Jandiê Araújo Silva

Rendimento de feijão-vagem em função de doses de K2O

Aiming to evaluate the effect of K2O levels on the increase of snap bean yield, an experiment was performed in Paraiba State, Brazil, in a Quartz Psamment soil. The experimental design was of randomized blocks, with six treatments (0; 50; 100; 150; 200 and 250 kg ha-1 of K2O), in four replications. Each plot contained 40 plants spaced 1.0 m x 0.2 m. Pods maximum number/plant (20 pods) and the maximum yield/plant (171 g), were obtained, respectively with 145 and 173 kg ha-1 of K2O, and pods yield reached maximum value around 25,3 t ha-1 at the level of 171 kg ha-1 of K2O. The most economic level of K2O for the production of pods was of 165 kg ha-1. The most economic level represented 96% comparing to that responsible for maximum pods production. The K2O levels that obtained maximum pods production and economic return were correlated, respectively, with 181 and 176 mg dm-3 of K available for the extractor Mehlich 1.

Rendimento produtivo e econômico do feijão-caupi em função de doses de potássio

O feijao-caupi [Vigna unguiculata (L) Walp], tambem conhecido como feijao-macassar, feijao-de-corda ou fradinho e uma das principais culturas do Nordeste do Brasil. Objetivou-se, com este trabalho, avaliar o efeito da adubacao potassica sobre o rendimento produtivo e economico do feijao-caupi, cultivar Pitiuba. O trabalho foi realizado na Universidade Federal da Paraiba, em Areia (PB), em Neossolo Regolitico Psamitico tipico, no periodo de julho a setembro de 2005. O delineamento experimental empregado foi o de blocos casualizados, com seis tratamentos (0, 50, 100, 150, 200 e 250 kg ha-1 de K2O) e quatro repeticoes. Cada parcela continha 40 plantas espacadas de 0,80 m x 0,40 m. A producao maxima de vagens por planta (285 g) de graos verdes (143 g) e de graos secos (120 g) foram obtidas, respectivamente, com 160, 153 e 200 kg ha-1 de K2O. As doses de 210, 151 e 170 kg ha-1 de K2O, respectivamente, foram responsaveis pelas produtividades maximas de 4,18 t ha-1 de vagens, 3,48 t ha-1 de graos verdes e de 1,89 t ha-1 de graos secos. A dose de maxima eficiencia economica para a produtividade de graos secos foi de 141 kg ha-1 de K2O, com produtividade de 1,87 t ha-1.

Efeito de extratos vegetais no controle de Fusarium oxysporum f. sp tracheiphilum em sementes de caupi

A fusariose e uma doenca de grande importância para a cultura do feijoeiro em virtude da reducao da produtividade. O controle da doenca vem sendo realizado com aplicacoes indiscriminadas de fungicidas quimicos, acarretando problemas ao homem e ao meio ambiente. Objetivou-se, no presente trabalho, avaliar o efeito de extratos vegetais no controle de Fusarium oxysporum f. sp tracheiphilum, proveniente de sementes de caupi, comparando-se com o efeito do fungicida quimico. Utilizaram-se extratos de alho, angico e manjericao, isolados ou combinados entre si e ou em associacao ao fungicida Mancozeb. Uma aliquota de 50 µL de cada tratamento foi adicionada em orificio feito no centro das placas de Petri com BDA, sobre o qual depositou-se um disco de micelio do fungo. Avaliou-se durante sete dias, medindo-se o crescimento micelial do patogeno. Sementes de caupi foram desinfestadas com hipoclorito de sodio a 4,0%, semeadas em sacos de polietileno contendo solo autoclavado. Oito dias apos germinacao, efetuaram-se ferimentos no colo das plântulas, aplicando-se suspensao de esporos do fungo (1,4 x 10-5 con/mL). As avaliacoes de severidade da doenca foram realizadas diariamente durante 30 dias apos a inoculacao, utilizando-se escala de notas. Os extratos combinados de alho + manjericao e angico + manjericao nao inibiram o crescimento micelial do fungo, enquanto o extrato de manjericao isoladamente, proporcionou o menor crescimento micelial, indicando a acao fungicida e inibitoria desse tratamento sobre o fungo F. oxysporum f. sp tracheiphilum nas condicoes analisadas. O fungicida Mancozeb + o extrato de angico proporcionou menor media de severidade nas plantas avaliadas.

Produtividade da pimenta-do-reino em função de doses de esterco bovino

Although Paraiba State, has shown aptitude for black pepper cultivation, being possible to recommend it as an alternative for agricultural diversification in that area, no recommendation for black pepper crop fertilization exists. This research was conducted at the Universidade Federal da Paraiba, in Areia, Paraiba State, Brazil, to evaluate black pepper genotypes submitted to increasing levels of cattle manure. The experimental design was of randomized blocks, with treatments in the factorial 5 x 3 scheme. The first factor was represented by cattle manure levels (0; 4; 8; 12; and 16 kg plant-1) and the second factor, by the black pepper genotypes (Iacara, Cingapura and Bragantina), with four replications. Black pepper production increased with the use of cattle manure in environmental conditions. The highest pepper yield per plant of Bragantina (1012 g), Iacara (1269 g), and Cingapura (627 g) were obtained with 7.3; 8.6; and 7.0 kg of cattle manure/plant, respectively. The estimated yields of dry pepper were of 6.5; 8.9; and 7.8 kg plant-1, responding to maximum yields of 358, 793 and 204 g plant-1 for Bragantina, Iacara and Cingapure genotypes, respectively.

Gherkin yield influenced by spacing between rows and between plants in a row

The yield of the gherkin cv. Nordestino was evaluated with different spacings between rows and plants in a row in an essay which was carried out at the Universidade Federal da Paraiba, Brazil, from August/2007 to January/2008. The randomized block experimental design was used and the treatments were arranged in the factorial scheme 3 x 4 - three spacings between rows (1.0; 2.0; and 3.0 m) and four spacings between plants (0.5; 1.00; 1.5; and 2.0 m) - with four replicates. The experimental plot comprised four rows with ten plants in each one, totaling 40 plants, with one plant per hole. Two central rows were considered as the useful area. The evaluated variables were the average mass of commercial fruits, the number and production of the commercial fruits plant-1 and the commercial productivity of fruits. Setting 0.5 m between plants, all the characteristics under evaluation decreased as consequence of increasing spacings between rows. The highest values for average fruit mass (38 g), number of fruits (67 and 78) and productivity of fruits plant-1 (36 and 34 kg) were obtained at spacings of 2.0 and 3.0 m between rows and 1.0 m between plants, respectively. The highest productivities of commercial fruits (16 and 12.9 t ha-1) were obtained with 1.0 and 1.5 m between plants and 2.0 and 1.0 m between rows. On the other hand, the highest spacing between plants (2.0 m) reduced fruit productivity.

Adubação fosfatada em inhame em duas épocas de colheita

The low content of phosphorus in tropical soils makes essential the research about fertilization in crops which are poorly studied such as yam. Thus, this study aimed to evaluate the yam productivity (cultivar Da Costa) depending on phosphorus doses and harvest seasons. From February to December 2009, an experiment was carried out using the randomized blocks experimental design in subdivided plots, with four replications. In the plots six doses of phosphorus were evaluated (0, 100, 200, 300, 400 and 500 kg ha-1 of P2O5), and in the subplots two harvest seasons (seven and nine months after planting). The highest weight of tubers in seven and nine months was 1.94 and 2.20 kg with 245 and 240 kg ha-1 of P2O5, respectively. There was no significant effect of phosphorus doses on the total productivity in seven months and the average value was 13 t ha-1. The highest marketable productivity was 11.8 t ha-1 with 266 kg ha-1 of P2O5. In nine months, the highest total and marketable yield (24.7 and 20.5 t ha-1, respectively) was achieved with the application of 285 and 226 kg ha-1 of P2O5, respectively. The yield of tubers classified as first was 80 and 90% in seven and nine months, respectively, and was obtained with the application of 320 and 277 kg ha-1 of P2O5, respectively. The economic doses were 219 and 233 kg ha-1 of P2O5 to obtain 20.19 t ha-1 and 12.88 t ha-1 of marketable tubers in seven and nine months, representing increments of 19.17 and 3.9 t ha-1 in comparison to no application of phosphorus, respectively.

Parceling and nitrogen fertilization sources for gherkin yield

The nitrogen sources and parceling were evaluated concerning to gherkin plant, Nordestino cv., in the Universidade Federal da Paraiba, Brazil. The experimental design was the randomized block design in the factorial scheme 2 x 7, constituted of two nitrogen sources (urea and ammonium sulfate) and seven application times: a) (100% at sowing date; b) 100% 30 days after sowing (DAS); c) 100% 60 DAS; d) 50% at sowing date and 50% at 30 DAS; e) 50% at sowing date and 50% at 60 DAS; f) 50% at 30 and 50% at 60 DAP; g) 33% at sowing date, 33% at 30 33% at 60 DAP, with four replicates. The average weight of the fruits was inferior, 27 and 21 g, respectively, when the ammonium sulfate was 100% supplied at sowing and 100% at 60 DAS, as no alteration occurring in the urea source nor between those N sources. The yield of fruits of one plant (2.364 kg plant-1), the number of fruits of one plant (64 fruits plant-1) and fruit productivity (20.93 t ha-1) were significantly higher, when the nitrogen (ammonium sulfate source) was 50% parceled at 30 and 50% at 60 DAS. When urea was the nitrogen source, the yield of fruits of one plant (1.437 kg plant-1), the number of fruits of one plant (48 fruits plant-1) and the fruit productivity (12.66 t ha-1) were significantly higher, when it was parceled 50% at sowing date and 50% at 30 DAE.

Resposta do quiabeiro às doses de fósforo aplicadas em solo arenoso

The influence of phosphorus fertilization on yield of okra, cv. Santa Cruz was evaluated. The research was carried out in the experimental design of randomized blocks, with five treatments (0; 44; 88; 132 and 176 kg ha-1 of P), and four replications. The maximum number of fruits per plant (43) was obtained with the maximum level of 176 kg ha-1 of P. The estimated maximum yield of commercial fruits (38.6 t ha-1), was related to 139 kg ha-1 of P. The application of 137 kg ha-1 of P provided the highest economical income, yielding 38.3 t ha-1 of commercial fruits, with an increment of fruits of 17.4 t ha-1. The most economic level represented 98% of that responsible for the maximum yield, indicating that the okra responded economically to the use of P in sandy soil and, of the P level responsible for the maximum commercial yield of fruits were related to 40 mg dm-3 of available P in soil (Mehlich 1), and the level responsible for the highest economic income was related to 38 mg dm-3.

Tecnologia alternativa para produção de túberas-semente de inhame e seus reflexos na produtividade

This study was carried out in two steps at UFPB, in Areia, Paraiba state, Brazil, to evaluate the yam seed production by a high density planting system of tuber-seed portions and its effect on tuber yield. The experimental design in the two steps was randomized blocks with eight treatments and four replications. In the first step were produced yam tuber-seeds through planting of tuber-seed. Initially, we produced tuber-seed portions by planting pieces of 25, 50, 75, 100, 125, 150, 175 and 200 g, spaced 20 x 20 cm. The seeds produced in the previous step, had average weight of 108, 133, 157, 181, 205, 229, 253 and 277 g, which were planted to evaluate the yam yield. We evaluated the average mass and the production of seed tubers and the total and commercial yield. The production and average weight of tuber-seeds increased linearly with increasing weight of the pieces of tuber-seeds planted, with maximum values of 277 and 4,170 g, respectively, obtained with a piece of 200 g of tuber-seeds. The total average yield was 13.6 t ha-1 depending on the weight of the planted seed-roots. The marketable yield of tubers was 10.8 t ha-1 obtained with tuber-seeds with an average weight of 181 g, which represents a savings of 34% in the amount of tuber-seeds necessary for the implementation of a hectare of yam.