Guava Plants Research Articles

Ovary Histology of the PredatorBrontocoris tabidus(Hemiptera:Pentatomidae) of Two Ages Fed on Different Diets

The effect of different diets [Tenebrio molitor L. (Coleoptera: Tenebrionidae) pupae without plant; T. molitor pupae and Eucalyptus cloeziana plant; T. molitor pupae and Eucalyptus urophylla plant; T. molitor pupae and guava plant (Psidium guajava)] on the ovary histology of 15 and 21 day old female Brontocoris tabidus (Signoret, 1863) (Hemiptera: Pentatomidae) was analyzed. Females of B. tabidus have ovaries of the meroistic telotrophic type. The vitellarium of this predator presents oocytes with a linear arrangement in different development stages. The follicle cells are cubic with spherical nucleus when the oocytes are placed near the germarium in the initial developmental stage. These cells become flatter and compacted with the development of the oocytes. The ovaries of B. tabidus present similar histological features in all diets and ages. However, females of this predator reared on plants present more oocytes in advanced developmental stages inside the ovarioles than females of same age fed only on prey.

Água salina e esterco bovino líquido na formação de mudas de goiabeira cultivar Paluma

A salinidade dos solos e das águas, em muitas regiões de áreas áridas e semi-áridas do Nordeste brasileiro constitui sério obstáculo ao sistema de produção agrícola. No período de novembro de 2007 a fevereiro de 2008, foi desenvolvido um experimento para avaliar os efeitos da salinidade da água de irrigação e do esterco líquido bovino durante o período de formação de mudas de goiabeira Paluma. Os tratamentos foram distribuídos em blocos ao acaso, em esquema fatorial 5 × 2, referente aos níveis de salinidade da água: 0,5; 1,0; 2,0; 3,0 e 4,0 dS m-1 no solo sem e com esterco líquido bovino, em seis repetições e seis plantas por parcela. A salinidade do solo foi marcadamente elevada com o aumento da salinidade da água de irrigação, refletindo em declínio no crescimento das plantas em altura, diâmetro caulinar, área foliar, crescimento de raízes e produção de biomassa pelas goiabeiras, mas sempre com menor intensidade nas plantas com esterco líquido bovino. As plantas sob irrigação com água salina e o insumo orgânico superaram as dos tratamentos sem o insumo em 86,9; 72,4; 11,0; 252,4; 351 e 39,7% o crescimento em altura, diâmetro do caule, comprimento de raízes, área foliar e biomassa das raízes e parte aérea, respectivamente.

Composition of the essential oil from the leaves of tree domestic varieties and one wild variety of the guava plant (Psidium guajava L., Myrtaceae)

The compositions of the essential oils from the leaves of three domestic varieties of the guava tree Psidium guajava L. (Paluma, Século XXI and Pedro Sato) and of one wild variety were compared. Essential oils were extracted by steam distillation, the components were identified by gas chromatography coupled to mass spectrometry GC-MS, and the apparent concentrations were determined by gas chromatography with a flame ionization detector. The results demonstrated that the three essential oils contained many common substances with a prevalence of 1,8-cineole, whereas the essential oil of the Paluma variety contained 1,8-cineole (42.68%) as the major constituent, as well as α-terpineol (38.68%). The principal components of the essential oil of the Século XXI variety were 1,8-cineole (18.83%), trans-caryophyllene (12.08%), and selin-11-en-4-αol (20.98%), while those of the Pedro Sato variety and of the wild plant were 1,8-cineole (17.68%) and (12.83%), caryophyllene oxide (9.34%) and (9.09%), and selin-11-en-4-α-ol (21.46%) and (22.19%), respectively.

Antibiosis of Eucalyptus plants on Podisus nigrispinus

The predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) has been used as a natural enemy to control herbivorous insects in eucalyptus plantations. However, because of the short co-evolutionary history of the predator with this imported plant species, the defensive compounds of eucalyptus may have a negative effect on the predator. Therefore, the survival and development of P. nigrispinus were studied on eucalyptus (Eucalyptus urophylla; exotic host plant) and guava (Psidium guajava; native host plant). P. nigrispinus performance was indeed superior on guava plants than on eucalyptus. The number of fertile eggs and nymphal survival were 52.6% and 12.0% on guava compared with 20.0% and 1.3% on eucalyptus, respectively. Longevity of P. nigrispinus was 115 days on guava and 98 days on eucalyptus. This shows that the predator is not yet fully adapted to the exotic host plant. One possible reason is that the plant toxic compounds in eucalyptus act on this predator by antibiosis.

UTILITY OF RAPD DNA MARKERS IN THE SELECTION OF GRAFTS OF THE MEXICAN GUAVA CULTIVAR 'MEDIA CHINA' WITHOUT SYMPTOMS OF DEFICIENCY FOR IRON AND ZINC

ISHS II International Symposium on Guava and other Myrtaceae UTILITY OF RAPD DNA MARKERS IN THE SELECTION OF GRAFTS OF THE MEXICAN GUAVA CULTIVAR 'MEDIA CHINA' WITHOUT SYMPTOMS OF DEFICIENCY FOR IRON AND ZINC

NATURAL RESOURCES CONSERVATION: GUAVA AND OTHER MYRTACEAE GERMPLASM EX SITU CONSERVATION IN MÉRIDA, VENEZUELA

In this report we deal with the germplasm collection of guava plants and other Myrtaceae, grown in a suburban environment of Merida, Venezuela. This ex situ bank of germplasm was established from seeds and it is the first in Venezuela. Its existence will allow the detection of genes of interest that might contribute to the genetic improvement of the species. The samples of wild guavas and other Myrtaceae were collected in different areas of the country (other Myrtaceae mainly south to the Orinoco River). Currently, the collection comprises 159 samples, of which 101 samples are P. guajava and 58 samples are other species of Myrtaceae. Of the latter, at least 20 samples have already been identified. This collection includes herbarium vouchers, seeds, DNA samples, and information concerning the origin of the trees. The seeds were aseptically germinated and acclimated in a greenhouse before transfer to the field. The ex situ collection comprises 50 different samples of P. guajava and 4 samples of other Myrtaceae. Presently, the plants are approximately two years old and in transition to the reproductive stage. The plants established in the field were used to extract nucleic acids for the DNA collection. The phenotypic traits were evaluated and compared with those of the donor plants. Some of the plants exhibit a promising phenotype and were cultivated in vitro, using apical and axial meristems as well as nodal segments as the starting material.

COBERTURAS DE CAJETE, MANEJO DEL RIEGO Y RENDIMIENTO DE GUAYABA

Mexico is the second producer of guava in the world with approximately 20,000 hectares under cultivation. Of these, 67% are located in the Calvillo-Tube region where the yield reaches 14±1 tons per hectare (SAGARPA, 2001). In Calvillo, some 2800 producers are dedicated to the production of guava on 7.600 hectares. The orchards are irrigated by flood of cajete, using volumes in the order of 551 m 3 ha -1 of irrigation -1 . The area of guava cultivation is being reduced due to the insufficient water availability for irrigation. The objective of the investigation consisted of reducing losses by evaporation by means of the cap of cajetes with organic materials and fitting the volumes of applied water to the requirements of the tree. The treatments were: SM (without weeds), CM (with weeds), CM + PM (150 kg of ground straw of strubble maize), CM + EG (20 kg hen dung), CM+ EB (40 kg of bovine dung), CM+BIO (20 kg of biorgan), CM+ZEO (20 kg of zeorgan) and CM+HTEC (20 kg of humutec). The results indicate that the treatments in comparison to the control affected the water retention positively. The treatments: CM+EG, CM+HTEC, CM+BIO and CM+PM surpassed the control (SM) in the number of fruits per m 2 of producing surface. The covers of cajete in guava favor the conservation of water, reduce erosion, and improve the nutrition of the guava plants.

Radiant energy distribution in guava (Psidium guajava L.) plants at different spacings

The study on radiant energy distribution in guava was carried out to optimize the planting density with respect to solar radiation interception by the plants to get higher yield of good quality fruits per unit area. The present investigations reveals that with increase in plant spacing from 6x2m to 6x4m the interception of radiation increased significantly during both rainy and winter crop seasons. However, it starts declining with further increase in plant spacing to 6x5m level. The interception of radiation remains somewhat static during the summer and rainy season months (May-September) and then starts decreasing with the advent of winter season upto April with sharp decline during the month of December to February. In the upper 1/3rd portion of plant canopy, more than 75% radiations were intercepted irrespective of plant spacing followed by 12-16% in middle and 6-9% in the lower 1/3rd parts of plant canopies. The plant spacing of 6x2m and 6x3m was found to be not encouraging owing to lower distribution of radiations particularly in middle and lower parts of plants. The plant spacing of 6x4m was found to be best due tomaximum absorption of solar radiation for higher fruiting of better quality fruits.

Körpergewicht und Proteingehalt der Hämolymphe von Weibchen der zoophytophagen Raubwanze Brontocoris tabidus (Heteroptera: Pentatomidae) in Abhängigkeit von Ernährung und Alter

The effect of different diets [1. Tenebriomolitor L. (Coleoptera: Tenebrionidae) pupae; 2. T. molitor pupae and Eucalyptus cloeziana plants; 3. T. molitor pupae and Eucalyptus urophylla plants; and 4. T. molitor pupae and guava plants (Psidium guajava L.)] on the body weight and the protein content of haemolymph of Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae) females were analyzed. Fifteen days old females of B. tabidus were heavier on plants and T. molitor pupae than only with pupae of this prey. Twent-one days old females of this predator were heavier with E. cloeziana or guava plants and lower with E. urophylla and T. molitor pupae or only with pupae of this prey. The body weight of 15 and 21 days old females of B. tabidus was similar in most treatments and lower with E. urophylla and T. molitor pupae. Fifteen days old females of this predator were heavier when fed on T. molitor pupae and guava plants than those 21 days old. The protein content in the haemolymph of females of this predator was similar in all diets and ages. The phytophagy increased the body weight, but not the protein content in the haemolymph of females of the predator B. tabidus.

Concentration of Heavy Metals in Guava Plant Parts and Soil in the Sungai Wangi Plantation, Perak, Malaysia

Concentration of Heavy Metals in Guava Plant Parts and Soil in the Sungai Wangi Plantation, Perak, Malaysia

Herbivory affects ovarian development in the zoophytophagous predator Brontocoris tabidus (Heteroptera, Pentatomidae)

The effect of prey-based and combination prey and plant-based diets [Tenebriomolitor pupae alone; T. molitor pupae and Eucalyptus cloeziana plants; T. molitor pupae and Eucalyptus urophylla plants; and T. molitor pupae and Psidium guajava (guava) plants] on the morphometry of the ovary of Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae) was analyzed in the field. Females fed on T. molitor pupae without plants presented with smaller ovarioles. The number of oocytes per ovary was higher for B. tabidus females fed on a combination diet of E. urophylla and T. molitor pupae when compared to females fed only on prey. In addition to diet, the number of oocytes in the ovariole was shown to vary with the age of B. tabidus. The 21-day-old B. tabidus females were found to have a higher number of oocytes per ovariole than the 15-day-old females in all diet conditions. The 15-day-old females exhibited more developed oocytes when fed on diets containing both prey and eucalypts plants and less developed oocytes when fed with a combination diet containing guava plants or T. molitor pupae alone. The 21-one-day-old B. tabidus females which were fed with a diet without plants had smaller oocytes than those fed with plants. Herbivory improves the morphology of the ovary of B. tabidus, affecting the size of the reproductive structures and the oogenesis of this natural enemy in the field.

Tamanho da amostra foliar para avaliação do estado nutricional de goiabeiras com e sem irrigação

A precisão do tamanho ideal da amostra foliar determina a otimização de mão-de-obra, e diminui erros inerentes ao laudo de diagnose do estado nutricional. Com este trabalho se objetivou determinar, em pomares de goiabeira submetidos a dois regimes hídricos, o tamanho de amostras foliares e a variação do erro amostral para a diagnose do estado nutricional dessa frutífera. O respectivo trabalho contou com o emprego de dois estudos, ambos sob um delineamento experimental inteiramente casualizado, sendo: Estudo 1: Realizado em pomar sob regime não irrigado, com quatro tratamentos e seis repetições, que constaram da coleta de folhas em 5, 10, 20 e 40 plantas. Estudo 2: Realizado em pomar sob regime irrigado, com cinco tratamentos e dez repetições, que constaram da coleta de folhas em 10, 20, 30, 40 e 50 goiabeiras. Concluiu-se que em pomares não irrigados é necessário amostrar folhas em 40 plantas, a fim de manter o erro amostral de macronutrientes entre 5 a 10%; já para os micronutrientes seriam necessárias, no mínimo, 40 plantas e, se considerados o Fe e o Zn, a amostra deverá ser maior. Em pomares irrigados folhas provenientes de 10 plantas seriam suficientes para manter o erro amostral entre 5 e 10%; considerando-se, porém, os micronutrientes, seriam necessários amostrar 20 goiabeiras.

Fat body of the zoophytophagous predator Brontocoris tabidus (Het.: Pentatomidae) females: Impact of the herbivory and age

The effect of different diets [ Tenebrio molitor L. (Coleoptera: Tenebrionidae) pupae; T. molitor pupae and Eucalyptus cloeziana plant; T. molitor and Eucalyptus urophylla plant and T. molitor pupae and guava plant ( Psidium guajava)] on the morpho-physiological features of the fat body of Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae) females was studied in the field. Adult females of B. tabidus have trophocytes about twofold larger (966.32 μm 2) when fed on E. urophylla and T. molitor than those fed on other diets. The trophocytes of B. tabidus showed similar morphological aspects with the different diets and age of this predator. The histochemical tests indicated a reduced quantity of proteins and carbohydrates in the fat body of B. tabidus females with all diets and age of this predator.

Inibidores de proteases de hospedeiros nativos e exóticos e sua ação em intestinos de lagartas de Thyrinteina leucoceraea

Os insetos podem causar perdas consideráveis aos seus hospedeiros, entretanto alguns deles habitam em plantas sem causar-lhes danos. Por exemplo, Thyrinteina leucoceraea, herbívoro da entomofauna brasileira, pode ser encontrado na goiabeira, hospedeiro nativo da família Myrtaceae, sem que cause danos severos a essa planta. Os Eucalyptus ssp., entretanto, são hospedeiros exóticos (também da família Myrtaceae) no Brasil, vindos da Austrália, os quais sofrem ataques das lagartas de T. leucoceraea, que se tornaram pragas severas dessas plantas. Sabe-se que as plantas podem se defender contra o ataque de herbívoros e que um dos seus mecanismos de defesa pode ser a produção de inibidores de proteases, que possuem a capacidade de diminuir o desenvolvimento dos insetos e podem levá-los à morte. Baseado no desempenho da lagarta de T. leucoceraea nesses dois hospedeiros e na possibilidade de defesa da planta, o objetivo deste trabalho foi verificar a produção de inibidores de proteases por plantas de eucalipto e de goiaba quando atacadas por essas lagartas, bem como observar a resposta bioquímica no intestino das lagartas a esses inibidores. Notou-se que as plantas de eucalipto produzem mais inibidores de proteases que as goiabeiras. O bom desenvolvimento de T. leucoceraea em plantas de eucalipto, apesar da alta concentração de inibidores de proteases, pode ser devido ao aumento da atividade enzimática nos intestinos das lagartas quando alimentadas com essa planta. Os dados evidenciaram que T. leucoceraea desenvolveu uma adaptação aos inibidores de proteases produzidos pelo eucalipto, por meio do aumento das atividades de serino-proteases e cisteíno-proteases.

Effect of Liming on the Mineral Nutrition and Yield of Growing Guava Trees in a Typic Hapludox Soil

: High soil acidity influences the availability of mineral nutrients and increases that of toxic aluminium (Al), which has a jeopardizing effect on plant growth. The objective of this research was to evaluate the effects of soil liming on the development of guava (Psidium guajava L.) plants, on soil chemical characteristics, and on fruit yield. The experiment was carried out at the Bebedouro Citrus Experimental Station, state of São Paulo, Brazil, in a Typic Hapludox soil, from August 1999 to March 2003. The treatments consisted of limestone dose: D0 = zero; D1 = half dose; D2 = total dose; D3 = 1.5 times the dose, and D4 = 2 times the dose to raise the V value to 70%. The doses corresponded to zero, 1.85, 3.71, 5.56, and 7.41 t ha−1 applied to the upper soil layer (0–30 cm deep) before planting. The results showed that liming caused an improvement in the evaluated soil chemical characteristics up to a depth of 60 cm in soil samples both in the line and between lines. The highest fruit yields were obtained when the base saturation reached a value of 55% in the line and 62% between the lines. Foliar levels of calcium (Ca) and magnesium (Mg) were 8.8 and 2.5 g kg−1, respectively. The highest limestone dose maintained the soil base saturation (at the layer of 0–20 cm) in the line close to 55% during at least 40 months after the incorporation of limestone.

Influência da aplicação de cálcio, de magnésio e de potássio no solo sobre a produção de goiaba (Psidium guajava L.) cv. Paluma

The objective of the present research was to study the influence of application of calcium, magnesium and potassium in the soil on guava production. The experiment was carried out in Sao Tome, PR. The guava plants were 2 years and nine months old. The randomized design was used as a statistical model consisting of 4 treatments (control, 450 g/plant of calcium, magnesium and potassium) with 4 replications. The parameters evaluated were the nutrients in soil and leaves and production (number of fruits per plant, weight of the fruits and total production per plant (kg per plant)). There were significant differences in relation to calcium, magnesium and potassium concentration in the soil. On the other hand, no significant differences in relation to the pH values, H+Al and P were observed. It was verified that the concentration values of nitrogen, calcium and magnesium in the guava leaves were significantly higher in relation to control. It was noticed that the concentration of potassium in the guava leaves reduced over time, and the reduction was of 28% in the third analysis in relation to the first one, characterizing its mobility and exportation by harvesting. At the first harvest, the production was more dependent on the treatment in which magnesium was added in the soil. At the second harvest, howewer, there was no significant difference in the production between the treatments. The increase in the number of fruits per plant resulted in a reduction of their weight

Efeito da cinza da indústria de cerâmica no solo e na nutrição de mudas de goiabeira

Considerando a inexistência de informações sobre o uso de resíduos da indústria da cerâmica como insumo agrícola, procurou-se estudar o efeito da aplicação de cinza em características químicas do solo e na nutrição das mudas de goiabeira, Psidium guajava (Myrtaceae), em um subsolo apresentando dois níveis de valores de saturação por bases (50% e 80%) e cinco doses de cinza. As doses de cinza foram calculadas, a partir do V% inicial de 50%, objetivando elevar a saturação por bases em meia, uma vez, uma vez e meia e duas vezes o valor teórico de 70%, além da testemunha. A aplicação da cinza resultou em redução da acidez do solo, com aumento na concentração de Ca e Mg, no valor de saturação por bases e na concentração dos micronutrientes B, Cu e Mn do solo. Os teores dos nutrientes nas folhas aumentaram especialmente para P, Ca, Mg, B, Cu e Mn. Na ausência de calcário, a aplicação de cinzas foi suficiente para garantir adequada nutrição das plantas de goiabeira. A cinza da indústria de cerâmica apresentou resultados benéficos para a fertilidade do solo e na nutrição das plantas de goiabeira durante o período considerado

Composição mineral de folhas da goiabeira Paluma em função da adubação sulfato-nitrogenada

Determining   the correct nutrient supply of cultivated plants is fundamental to obtain high yields, especially for guava, an important fruitcrop for Brazil whose fertilization is still based on empirical methods. In this way, the effects of ammonium sulfate doses (0; 1,25; 2,5; 3,9 e 5,0 kg ha -1 ), applied through irrigation water, on the macro and micronutrient leaf concentrations of guava ( Psidium guajava L.) cv. Paluma were evaluated. The experiment was carried out in the municipality of Remigio, Paraiba State, Brazil with treatments distributed in a randomized block design, with four replications. After 22 days of transplanting, guava plants were adequately supplied with N, Mg, S, Fe, Mn e Zn, but deficient in Ca, B and Cu. Potassium supply was optimum, except for control treatment, while phosphorus was sufficient only for the 3,90 kg ha -1 dose. The nitrogen-sulfate fertilization affected N, P, K, Ca, Mg, Fe and Mn leaf content, but had no influence on B, Cu and Zn concentration leaf.

Acúmulo de massa seca e marcha de absorção de nutrientes em mudas de goiabeira 'Pedro Sato'

Objetivou-se determinar a curva de acúmulo da matéria seca de mudas e a marcha de absorção de macro e micronutrientes de goiabeira cultivar 'Pedro Sato'. O delineamento experimental foi o inteiramente casualizado, com três repetições. Foram utilizadas sete coletas de plantas de goiabeira 'Pedro Sato', em cultivo hidropônico, em casa de vegetação da Unesp, Campus de Jaboticabal. Nas coletas, avaliaram-se o crescimento das plantas e o acúmulo de nutrientes, a cada 15 dias, durante 120 dias após o transplantio. As mudas de goiabeira proporcionaram maior acúmulo de biomassa no órgão folha em relação ao caule e à raiz. Observou-se alta absorção dos nutrientes, no período de 60 a 90 dias após o transplantio, nas mudas de goiabeira. O acúmulo de nutrientes das mudas de goiabeira (planta inteira) foi de 340, 44, 380, 173, 33 e 40 mg planta-1, respectivamente para N, P, K, Ca, Mg, S, e de 743, 118, 5.114, 2.151, 566 mg planta-1, respectivamente, para B, Cu, Fe, Mn e Zn.

Efeito de diferentes substratos e épocas de coleta no enraizamento de estacas herbáceas de goiabeira, cvs. paluma e século XXI

Este trabalho objetivou avaliar o enraizamento de estacas herbáceas das goiabeiras 'Paluma' e 'Século XXI' em diferentes substratos, coletadas na primavera e no verão. As estacas foram obtidas de ramos jovens não-lignificados de árvores de quatro anos, com um par de folhas no nó superior e 10 cm de comprimento. Para cada época testada, as estacas foram tratadas por imersão rápida, com cinco doses de AIB (0; 500; 1.000; 1.500 e 2.000 mg/L) e dispostas em bandejas plásticas perfuradas com dois substratos (casca de arroz carbonizada e vermiculita) em câmara de nebulização. Após 70 dias da estaquia, foram avaliadas as seguintes variáveis: porcentagem de enraizamento; massas seca e fresca das raízes; número de raízes por estaca; comprimento das raízes; sobrevivência; retenção foliar e porcentagem de estacas com calo. Concluiu-se que houve maior enraizamento das estacas coletadas no verão e que as doses de 1.500 e 2.000 mg/L de AIB são as mais adequadas para promover as melhores características de enraizamento das estacas para as cvs. Paluma e Século XXI, respectivamente. Os dois substratos utilizados são indicados para a estaquia das goiabeiras estudadas.