystem services delivered to agriculture worldwide is the reduction of pests by natural enemies. However, the landscape composition affects multiple dimensions of pest control, and non-crop habitat surrounding farm fields shows variable responses across geographies. Here, crop damage and pest abundance were compared between local farms with two antagonistic land cover and land use aspects (1- High conservation, landscape with high structural complexity; 2- High degradation, landscapes with low complexity). The field data were collected at experimental guava orchards in the Cariri Paraibano, one of the driest regions in the Brazilian Caatinga. The results show that damage caused by orthopterans and their abundance was significantly smaller in the landscape with high structural complexity. Therefore, the results support the hypothesis that crop damage and pest abundance are smaller in landscapes with high structural complexity. Additionally, the results are very important for the dryland regions as they provide information about the relationship between landscape structure and crop damage plus pest abundance in a regional gap. As drylands are critically endangered in all American continents, sustainable agricultural landscapes with the application of natural cover restoration can help drylands to achieve sustainable development.

ABSTRACT Developing fast-cooking, mineral-biofortified common bean lines represents an important innovation for breeding programs. Thus, this study was conducted to determine whether elite Mesoamerican common bean lines differ for cooking time and mineral concentration and to select fast-cooking, mineral- biofortified lines. The experiments were carried out in two growing seasons, in which 16 common bean genotypes were evaluated. Cooking time was determined using a Mattson cooker, and the minerals were analyzed by acid digestion. The resulting data were subjected to individual analysis of variance, combined analysis of variance, clustering by the Scott-Knott test, and selection index (multiplicative). There was a significant genotype × environment interaction effect for cooking time and the concentrations of potassium, iron, zinc and copper. Only the phosphorus concentration showed no genetic variability between the common bean lines. The ranking of the best common bean lines differed for all traits examined in the different environments, according to the Scott-Knott test. The use of the multiplicative selection index allows selecting superior common bean lines for all traits, namely, DF 07-11, DF 08-21, DF 08-20 and DF 08-28. These lines exhibit a very short cooking time (up to 15 min), high potassium concentration (> 12.00 g kg-1 of dry matter) and the highest mean values of micromineral concentration, and will thus be selected by the breeding program.

ABSTRACT Powdery mildew is an important disease in tomato, which requires technologies for its control. Homeopathy is a science that has been improved as an alternative method in agriculture. Thus, this study aimed to evaluate the homeopathic medicine Ferrum sulphuricum in 6, 12, 24, 48, 72 and 96CH dynamizations on powdery mildew control. The experiment was conducted from May to June 2013 in a greenhouse, in split-split- plot design, and the results were compared with the controls 30% ethanol and distilled water. We evaluated the area under disease progress curve (AUDPC), relative chlorophyll index (SPAD), influence on plant growth by volume and mass of roots, and mass of fruits and shoots and even the pathogen sporulation on leaves. For the AUDPC, all the dynamizations reduced the disease. The Santa Clara genotype showed up to 41% less and Cedro 31% less disease compared with the control ethanol, in the upper third of the plant. For the SPAD index, there was an increase of up to 322% in the middle third of the plant treated with 24CH dynamization. For the growth variables, all the dynamizations increased up to 197% the volume and weight of roots for Cedro and Santa Clara. The 6, 12, 24, 72 and 96CH dynamizations reduced the pathogen sporulation on Santa Clara tomato leaves by up to 40%. The data indicate that the medicine Ferrum sulphuricum can control powdery mildew on tomato, increase the growth of plants and that there is a differential response according to the host genotype.

ABSTRACT Lima bean (Phaseolus lunatus L.) is the second most important socioeconomic species of the genus, consisting of a food alternative as green or mature beans. It is an income option for family farmers and the lack of superior varieties makes its recommendation difficult, considering the peculiar lima bean variability. Thus, aimed to select landraces of lima beans based on desirable agronomic traits, enabling their use in breeding programs and later recommendations to family farmers. Evaluation trials were carried out with 14 landraces of lima beans in the municipalities of São Domingos do Maranhão - MA, Teresina - PI, Bom Jesus - PI, and Tianguá - CE. The agronomic traits were evaluated: number of days until flowering, number of days until pod maturation, pod length, pod width, pod thickness, number of seeds per pod, 100-seed weight, and grain yield. The data were initially subjected to univariate analysis of variance to determine the genetic variability in different environments and, subsequently, to multivariate and cluster analyses. The evaluated landraces showed genetic divergence, not being grouped according to geographic origin, demonstrating the existence of similarity between germplasms of rural communities in neighboring states. The varieties Boca de Moça, Raio de Sol, and Fava Branca CE are the earliest; Boca de Moça, Rajada, and Raio de Sol presented the longest pods and largest seeds; and Boca de Moça, Rajada, and Mulatinha are the most productive. Therefore, it qualifies them for recommendation to family farmers and/or incorporation in lima bean breeding programs.

ABSTRACT Cordia oncocalyx Allemão Baill., widely known as “pau-branco”, is a native species from the Caatinga (Brazilian Savannah) and has socioeconomic and environmental potential; however, there are few silvicultural studies on this species. Therefore, this paper aimed to analyze and compare the biometric characteristics of diaspores and seeds through manual biometrics and by digital image processing, and to evaluate the in vitro and ex vitro germination of C. oncocalyx. In the biometrics evaluation, three hundred diaspores and three hundred seeds were used, applying manual and digital biometrics. Subsequently, ex vitro emergence was determined, testing mechanical scarification (in different regions of the diaspore) and chemical scarification (immersion in sulfuric acid for 90 min and 180 min). Finally, in vitro germination was tested with different compositions of Murashige & Skoog (M&S) culture medium and sucrose addition. Results showed that digital image processing is a viable and fast technique to obtain the biometric parameters of C. oncocalyx fruit and seeds. Chemical and mechanical treatments on diaspores have not influenced seed emergence (0.33%). The composition of the culture medium has influenced the germination percentage, and the maximum value of 96% % was obtained with 6 g/L of sucrose and 0.90 g/L of M&S medium. Thus, the seminiferous propagation of C. oncocalyx can be performed successfully when the seeds are germinated in vitro, and the digital image processing shows the solidity and applicability aiming to evaluate the quantitative parameters of seed and fruit of this species.

ABSTRACT Absence of drainage associated with high evapotranspiration and irregular precipitations contributes to the accumulation of salts in the soil, reducing nutrient absorption and yield. Nutritional management is important for the crop to express its maximum production potential, and nitrogen is the macronutrient most required by the corn crop. The objective of this study was to evaluate yield and leaf contents in corn under different nitrogen fertilization recommendations and salt stress. The experiment was conducted from June to September 2019, at the University of International Integration of Afro-Brazilian Lusophony in Redenção-CE, Brazil. The experimental design used was completely randomized, in a 2 x 3 factorial arrangement, with 6 replicates, with two levels of electrical conductivity (0.3 dS m-1 and 3.0 dS m-1) and three nitrogen fertilization recommendations (0, 50 and 100% of the recommendation). The variables analyzed were unhusked ear weight, husked ear weight, yield and leaf contents of N, P, K, Ca, Mg and Na. Irrigation with saline water (3.0 dS m-1) reduces the unhusked ear weight, husked ear weight and yield. Nitrogen fertilization recommendations of 50% and 100% promoted higher values of unhusked ear weight, husked ear weight and leaf N contents, but reduced leaf P contents. The 50% and 100% recommendations promote higher yield values for the two levels of electrical conductivity studied (0.3 and 3.0 dS m-1). The 50% and 100% recommendations associated with saline water irrigation increased the leaf contents of K, Na, Mg and Ca.

ABSTRACT The biological control, thinking about the integrated management, has been inserted with other management techniques to disease control, such as soybean anthracnose. The aims of this work were to verify the action of Trichoderma and Bacillus isolates in the induction of soybean resistance mechanisms to anthracnose as a function of seed treatment. The statistical design was entirely randomised, in a 5 x 2 (agent species x sampling times) factorial scheme with five replicates. Soybean seeds were treated with Bacillus amyloliquefaciens BV03, B. subtilis BV02, Trichoderma asperellum BV10, Carbendazim + Thiram and distilled water (control). Seven days after seedling emergence, 2 μL of 1 x 10−4 Colletotrichum truncatum spores were inoculated on the cotyledons. Catalase (CAT), peroxidase (POX), phenylalanine ammonia lyase (PAL) and glyceollin (GLY) activities before and after pathogen inoculation, as well as the diameter of the anthracnose lesion on the cotyledons, were evaluated. Data were submitted to analysis of variance and, when significant, the mean values were compared by Fisher’s test (p < 0.05). The treatments did not influence the first sampling time before inoculation. Trichoderma asperellum BV10 increased POX and PAL activities up to 173%, while B. amyloliquefaciens BV03 increased POX activity. Glyceollin was not influenced by the treatments. The T. asperellum BV10 reduces the diameter of the anthracnose lesion by up to 61%. Thus, T. asperellum BV10 has the potential to control soybean anthracnose, improved the response defense against C. truncatum, when performed on seed treatment.

ABSTRACT The action of photosystem I (PSI) inhibiting herbicides depends on light to cause oxidative stress in plants. However, their translocation is inhibited due to their rapid action in the presence of light. The aim was to evaluate the efficacy of the herbicide diquat for control of corn plants subjected to different periods of absence of light after application. Two experiments (field and greenhouse) were conducted, applying the herbicide diquat (200 g a.i. ha−1) to maize plants at stage V4. The plants were subjected to different periods of absence of light after diquat application: 0; 1; 2; 3; 4; 5 and 6 hours. A treatment without herbicide application was used as a control. The control (%) and biomass of corn plants were evaluated in both experiments, and photosynthetic activity and hydrogen peroxide (H2O2) accumulation in leaves were evaluated in the greenhouse experiment. The results showed that diquat needs at least 5 hours of absence of light after application to fully control corn plants. The plants recovered when using shorter periods (4 hours or less) of darkness, and injuries were restricted to points where the herbicide had contact with the plant. The ability of plants to recover was related to the higher photosynthetic activity and oxidative stress induction due to early light exposure. Thus, the lower production of H2O2 in plants kept in the dark for longer periods after herbicide application allows the translocation of the herbicide to meristems, which prevents regrowth of corn plants.