Sugar apple fruit are widely appreciated because of their flavor and functional qualities. However, the final value of the fruit varies according to its physical, physicochemical, and organoleptic qualities. The production and attributes that make up the quality of fruit can be influenced by climatic seasonality in both seasons (dry and wet). Therefore, this work aimed to evaluate whether the production and quality of fruit production of different size classes of A. squamosa L. in two seasons are affected by climatic seasonality. The experiment consisted of a randomized block design, with 4 blocks and 10 plants per block. The variables evaluated were number of fruit per hectare, production, and yield. The postharvest evaluation of the fruit consisted of a completely randomized experimental design, in a 3 × 2 factorial scheme, which referred to the three sizes and two seasons, and evaluated fruit length and diameter; firmness; fruit, bark, and seed weight; number of seeds; soluble solids; hydrogen ionic potential (pH); titratable acidity (TA); and ratio. The 2014 season had larger fruit in relation to those of the 2015 season; conversely, it showed a lower number of fruit per plant, production, and yield, besides inferior organoleptic quality. Fruit of size class 2 stood out in the 2014 season because of their physical characteristics. However, they had inferior organoleptic quality when compared with fruit of the same size collected during the 2015 season. Fruit of size class 3 (≥8.1 cm) had greater firmness, providing longer durability and shelf life.

Abstract:The rational use of water is essentual as it is a finite resource. Consequerntly, studies of methids that minimize water use water are essential. As a result, agricultural hydrogels have been extensively tested in as a means of promoting agriculture improvements because of their water-and nutriente-retention characteristics. However, even though hydrogels are used in several sectors of Brazilian agriculture, there are still very few studies on their applications, the best methods and the quantities to be used. Consequently, there is a need for research into the applicability of this technology in Brazil, so that future research needs can be identified and appropriate decisions made at the production level. Therefore, the aim of this study was to collate currently available information on the applicability of agricultural hydrogels in Brazilian agriculture. Over the last decade, forestry is the sector in Brazil that has most studied and used hydrogels, but others such as fruit-and coffeegrowing have also been involved. The method of applying the polymer in granules directly mixed-in with growth substrates is the most used in the production of seedlings. However, use of hydrated gel at planting sites has also been explored. While synthetic hydrogels are most commonly used, those made of natural materials have great potential due to the low preparation costs and their in-soil biodegradability. The quantities of hydrogel used vary according to the target species, application method and objective.Key words: Water sustainable use. Hydro absorvent polymer. Application. Agricultural cultures.Resumo: A utilização racional da água faz-se necessária uma vez que esse recurso é finito, assim, estudos sobre a produção e minimização do uso da água são essenciais. A partir disso, os hidrogéis agrícolas vêm sendo amplamente testados na agricultura por promoverem benfeitorias às plantas pelas suas características de retenção de água e nutrientes. No entanto, mesmo sendo utilizados em diversos ramos da agricultura brasileira, estudos quanto aos métodos de aplicação e às quantidades utilizadas ainda são escassos, justificando a necessidade de pesquisas que elucidem a aplicabilidade dessa tecnologia, para assim gerar informações que sustentem decisões precisas no nível produtivo e experimental. Portanto, objetivou-se com este trabalho compilar as principais informações atuais quanto à aplicabilidade dos hidrogéis agrícolas na agricultura brasileira. A silvicultura é o setor que mais vem estudando e utilizando o uso dos polímeros hidrorretentores nos últimos 10 anos no Brasil, porém, setores como a fruticultura e a cafeicultura também vêm se destacando. O método de aplicação do polímero em grânulos em mistura direta com substratos é o mais utilizado na produção de mudas, todavia, a utilização do gel hidratado no local de plantio apresenta-se como uma alternativa promissora à agricultura brasileira. Os hidrogéis sintéticos são os mais utilizados, no entanto, os constituídos por materiais naturais têm grande potencial em funçã...

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Camu-camu (Myrciaria dubia (Kunth) McVaugh) is a native fruit tree, which is in domestication process, therefore, knowledge of nutritional needs is essential to improve the fertilization efficiency throughout plant development. The aim of this research was to determine the nutrient content of camu-camu plants as a function of nitrogen fertilization via fertirrigation in the first year of cultivation. An experiment was carried out in a randomized complete block design, with 5 treatments as follows: 0; 40; 80; 120 and 160 kg.ha -1 of N, eight replicates and seven plants per experimental unit. The evaluated variables were as follows: total dry matter and nutrient contents in camu-camu leaves. The results show total dry matter of camu-camu plants, which were performed a significant quadratic behavior in response to increasing N doses. In Fact, N doses greater than 128 kg.ha -1 aroused a depressive effects. In addition, leaf contents of N, K, and Ca, had achieved a significant quadratic response and highest concentrations were recorded between 113 and 115 kg of N.ha -1 . On the other hand, micronutrients had a polynomial depressive behavior according to an increasing N doses. It can be concluded that nutrient foliar contents are adequate for the camu-camu plants development. In fact, N, Ca, K, Fe, Mn and B, were the most required nutrients. Micronutrients determined in leaves, corresponded to the following decreasing order: N> Ca> K> Mg> S> P> Mn> Fe> B> Zn> Cu, respectively. Key Words: Dry matter, micronutrients, nutrient balance (plants), plant development, plant nutrition. ResumoO camu-camu (Myrciaria dubia (Kunth) McVaugh) é uma fruteira nativa que está em processo de domesticação, portanto, o conhecimento das necessidades nutricionais é essencial para melhorar a eficiência da adubação durante seu desenvolvimento. O trabalho teve como objetivo determinar os teores de nutrientes em plantas de camu-camu em função da adubação nitrogenada via fertirrigação no primeiro ano de cultivo. O experimento foi conduzido mediante delineamento experimental em blocos casualizados, com 5 tratamentos: 0; 40; 80; 120 e 160 kg ha -1 de N, oito repetições e sete plantas por unidade experimental. As variáveis avaliadas foram a massa seca total e os teores de nutrientes nas folhas. Os resultados mostram que a massa seca total das plantas de camu-camu apresentou comportamento quadrático significativo em resposta às doses crescentes de N, sendo que doses maiores a 128 kg ha -1 propiciaram efeitos depressivos. Além disso, os teores foliares de N, K, Ca tiveram uma resposta quadrática significativa, sendo que as maiores concentrações foram registradas entre as doses de 113 e 115 kg de N ha -1 . Por outro lado, os micronutrientes tiveram um comportamento polinomial depressivo de acordo com os incrementos das doses de N. Pode-se concluir que os teores foliares dos nutrientes estão dentro dos adequados para o desenvolvimento das plantas de camu-camu, e os nutrientes mais exigidos foram o N, Ca, K, Fe, Mn e B, e finalmente os teores de...

The objective of this work was to evaluate the influence of arbuscular mycorrhizal fungi (AMF) on the accumulation of shoot and root biomass and on the nutrient contents of Urochloa decumbens grown in soils with different densities. The experiment was carried out in a randomized complete block design, in a 4x2 factorial arrangement: four soil densities (1.0, 1.2, 1.4, and 1.6 kg dm-3) with and without inoculation of AMF, with four replicates. The biomass accumulation (dry matter weight of shoot and roots) and macro- and micronutrient contents of U. decumbens were determined at different soil densities. The mycorrhizal colonization of the plants was evaluated, and the number of mycorrhizal spores present in the soil was determined. The biomass accumulation of shoot and roots and macro- and micronutrient contents, as well as the number of mycorrhizal spores in the soil, were negatively affected by the increase in soil density. Only root biomass increased with AMF inoculation. There was no interaction between soil density and inoculation for shoot and root biomass accumulation. Arbuscular mycorrhizal fungi influence the accumulation of biomass in the roots and of N and Ca contents in the shoots of Urochloa decumbens even at the highest soil densities.

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Camu-camu is an native species in domestication processes. Therefore, studies related to the root system are necessary to evaluate the best cultivation practices for an orchard. Two trials were conducted, one with nitrogen (N) and the other with potassium (K), at doses of 0, 40, 80, 160, and 320 kg · ha -1 . Root distribution was determined using nondestructive analyses in which two-dimensional (2D) root images were obtained from trenches under the plants' canopy. Variables included width (measured in cubic millimeters), area (measured in square millimeters), and length (measured in millimeters, and were analyzed using Safira software (version 2010, Embrapa, Brazil). To have better spatial visualization of variable distribution in the soil profile, data were analyzed using the ordinary kriging technique with the geoR software package and R software (version 2016). Both N and K doses influenced positively the camu-camu root system with regard to length, volume, and area. Better root distribution was verified with 80 kg · ha L1 N and 160 kg · ha L1 K doses. The nondestructive analysis via 2D images allowed sound characterization of root spatial distribution.Camu-camu is an native species of the Amazon Basin that attracts attention as a result of its high content of vitamin C, reaching up to 7355 mg/100 g pulp in native populations of Roraima State (Chagas et al., 2015). It is currently considered functional food, with

Ground basalt rock may represent a labile reservoir of nutrients, providing a low-cost, nutrient-rich substrate for seedling formation and plant growth. The study aimed to evaluate the development of a native plant murici [Byrsonima crassifolia (L.) H.B.K.] seedlings using two different application rates of ground basalt rock with two particles sizes. The experiment was performed in a greenhouse, in which treatments were arranged in a random block design with five replications in a factorial scheme (2 x 5 + 1), with five doses of finely ground basaltic rock (0.42; 1.04; 2.08; 4.17 and 8.33 g kg-1), two grain sizes (G1 Ø < 0.05 and G2 Ø < 0.10 mm mesh), and a treatment with soil without rock powder addition (the control 0.0 g kg-1 of rock powder). The seedlings were cultivated in substrate incubated for 120 days with the ground basaltic rock. Six months after the seedlings were planted variables involving growth and nutrient content variables were evaluated. Grain size affected nutrient availability from finely ground rock (Ca, Mg, Fe, and Zn). The growth of murici seedlings linear increase with ground basaltic rock application rates, with better results when a 0.05 mm grain size was used.