Artificial pollination and use of growth regulators in atemoya 'Gefner' fruits

The objective was to study the effectiveness of the growth regulator (ANA + GA3) associated or not to the application of adjuvant and artificial pollination in 'Gefner' atemoya. The experiment was conducted in the experimental orchard at Florida's Tropical Research and Education Center. The experimental design was in a randomized block, with 14 treatments, 10 repetitions and 3 flowers per plot. The highest percentages of fixed fruits were obtained with hand pollination ­ HP and 450 NAA + 1250 GA3 mg L-1 + adjuvant and HP. The use of hand pollination for 'Gefner' atemoya tree proved to be the most efficient method so far. Applying growth regulator without artificial pollination produces parthenocarpic fruits, however with high rate of abortions, and small fruits. Growth regulators together with hand pollination produces small and uneven fruits, and cause reduction in the fruits' titratable acidity. The use of adjuvant caused low fixation and toxicity to fruits, and its use is not recommended.

Associations between Integument Color and Physical and Physiological Quality in Pterodon pubescens Seeds.

Pterodon pubescens is a native Brazilian species typical of the cerrado biome, belonging to the Leguminosae-Papilionoideae (Fabaceae) family and popularly known as sucupira branca or faveiro. Its seeds exhibit different integument colors, which may exhibit a direct association to physiological quality related to higher germination percentage rates, vigor, and germination speed index (GSI). Therefore, selection and evaluation methods concerning P. pubescens seed quality are required for the preservation of this species. In this context, the aim of the present study was to determine the relationship between P. pubescens seed integument color and seed quality, through a combination of radiographic imaging and physiological, histochemical and biochemical assays. P. pubescens seeds were obtained from five matrices, and visually classified into four color classes, yellow, light brown, dark brown and black. The coordinates "L", "a" and "b", indicated by the colorimeter and the calculations of the chroma and hue angle values, verified that there was a difference in the color of the seeds, eliminating the subjectivity of the visual classification. Thus, the clearer the integuments, the greater their density, filling and α-amylase and ß-amylase hydrolytic enzyme activities, the latter comprising important germination power indicators, in addition to high ascorbate peroxidase (APX) enzyme activities, responsible for hydrogen peroxide (H2O2) elimination. Because of this, lighter colored seeds led to higher vigor, germination and GSI rates. The removal of darker seeds from P. pubescens seed lots guarantees higher germination rates and vigor of new plants in nurseries destined to recompose P. pubescens populations.

Radiographic Imaging as a Quality Index Proxy for Brachiaria brizantha Seeds.

Efficient methodologies for automated seed quality evaluations are important for the seed industry. Advanced seed technology research requires the use of adequate methods to ensure good seed performance under adverse environmental conditions; thus, providing producers with detailed, quick, and accurate information on structural seed integrity and ensuring vigorous production. To address this problem, this study aimed to determine Brachiaria brizantha (Marandu cv., Piatã cv. and Xaraés cv.) seed quality through radiographic imaging analyses associated with vigor tests and anatomical characterizations. Brachiaria seed cultivars displaying different physical and physiological attributes were selected and subjected to the 1000-seed weight test, water content determinations, X-ray analyses, germination tests, and anatomical characterizations. The X-ray analyses made it possible to establish a relationship between the X-ray images and other determined variables. Furthermore, the X-ray images can indicate evidence of internal and external damage that could later compromise germination. The Marandu and Piatã cultivars presented the highest germination percentages, germination speed indices, normal seedling development, and cellular structure preservation compared to the Xaraés cultivar. To summarize, X-ray analyses are efficient methods used for the selection of higher physical quality cultivars and can aid in the decision-making processes of companies and seed producers worldwide.

Vegetative propagation of pequi (souari nut) by cutting / Propagação vegetativa do pequizeiro por estaquia

ABSTRACT: Pequi is propagated mainly by the seminal pathway (seminal route) and presents an uneven and reduced germination. The increasing demand for fruits and seedlings for reforestation indicate the need for new strategies for the propagation of this species which would minimize the negative impact of predatory extractivism on Caryocar brasiliense. The present study aimed to assist the development of a protocol for the cutting of the pequi tree (pequizeiro). Different ages of the matrix plant and levels of foliation and pruning were assessed through the collection (sampling) of cuttings (stakes) from plants in the field. It was noted that cuttings (stakes) from seedlings (young plants) have greater rooting capacity when compared to cuttings derived from adult plants. Pequi leafless stakes failed to root. In contrast, stakes with 50% of leaflets cut from their original size showed 2.5% of rooting whereas those with 6 leaflets showed 22.5% of rooting. Stakes from pruned apical branches exhibited 21.2% of rooting. Both callogenesis and rooting of pequi stakes demonstrated the potential of this particular species from the Cerrado (Brazilian savanna) for cutting.

RESUMO: O pequizeiro é propagado predominantemente por via seminal apresentando germinação desuniforme e reduzida. A crescente demanda por frutos e mudas para reflorestamento indicam a necessidade de novas estratégias para a propagação desta espécie, minimizando os impactos do extrativismo predatório. Objetivou-se com este estudo auxiliar no desenvolvimento de um protocolo para estaquia do pequizeiro, avaliando diferentes idades da planta matriz, níveis de enfolhamento e podas, por meio de coleta de estacas em plantas a campo. Verificou-se que estacas oriundas de plantas jovens possuem maior capacidade de enraizamento, quando comparada às estacas derivadas de plantas adultas. Estacas de pequizeiro sem folhas não enraizaram, embora estacas com 50% de folíolos cortados do seu tamanho original apresentaram 2,5% de enraizamento e com seis folíolos 22,5%. Estacas oriundas de ramos apicais podados exibiram 21,2% de enraizamento. A calogênese e o enraizamento de estacas de pequi demonstram o potencial desta espécie do Cerrado para estaquia.