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A soja tem apresentado aumento de produtividade nos últimos anos e o manejo adequado das plantas tem melhorado a qualidade fisiológica das sementes. A aplicação com micronutrientes, especialmente molibdênio (Mo) e níquel (Ni) tem importante estratégia para aumentar o rendimento de grãos. Este estudo teve como objetivo avaliar os efeitos da aplicação foliar de Mo e Ni sobre o teor foliar de nitrogênio (N), qualidade da germinação (protrusão radicular, envelhecimento em termos de vigor, germinação e tamanho de plântulas) e tamanho de sementes de soja cultivadas sob duas condições edafoclimáticas. Os tratamentos consistiram em quatro doses de Mo (0, 400, 800 e 1600 g ha-1) e três doses de Ni (0, 60 e 120 g ha-1) aplicadas no início do estádio reprodutivo (R1 e R2). Os plantios foram realizados em Londrina (Brasmax Desafio RR) e Selviria (TMG 7063 IPRO e Brasmax Desafio RR). A protrusão radicular, vigor e tamanho das plântulas foram influenciados pela aplicação foliar de Mo, enquanto a aplicação de Ni em altas doses diminuiu a protrusão radicular. A aplicação de Mo influenciou positivamente o teor de N, tamanho dos grãos e qualidade fisiológica das sementes na dose de 800–1600 g ha-1.

Abstract Background and aims Nano-zinc (Zn) fertilizer is an easily adaptable and environmentally safe alternative option that can effectively improve growth, yield and biofortification of common bean. Plant growth-promoting bacteria (PGPBs) could promote plant growth and nutrients availability in sustainable manner. Therefore, this study aimed to investigate the influence of foliar nano-Zn application in association with seed co-inoculations of PGPBs on growth, yield, biofortification and Zn use efficiencies in common bean cultivation. Two field experiments were performed with seven co-inoculations of PGPBs and three foliar nano-Zn doses applied 50% at R5 and 50% at R8 stages of common bean to determine plant height, shoot dry matter, grain yield, Zn concentration and uptake in shoot and grains, Zn partitioning index, daily Zn intake and Zn use efficiencies for agronomic biofortification. Results The combined foliar nano-Zn application and co-inoculation of R. tropici + B. subtilis enhance grain yield, leaf chlorophyll index, total protein content, grain Zn concentration and uptake, daily Zn intake, Zn use efficiency, applied Zn recovery and Zn utilization efficiency in common beans in 2019 and 2020 cropping seasons. Foliar nano-Zn application at a dose of 1.5 kg ha−1 increased plant height, shoot dry matter, shoot Zn uptake, Zn partitioning and agro-physiological efficiency under co-inoculation with R. tropici + B. subtilis in both cropping years. Conclusions The treatments with foliar nano-Zn application at a dose of 1.5 ha−1 and co-inoculation with R. tropici + B. subtilis improved performance, chlorophyll index, protein content, grain yield, and Zn efficiencies that can lead to better biofortification of common bean in tropical savannah. Therefore, it is recommended that applying nano-Zn via foliar along with co-inoculation of PGPBs could be the better option for productivity and biofortification of common bean. Graphical Abstract

The selection of an appropriate nitrogen (N) source can mitigate the negative effect of root-knot nematodes on the yield of common beans. A greenhouse experiment was conducted to assess the application efficiency of four N sources (urea, ammonium sulfate, ammonium nitrate, and sodium nitrate) and inoculation with Rhizobium tropici on the yield components, chlorophyll, and total nitrogen (N) leaf contents of four common bean cultivars (IDR Curió, IDR Sabiá, IDR Tuiuiú, and IDR Bem-te-vi). These beans were cultivated in substrates both infected and uninfected with Meloidogyne incognita. In the soil containing phytonematodes, the IDR Curió cultivar exhibited the highest shoot and root dry weight yield, resulting in the greatest root volume, total N content, and grain yield. Among the N sources, the application of either urea or ammonium sulfate proved the most effective in enhancing common bean productivity in soil, irrespective of the cultivar or whether the soil was infected with Meloidogyne incognita.

Abstract The objective of this work was to evaluate the application of silicate ultramafic alkaline rock, with different granulometry, as an alternative potassium source on the increase of soil fertility and on the nutritional status and biomass yield of the alfalfa and centrosema crops. The used soil was a Typic Ultisol with 27.4 mg dm-3 K and 733 g kg-1 clay. The experimental design was completely randomized, in a 4 × 2 + 1 factorial arrangement. The treatments consisted of two granulometries (

Micronutrient fertilization is usually neglected by producers, especially for peanut, a crop that is frequently grown in crop rotation systems due to its low perceived nutrient requirements. New peanut cultivars are able to achieve high yields when grown under suitable conditions. However, fertilization recommendation tables are dated and do not consider the need for micronutrients. To support improvements in these recommendations, this study quantified the micronutrient demand (B, Cu, Fe, Mn, and Zn) of three runner peanut cultivars (IAC Runner 886, IAC 505, and IAC OL3) during the biological cycle and the transport of these micronutrients to pods and kernels. The experiment was carried out in a randomized complete block with a split-plot design and nine replications. The whole plots consisted of the three peanut cultivars, and the subplots comprised nine plant samplings (at 14, 28, 42, 56, 70, 84, 105, 126, and 147 days after emergence (DAE)). These modern peanut cultivars exhibited high uptake and accumulation of Fe, but the proportion of Fe removed by pods and kernels was lowest among all analyzed micronutrients. The second-most-accumulated micronutrient was Mn. The maximum requirement for micronutrients of peanut occurred around 84 DAE, and IAC 505 had the highest micronutrient uptake and accumulation among the cultivars (especially at later stages), followed by IAC OL3 and IAC Runner 886. Our results provide new insights into micronutrient requirements for peanut and demonstrate the need for new fertilizer recommendation programs for peanut cultivation.

Abstract: Soybean has shown increasing performance in terms of yield in recent years. However, despite this growth, the lack of quality control and knowledge about the effects of the nutritional status of plants has compromised the germination and vigor of a significant proportion of seeds. The aim of this study was to evaluate the physiological performance of seeds and root growth of soybean cultivated with boron (B) sources with different solubilities incorporated into the soil. The experimental design was completely randomized in a 2×5 factorial arrangement, with two B sources (boric acid and ulexite) and five B rates (0, 2, 4, 8, and 16 mg.kg-1). 100-seed weight (100SW), germination, seedling shoot length (SSL), seedling root length (SRL), accelerated aging (AA), root protrusion (RP), lignin content in the seed coat (LCSC), and root volume (RV) were evaluated. The B sources and rates showed a significant interaction with increases in RV, RP, SSL, SRL, and 100SW, while the LCSC decreased with increasing rates with no interaction effect, indicating a reduction of seed quality with rates up to 8.0 mg.kg-1, regardless of the B source used.

Entre as espécies de fitonematoides que provocam perdas de produção à cultura da soja estão os nematoides da haste verde (Aphelenchoides besseyi) e o das galhas (Meloidogyne incognita). Diante disso, o objetivo deste trabalho foi estudar os efeitos de diferentes níveis populacionais de A. besseyi e M. incognita na soja. O experimento foi realizado com nove combinações de diferentes níveis populacionais dos nematoides (T1 – Controle não inoculado, T2 - A. besseyi 500 indivíduos, T3 - M. incognita 2000 indivíduos, T4 - A. besseyi + M. incognita 250 + 2000 indivíduos, T5 - A. besseyi + M. incognita 500 + 2000 indivíduos, T6 - A. besseyi + M. incognita 250 + 4000 indivíduos, T7 - A. besseyi + M. incognita 500 + 4000 indivíduos, T8 - A. besseyi + M. incognita 250 + 8000 indivíduos, T9 - A. besseyi + M. incognita 500 + 8000 indivíduos e T10 - A. besseyi + M. incognita 1000 + 8000 indivíduos) e seis repetições. As variáveis analisadas foram: altura de planta, massa fresca da parte aérea (MPA), massa fresca de raízes (MR), número de vagens (V), massa fresca de vagens (MV), número de grãos (G), massa fresca de grãos (MG), quantidade de A. besseyi na parte aérea e de M. incognita nas raízes. O mapa de calor indicou que populações iniciais inoculadas de 500 A. besseyi + 8000 M. incognita apresentou maiores danos ao desenvolvimento da soja, reduzindo todas as variáveis analisadas. As variáveis MG, G e V reduziram na presença de diferentes densidades populacionais das espécies de fitonematoides nematoides, influenciando negativamente o desenvolvimento da soja.

In an effort to improve fertility, recover degraded areas and increase support for the capacity of livestock on pasture, new forms of fertilizer are being developed. Polymer-coated monoammonium phosphate (MAP) is an innovative source of phosphorus (P) for maintaining forage grass productivity. The aim this study was to evaluate the agronomic efficiency of P rates with the presence and absence of the polymer on the productivity, development and nutritional value of hybrid signalgrass (Urochloa spp.) cv. Mavuno. The field research was conducted on a dystrophic Ultisol. The experiment was arranged in a randomized complete block design with four replications and treatments applied in a factorial scheme (2 × 4) + 1. The treatments included two P sources (uncoated MAP and polymers-coated MAP) at four rates (20, 40, 80 and 160 kg ha−1 of P2O5), and the control received no P fertilization. The measured variables showed no differences between sources with or without polymer. The maximum production of accumulated shoot dry weight yield (SDWY) of the ‘Mavuno’ grass was 20.2 Mg ha−1 with the dose of 114 kg ha−1 of P2O5. The value of crude protein and in vitro dry matter digestibility showed a quadratic response with maximum production of 76.5% and 15.9% for the P2O5 rates of 37.2 and 91.1 kg ha−1, respectively, while the acid detergent insoluble fiber showed a linear increase up to the rate of 80 kg ha−1 of P2O5. No differences were observed in plant height, number of tillers, or the relative chlorophyll content between treatments.

This study evaluated the combined effect of foliar spray inoculation with plant growth-promoting bacteria (PGPB) and nitrogen doses on the yield, development, and nutritive value of Megathyrsus maximus cv. BRS Zuri. The experimental design was randomized blocks with four replications, with repeated measures in time. Foliar inoculation of two bacteria (Azospirillum brasilense Ab-V5 (CNPSo 2083) and Ab-V6 (CNPSo 2084) and Pseudomonas fluorescens (CNPSo 2799)) and 40 and 80 kg ha−1 N (urea) rates, in addition to the control (without inoculation and N fertilization), were applied. In the rainy season, at the level of 40 kg ha−1 of N, inoculation of both A. brasilense and P. fluorescens increased, respectively, the tiller number by 33% and 25% (22 February), and the N accumulated in tissues by 42% and 25% (22 January), while in the previous year (21 February) the beneficial effects of both bacteria were observed in the percentage of leaf blade and in the true digestibility in vitro. When the foliar spray was inoculated with A. brasilense Ab-V5 and Ab-V6 and P. fluorescens CNPSo 2799, with 80 kg N ha−1, the root system of Zuri grass increased by 61% and 30%, respectively.

Mato Grosso do Sul State in Brazil is characterized by the ‘Cerrado’ ecoregion, which is the most biologically rich Savannah globally. In agricultural terms, the region produces several commodities that are exported around the world. This level of productivity has been achieved through the large-scale use of synthetic fertilizers, which has created several economic and environmental concerns. New approaches in soil fertility management are required to avoid environmental degradation, pollution, and socio-environmental damages. A field experiment, lasting two years, was conducted to investigate the composted sewage sludge (CSS) effects on an infertile acidic soil (Oxisol) planted to maize (Zea mays L.). The following complete randomized complete block design with a 4 × 2 + 2 factorial scheme (four replications) was applied: four CSS increasing rates (from 5.0 to 12.5 Mg ha−1, w.b.) following two application methods (whole area and between crop rows). A control, without CSS or synthetic fertilizers, and conventional synthetic fertilization without CSS were also investigated. Evaluated parameters were: (i) soil and leaf micronutrient concentrations; (ii) maize development, yield, and production. The CSS application increased: (i) the concentration of micronutrients in both soil and leaves; and (ii) the crop yield. Both were particularly true at the higher CSS applied rates. Such organic fertilizer can be safely used as a source of micronutrients for crops as an important low-cost and environmentally friendly alternative to mineral fertilizers, thus safeguarding soil health.

ABSTRACT Brazil is currently the 4th world’s largest banana producer, producing around 7 million tons. In this scenario, several studies have been developed with a large amount of data, such as climatic, morphological, and nutritional data, in an attempt to improve these numbers even further. This study aims to classify banana ripening stages by artificial neural networks (ANN) as a function of plant physical, physicochemical, and biochemical parameters. The used ANN consisted of a three-layer feedforward backpropagation network, with eight neurons in the input layer (physical, physicochemical, and biochemical parameters), ten neurons in the intermediate layer, and two neurons in the output layer (classification of banana ripening stages). The results showed three configurations. ANN presented an excellent result for the training phase, with 100% accuracy in the sample classification for the three configurations. The validation and testing phases, that is, the classification of samples that were not part of the training, showed 91.6% and 94.4% accuracy in the first and second configurations, respectively, and 89.5% accuracy in the third configuration.