Francisco Wesley Alves Pinheiro

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.

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.