Valdinei Sofiatti

Efeito da adubação fosfatada sobre o crescimento e teor de macronutrientes de mudas de pinhão manso

A adicao de fosforo na composicao do substrato para producao de mudas ajuda as raizes e as plântulas a crescerem mais rapidamente, aumenta a resistencia aos estresses ambientais e doencas e melhora ainda a eficiencia no uso de nutrientes e da agua em varias especies vegetais. Objetivou-se, com este estudo, avaliar o efeito da adicao de superfosfato simples no substrato sobre o crescimento e teor foliar de macronutrientes de mudas de pinhao manso (Jatropha curcas). O substrato contendo material de solo e composto de lixo recebeu as doses de 0; 2,5; 5,0; 7,5; 10 e 12,5 kg m-3 de superfosfato simples. As mudas foram avaliadas 30 dias apos o plantio. O crescimento maximo das plantas de pinhao manso foi observado com a adicao de superfosfato simples ao substrato em doses estimadas na faixa de 5 a 8 kg m-3 de substrato. O fertilizante fosfatado favoreceu o crescimento principalmente de raizes e area foliar e propiciou aumento do teor de todos os macronutrientes no tecido vegetal, exceto o calcio.

Redistribuição de nutrientes em folhas de pinhão-manso entre estádios fenológicos

Nutrient redistribution from mature leaves to growing structures is an important process in plant physiology. Each nutrient is redistributed in a different rate and time. This study aimed to quantify redistribution of macronutriens and minor nutrients in Jatropha curcas leaves through five phenological phases (expanding leaf, young leaf, mature leaf, senescing leaf, and dry leaf). It was observed that the nutrients P, K, Cu, and Zn are intensively redistributed from older to younger jatropha leaves, while N, Ca, Mg, Fe, and Mn are poorly redistributed. Leaf senescence causes a loss of the nutrients that are not redistributed because they will need to be re-absorbed for supporting the growth of new structures in the plant.

Casca de mamona associada a quatro fontes de matéria orgânica para a produção de mudas de pinhão-manso

Castor hull combined with four organic matter sources for physic nut seedling production Substrates consisting of mixtures of soil and organic materials have usually been recommended for production of physic nut (Jatropha curcas L.) seedlings. Castor hull is a residue produced in large quantities during the hulling process. This residue contains high amounts of macronutrient s. The objective of this study was to evaluate four organic materials for mixing with soil and castor hull. The experiment was conducted in a greenhouse at EMBRAPA Cotton Research Center between October and December 2006. The treatments were arranged in a complete randomized design with four replications and two plants per plot. Treatments were a mixture of soil and castor hull with one of the following materials: garbage compost, bovine manure, sewage sludge and castor presscake. The Control was a mixture of soil and castor hull. At 55 days after sowing, data on plant height, number of leaves, leaf area, stem diameter , dry weight of shoots and roots and leaf content of N, P, K, Ca, Mg and S were measured. All substrates were found suitable for production of physic nut seedlings, however the use of soil with castor hull only showed the lowest seedling

Posição da folha e estádio fenológico do ramo para análise foliar do pinhão-manso

ABSTRACT Leaf analysis is an important tool for prediction of nutritional disorders and evaluation of nutritionalstatus of plants. This procedure only can be effective if samples are standardized regarding leaf positionand phenological stage of the branch. This study had the objective of defining the most appropriate leafposition and type of branch for nutritional diagnosis of Jatropha plants. A factorial combination of fiveleaf positions (1 st , 2 nd , 3 rd , 5 th , and 10 node from apex to base) and two types of branch (vegetative andflowering) was adopted in a completely randomized design with four replications. Each leaf sample wascollected in 4 secondary branches of 20 plants in the flowering phase. Leaves in the position 2 and 3 arethe most adequate for analyzing N, P, K, S, Cu, Fe, Mn, and Zn, because they present mean values morestable when compared to the other studied positions. Leaves in the position 5 and 10 are more adequatefor analyzing Ca and Mg. The phenological stage of the branch does not influence nutrient content,except of Cu and Fe.

Uso de hipoclorito de sódio para degradação do endocarpo de sementes de cafeeiro com diferentes graus de umidade

The objective of this study was to evaluate the combinations between sodium hypochlorite concentrations and presoaking times that would provide higher germination of coffee seeds with moisture contents from 13 to 33% (w.b.). The seeds of Catuai Vermelho IAC 44 variety were dried in the shade until they reached the desired moisture contents. Five assays were accomplished, one for each moisture content of the seeds (13, 18, 23, 28 and 33%). Each assay consisted of 12 treatments, each one consisting of combinations of five sodium hypochlorite concentrations (3, 4, 5, 6 and 7% active chlorine) in the presoaking solution and two presoaking times (3 and 6 hr), besides the seeds with or without endocarp that were manually removed (control). The seeds were evaluated, by using the following tests: first germination counting, germination, germination speed index and seedling vigor. According to the results, the presoaking of the coffee seeds into sodium hypochlorite at 6% concentration active chlorine for three hours promoted an efficient degradation of the endocarp, besides providing germination speed index similar to the control, when seeds showed initial moisture content between 23 and 33%. In those seeds with moisture content at 18 and 13%, the presoaking in sodium hypochlorite led to an inferior germination performance of the seeds relative to the seeds without endocarp that was manually removed, regardless of the combination between concentration and the presoaking time.

Atributos químicos de substrato de composto de lixo orgânico

O composto de lixo urbano e um material orgânico rico em alguns nutrientes, comumente utilizado na formulacao de substratos para producao de mudas. Este trabalho objetivou avaliar os efeitos da aplicacao de doses de composto de lixo em atributos quimicos do solo. O experimento foi conduzido em casa de vegetacao, em Campina Grande, PB, utilizando-se o delineamento experimental inteiramente ao acaso, com quatro repeticoes e 10 tubetes por parcela. Os tratamentos corresponderam a quatro doses de composto de lixo urbano (0, 10, 20 e 40% - v/v) adicionadas a um solo Neossolo Regolitico arenoso. Tubetes de 288 cm3 foram utilizados como recipiente de incubacao. A mistura de solo e composto de lixo orgânico foi incubada durante 40 dias, em umidade do solo equivalente a 60% da capacidade de campo. Apos a incubacao os substratos foram analisados para determinacao de pH em CaCl2 e teor de Ca2+, Mg2+, Na+, K+, Soma de bases trocaveis e capacidade de troca de cations (mmolc dm-3), Saturacao de bases (%) e Teor de materia orgânica (g kg-1). O uso de composto de lixo urbano na formulacao de substratos para o cultivo de plantas em recipientes contribui significativamente para a melhoria da fertilidade do substrato.

Variabilidade espacial da fertilidade do solo em área cultivada com algodoeiro no Cerrado do Brasil

The objective of this work was to analyze the spatial variability of fertility attributes in an Oxisol under tillage to cotton cultivation in Cristalina, GO, aiming the adoption of precision agriculture in the area management. The soil was collected using a sample grid, which consisted of 90 points (80 x 80 m), distributed into 57.6 ha. Were determined contents of P, K, Ca, Mg, S, Na, Cu, Mn, B, Zn, Fe, organic matter (OM), pH, sum of bases (SB), base saturation (V), aluminum saturation (m), as well as the apparent electrical conductivity of soil (EC) measured at 30 and 90 cm depth. Classic descriptive analysis was conducted and then, semivariograms were modeled for all attributes and krigging maps. The spatial dependence of analyzed soil properties indicates that the spatial variability should be considered during the planning of soil sampling and also to soil management practices. Concerning to precision agriculture adoption and the application of inputs in variable rates, it is required to do a careful study of the soil fertility variability, creating maps based on fertility classes for each attribute, allowing to identify for which attributes this management practice should be adopted.

Qualidade da semente e fibra de algodão na caracterização do descaroçador de 25 serras 1

A B S T R A C T The cotton is one of the most important crop in the fiber group due to its volume and valued production. This study was conducted with the aim to characterize a ginner regarding physical and physiological quality of seeds and some technological qualities of the cotton fiber. The ginner was made with the following components: cleaner, cylinder saws, cylinder brushes, condenser, and a three-phase electric motor of 3 CV to turn on the equipment. The experimental design was a completely randomized factorial (2 x 2 x 2 x 4), with two cotton cultivars (BRS 187 and BRS Safira 8H), two types of saws (11¾” and 12”), two cleaning process (with and without cleaner) and four rotations (500, 550, 600 and 650 rpm) and four replications. During the processing of seeds, types of saws and cleaning processes did not affect the physical and physiological quality of seeds. Meanwhile, in the technological characteristics of the cotton fiber, the ginner showed efficient performance with the rotation of 550 rpm, using the 12” saws and cleaning device turned activated (cleaner). Palavras-chave: beneficiamento qualidade de sementes qualidade de fibras

Tolerância de mamoneira ao herbicida pendimethalin em solos com diferentes capacidades de adsorção

The castor bean is a species of slow initial growth. The absence of registered herbicides for this crop is still a limiting factor for its expansion. The aim of this study was to evaluate the castor bean tolerance to the herbicide pendimethalin in soils with different adsorption capacities. The experiment was conducted under greenhouse conditions in a completely randomized design with five replications and consisted of a factorial combination of eight doses of the herbicide pendimethalin applied as pre-emergence (0; 187,5; 375; 750; 1500; 3000; 6000 and 12000 g ha-1 i.a.), and four types of substrate (clay loam, sandy clay loam, sandy loam and sandy soil). At 22 days after sowing the variables: plant height, leaf area, fresh and dry mass of shoots, root system volume and dry weight were determined. It was concluded that the dose of the herbicide pendimethalin tolerated by the castor bean is influenced by the adsorption capacity of the soil. The herbicide was found to be very selective to this crop, not causing significant reduction of plant growth at the doses indicated to be used for weed control.

Uso de hipoclorito de sódio para acelerar a emergência das plântulas e o desenvolvimento das mudas de cafeeiro

The objective of this study was to evaluate the effect of seed imbibition in water solution at different concentrations of sodium hypochlorite on the rate and speed of emergence of coffee seedlings as well as to assess the development of the seedlings. One trial was conducted for each of the five seed moisture content (13%, 18%, 23%, 28% and 33% wet weight). Each one consisted of five treatments, represented by seeds previously imbibed for three hours in water solution with three sodium hypochlorite concentrations (4, 5 and 6% of active chlorine), besides seeds with parchment and seeds without parchment (control). The seedlings were evaluated for the emergence rate and speed, and the seedlings for height, number of leaves and leaf area. The preimbibition of seeds with initial moisture degree of 23, 28 or 33% in water solution with sodium hypochlorite at 4% active chlorine increased the rate and speed of seedling emergence, and improving the seedling development compared to seeds with parchment.