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Os autores desta obra DECLARAM para os seguintes fins que:1. Não possui qualquer interesse comercial que enseje um conflito de interesses em relação ao conteúdo publicado;

Abstract:The current study aimed to evaluate the effect of indole butyric acid (IBA) and boric acid to induce rooting on atemoya "Thompson" cuttings. A randomized block design with 10 treatments and four blocks was laid out. The treatments consisted in the use of different levels of IBA (i.e., 0, 500, 1,000, 2,000 and 4,000 mg/L) with or without boric acid at 150 mg/L. The cuttings were placed to root in expanded polystyrene (EPS) trays with 72 cells and kept in a greenhouse under misting. At 120 d after planting, leaf dry and fresh masses (g), root dry and fresh masses (g), percentage of rooting, live cuttings (LC), live cuttings with callus (LCC), number of roots per cuttings and number of emitted leaves (NEL) were evaluated. Data were submitted to analysis of variance and comparison of means by Tukey test at 5% probability. Results indicated no statistically significant differences in both application methods (separate or associated with boric acid) for all evaluated variables, except for LC, in which boric acid provided higher survival rates. It could be concluded that the propagation method using either separate IBA application or associated with boric acid is unsuitable to induce rooting on atemoya "Thompson" cuttings.

A adubação com silício (Si) pode ser utilizada como fonte de nutriente e resistência a pragas, refletindo em benefício na produção do milho (Zea mays L.). No entanto, para potencializar o seu efeito deve-se adotar como critério a escolha da fonte, o método de aplicação e a dose de silício. Dessa forma, o objetivo desse trabalho foi avaliar o efeito do método de aplicação e de diferentes doses de silicato de potássio (K2SiO3) sobre características de produção e resistência de plantas de milho a lagarta-do-cartucho (Spodoptera frugiperda). Adotou-se o delineamento em blocos casualizados e esquema de parcelas subdivididas, com quatro repetições. As parcelas foram constituídas pelos métodos de adubação (via foliar e solo) e as subparcelas por doses de K2SiO3, iguais a 1,0, 2,0, 3,0, 4,0 e 0,0 (controle) L ha-1. Determinou-se peso médio e produtividade de espigas, teor de clorofila, número e porcentagem de plantas danificadas, além do número de lagartas nas espigas e nível de dano foliar. Dos resultados, o K2SiO3 na dose de até 4 L ha-1, aplicado via solo ou foliar, apesar de reduzir a quantidade de S. frugiperda em espigas de milho, no entanto, não influencia a produtividade de plantas de milho verde, BRS 3046. Conclui-se que, o incremento das doses de K2SiO3 tende atenuar danos de lagarta-do-cartucho (S. frugiperda) em espigas de milho verde, BRS 3046, nas condições edafoclimáticas do município, Teresina, PI.

This study was conducted to evaluate the production and quality of watermelon fruits, submitted to different doses of potassium chloride (KCl) in fertigation and conventional fertilization systems. Talisman F1 was used as a plant material. It was carried out in a randomized complete block design, in a 2x4 split-plot scheme, with four replications. In the plots, the conventional and fertigation systems were tested and in the subplots the doses of KCl, equals: 0, 60, 120 and 180 kg ha-1 of K2O were tested. Seventy days after planting, were determined: total number of fruits; average weight of total fruits; total fruit production; average number of commercial fruits; average weight of commercial fruits and commercial fruit production, as well the hydrogenic potential (pH), total soluble solids (TSS), total titratable acidity (TTA) and TSS/TTA ratio. There was interaction between fertilization systems and K2O rates for commercial productivity with a linear increase under fertigation, which, in turn, increased TTA. 180 kg ha-1 of K2O in a conventional fertilization system, confirm possible metabolic changes not conducive to the cultivation and production of 'Talisman F1' watermelon. The fertilization system by fertigation represents an alternative for the cultivation of watermelon, considering the productivity and quality of fruits.

Peppermint (Mentha x piperita L.) is a medicinal plant that produces an essential oil used as an additive in food and pharmaceutical formulations. Salicylic acid is a phenolic compound widely distributed throughout the plant kingdom, being able to modify plant physiological and metabolic responses. The objective of this study was to evaluate the effects of the application of salicylic acid on the production of biomass, pigments, as well as gas exchange of peppermint plants. For this purpose, a completely randomized design composed of four replications was applied. Pigment evaluations were carried out in a 4x4 factorial scheme, consisting of the application treatments: 0 (control), 75, 150, and 225 mg L-1 of salicylic acid and four harvest periods. Gas exchange and physiological growth rates were evaluated in a 4x3 factorial scheme. Data were submitted to analysis of variance and regression. The application of salicylic acid increased CO2 assimilation and use, stomatal conductance, water use efficiency, and transpiration, which in turn, resulted in increased height, and dry stem and root mass production. It is concluded that the application of salicylic acid influences the primary metabolism, increasing gas exchange and biomass production of peppermint plants.