Phenolic compounds and carotenoids amounts on guava epicarp injury, 'girdling'

A anomalia do epicarpo da goiaba, comumente relatada por agricultores e técnicos como o "anelamento juvenil da goiaba", tem causado preocupação devido à desinformação sobre o assunto. O objetivo deste estudo foi analisar quimicamente as concentrações de substâncias fenólicas e carotenoides na região do epicarpo de goiabas afetadas pelo "anelamento", visando a caracterizar essa anomalia previamente relatada. Foram analisadas substâncias fenólicas (taninos, flavonas/flavonóis, antocianinas e fenóis totais) e carotenoides em epicarpos de frutos verdes e maduros de goiabeiras cv. Paluma, com e sem anomalia. O delineamento experimental adotado foi o inteiramente casualizado, sendo estabelecidos seis tratamentos com o epicarpo dos frutos maduro sem anomalia na região inferior (FMSI); frutos maduros sem injuria na região superior (FMSS); frutos verdes sem anomalia na região inferior (FVSI); frutos verdes sem anomalia na região superior (FVSS); frutos verdes com anomalia na região inferior (FVCI); frutos verdes com anomalia na região superior (FVCS). Dentre as substâncias analisadas, os carotenoides, os taninos e os fenóis totais mostram indicativos para a caracterização do anelamento. Tanto substâncias fenólicas quanto carotenoides apresentam propriedades antioxidantes e, dessa forma, poderiam estar relacionadas à defesa antioxidante causada por um fator de estresse ainda desconhecido, que promove o "anelamento" característico apresentado pelas goiabas.Guava epicarp injuries, popularly known as "girdling", have been concerned technicians and producers due to misunderstand about their causes. The objective of this study was to analyze the amounts of phenolic compounds and carotenoids present on guava epicarp region affected by injury ("girdling") in order to characterize chemically those regions. Concentrations of phenolic compounds (tannins, flavones/flavonols, anthocyanins and total phenolic compounds) and carotenoids were analyzed on tissue from unripe and ripe guava injured and non-injured epicarp fruits (Psidium guajava cv. Paluma). The experimental design was randomized, and were established six treatments: epicarp from ripe fruit without injury in the lower (FMSI) and upper region (FMSS) of the fruit, unriped fruit without injury (lower - FVSI - and upper region - FVSS), injured unriped fruit with injury (lower - FVCI - and upper region - FVCS). Higher concentrations of phenolic compounds, carotenoids of tannins, were found on tissues of unripe fruit epicarp with "girdling" when compared with health epicarps. Results showed the participation of phenolics compounds (tannins) and carotenoids as possible substances that characterized the injury formation. Although phenolic compounds and carotenoids have antioxidant properties and are often related as antioxidant defenses, the causes of "girdling" of guava fruits are still unknown

Compositional meta-analysis of citrus varieties in the state of São Paulo, Brazil

Brazil is the largest orange (Citrus sinensis) producer worldwide. The nutrient management of orange orchards is designed from experiments on a limited number of varieties. This knowledge is transferred to other varieties by diagnosing tissue nutrient composition. Nutrient diagnostic tools are based on nutrient concentration (critical minimum value or CMV) and ratio (Diagnosis and Recommendation Integrated System or DRIS) norms that disregard the compositional nature of analytical data and the limited number of nutrient ratios that can be diagnosed independently in a given composition. The diagnosis of cationic micronutrients is also biased by contamination from fungicides. Compositional data analysis that can avoid such problems has been first applied to tissue analysis of agricultural crops using centered log ratios (Compositional Nutrient Diagnosis – CND-clr). The isometric log ratio (ilr) transformation is a new approach based on binary nutrient ratios and the principle of orthogonality (CND-ilr). Binary partitions can be defined and varietal nutrient profiles classified based on positive and negative nutrient interactions and meta-analysis. We analyzed 11 nutrients (N, S, P, K, Ca, Mg, B, Cu, Zn, Mn, Fe) in tissue samples across 108 orchard areas, i.e. 31 ‘Valencia’, 22 ‘Hamlin’, 20 ‘Pêra’, and 35 ‘Natal’. Nutrients were partitioned between macro- and micro-nutrients as well as anionic and cationic species. The effect size of varieties over ‘Valencia’ was quantified by the mean and standard deviation of ilr values across ilr coordinates. Specific varietal nutrient profiles and ilr norms were defined. To guide correcting nutrient deficiencies by appropriate nutrient management, compositions can be varied by a perturbation vector on nutrients with to the largest and most negative influence on ilr differences from ilr norms until the Aitchison distance falls below critical value

Sucker pruning management to change the harvest date in banana

In banana crop, sometimes it is necessary to manage seasonal production variations. The aim of the present study was to evaluate the effect of the selection of late successor sucker on the productive unit, compared to the selection of early successor sucker on the growth, harvest date and bunch mass of 'Prata' and 'Nanica' banana. The experimental design was completely randomized, with two treatments and ten replicates, considering two experiments, one for each cultivar. Treatments were conventional pruning (selection of early successor sucker) and modified pruning (selection of late successor sucker), which were established in September, with the destruction of the apical meristem of the successor sucker in modified pruning. The growth of the first and second suckers was quantified at intervals of about 60 days until the reproductive stage and bunch mass was determined. For both cultivars, pruning reduced the height and perimeter of the first successor sucker pseudostem and delayed the harvest date for at least 30 days, without reducing bunch mass. Regardless of sucker pruning management, production averages were 26.68 and 50.64 ton ha-1, respectively, for 'Prata' and 'Nanica' cultivars. For the second sucker, there was residual effect of pruning on the height of 'Nanica' cultivar, but not on production. Establishing the modified pruning is feasible for change harvest date of two cultivars, without increasing costs

AVALIAÇÃO DO ESTADO NUTRICIONAL DE PLANTAS DE COUVE-FLOR CULTIVADAS EM SOLUÇÃO NUTRITIVA SUPRIMIDAS DE MACRONUTRIENTES

Com o objetivo de avaliar o efeito da omissão de macronutrientes no crescimento e no estado nutricional da couve-flor, bem como descrever sintomas visuais de deficiência nutricional, foi conduzido um experimento em casa de vegetação, em solução nutritiva. O delineamento experimental foi inteiramente casualizado, com sete tratamentos, que corresponderam à solução completa e à omissão individual de N, P, K, Ca, Mg e S, com três repetições. Foram avaliados a altura das plantas, o número de folhas, a área foliar, a massa seca da parte aérea, das raízes e planta inteira, os teores dos macronutrientes da parte aérea e raízes e descritas as desordens nutricionais. As omissões individuais de N, P, K, Ca e Mg foram as mais limitantes para o crescimento vegetativo da couve-flor, reduzindo consideravelmente a altura, o número de folhas, área foliar, assim como massa seca da parte aérea, raízes e planta inteira. Foram observados sintomas de deficiência nutricional de cada elemento. Os teores dos macronutrientes na parte aérea do tratamento completo e com omissão dos nutrientes foram respectivamente: N = 36,3 – 11,0; P = 5,0 – 1,0; K = 37,0 – 4,7; Ca = 26,0 – 5,7; Mg = 5,3 – 1,0; S = 15 – 3,0 g kg-1.An experiment was conducted under greenhouse conditions, to evaluate the effects of macronutrient omission on cauliflower nutritional status and development, as well as describe nutritional deficiency symptoms. The experiment was arranged in completely randomized design with three replications and seven treatments, corresponding to complete nutritive solution and individual N, P, K, Ca, Mg and S omission. Plant height, number of leaves, leaf area, shoot, root and whole plant dry mass and macronutrient levels were determined and nutritional deficiency symptoms were described. Individual omissions of N, P, K or Ca were the most limiting for cauliflower growth, considerably reducing plant height, number of leaves, and shoot, root and whole plant dry mass. Nutritional deficiency symptoms were observed for each element. Shoot macronutrient levels in control and nutrient omission treatments were, respectively: N = 36.3 – 11.0; P = 5.0 – 1.0; K = 37.0 – 4.7; Ca = 26.0 – 5.7; Mg = 5.3 – 1.0; S = 15.0 – 3.0 g kg-1

OMISSÃO DE MACRONUTRIENTES NO CRESCIMENTO E NO ESTADO NUTRICIONAL DE CAPIM-ELEFANTE (CV. MOTT) CULTIVADO EM SOLUÇÃO NUTRITIVA

The objective of this work was to evaluate the effect of omission of macronutrients in the growth and the nutritional state of elephant-grass plants (Pennisetum purpureum Shum cv. Mott). The experiment was developed in the FCAV/UNESP, in Jaboticabal-SP,Brazil, using nutrient solution. The experimental design was completely randomized blocks, with seven treatments (the complete solution proposed by Hoagland & Arnon (1950) and the individual omission of N, P, K, Ca, Mg and S, in these solution), in three repetitions. Pre-germinated plants were placed in pot (5 dm3), containing the nutrient solution, which was aerated constantly during the experimental period and the respective treatments, with three replications each. Weekly, the height of the plants, the leaf number, apex diameter and number of tillers were evaluated as well as plant nutritional state. The omission of N, P, K, Ca, Mg and S limited the production of dry weight of shoot the elephant grass, compared to the full treatment. The deficiency of a macronutrient, in addition to promoting reduction of its content in the shoot, resulted in reducing the accumulation of most macronutrients, with resultant morphological changes, translated as characteristic symptoms of deficiency.Objetivou-se avaliar o efeito da omissão de macronutrientes no desenvolvimento e no estado nutricional de plantas de capim-elefante (Pennisetum purpureum Shum cv. Mott). O experimento foi desenvolvido na FCAV/UNESP, em Jaboticabal-SP com o uso de solução nutritiva. O delineamento experimental foi inteiramente casualizado, com sete tratamentos (solução completa Hoagland & Arnon (1950) e a omissão individual de N, P, K, Ca, Mg e S nessa solução). Após o brotamento dos colmos, as plantas foram colocadas em vasos (5 dm3), contendo solução nutritiva sob aeração constante, aplicando-se os tratamentos com três repetições cada. Semanalmente, avaliou-se a altura das plantas, o número de folhas, o diâmetro do colmo e número de perfilhos, além do estado nutricional. A omissão de N, P, K, Ca, Mg e S limitaram a produção de massa seca da parte aérea do capim-elefante, em relação ao tratamento completo. A deficiência de um macronutriente, além de promover diminuição do seu teor na parte aérea, resultou em redução da acumulação da maioria dos macronutrientes, com conseqüente alterações morfológicas, traduzidas como sintomas característicos de deficiência

EFEITO RESIDUAL DE MODOS DE APLICAÇÃO DE ZINCO NA NUTRIÇÃO E NO CRESCIMENTO INICIAL DA CULTURA DO ARROZ

Em sistemas de alta produção os micronutrientes, especialmente o zinco é importante para a cultura do arroz. O presente trabalho objetivou avaliar o efeito residual de modos de aplicação de Zn sobre a nutrição e o crescimento inicial de plantas de arroz. O delineamento experimental utilizado foi inteiramente casualizado, com quatro tratamentos, tendo zinco aplicado via foliar, incorporado no solo e nas sementes e a testemunha (sem zinco), em quatro repetições. Aos 42 após a emergência, avaliou-se o teor de Zn no solo e na planta e o crescimento inicial das plantas de arroz . A aplicação de Zn via solo incorporado proporcionou efeito residual no teor do micronutriente no solo. A aplicação de Zn via foliar promoveu maior absorção do nutriente pelas plantas de arroz. Os modos de aplicação de Zn via semente, foliar e solo foram semelhantes em promover o incremento na produção de matéria seca de plantas de arroz

Amostragem de plantas em cafeeiro para avaliação do estado nutricional

The foliar fertilization assists programs in order to obtain higher yields, however, it is essential to know the ideal number of plants to be sampled. The study aimed to determine in commercial coffee plantations, subjected to two water regimes, the number of plants to be sampled and estimate the sample error for the diagnosis of nutritional status of that culture. The work consisted of two studies where samples of leaves were collected in rainfed and irrigated farming. For both studies the completely randomized design, with four treatments and five repetitions that consisted of leaf collection in 5, 10, 20 and 40 coffee plants per sampling unit was used. So to keep the sampling error below 10 % for the macronutrient, leaf sampling five composite samples at 10 and 20 plants per sampling unit under irrigated and rainfed conditions, respectively, is sufficient. As for the content of micronutrients collecting 20 plants in systems except Cu and Mn requiring higher sampling five composite samples of 40 plants in rainfed systems are needed.A análise foliar auxilia os programas de adubação com o intuito de obter maiores produtividades, no entanto, é imprescindível conhecer o número adequado da amostra. Objetivou-se, no trabalho, determinar em lavouras comerciais de café, submetidas a dois regimes hídricos, o número de plantas a serem amostradas e estimar o erro amostral para a diagnose do estado nutricional dessa cultura. O trabalho foi composto por dois estudos, onde foram realizadas amostragens de folhas, em lavoura de sequeiro e irrigado. Para ambos os estudos foi utilizado o delineamento experimental inteiramente casualizado, com quatro tratamentos e cinco repetições, que constaram da coleta de folhas em 5, 10, 20 e 40 plantas de cafeeiro por unidade amostral. Assim, para manter o erro amostral menor que 10% para os teores de macronutrientes, a amostragem de folhas de cinco amostras, compostas em 10 e 20 plantas por unidade amostral nos sistemas irrigado e sequeiro, respectivamente, é suficiente. Já para o teor de micronutrientes é necessária coleta de 20 plantas nos sistemas, exceto o Cu e Mn que necessitam de amostragem superior a cinco amostras, compostas de 40 plantas, no sistema de sequeiro.