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.

It is acknowledged that mechanical damage is a major cause of post-harvest losses of potato tubers and the curing is an indispensable process to increase resistance to excoriation. Furthermore, the use of lower curing temperatures is required to maintain the quality and prolong the durability of the tubers. However, they may not allow adequate regeneration of the damage periderm, besides this effect being variable among genotypes. The present study evaluates histological outcomes in the periderm derived from the mechanical damage through a simulation of excoriation, as it is the most common during the harvest and post-harvest stages. Therefore, the objective of this study was to determine the effect of reducing the curing temperature on the number of layers and on the thickness of the damage periderm of potato tubers of cv. Innovator. Histometric analysis of the cork, phellogen, phelloderm and the total periderm of tuber, was performed using the Image-Pro Plus software (MediaCybernetics) after curing for 15 days. The number of layers and thickness of each periderm structural layers were determined from six measurements for each repetition. After curing, there was no formation of the cork and phelloderm in the tubers conducted at 8 ° C under the excoriation treatment, while all components of the periderm were formed at 14 and 20 °C. At 8 and 14 °C, the phellogen differentiated similarly in tubers conducted at control and mechanical damage treatments, while at 20 °C the thickness did not differ in any component of the periderm. The phellogen at 14 and 20 °C did not differ in the number of layers and thickness. The visual aspect of the tuber injuries at 14 and 20 °C emphasizing the regeneration. It is concluded that the reduction of the curing temperature to 8 °C provided slower cell regeneration. However, it is possible to conduct the curing procedure at 14 °C, without compromising the formation of the damage periderm. The cultivar Innovator has rapid cell regeneration at higher curing temperatures, therefore it is recommended that the tubers of this cultivar be cured at 14 or 20 ° C. The study evaluates the mechanical damage through a simulation of the damage by excoriation. The however, for a better understanding of the formation of the damage periderm, it is interesting that other studies evaluate different types of damage, such as impact, comprehension and abrasion, in order to assess the regeneration capacity according to the damage of this cultivar.

The objective of this study was to determine the storage efficiency and reconditioning of potato cv. Innovator for processing. Tubers were stored at 6, 7 and 8 °C in the dark for 30, 60, 90, 120 and 150 days and reconditioned at 15 °C for 15 days. TRS and RS were reduced as storage temperature increased from 6 + 15 °C to 8 + 15 °C. Regardless of temperature and storage time, sugar contents were suitable for industry; however non-enzymatic browning remained in category 2 for up to 60, 90 and 150 days in tubers stored at 6 + 15 °C, 7 + 15 °C and 8 + 15 °C, respectively. Starch was influenced by storage time, despite the absence of temperature effect. Regardless of the temperature, sprouting started at 90 days, but the growth of shoots was directly proportional to the increase in temperature. The PPO and POD increased at the beginning of storage but did not cause darkening before the frying. Reduction in storage temperature followed by reconditioning did not delay the onset of sprouting, but reduced the size of sprouts, maintained adequate sugar levels, however it promoted non-enzymatic browning.

Mechanical damage and storage conditions may alter carbohydrate metabolism and oxidative enzyme activity, causing darkening and impairing the use of tubers in pre-fried potato processing industry. The objective of this study was to evaluate the enzymatic changes and carbohydrate metabolism of ‘Markies’ potato tubers subjected to mechanical damage and exposed to high temperatures before processing. The tubers were stored for 4 months at 8 °C, and further divided into treatment with impact and abrasion damage; and control treatment, in which the tubers were not damaged. Afterwards, they were stored at 28 °C room temperature, evaluated for loss of accumulated fresh mass (FML); total soluble sugar (TSS), reducing sugar (RS) and non-reducing sugar (NRS); color after frying and activity of polyphenoloxidase (PPO) and peroxidase (POD) at 0, 12, 24, 36 and 48 h after placed at room temperature. The mechanical damages incremented FML, RS, PPO and TSS, NRS and POD up to 35.6, 34, and 22 h, respectively. Regardless of the occurrence of mechanical damage and the period of evaluation, the sticks showed a light color after frying and were classified in category 2. The increase in the evaluation time led to the rise in FML and the PPO activity. It is concluded that the mechanical damages increase the FML and cause darkening of the tips of the sticks after frying, however this variety still display qualities that are suitable for industrial processing.

The refrigerated induce the sweetening of the potato, which results in the dark color. The objective of this study was to determine the temperature and shelf life of Markies potato tubers under refrigerated storage for the processing of French fries. The levels of total soluble sugar (TSS), reducing sugars (RS), peroxidase (POD) and polyphenoloxidase (PPO) activity, color after frying and start of sprout were determined. The accumulation of TSS started at 30 days in the tubers at 4 and 5 °C and in the tubers at 6 and 8 °C, at 150 days. The activity of POD and PPO were not influenced by temperature or storage time. Tubers at 4 e 5 °C showed higher TSS and RS contents and darker color after frying than tubers stored at 6 and 8 °C which had their color maintained within the industry-acceptable standard up to 240 days of storage. Temperatures of 4 and 5 °C delayed the onset of sprouting, starting at 150 days, and at temperatures of 6 and 8 °C, the onset of sprouting occurred from 90 and 60 days of storage, respectively. It is concluded that the cultivar Markies should be stored at 6 °C for 240 days.

The objective of this study was to determine the effect of 1-methylcyclopropene (1-MCP) on vase life of rose cv. Osiana in different storage conditions and in the presence of exogenous ethylene. The roses were treated with 0.5; 1.0; 1.5 and 2.0 g m-3 of Ethylbloc  , and submitted to the following conditions: Storage at 5 °C with stems in water; Storage at 22 °C with stems in water; Storage at 5 °C in 'Strong' type paper for 3 days and subsequent storage at 22 °C. The best storage condition was at 22 °C with the stems in the water. Doses greater than 1.0 g m-3 of Ethylbloc  prolonged vase life. In this condition, the stems were treated with 1.0 g m-³ Ethylbloc  ; 1.0 g m-3 Ethylbloc  + 10 µL L-1 ethylene and 10 µL L-1 ethylene for 24 h. The Ethylbloc  increased vase life even in the presence of ethylene and fresh mass on the first two days. It reduced ethylene production by flowers in the first 24 h, and respiratory activity after 36 h. It can be concluded that the concentration of 1.0 g m-3 of Ethylbloc  prolongs the vase life of cv. Osiana stored at room temperature with the stems in water even in the presence of exogenous ethylene.

Excoriation damage is among the major causes of postharvest potato losses. Curing is known to increase the resistance of tubers to excoriation injury, with the temperature influencing the traumatic phellogen and periderm regeneration, as well as tuber processing quality. This study aimed to evaluate the effects of excoriation procedure and curing temperature on the industrial quality, histological characteristics, carbohydrate metabolism, and oxidative enzyme activity of potato tuber. Tubers with or without excoriation were cured at 8, 14, and 20°C for 15 days. Excoriation did not influence the levels of reducing sugars (RS), as well as polyphenoloxidase (PPO) and peroxidase (POD) activities. The concentrations of total soluble sugars (TSS) and non-reducing sugars (NRS) were higher in injured tubers, while reduction in curing temperature increased the concentrations of TSS, NRS, and RS. However, the sugar content was adequate as per the criteria of the pre-fried potato industry and potatoes classified in category 2 (USDA/fast-food industry color grading). The reduction in curing temperature also increased the activity of POD, despite the activity of PPO remaining unchanged. Formation of a closure layer from the outer parenchyma cells of the tuber that prevents desiccation and death of superficial cells, was observed. This protection was completed with the formation of the damage periderm. Periderm regeneration is faster at higher temperatures, 15 and 20°C, leading to a lower fresh mass loss and no enzymatic or non-enzymatic browning. The excoriation carried out at 14/20oC for 15 days was sufficient for curing, and for maintaining suitable post-fry quality of potatoes.

Reducing the storage temperature delays sprouting and increases the storage period, prolonging the supply to the industry. However, it may cause enzymatic browning before frying and non-enzymatic browning over frying. Therefore, the objective of this study was to determine the effects of a reduction in the temperature and storage time on the quality of cv. Innovator intended for frying. Potato tubers were stored at 6, 7 and 8 °C for 150 days. This study analyzed the total soluble sugars (TSS), non-reducing sugars (NRS), reducing sugars (RS), post-frying coloring, fresh mass loss (FML), sprouting onset, peroxidase (POD) and polyphenoloxidase (PPO) activity. The TSS, NRS and RS contents were higher in tubers stored at 6 °C, classified in category 3, while at 7 and 8 °C, it was classified in category 2. Storage time affected sugar concentrations only in tubers at 6 °C. Also at 6 °C, the FML was lower and sprouting was delayed by 30 days. Regardless of temperature and storage time, there was no enzymatic darkening due to POD and PPO activity. It is concluded that reducing the storage temperature to 6 °C prolongs the dormancy period, reduces fresh mass loss, increases reducing sugar content and non-enzymatic browning.