Nutrient contents and fertirrigation in camu camu (Myrciaria dubia (Kunth) McVaugh) crop with different nitrogen doses

Abstract

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...

Camu-camu Root Distribution under Different Nitrogen and Potassium Doses through Drip Fertigation

“…The results obtained in our work are in agreement with those of Abanto-Rodriguez et al (2018), who evaluated the total dry weight of camu-camu plants under different N doses. They demonstrated that there was a greater increase in the total dry weight with about 80 kg · ha -1 and a growth decrease at greater doses.…”

Initial production and quality of camu-camu fruits under organic and mineral fertilization

“…Apparently, a rapid nutrient availability in the soil was detrimental to the camu-camu fruit production. The same behavior was also observed in camu-camu seedlings when there was a rapid change in the physical characteristics of the soil due to organic fertilization (Abanto-Rodríguez et al 2018). Coincidentally, Sousa (2009), who studied camu-camu under the same conditions of this experiment, found that the camu-camu growth is more impaired by mineral fertilization than by organic fertilization in the first year of growing, and Initial production and quality of camu-camu fruits under organic and mineral fertilization this could have influenced the low fruit production in the experiment.…”

“…Abanto-Rodríguez et al (2014 found that 160 kg ha -1 of potassium under a fertigation system provided better results, in relation to the height, diameter and number and total length of branches, as well as total mass and Dickson quality index, for the initial growth stage of camu-camu plants on dry land. In addition, Abanto-Rodríguez et al (2018) evaluated the nutrients of camu-camu plants fertigated with nitrogen doses and found that doses greater than 128 kg ha -1 cause a decrease in biomass in the initial growth stage of plants.…”

Status of Nitrogen in Different Parts of Cupuassu Tree in Oriental Amazon

“…Several studies confirmed that fruit trees are strongly responsive to the addition of nitrogen fertilizers, positively reflecting on development and productivity (Amorim et al, 2015;Paramo et al, 2016;Abanto-Rodrí guez et al, 2018). However, despite the great importance of cupuassu cultivation in the Amazon, studies related to extracting, exporting, and accumulating nitrogen in the cupuassu tree are scarce and limited to the leaves (Alfaia and Ayres, 2004).…”

“…Maximum production and optimal fruit quality are achieved when the nutritional status of plants is ideal (Silva et al, 2016). In many agricultural situations, this condition is satisfied by annual supply of fertilizers and correction of soil acidity (Bambolim et al, 2015;Abanto-Rodrí guez et al, 2018). Among the essential nutrients for the development of cupuassu, nitrogen is the most critical because it is crucial for several physiological processes in the plant.…”