Gas exchanges and chlorophyll content in green pepper plants under bio-fertilization and times of application

This study aimed to determine the gas exchange and the chlorophyll content of green pepper plants under doses and times of application of bio-fertilizers based on manure and enriched organic compost. Two experiments were carried out simultaneously with applications of bio-fertilizers prepared from manure and enriched organic compost, one using cattle manure (CBF) and the other sheep manure (SBF). For these, four doses of biological fertilizers (100, 200, 300 and 400 dm³ ha-1), three application times (0, 30 and 60 days after transplantation - DAT) and absolute control, referring to the absence of fertilization, were used. treatments. were arranged in a randomized block design, totaling 13 treatments. The variables evaluated were: the relative chlorophyll a, b and total content; liquid photosynthesis (A); stomatal conductance (gs); internal CO2 concentration (Ci); instant carboxylation efficiency (iCE - A/Ci); transpiration rate (T); intrinsic water use efficiency (iWUE - A/gs); and water use efficiency (WUE - A/E). Gs, A and T, showed significant effect at 60 DAT with the application of SBF and Ci at 30 DAT with CBF. The dose of 400 dm³ ha-1 of SBF provided greater gas results, and the doses of 200 and 300 dm³ ha-1 of CBF promoted a greater Ci, greater stomatal conductance, greater liquid photosynthesis and better water use efficiency, which results in a greater plant fresh weight at the time of flowering induction.

Saline water and bovine biofertilizer chemically enriched on jackfruit seedlings var. soft / Água salina e biofertilizante enriquecido em mudas de jaqueira var. mole

Water scarcity and water quality is a subject of constant debate around the world, with the accumulation of salts in water and on soils causing a negative impact on food production, man and herds, especially in the arid and semi-arid regions. The use of bovine manure biofertilizers that potentiate the use of brackish water, normally restricted in agriculture due to its salinity, has been suggested for seedling formation and crop production, including jackfruit plants. An experiment was carried out from October/2012 to February/2013, in a protected environment, at Agrarian Sciences Center, Federal University of Paraíba, Areia county, Paraíba State, Brazil, to evaluate the effects of saline water and bovine biofertilizer chemically enriched with gypsum, cow's milk and molasses. The experimental design was completely randomized, with five replications of a plant, in a factorial scheme 5 × 2, corresponding at values of electrical conductivity of the water of 0.5, 1.0, 2.0, 3.0 and 4.0 dS m-1 substrate with and without bovine biofertilizer. Measurements were made of substrate salinity, height of growth, stem diameter, length mean root, leaf area, leaf area ratio, and total dry mass (root, shoots and leaves). The biofertilizer enriched with cow's milk, sugar cane molasses and agricultural gypsum increased the salinity of the soil; however, it attenuated the negative effects of the salts during establishment of jackfruit seedlings, to 95 days after emergence. All the growth variables studied were higher for seedlings developed in substrate with bovine biofertilizer chemically enriched.

A escassez e a qualidade da água são assuntos de constante debate em todo o mundo, com o acúmulo de sais na água e nos solos, causando um impacto negativo na produção de alimentos, homem e rebanhos, especialmente nas regiões áridas e semiáridas. O uso de biofertilizante de esterco bovino que possibilita o uso de água salobra, normalmente restrita à agricultura devido à salinidade, tem sido sugerido para formação demudas e produção agrícola, inclusive de jaqueira. Um experimento foi desenvolvido entre outubro de 2012 e fevereiro de 2013, em ambiente protegido, no Centro de Ciências Agrárias, da Universidade Federal da Paraíba, Areia, Paraíba, Brasil, para avaliar os efeitos da água salina e biofertilizante bovino enriquecido quimicamente com calcário, leite de vaca e melaço. O delineamento experimental foi inteiramente casualizado, com cinco repetições e uma planta, em esquema fatorial 5 × 2. Água com condutividade elétrica de 0,5, 1,0, 2,0, 3,0 e 4,0 foram aplicadas no substrato com e sem biofertilizante bovino. Foi avaliada a salinidade do substrato, crescimento em altura, diâmetro caulinar, crescimento da raiz principal, área foliar, razão de área foliar e massa seca total (raiz, parte aérea e folhas). O biofertilizante enriquecido com leite de vaca, melaço de cana-de-açúcar e gesso agrícola aumentou a salinidade do solo, no entanto, atenuou os efeitos negativos da salinidade durante o estabelecimento das mudas de jaqueira, aos 95 dias após a emergência. Todas as variáveis estudadas foram maiores nas mudas que cresceram no substrato com biofertilizante enriquecido quimicamente.