This study aims to describe macronutrient and boron deficiencies in pepper grown in a hydroponic system in the presence of a substrate during the vegetative and fruiting phases. The experiments were carried out into a greenhouse, and consisted of a randomized block design with eight treatments: complete solution (control) and nitrogen (-N), phosphorus (-P), potassium (-K), calcium (-Ca), magnesium (-Mg), sulfur (-S) and boron (-B) deficient solutions, with four repetitions for each assay. Visual diagnoses of certain macronutrient and boron deficiencies can be applied by farmers to aid in soil management, since they are observed in leaves, while N, P, Ca, S and B deficiencies led to roots symptoms. Pepper fruits showed nutritional deficiency symptoms when grown under N, K, Ca, Mg, S and B deficits. The appearance of nutrient deficiency symptoms in pepper plants occurs in the following order: N, K, P, Mg, S, Ca and B. Graphical Abstract

The aim of the present study was to verify the effect of the nutritional stress caused by macronutrient and boron deficiencies on the biosynthesis of capsaicinoids and the mineral nutrient contents of dry Capsicum annuum fruits. The experiments were carried out in a shade house at Campos dos Goytacazes/RJ, Brazil, in sand fertigated with a nutrient solution, in randomized blocks applying an 8x2 bifactorial scheme, with eight treatments [Complete treatment and applying the element omission technique for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S) and boron (B)], and two fruit harvesting dates, with four replications. Pepper fruits produced under potassium deficiency displayed increased capsaicin contents, whereas sulfur deficiency decreased capsaicin contents. Capsaicin contents were different depending on the harvesting dates, ranging from 0.369 to 1.224 mg g⁻¹.

Forestry researchers often evaluate minicutting vegetative propagation of Australian cedar (Toona ciliata) as a viable technique for this species. However, the adoption of minigarden systems for commercial propagation still requires viability and quality testing of saplings produced after multiple harvests. In the present work, we evaluate survival, growth, and quality of Australian cedar saplings grown from minicuttings originating from multiple harvests of ministumps planted in gutter or tube systems. Experiments were conducted in a greenhouse using a completely randomized design with a 2 × 4 factorial treatment structure (two minigarden systems and four minicutting harvests). For the gutter system, six minicutting harvests were performed 50, 86, 115, 149, 177 and 212 days after planting ministumps, whereas for the tube system, four harvests were performed 115, 149, 177 and 212 days after planting ministumps. At the end of each sapling production cycle (105 days after each minicutting harvest), saplings were evaluated for survival, foliar area, dry mass of aerial parts, number and length of adventitious roots, dry mass of the root system, height to diameter ratio, ratio between the dry mass of aerial parts and dry mass of root system, and Dickson’s Quality Index. Sapling survival was not affected by minigarden system, except for a reduction observed in fourth cycle saplings from the tube system. Sapling quality was also similar between systems. However, sapling growth potential decreased with production cycle, indicating that ministumps lose vigor with multiple harvests.

A escassez de tecnologias relacionadas à fisiologia pós-colheita da atemoia constitui um dos entraves para a comercialização a longas distâncias, agravadas pela perecibilidade dos frutos. Objetivou-se com este trabalho prolongar a vida de prateleira dos frutos de atemoia com uso de 1-metilciclopropeno (1-MCP), atmosfera modificada por filme de polietileno de baixa densidade (PEBD), associados à refrigeração. O experimento foi conduzido em delineamento inteiramente casualizado em esquema de parcelas subdivididas, tendo nas parcelas as quatro doses de 1-MCP (0, 200, 400 e 600 ŋL-1), e nas subparcelas os cinco períodos de avaliação (0, 5, 10, 15 e 20 dias após o armazenamento), com quatro repetições. As atemoias foram colhidas no estádio de maturação fisiológica e tratadas com as doses de 1-MCP por 8 h. Logo após, os frutos foram dispostos em bandejas de poliestireno expandido, sendo armazenados em dois lotes uns sem embalagem e outros embalados com membrana plástica de PEBD 16 μm. O uso da atmosfera modificada e do 1-MCP, associados ou não, foram eficientes no atraso do amadurecimento dos frutos permitindo a conservação da sua qualidade físico-química. Nos frutos tratados com 1-MCP houve atraso no acúmulo de sólidos solúveis e na degradação do amido.

Micropropagated plantlets, after removal from controlled laboratory conditions, require an acclimatization period. Adaptation to the new environment induces anatomical and physiological changes controlled by cellular processes. This study investigated the involvement of the primary proton transport systems of total membranes in pineapple root colonization by diazotrophic bacteria and in the development of plantlets treated with different nitrogen doses, allowing an understanding of nutrient absorption and accumulation dynamics. The experiment followed a randomized block design (RBD) in a factorial scheme (2 × 3 × 2), with two inocula (a mixture of diazotrophic bacteria containing Burkholderia sp. UENF 114111, Burkholderia silvatlantica UENF 117111, and Herbaspirillum seropedicae HRC 54, and another without bacteria), three urea doses (0, 5, and 10 g L⁻¹), and two evaluation (90 and 150 days) and bacterial counting times (30 and 150 days), with three blocks. Diazotrophic bacterial populations were lower in older plantlets. H⁺ transport mediated by P H⁺-ATPases changed with acclimatization time. Inoculation did not induce transport; however, the F_max of V H⁺-ATPase was lower without nitrogen fertilization. Nitrogen fertilization affected V H⁺-ATPase proton transport activity in root membranes. The presence of diazotrophic bacteria did not induce proton transport. On the other hand, nitrogen fertilization and acclimatization time affected the proton transport activity mediated by H⁺-ATPases isolated from roots of micropropagated pineapple.

The introduction of rootstocks for the guava has become necessary due to the advance of guava decline. Among them, Psidium spp. or their hybrids have been evaluated. In addition to disease resistance, tolerance to salinity must be evaluated in the new rootstocks. The aim of this study was to verify the effect of rootstocks and intergrafts on the mineral composition of Psidium spp. submitted to salt stress. The experiment was setup in a randomized block design, with the following treatments (scion/rootstock):P. guineense/P. cattleianum; P. guajava/P. guineense/P. cattleianum; P. guajava‘Paluma’/P. guajava; P. guajava ‘Paluma’/P. guineense; P. guajava ‘Cortibel 1’/P. guajava;P. guajava ‘Cortibel 1’/P. guineense; P. cattleianum (purple) and P. cattleianum (yellow), with three replications and three plants per plot. The plants underwent irrigation with saline solution, and the levels of macronutrients, micronutrients and sodium in the scion leaves were evaluated. As rootstock, P. cattleianum results in greater Na uptake, with higher levels in the leaves of the scions, leading to less tolerance to salt stress.