The Physalis angulata L. species has attracted interest due to the production of compounds with pharmacological activity and its potential for fruiticulture. Given that it is a fast-growing and highly productive species, determining the most adequate nitrogen (N) doses could contribute to higher crop yields. This study aimed at assessing the influence of N concentrations, in a hydroponic system, on the growth and production of P. angulata, as well as determining the critical N level in leaves. The experiment was conducted in individual pots with nutrient solutions, applying a completely randomized design and twelve replications, using five N doses (0 mg L-1, 56 mg L-1, 112 mg L-1, 168 mg L-1 and 224 mg L-1). Growth and production indices, amount of total N on leaves and stems and critical N levels were assessed. The increase of N doses in the nutrient solution influenced plant growth and fruit production, as well as the accumulation of total N in the leaves and stems. Based on the maximum economic yield, a dose of 162 mg L-1 of N is recommended for hydroponics, which provided a fruit yield of 7.27 g m-2 and critical total N level in leaves of 51.98 g kg-1.

The objective of this work was to evaluate the physical-chemical and physiological changes during the maturation of fruits and seeds of P. peruviana and to determine the best stage for harvesting in the Brazillian semi-arid conditions. The fruits of P. peruviana were collected at five stages of maturation based on the color of the epicarp: stage 1: light green fruit; stage 2: yellowish-green; stage 3: light yellow with green color in the area that connects to the calyx; stage 4: yellow; stage 5: yellowish-orange. Physical and physico-chemical (length, diameter, fresh weight, fruit and calyx color, and total soluble solids) characteristics were evaluated. The physiological characteristics of the seeds were evaluated for water content and dry weight, germination percentage, germination speed index, emergence percentage, emergence speed index were also determined. The highest values of fruit weight, width, length and total soluble solids were recorded from stage S5, although it did not differ from stages S3 and S4. P. peruviana seeds reached their maximum physiological quality from S3 stage. On the other hand, the harvesting of fruits with characteristics meeting the minimum standards required for sale and consumption in natura should be carried out when the fruit and the calyx appear completely yellow, in the S4 stage. These findings point out which attributes may help improve current methods for monitoring ripening of physalis, in particular the commercially important specie P. peruviana.

O sisal (Agave sisalana Perrine) é utilizado para a extração das fibras contidas em suas folhas, sendo a principal fibra dura produzida no mundo. Entretanto, tem sido observado um declínio dessa cultura, devido a uma doença causada pelo fungo de solo Aspergilus niger. A biotecnologia, em especial as técnicas de cultura de tecidos, representa uma alternativa viável para a propagação dessa espécie. Dentre essas técnicas, está a embriogênese somática e, nesse sentido, este estudo objetivou caracterizar a morfogênese in vitro, durante a embriogênese somática, em A. sisalana Perrine. Em todos os experimentos, utilizaram-se bulbilhos como explantes e meio de cultura MS½ acrescido de sacarose (30,0 g L-1), solidificado com ágar (7,0 g L-1) suplementado com diferentes concentrações de auxinas e citocininas. Os explantes formaram calos com aspectos compactos e semicompactos, evidenciando células embriogênicas que se converteram em embriões somáticos, com o uso de 2,4-D e BAP. Por meio das análises anatômicas, pôde-se observar embriões em estádios globular e torpedo e a não conexão com o calo mãe.

Choosing an appropriate nitrogen source is of utmost importance, since it affects the plant development and fruit and seed yield. This study aimed to evaluate the quality of Physalis angulata fruits and seeds obtained from plants grown in a hydroponic system, under different concentrations of nitrate and ammonium. The treatments consisted of four NO3-:NH4+ ratios (100:0, 75:25, 50:50 and 25:75). After full grown, the fruits were collected for biometric and chemical analyses, and seeds were removed for the germination test. The germination test was conducted in a germination chamber and the parameters evaluated were the germination rate, mean germination time, speed, germination uniformity coefficient and relative frequency. Fruits with lower weight and diameter were obtained at doses above 50 % of ammonium; however, there was an increase for ºBrix and soluble solids/titratable acidity ratio. Such dosage also reduced the rate, speed and uniformity of germination. The combined use of nitrogen sources (50:50 of NO3-:NH4+) is recommended, because it produces larger and sweeter fruits with vigorous seeds.

Características biométricas de frutos e caracterização fisiológica de sementes de espécies de Physalis (Solanaceas) - DOI:10.5039/agraria.v12i3a5447

A seringueira na fase adulta possui um crescimento intermitente com o processo de troca de folhas, que é caracterizado pela senescência. Esse é um mecanismo que as árvores utilizam para reciclarem os nutrientes, por meio dos ciclos bioquímico e biogeoquímico. Estudos sobre o ciclo bioquímico são necessários para verificar o comportamento dos nutrientes minerais, nos diferentes estádios foliares, pois a conservação desses é importante, visto que os seringais são implantados em solos de baixa fertilidade. Desse modo, este trabalho teve por objetivo avaliar a dinâmica dos nutrientes minerais, durante os diferentes estádios foliares da seringueira. As folhas utilizadas foram provenientes de plantas do clone RRIM-600, de um seringal localizado em Nepomuceno, MG. Foram selecionadas oito árvores adultas que possuíam folhas nos diferentes estádios (B1, B2, C e D) e as senescentes (Sen.). As folhas nos estádios B1, B2, C e D foram coletadas nos quatro pontos ortogonais e as senescentes foram coletadas no solo após a agitação mecânica dos galhos. Observou-se que os nutrientes N, P, K, S, Cu e Zn diminuíram os seus teores nos diferentes estádios foliares da seringueira. No entanto, para Ca, Mg, B, Fe e Mn, verificarou-se um comportamento inverso. A redistribuição dos nutrientes foi maior para N, P, K e Cu. A ordem relativa dos teores de macronutrientes encontrados nas folhas foi: N>K>Ca>Mg>S>P e, para os micronutrientes, a ordem foi: Mn>Fe>Zn>B>Cu.