Elvis Lima Vieira

Germinação de sementes de jenipapeiro submetidas à pré-embebição em regulador e estimulante vegetal

This work aimed to evaluate the genipap (Genipa americana L.) seed germination and its initial seedling growth, submitted to pre-soaking in regulator and vegetal stimulant. It was arranged in a randomized design with four repetitions of 25 seeds and eight treatments, in which seeds were impregnated for 12 hours: T1 - water, T2 - Liquid gibberellins 4% GA3 (GA3 4% L) (50 mL L-1), T3 - (GA3 4% L) (100 mL L-1), T4 - (GA3 4% L) (200 mL L-1), T5 - (GA3 4% L) (300 mL L-1), T6 - (GA3 4% L) (400 mL L-1), T7 - Stimulate® (5 mL L-1) e T8 - Stimulate® (10 mL L-1). The seeds were disposed on a paper, previously wet with distilled water and taken to the germinator chamber adjusted in 28oC. There were evaluated the germination percentage, roots length, hypocotyls, and seedling 21 days after the seeding and the Germination Velocity Index. The results had shown that the genipaps seed pre-soaking for 12 hours in GA3 4% L (50, 10 e 200 mL L-1) e Stimulate® (10 mL L-1), provides a higher germination velocity index. The Stimulate® 10 mL L-1, in pre-soaking for 12 hours provides a higher root growth and increase the number of genipap seedlings, comparing with others treatments.

Effect of gibberellic acid and the biostimulant stimulate® on the initial growth of tamarind

Plant growth regulators and biostimulants have been used as an agronomic technique to optimize the production of seedlings in various crops. This study aimed to evaluate the influence of gibberellic acid and the biostimulant Stimulate® on the initial growth of tamarind (Tamarindus indica L.). The experiments were conducted in a nursery with 50% shading, in a randomized block design with five replications and five plants per plot. Thirty eight days after sowing, the leaves were sprayed seven times a day with 0.0 (control), 0.8, 1.6, 2.4 and 3.2 mL of gibberellic acid L-1 aqueous solution and with 0.0 (control), 6.0,12.0, 18.0, and 24.0 mL Stimulate® L-1 aqueous solution. Stem diameter (SD), plant height (PH), longest root length (LRL), shoot dry mass (SDM), root dry mass (RDM) and RDM:SDM ratio were evaluated ninety days after sowing. Variance and regression analysis showed that GA3 at 4% promoted plant growth (height), but had no significant effect on stem diameter, longest root length, shoot and root dry mass and the RDM:SDM ratio. On the other hand, all concentrations of Stimulate® significantly increased plant height and shoot and root dry mass of tamarind seedlings.

Plant stimulant effect on Brasil-Bahia tobacco growth and production

The purpose of the study was to evaluate the effect of the Stimulate ® plant stimulant, applied to leaves by spraying, on tobacco ( Nicotiana tabacum L.) growth and production. The Brasil-Bahia tobacco and Stimulate ® , at the doses of 0.0 mL L -1 (control - water); 1.0 mL L -1 ; 3.0 mL L -1 ; 5.0 mL L -1 ; and 11.0 mL L -1 , in watery solution, were used. On the fifteenth day after sowing (DAS), the treatments were applied. A total of six sprayings were made, once a day, each five days. After forty-three DAS, the number of leaves; stem and root length; stem, roots, and leaves dry matter; and leaf area were evaluated, under nursery conditions. In the field, the plants remained for 64 days (107 DAS) and the number of leaves; number of viable leaves; plant height; stem and leaves dry matter; and leaf area were evaluated. Stimulate ® , under nursery conditions, decreased stem, root and leaf dry matter and leaf area for tobacco. Stimulate ® was also efficient to increase the number of leaves and stem length, under nursery conditions, for the Brasil-Bahia tobacco. Under field conditions, Stimulate ® , applied during the vegetative stage, was not efficient to increase leaf production, however, it increased stem height and dry matter. KEY-WORDS: Nicotiana tabacum L.; leaf pulverization; plant regulator; Stimulate ® .