The breakdown of dormancy and early sprouting is one of the main causes of losses of stored potatoes. Sprouting control becomes important especially when tubers are submitted to long-term storage for further processing by the potato industry. The objective of this work is to evaluate the effect of organic sprout inhibitors, eugenol and menthol essential oils, on the suppression of growth on non-dormant 'Asterix' tubers stored at 8 °C. Administration of eugenol and menthol essential oils reduced the number and the length of sprouts during cold storage up to fifty days. Nevertheless, the essential oils stimulated the break of bud apical dominance, stimulating auxiliary buds growth. The effect of the oils was restricted to inducing necrosis of superficial sprout cells without any apparent effect on the skin periderm structure. Repeated applications of oils are necessary to prolong the inhibitory effects of the essential oils on sprouts growth.

The objective of this work was to evaluate the action of paclobutrazol (PBZ) on the growth and ornamental value of two pepper accessions and two commercial cultivars of ornamental pepper - Biquinho Vermelha and Bode Amarela. A PBZ aqueous solution (250 mL) was used to soak the substrate at 0, 20, 40, and 60 mg L-1 a.i. concentrations when the plants had 12 cm height. At the end of plant growth, the follwoing parameters were evaluated: plant height, chlorophyll content in leaves, number of fruit and leaves, and canopy compactness at the time the plants reached maturity to be marketed, with 30% of ripe fruit. Irrespective of the applied PBZ concentration, plant height diminished, and chlorophyll content increased. PBZ did not improve the ornamental characteristics of the genotypes 'Biquinho Vermelha' and 2334PB, which resulted in unsuitable plants for market requirements. For the genotypes 2345PB and 'Bode Amarela', the application of 20 mg L-1 of PBZ is the most indicated, and it results in plants with adequate ornamental characteristics required by the national market of flowers and ornamental plants.

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The effects of three paclobutrazol (PBZ) application methods on ornamental characteristics of two pepper cultivars (‘Biquinho Vermelha’ and ‘Bode Amarela’) were evaluated. Plant growth regulator at 10 μM PBZ was added at transplanting by drenching 250 mL PBZ solution on the pot substrate, foliar spray of 10 mL PBZ solution or by submerging seedlings root + substrate for 10 seconds in the PBZ solution. Control plants were treated with tap water applied directly on the substrate. Plant height, canopy compactness, fruits and leaves number, and leaf chlorophyll content were evaluated when 50% of the plants had approximately 30% of mature fruits (commercial maturity). PBZ applied by drenching influenced positively the ornamental characteristics of ‘Bode Amarela’. Otherwise, the best PBZ application method for ‘Biquinho Vermelha’ was not established. The results suggest that search for suitable PBZ application method that no affects the pepper ornamental characteristics must be done specifically for each pepper cultivar.

The longevity of cut flowers is limited by their ephemeral nature and by multiple stresses. Impairment in water uptake, depletion of stored carbohydrates, increases in both respiratory activity and ethylene production are signatures of flower senescence. A wide range of techniques is available to extend flower preservation, including the use of flower preservative solutions, ethylene action inhibitors, growth regulators, and control of temperature and flower dehydration. The use of sucrose in pulsing solution, or as a component of vase solution, extends the vase life of flowers by either improving water balance and energy or delaying the senescence via reductions in ethylene biosynthesis. Inhibitors of ethylene production and action affect the longevity by extending the vase life of some ethylene-sensitive flowers. Flowers have intense respiratory activity, which may deplete the limited reserves of carbohydrates in the tissues. Lower temperatures markedly reduce both carbon dioxide concentration and ethylene production as well as its action. However, chilling-sensitive flowers, such as bird-of-paradise, heliconia, orchid, and ginger, cannot be stored below 10 to 13°C due to the intense development of tissue discoloration.

The increased demand for potato by the Brazilian processing industry requires long term refrigerated storage, but after a few months, natural dormancy ends, and sprouts start to grow. Thus, sprout inhibitors are necessary to reduce the rate of growth and allow further storage. The purpose of research described here was to determine the effects clove and menthol essential oils have on the inhibition of sprout growth in non-dormant ‘Asterix’ tubers. Both eugenol and menthol treatments reduced the rate of sprout growth during storage at 8oC for up to 50 days. Eugenol and menthol essential oils diminished the rate of accumulation of reducing sugar, which are responsible for browning of French fries. Color after frying was within acceptable levels when the tubers were treated with eugenol or menthol essential oils.

Dne of the major problems affecting potatoes quality on stored is the susceptibility to enzymatic browning, which occurs mainly after wounds during the harvest, at postharvest handling and by aging, leading to the development of dark color compounds. Enzymatic browning is associated with the action of polyphenoloxidases (PPD) and peroxidases (PDD), which use phenolic compounds and oxygen as substrates. The products of these enzymes cause undesirable changes of color and flavor of processed potato products. The present study aimed to evaluate some kinetic properties based to optimum pH and reaction temperature, and to determine changes on activity of potato tubers PPD and PDD treated with sprouting suppressors compounds menthol and eugenol. For each treatment, samples were collected in six different periods, before application (day 0) and 10, 20, 30, 40, and 50 days after the treatments to determine the influence of sprout inhibitors on the activity of PPD and PDD. Changes in pH and temperature affected drastically the activity of both enzymes. The use of eugenol and menthol as sprouting suppressors decreased enzymatic activity on the treated tubers compared to control with an inverse relationship between enzymes activity and content of phenolic compounds.

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