Search

Abstract Although there are fertilization recommendations for the cultivation of zucchini, there are just few researches about the effects of nutrients in seed production. Calcium and boron have a low mobility in plants, and some researches recommend foliar application for these nutrients. Thus, the objective of this research was to evaluate the foliar application of calcium and boron in the production and quality of zucchini seeds. The experimental design was randomized blocks with seven replications. Four treatments were evaluated: only calcium (0.2%) application, only boron (0.1%) application, combined application of calcium (0.2%) and boron (0.1%) and the control (without calcium and boron.) The following characteristics were evaluated: number of pollen grains per flower, hundred seeds weight; seed number and weight per fruit and seed physiological quality (germination; first germination count and speed of germination index - SGI). Only boron application reduced the number of seeds produced per fruit. The combined foliar application of calcium and boron, in addition to reducing the number of seeds, also reduced SGI. The calcium only application increased the amount of pollen per flower (superior to all other treatments) and also the number of seeds per fruit (compared to the combined application of calcium + boron), without affecting the quality of the zucchini seeds. So, it can be recomended the aplication of Ca during zucchini flowering for seed production.

Herbicides with desiccant actions may be used to anticipate the harvesting of soybean seeds. This technique aims to minimize the negative influence of biotic and abiotic factors on seed physiological quality at the end of the plant cycle. However, forced seed maturation with the application of herbicides can compromise the acquisition of seed quality components, especially longevity. Thus, the objective of this research was to evaluate the physiological quality of soybean seeds subjected to forced maturation with desiccants. The experiment was performed in a completely randomized design, with a treatment consisting of soybean plants subjected to the application of herbicides with desiccant action at stage R7.3 and another that underwent the natural process of maturation, that is, without herbicide application. The herbicide used was Paraquat. Seed germination, vigor (first germination count, dry mass, seedling length, time to reach 50% germination(t50), emergence index, and emergence speed), and longevity(P50) were evaluated. The herbicides did not affect germination (normal seedlings). However, the acquisition of vigor and longevity, and the preservation of seed vigor during storage were affected. Thus, the results indicate that the application of herbicide with desiccant action interrupts the process of acquisition of seed physiological quality, notably longevity in soybean seeds.

Climate change is causing an increase in dry spells, altering rainfall patterns and soil moisture, and affecting water and nutrient plant uptake, which inevitably affects vegetable production. To mitigate this issue, some technologies that allow the maintenance of the ideal soil moisture for the uptake process are being investigated. Considering this, we hypothesize that the use of water treated with a magnetic field can increase water use efficiency in lettuce crop production. Thus, the present study aimed to evaluate the effect of the irrigation rate of magnetically treated water on biomass accumulation and nutrient uptake by lettuce plants. An experiment was conducted in a randomized block design with a 2 × 5 factorial arrangement of two water sources (conventional water and magnetically treated water) and five irrigation application rates to replace crop evaporation: 25, 50, 75, 100, and 125%, with five replicates. The use of magnetically treated water increased the concentrations of nitrogen and phosphorus in leaves, meaning that it induced higher nitrogen assimilation, leading to increases in agronomical characteristics (leaf number, fresh and dry shoot weight, fresh and dry root weight). The conclusions of this study showcase that magnetically treated water has beneficial effects on lettuce plants, improving their nutritional status and yield. Moreover, the results presented can lead to an increase in water use efficiency, thus optimizing irrigation management.

Soil management systems directly interfere in the soil–plant relationship. However, there are still few studies evaluating the influence of long-term management systems on the physiological quality of soybean seeds. Another little-known topic is the influence of pre-harvest desiccation on the physiological quality of soybean seeds, especially on seed longevity. Thus, the aim of this research was to evaluate the physiological quality of soybean seeds cultivated under conventional tillage and no-tillage systems with and without desiccant use. The experiment was carried out in design is a split plot in a randomized complete block design. The treatments consisted of soil management systems (conventional tillage and no-tillage), with and without pre-harvest desiccation. In the treatment with desiccation, the herbicide Paraquat was applied, when the plants were at the R7.3 phenological stage (most of the seeds had a yellowish coat, with a shiny surface and were already detached from the pod). Seed germination, vigor (first germination count, seedling dry mass, seedling length, time to reach 50% germination (T50), seedling emergence and emergence speed index) and longevity (P50) were evaluated. Seeds cultivated under conventional tillage showed greater vigor for most traits evaluated, with values of T50 and seedling length higher by 24.39% and 24.77%, respectively, compared to NT. In addition, non-desiccation increased the seedling length and dry mass, in 15.45% and 21.59%, respectively. The use of desiccant aiming at seed vigor is dependent on the soil management system. Soybean seed longevity was superior in the no-tillage system, but desiccant application reduced seed longevity.

Abstract The post-harvest resting of the fruits can improve seed physiological quality ,once it allows the seed to complete the maturation process, so it has been a common practice in vegetable seed companies, however, there are a few studies of this technique in sweet pepper. The objective of this research was to evaluate physiological quality, and biochemical response of sweet’s peppers in regarding on the stage of maturation and the post-harvest rest of the fruits. The experimental was conducted in a 4x2 factorial, being the first factor comprised four maturation stages (35, 50, 65 and 80 days after anthesis) and, the second the post-harvest management of fruits, with and without a temporary storage of seven days. Seeds were evaluated for water content, weight of thousand seeds, germination, vigor, superoxide dismutase, catalase and peroxidase activities, lipid peroxidation and hydrogen peroxide content. Fruit harvest time indicated is 80 days after anthesis (fruits 100% yellow) when seeds showed maximum germination and vigor. The post-harvest resting of the fruits was beneficial to seed physiological quality, weight of one thousand seeds and to reduce hydrogen peroxide content. Seeds of higher physiological quality showed lower superoxide dismutase and catalase enzyme activity, so they can be used as a marker of physiological quality in sweet pepper seeds.

Management of irrigation and fertilization in greenhouses, if not done correctly, can cause soil salinization. The use of water treated with very low-frequency electromagnetic resonance fields (WVLF) can reduce salinization effects on the photosynthetic and biometric systems. Thus, the purpose of the research to evaluate the metabolism of photosynthesis and the impact of WVLF on the cultivation of tomato crops subjected to different levels of fertigation. For this, the gas exchange parameters were evaluated, as well as chlorophyll a fluorescence, sugar contents, sucrose, chlorophylls, and phaeophytins and fruit production. The gas exchange parameters had greater activity when subjected to irrigation with electromagnetic water, consequently the production of sugar and sucrose increased. Photosynthetic System II showed less salinity effect, being favored by very low-frequency electromagnetic resonance fields. The production increased by 20% for the dose of 2.5 d·Sm−1 of WVLF reducing the effects caused by higher doses. Hence, the induction of water by electromagnetic fields can provide less damage to the photosynthetic system and to the cultivation of the tomato crop when subjected to saline stress and, consequently, favor the production of fruits by this crop under such conditions.

Soil cover species as well as the sowing system can interfere with the production of dry matter (straw) and the development of further crops. The objective of this study was to evaluate sowing systems for black oat (Avena strigosa schreb) and white lupine (Lupinus albus) species as cover crops, dry matter production and their influence on lettuce yield, americana and curly varieties. Two experiments were conducted, one for each cultivar of lettuce. The research was composed of eight treatments, in factorial 4x2, evaluated in randomized blocks, with five replications. The first factor was four coverages (black oat, white lupine, black oat + white lupine and spontaneous vegetation) and the second, two sowing systems (manual and mechanized). The desiccation of cover crops was performed 47 days after planting, measuring the amount of dry matter (straw) produced in the area. After 30 days from desiccation, curly and americana lettuce were grown under the straw. Lettuces were evaluated for fresh mass, shoot height and head diameter. White lupine and black oat + white lupine provided superior development of lettuce, although black oat combined with manual sowing system, is the most suitable as soil cover due to its high dry matter yields.

A cultura da melancia constitui a principal Cucurbitácea cultivada em Tocantins. Porém, nos últimos anos o cultivo vem limitando-se devido algumas doenças, principalmente as ocasionadas por vírus, causando prejuízos na produção. Assim, o desenvolvimento de genótipos com maior nível de resistência pode contribuir para reduzir os custos de produção da cultura. Portanto, o objetivo desse trabalho foi avaliar a qualidade pós-colheita e sensorial de frutos de famílias de melancia obtidas de quatro retrocruzamentos. O trabalho foi conduzido na Universidade Federal do Tocantins. Foram utilizados frutos obtidos de 12 famílias de melancia e a cultivar comercial Crimson Sweet. Para as avaliações físico-químicas foram selecionados dois frutos, sendo avaliados: acidez titulável, sólidos solúveis e coloração interna da polpa. A análise sensorial dos frutos de melancia foi feita através de testes com 30 avaliadores. Foi utilizada escala hedônica de 5 pontos, variando de maior a menor aceitabilidade para as características de aparência global, aceitação comercial e sabor. Em geral, algumas famílias comportaram-se de maneira satisfatória quanto às características físico-químicas e sensoriais, mostrando que podem ser utilizadas nos programas de melhoramento, pois estão com boas características comerciais e com resistência as principais viroses.

O cultivo de plantas medicinais assume importância mundial devido à demanda exercida pelas indústrias químicas, farmacêuticas, alimentares e de cosméticos. Entre as plantas medicinais, a Mentha spicata L., apresenta óleo essencial de grande interesse econômico. A aplicação de esterco bovino curtido melhora as condições físicas do solo, além de fornecer nutrientes para as plantas. Nutrientes que contribuem para diversos processos metabólicos no vegetal. Dentre estes, a síntese e manutenção de pigmentos. Este trabalho teve como objetivo avaliar a produção de massa fresca de folhas, massa fresta total os teores de clorofila de plantas de hortelã verde da Mentha spicata L., sob cultivo com diferentes doses de esterco bovino na Universidade Federal do Tocantins - Campus Universitário de Gurupi. Os tratamentos constituíram-se de sete doses de esterco (0, 25, 50, 75, 100, 150 e 300 kg m²), com três repetições. O resultado para tais condições de cultivo recomenda-se 16,3 kg m2 de esterco bovinoquando o objetivo é a produção de massa fresca de folhas, e 19,47 kg m2 de esterco bovino para obtenção de uma maior produção de massa fresca da parte aérea(folhas com talos). Já os resultados sobre o fornecimento de nutrientes via adubação orgânica mostraram não tem efeito sobre os teores de clorofila total, clorofila a, clorofila b e a relação clorofila a/b.

O objetivo do trabalho foi avaliar a reação de genótipos de batata-doce oriundos de sementes botânicas quanto a nematóides de galhas (M. incognita raça 2 e M. javanica) em condições de temperatura elevada. Para cada espécie de nematóides, foi instalado um experimento utilizando o delineamento experimental inteiramente casualizado com três repetições. Foram avaliados 25 genótipos dos quais 20 são famílias de meios-irmãos (oriundo de um campo de policruzamento); cinco cultivares (Amanda, Ana Clara, Bárbara, Duda e Marcela) e a cultivar de tomate Santa Clara, suscetível aos nematóides. A classificação da resistência foi feita pelo índice de Reprodução (IR%), no período mais quente do ano (janeiro/fevereiro), sobre condições temperatura média do solo de 26 ºC na região Sul do Estado do Tocantins. Avaliou-se também o número médio de galhas por sistema radicular, tamanho médio das galhas e posicionamento das galhas. Em condição de temperatura elevada, a espécie M. javanica foi mais agressiva do que M. incognita raça 2, originando galhas em maior número e de maior tamanho, principalmente nas raízes secundárias. Os genótipos BDFMI-16, BDFMI-78, Bárbara e Marcela são resistentes a M. incognita raça 2. Para o isolado M. javanica, o genótipo BDFMI-04 e BDFMI-16 e as cultivares Amanda e Duda são classificados como muito resistentes. O genótipo BDFMI-16 resistente a M. incognita raça 2 e M. javanica é promissor para uso no Estado do Tocantins ou então compor programas de melhoramento cujo objetivo é desenvolver genótipos resistentes às duas espécies de nematóides.

O estudo foi conduzido na Universidade Federal do Tocantins – Campus de Gurupi-TO, com propósito de avaliar os efeitos de intervalos de aplicação de urina de vaca, sobre a produção de alface, cultivar ‘Elba’. O experimento constituiu-se de cinco tratamentos: 1 – Apenas adubação mineral de base (testemunha); três diferentes intervalos de aplicação da urina de vaca em solução (2 – Aplicação da urina a cada cinco dias; 3 – Aplicação da urina a cada dez dias e 4 – Aplicação da urina a cada quinze dias); e 5 – Adubação convencional. O experimento foi implantado em ambiente protegido, utilizando-se delineamento em blocos casualizados, com quatro repetições. Ao longo do ciclo avaliou-se o estado do nitrogênio foliar e na colheita, o número de folhas, massa fresca e seca de folhas, comprimento de caule, massa fresca e seca de caule, massa fresca e seca de raízes, volume de cabeça, massa fresca e seca de cabeça, produtividade comercial e quantidade de N em massa seca da folha. Quando aplicadas em intervalos de cinco e quinze dias, a solução de urina proporcionou respostas relevantes para todas as características fitotécnicas avaliadas. O resultado de índice de clorofila foliar (ICF) foi significativo em relação à aplicação da solução de urina de vaca. A solução de urina de vaca constitui uma importante alternativa de adubação da alface para produção orgânica.