Paspalum notatum growth and pigment content in response to the application of herbicides

A grama batatais (Paspalum notatum) é uma poacea, resistente ao pisoteio, restrição hídrica e baixa fertilidade do solo, porém, exige cortes frequentes para eliminar o excesso de biomassa produzido. Para inibir o crescimento dos gramados e evitar ou retardar a operação de corte, têm sido testados reguladores de crescimento e herbicidas. O objetivo do trabalho foi avaliar o potencial de três herbicidas como reguladores de crescimento em grama batatais, e sua influência no crescimento e teor de pigmentos cloroplastídicos. O delineamento experimental foi em blocos casualizados, em esquema de parcelas subdivididas, com três herbicidas (glyphosate, isoxaflutole e tembotrione) e cinco doses (0, 68, 136, 272, 544 g e.a. ha-1; 0, 24, 48, 96, 192 g i.a. ha-1 e 0, 13, 26, 52, 104 g i.a. ha-1), respectivamente, com quatro repetições. Foram avaliadas as características, fitointoxicação, massa seca, altura do gramado e teor de pigmentos cloroplastídicos. Os dados foram submetidos a análise de variância e, quando constatada significância, foi realizado o teste de regressão até segundo grau separadamente para cada herbicida. Os herbicidas demonstram eficiência no controle do porte do gramado, no entanto, constata-se efeito fitotóxico com o incremento das doses e o prejuízo no o aspecto estético do gramado. O isoxaflutole possui maior potencial para ser utilizado com redutor de crescimento para a grama batatais, devido à baixa dose necessária para reduzir a altura e a pouca fitointoxicação. O teor de pigmentos cloroplastídicos é alterado de maneira singular por cada herbicida utilizado, e têm relação direta com a massa seca das folhas.Bahiagrass (Paspalum notatum) is a poacea resistant to trampling, water restriction and low soil fertility; however, it requires frequent cutting to eliminate the biomass excess it produces. To inhibit the growth of turfs and to avoid or delay cutting, growth regulators and herbicides have been tested. The goal of this work was to evaluate the potential of three herbicides as growth regulators on bahiagrass, and their influence on growth and chloroplast pigment content. The experimental design was in randomized blocks, in split-plot scheme, with three herbicides (glyphosate, isoxaflutole and tembotrione) and five doses (0, 68, 136, 272, 544 g a.e. ha-1; 0, 24, 48, 96, 192 g a.i. ha-1 and 0, 13, 26, 52, 104 g a.i. ha-1), respectively, with four replications. The following characteristics were evaluated: phytointoxication, dry mass, grass height and chloroplast pigment content. Data were submitted to analysis of variance and, when significance was observed, the regression test was performed, up to the second degree, separately for each herbicide. Herbicides demonstrated effectiveness in controlling turf size; however, the phytotoxic effect was observed with the increase of the doses and a damage in the aesthetic aspect of the grass. Isoxaflutole has greater potential to be used as a growth reducer on bahiagrass, due to the low necessary dose to reduce height and to low phytointoxication. The content of chloroplast pigments is changed singularly for each used herbicide, and it has a direct relation with the dry mass of leaves

Phytometric performance of corn on the effect of doses of trinexapac-ethyl and clomazone

O incremento produtivo da cultura do milho pode ser maximizado pelo adensamento da lavoura e, para isso, a utilização de herbicidas e reguladores de crescimento, por favorecer a diminuição de porte das plantas, torna-se ferramenta importante. Assim, objetivou-se avaliar doses dos redutores de crescimento trinexapac-ethyl e clomazone sobre o desempenho fitométrico de híbrido simples de milho. O delineamento adotado foi inteiramente casualizado, em esquema fatorial 2 x 5, com quatro repetições. Como primeiro fator considerou-se os redutores de crescimento (trinexapac-ethyl e clomazone) e no segundo foram consideradas as cinco doses de cada redutor (0, 50, 100, 200 e 400 g i. a. ha-1). Os redutores de crescimento trinexapac-ethyl e clomazone modificam o desempenho fitométrico das plantas de milho. Cerca de 113 g i.a. ha-1 de clomazone proporciona aumento do diâmetro do colmo e da massa fresca. O herbicida clomazone também pode ser utilizado como redutor de crescimento.The productive increase of the maize crop can be maximized by crop densification and, for this, the use of herbicides and growth regulators, because it favors the reduction of plant size, becomes an important tool. Thus, the objective of this study was to evaluate the rates of growth reducers on the phytometric performance of maize simple hybrids. The design was completely randomized, in a 2 x 5 factorial scheme, with four replications. Growth factors (trinexapac-ethyl and clomazone) were considered as the first factor and in the second, the five doses of each reducer (0, 50, 100, 200 and 400 g i.a. ha-1) were considered. The trinexapac-ethyl and clomazone growth modifiers modify the phytometric performance of maize plants. About 113 g i.a. ha-1 of clomazone provides an increase in stem diameter and fresh mass. The herbicide clomazone can also be used as a growth-reducing agent

Adenium obesum as a new potted flower: growth management

Adenium obesum, also known as desert rose, has recently become popular in Brazil, due to its exuberance and sculptural shape. However, the production of the species in commercial scale has been facing challenges regarding propagation of hybrids by in vitro cultivation techniques, potting medium composition, irrigation and fertilization management, disease and pest control. Unlike other species sold as potted plants, there are no commercial production protocols established for Adenium, mainly due to the scarcity of technical information about this species. Thus, this technical article aimed to provide information related to the Adenium growth, in view of its commercial scale production. In addition, aspects related to floral morphology, pollination and seed production of the species, as well as, vegetative propagation strategies were discussed

Cryoprotectant solutions in star orchid seeds and bamboo orchid conservation in liquid nitrogen

An alternative for the conservation of orchid species threatened with extinction is the seeds preservation for long periods by cryopreservation. This work aimed to evaluate the influence of cryogenic solutions on the orchids Epidendrum radicans and Arundina bambusifolia seeds cryopreservation in liquid nitrogen. Seven treatments were performed: 0.4 M sucrose; 2 M glycerol; PVS1; PVS2; PVS3; PVS2 + 1% phloroglucinol and the control. After liquid nitrogen removal, half of the seeds were subjected to tetrazolium test, and another half was in vitro cultured. After 30 days seed germination was evaluated. There was no significant difference between A. bambusifolia and E. radicans in tetrazolium test and seeds germination. On the other hand, it was observed that in A. bambusifolia tetrazolium and seed germination tests the solutions of PVS1, PVS2, PVS2 + 1% phloroglucinol showed the best results. E. radicans seeds with 4% water content cryopreservation does not require the use of cryoprotectant. On the other hand, cryoprotectant´s use resulted in positive effect in maintenance and viability preservation of A. bambusifolia seeds. PVS1, PVS2 and PVS2 + 1% phloroglucinol showed best seeds survival rates after cryopreservation in liquid nitrogen

Cryopreservation of seeds of Brazilian edelweiss (Sinningia leucotricha)

The objective was to evaluate the use of cryogenic solutions in cryopreservation Sinningia leucotricha seeds by the vitrification method in liquid nitrogen. The treatments were: T1 - control: without cryoprotective solution; T2 - PVS1; T3 - modified PVS1; T4 - PVS2; T5 - modified PVS2; T6 - PVS3; T7 - PVS3 modified; T8 - PVS2 + 1% phloroglucinol. After 15 days of immersion of seeds in LN, the cryotubes were removed and rapidly reheated to a temperature of 40 °C water bath for 1.5 minutes. Then, the seeds were washed with wash solution for 20 min. Later they were submitted to the germination test which was conducted on blotting paper moistened with distilled water packaged in crystal polystyrene boxes kept in a growth chamber at 25 ± 2 °C and 16 hours photoperiod. Was evaluated the germination percentage the germination speed index (GSI), and at the end of the experiment will determine the length of shoot (LS) and root (LR), and dry mass of seedlings (DMS). We used a completely randomized design with eight treatments and five replications, consisting of 100 seeds. The direct submission of the queen of the abyss seeds in liquid nitrogen provided the highest germination values, GSI, LS, LR and DMS. The queen of the abyss seeds can be cryopreserved in liquid nitrogen directly without the need to cryoprotectant solutions

Condutividade elétrica e frequência de aplicação de fertilizantes no crescimento da orquídea Brassia verrucosa lindley

A condutividade elétrica e frequência de aplicação na fertirrigação de orquídeas, não estão estabelecidas. O objetivo foi avaliar a influência da condutividade elétrica e das frequências de aplicação de fertilizantes, no crescimento e nutrição de Brassia verrucosa. Mudas de Brassia verrucosa foram cultivadas por 18 meses. As fertilizações tiveram como fonte de nitrogênio (N), fósforo (P) e potássio (K): ureia, cloreto de potássio e fosfato monoamônico diluídos em três concentrações: C1 (0,5:0,5:0,5; g L-1), C2 (1:1:1; g L-1) e C3 (2:2:2; g L-1). As condutividades elétricas apresentaram 1,25, 2,5 e 4,7 mS cm-1, respectivamente. Foram adotadas três frequências de aplicação: mensal (F1), quinzenal (F2) e semanal (F3). Plantas somente irrigadas foram o controle. O delineamento foi inteiramente casualizado com 10 repetições, em esquema fatorial 3x3+1. Os parâmetros fotométricos e teores de macronutrientes na parte aérea, foram submetidos a ANOVA e teste Tukey a 5% de significância. A condutividade das soluções resultou em maiores incrementos sobre as variáveis fitométricas. Aumento da condutividade elétrica promoveu incrementos no crescimento da Brassia verrucosa, bem como aumentos nos teores de N, P e K. A condutividade C3 (4,7 mS cm-1) aliada a frequências de aplicação quinzenais (F2) ou semanais (F3), resultaram no aumento de brotações

Cattleya forbesii x Cattleya bowringiana: a new hybrid of Cattleya orchid

Abstract The hybrid between Cattleya forbesii x Cattleya bowringiana shows flowers of lilac coloration, labellum with a light yellow center and striated with purple stripes of the same tone of other floral whorls. The plant flourished four years after seeding and produced, on average, six flowers

Agricultural fertilizers applied as nutrient solution in Cattleya labiata Lindl

Fertilization through nutrient solution is commonly used in commercial production of potted flowers, being employed soluble NPK formulations. However, most commercial formulations available in the market have high costs and the use of agricultural fertilizers can be an economically viable alternative. The objective of this study was to evaluate the effectiveness of agricultural fertilizers applied as nutrient solutions, in replacement of commercial formulations, on initial growth of Cattleya labiata. C. labiata seedlings in vitro propagated were grown in a greenhouse with controlled temperature, 27 ± 2° C, and retaining 50% brightness. Polypropylene pots were used with 0.415 L capacity, containing a mixture of pine bark and charcoal (1:1, v:v) as substrate. Altogether were used 4 treatments: without fertilization (control); Peters® - NPK 20 20 20 (3.0 g L -1 ); NPK - urea (1.3 g L -1 ), superphosphate (3.3 g L -1 ) and potassium chloride (1.0 g L -1 ); NK - urea (1.3 g L -1 ) and potassium chloride (1.0 g L -1 ). The nutrient solutions were applied 50 ml per pot every two weeks, according to the treatments. Were evaluated phytometric characteristics, pH and electrical conductivity of the substrate beyond the levels and accumulation of macronutrients. The experimental design was completely randomized with 12 replications, being considered each pot with two plants as an experimental unit. The parameters were submitted to ANOVA and Tukey’s test at 5% probability. Regarding phytometric parameters no significant differences were observed between the treatments that received fertilization, which are superior to the control in height and dry mass of shoots. The more accumulated nutrients were K>Ca>N, in the treatments that received fertilization. The use of urea, superphosphate and potassium chloride, applied in nutrient solution, have potential to replace the commercial formulations in the initial growth of native orchid Cattleya labiata

Novo híbrido de orquídea Cattleya

O híbrido, obtido do retrocruzamento entre (Cattleya labiata x Cattleya forbesii) x Cattleya labiata é uma planta vigorosa, bi ou unifoliada, apresenta pseudobulbos delgados e cilíndricos e folhas coriáceas com tonalidade verde escuro, com formato oblanceolado, de pontas obtusas, apresentando o primeiro florescimento após quatros anos da semeadura. O florescimento em Londrina ocorreu duas vezes no ano, entre os meses de abril e maio e outubro e novembro com 2-4 flores por pseudobulbo e durabilidade entre 15 a 20 dias. As flores do novo híbrido possuem coloração lilás e labelo com um centro amarelo e listras roxas