Leandro de Pádua Souza

Physiological Indices and Growth of Castor Bean Irrigated With Waters of Different Cationic Nature

It was proposed, in the present study, to evaluate the gas exchange and the growth of the castor bean cv. BRS Energia due to the isolated or mixed cationic nature of irrigation water. The study was conducted in drainage lysimeters under greenhouse conditions, using an Eutrophic Greyish Argissolo with a sandy-loam texture in the municipality of Campina Grande, Brazil. A randomized block design was used with six cationic composition of irrigation water (S1-control, S2-Na+, S3-Ca2+, S4-Na++Ca2+, S5-K+ and S6-Na++Ca2++Mg2+ with four replicates, each composed of five plants. The plants under the control treatment were submitted to irrigation with low salinity water (ECw = 0.6 dS m-1) and the remaining treatments were irrigated with ECw of 4.5 dS m-1 prepared with salts of different cations in chloride form. The gas exchanges and the growth of the castor bean cv. BRS Energy were determined at 100 days after sowing. The gas exchanges and the growth of the castor cv. BRS Energy were more sensitive to the variation in the electrical conductivity of the water compared to the cationic nature of the water, being the least deleterious effect observed in the plants irrigated with potassic water. The plants irrigated with water of potassium composition obtained the highest values for stomatal conductance, transpiration and rate of assimilation of CO2; at 100 days after sowing; the castor bean cv. BRS Energia showed sensitivity to the presence of sodium and calcium salts in irrigation water.

Morphophysiology of ‘Faga 11’ Cashew Rootstock Under Saline Water Irrigation and Exogenous Proline Application

Due to the reduced availability of good-quality water in the semi-arid region of Northeast Brazil, the utilization of saline waters in irrigation became an alternative for the expansion of agriculture in this region. Thus, it is necessary to develop techniques which can make viable the use of these waters in agriculture. Given the above, this study aimed to evaluate the morphophysiology of ‘FAGA 11’ cashew rootstock subjected to different levels of irrigation water salinity and exogenous proline application through the leaves. The experiment was carried out in a greenhouse of the Federal University of Campina Grande, at the Center of Sciences and Agri-Food Technology, Campus of Pombal, PB, Brazil, in a randomized block design, in 5 × 4 factorial scheme, with three replicates and two plants per plot. Treatments consisted of different levels of irrigation water electrical conductivity—ECw (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) combined with proline concentrations applied through the leaves—PC (0; 4; 8 and 12 mM). Irrigations with water up to ECw of 1.37 dS m-1 may be used as it causes an acceptable 10% reduction in the variables of morphology of cashew FAGA 11 seedlings. The proline concentrations tested, with the exception of the Dickson’s quality index of seedlings, did not attenuate the deleterious effects of irrigation water salinity on the cashew FAGA 11 rootstock seedlings.

PRODUÇÃO DE PORTA-ENXERTO DE CAJUEIRO IRRIGADO COM ÁGUAS SALINIZADAS E ADUBAÇÃO POTÁSSICA

A formacao de porta-enxerto de cajueiro, na regiao semiarida do nordeste brasileiro, onde as aguas nem sempre sao de boa qualidade, esta na dependencia do uso de tecnicas que viabilizem o manejo do solo e da agua com teor elevado de sais. Desta forma, objetivou-se avaliar a producao de fitomassa de cajueiro comum submetidos a diferentes niveis de salinidade da agua de irrigacao e doses de potassio. A pesquisa foi desenvolvido em um Neossolo Fluvico em condicao de ambiente protegido (casa de vegetacao) no municipio de Pombal – PB. Utilizaram-se o delineamento de blocos casualizados em esquema fatorial 5 x 4, com quatro repeticoes e duas plantas por parcela, sendo os tratamentos composto por cinco niveis de condutividade eletrica da agua de irrigacao - CE (0,3; 1,3; 2,3; 3,3 e 4,3 dS m -1 ) e quatro doses de potassio - K (70, 100, 130 e 160% de K) sendo a dose padrao 100% de K referente a 150 mg de K dm - 3 de solo. Irrigacao com agua CEa de ate 2,62 dS m -1 promove reducao aceitavel na fitomassa de porta-enxerto de cajueiro comum de 10%. A dose de 105 mg de K dm -3 de substrato (equivalente a 70% da dose recomendada) estimula, o acumulo de fitomassa seca da parte aerea e fresca de raiz dos porta-enxerto de cajueiro comum.

Evaluation of West Indian cherry (Malpighia emarginata) rootstock under saline water irrigation and nitrogen fertilization

This study aimed to evaluate the growth and quality of CMF 102 West Indian cherry rootstock subjected to irrigation with different salinity levels and nitrogen (N) doses. The experiment was carried out under protected environment, using a randomized block design in a 5 × 4 factorial scheme, with four replicates. Treatments consisted of five levels of electrical conductivity of water – ECw (0.3 – Control; 1.3; 2.3; 3.3 and 4.3 dS m -1 ) and four nitrogen doses (70, 100, 130 and 160% of N recommendation). CMI 102 West Indian cherry rootstock growth was evaluated through plant height, stem diameter, number of leaves, leaf area, shoot and total dry phytomass and Dickson quality index of seedlings 165 days after emergence. Additionally, the absolute growth rate of plant height was evaluated from 45 to 165 days after emergence. The results indicated that irrigation with ECw up to 2.22 dS m -1 leads to a maximum reduction of 10% in growth and in the quality of CMF 102 rootstock. Highest growth of CMF 102 West Indian cherry rootstock is obtained with fertilization of 70% of N. The plants of West Indian cherry irrigated with 4.3 dS m -1 of saline water showed an acceptable Dickson quality index; therefore, seedlings with IQD higher than 0.2 considered as good quality. In general, West Indian cherry plants can be classified as sensitive to irrigation with saline waters higher than 0.3 dSm -1 . No significant effect was found for the interaction between water salinity and N doses.

Production of guava rootstock grown with water of different salinities and doses of nitrogen

The scarcity of good-quality water and the occurrence of low-fertility soils are limiting factors in irrigated agriculture, especially in arid and semi-arid regions, which leads to the use of salt water and nitrogen fertiliser as alternatives for agricultural production in these regions. The aim of this work therefore, was to evaluate growth, biomass production and rootstock quality in the guava ‘Crioula’ under salt stress and doses of nitrogen fertiliser in a protected environment at CCTA/ UFCG. The experimental design was of randomised blocks in a 5 x 4 factorial scheme, with four replications. The treatments consisted of a combination of five levels of electrical conductivity of the irrigation water (0.3, 1.1, 1.9, 2.7 and 3.5 dS m-1) and four doses of nitrogen (70, 100, 130 and 160% of the recommended dose for guava seedlings). The dose of 541.1 mg N dm-3 soil (70% of the recommended N) stimulated growth, the accumulation of shoot biomass, and the quality of the guava ‘Crioula’ rootstock. Irrigation with an ECw greater than 0.3 dS m-1 had a negative effect on the absolute growth rate of the stem diameter, shoot dry matter, root to shoot ratio, and the Dickson quality index. Nitrogen fertiliser at 70 and 100% of the recommended level of N reduced the effect of irrigation water salinity on the relative growth rate of the stem diameter in the guava rootstock.A escassez de agua de boa qualidade e a ocorrencia de solos com baixa fertilidade sao fatores limitantes para a agricultura irrigada, principalmente em regioes aridas e semiaridas, o que induz a utilizacao de aguas salinas e adubacao nitrogenada como alternativas para a producao agricola nessas regioes. Desse modo, objetivou-se avaliar o crescimento, producao de fitomassa e qualidade de porta-enxerto de goiabeira ‘Crioula’ sob estresse salino e doses de adubacao nitrogenada, em condicoes de ambiente protegido no CCTA/UFCG. O delineamento estatistico foi o de blocos casualizados em esquema fatorial (5 x 4), com quatro repeticoes. Os tratamentos consistiram da combinacao de cinco niveis de condutividade eletrica da agua de irrigacao (0,3; 1,1; 1,9; 2,7 e 3,5 dS m-1) e quatro doses de nitrogenio (70, 100, 130 e 160% de N da dose recomendada para cultivo de mudas de goiabeira). A dose de 541,1 mg de N dm-3 de solo (70% de N recomendada) estimulou o crescimento, o acumulo de fitomassa na parte aerea e a qualidade dos porta-enxertos de goiabeira ‘Crioula’. Irrigacao com CEa acima de 0,3 dS m-1 afetou negativamente as taxas de crescimento absoluto do diâmetro do caule, fitomassa seca da parte aerea, relacao raiz/parte aerea e indice de qualidade de Dickson. A adubacao nitrogenada nas doses de 70 e 100% de N recomendada reduziu o efeito da salinidade da agua de irrigacao sobre a taxa de crescimento relativo do diâmetro do caule de porta-enxertos de goiabeira.

ÍNDICES FISIOLÓGICOS DO GIRASSOL EM FUNÇÃO DA ADUBAÇÃO COM BIOCARVÃO E NPK

A utilizacao de fontes alternativas de biomassa pode contribuir para manutencao das propriedades do solo e, portanto, para a producao de energia sustentavel e alimentos. Objetivou-se avaliar o efeito da adubacao com biocarvao de cama de frango em combinacao com fertilizante mineral, nos indices fisiologicos do girassol cv. Embrapa122/V 2000. O experimento foi desenvolvido em ambiente protegido da UAEAg/CTRN/UFCG em vasos com capacidade para 20 dm3 sob delineamento experimental inteiramente casualizado, com tratamentos arranjados em esquema fatorial (5 x 4) e quatro repeticoes. Os tratamentos corresponderam a cinco doses de adubacao mineral: D1=0, D2=25%, D3=50%, D4=75% e D5=100% da indicacao de adubacao com NPK (100; 300 e 150 mg kg-1) e quatro doses de biocarvao de cama de frango: B1=0; B2=5% (400g/vaso); B3=10% (800g/vaso) e B4=15% (1100g/vaso), calculadas com base no volume de solo. A adubacao com 50% da recomendacao de NPK (50:150:75 mg kg-1) promoveu os maiores valores de area foliar (AF) aos 60 DAS, producao de fitomassa de folhas, de caule, de capitulo e da parte aerea. A aplicacao de doses crescentes de biocarvao promoveu a reducao da AF, da razao de area foliar (RAF) e da area foliar especifica (AFE).