Understanding the growing process and fruit size differences among peach cultivars is extremely important in the technological domain of the crop and can provide information to improve the proper crop management (thinning and harvesting seasons) and the crop breeding of fruits with a larger caliber. However, this information is still incipient in subtropical regions and requires further research, especially in Brazil. The aim of this study was to determine the influence of temperature on the growing of four peach cultivars (Tropical, Aurora-2, Ouro Mel-4, and Biuti) under subtropical conditions of field cultivation. Fruit development was determined every two weeks throughout the cycle with 30 fruits from previously identified branches from six different plants of each cultivar. Regarding the thermal accumulation in growing degree-days (GDD), the cultivar ‘Tropical’ showed the lowest agronomic fruit properties (size and mass) and required a lower GDD accumulation during the development stages of the fruits, whereas the cultivar ‘Biuti’ showed higher thermal requirements and higher agronomic properties. The number of cells had greater influence on the final fruit size than the cell area.

Resumo -O cultivo de Physalis peruviana L., popularmente conhecido como fisális, apresenta grande potencial econômico e está sendo aos poucos incorporado aos plantios do grupo de pequenas frutas no Brasil. Entretanto, ainda há necessidade de se aprimorar o manejo cultural, principalmente em questões relativas às necessidades nutricionais, bem o estabelecimento de parâmetros de diagnose visual de deficiência nutricional. Objetivou-se com este trabalho descrever os sintomas visuais de deficiências nutricionais, bem como avaliar o efeito da omissão de nutrientes no crescimento e nutrição mineral de fisális. O experimento foi conduzido em casa de vegetação do Departamento de Ciências do Solo da Universidade Federal de Lavras, Lavras, Minas Gerais, Brasil. O delineamento experimental utilizado foi o inteiramente casualizado com três repetições e oito tratamentos, em solução nutritiva baseada em solução de Hoagland e Arnon com os seguintes tratamentos: omissões individuais de Ca, Mg, B, Zn, Mn, Fe e múltiplas de CaB e MgMn. Avaliou-se o número médio de folhas por planta (NF); altura (ALT); diâmetro do caule (DC); produção de matéria seca da parte aérea (PMPA), das raízes (PMR) e total (PMT); relação parte aérea/raízes (PA/R); o crescimento relativo da parte aérea e das raízes; bem como a diagnose visual. As deficiências dos nutrientes nas mudas de fisális se traduziram por sintomas típicos, com exceção da omissão do Zn que não manifestou nenhum sintoma de carência. As omissões de Fe e CaB foram as mais limitantes para o crescimento vegetativo dessa espécie.Palavras-chave: Pequenos frutos; Solução nutritiva; Fisális. Nutritional deficiency and growth of Physalis peruviana L.Abstract -The Physalis peruviana L. cultivation, popularly known as 'golden berry', has a great economic potential and is being gradually incorporated into the crops of the small fruits group in Brazil. However, there is still a need to improve management practices, especially in matters relating to the nutritional needs such as the establishment of visual diagnosis parameters of nutritional deficiencies, which would make it possible to achieve higher productivities. This study aimed to describe the visual symptoms of nutritional deficiencies and evaluate the effect of the omission of nutrients on the growth and nutrition of golden berry. The experiments were conducted in a greenhouse of the Department of Soil Science of the Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil. The experimental design was completely randomized with three replications and eight treatments in nutrient solution based on Hoagland and Arnon solution with the following treatments: individual omission of Ca, Mg, B, Zn, Mn, Fe and multiple omissions for CaB and MgMn. This study evaluated the number of leaves; plant height; stem diameter; dry matter weight of aerial parts; dry matter weight of roots; total dry matter weight; dry matter weight aerial:roots ratio; and the visual diagnosis of nutritional deficiencies. The observations of the nutritional deficiencies sho...

Popcorn (Zea mays var. everta) has a higher commercial value than common maize, in addition to being a popular food among consumers. Today, there is a constant search for cultivars with superior performance for several traits of interest in the case of popcorn, yield and popping expansion. On this basis, this project proposes to characterize progenies of popcorn with different values of expansion capacity regarding chemical composition and micromorphology. Kernels from the fifth cycle (C5) of intrapopulation recurrent selection were evaluated. The progenies were selected based on the popping expansion volume of their kernels. The kernels were quantified for amylose and analyzed for starch granule arrangement and pericarp thickness by scanning electron microscopy. Progenies with low popping expansion volume (0 and 7 mL g-1) showed amylose contents of 21.24 and 20.18%, respectively; a less compact endosperm, with individual starch granules interspaced with empty spaces; and pericarp thickness between 40.94 and 38.99 µm, respectively. By contrast, progenies with high popping expansion volume (30 and 35 mL g-1) showed amylose contents of 23.92 and 26.10%; a vitreous endosperm; more-compact starch granules without empty spaces in between; and pericarp thickness between 107.66 and 107.84 µm. Progenies with higher popping expansion volume exhibited a thicker pericarp, a high amylose percentage and a more-compact endosperm, whereas those with the lower expansion volumes showed a thinner pericarp, a lower amylose percentage and individual starch granules.

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.

Establishing ideal conditions and speed in carrying out the germination test for sunflower seeds is of utmost importance in quality control programs of companies dedicated to the production of high technology seeds. In this regard, the aim of this study was to verify the possibility of reducing the evaluation time of the germination test of sunflower seeds in different substrates and temperatures. Six seed lots of the cultivar Helio 251 and six lots of the cultivar Helio 253 were used. As well as germination, determinations were made of first count germination and seed health. The seeds were kept in a germination chamber at 25 ºC, 30 ºC, and 20-30 ºC for the paper substrate, and 25 ºC and 30 ºC for the sand substrate. To verify the possibility of reducing the evaluation time of the germination test, the number of normal seedlings were counted daily, up to the tenth day after sowing. It was concluded that it is possible to conclude the germination test on the seventh day after sowing in sand at the temperature of 25 °C.