Open Access Original Research Article

Growth, Gas Exchange and Mineral Nutrition of Xaraés Grass (Brachiaria brizantha cv. Xaraés) in a Haplic Cambisol with Increasing Copper Doses

Eduardo da Silva Daniel, Mari Lucia Campos, David José Miquelluti, Clenilso Sehnen Mota, André Fischer Sbrissia

Journal of Experimental Agriculture International, Page 1-13
DOI: 10.9734/JEAI/2018/43648

Aims: To calculate the lower and upper critical doses of Cu applied to a Haplic Cambisol on growth, gas exchange and mineral nutrition of xaraés grass plants (Brachiaria brizantha cv. Xaraés).

Study Design: The experiment was arranged in a completely randomised design with four replications.

Locality of Study: Department of Soil Science of the Santa Catarina State University, Lages, Brazil, between February and March 2015.

Methodology: Xaraés grass plants were cultivated in a greenhouse in pots with soil containing Cu doses in the following increasing order: 0, 30, 60, 120 and 200 mg kg-1. Before plant cultivation, the Cu availability in the soil was determined. During plant growth, the net CO2 assimilation rate, transpiration rate, stomatal conductance, SPAD index and extended plant height were measured. After harvest, the plant leaf area, specific leaf area, plant dry mass, nutrient accumulation in the shoots and Cu concentration in the roots and shoots were evaluated.

Results: Application of Cu in increasing doses to the soil resulted in a linear increase in the Cu availability which led to parabolic functions for plant growth, gas exchange and nutrient accumulation in the shoots. There was an exponential increase in the Cu concentration in the roots. Despite the increase in the Cu concentration in the shoots, the values do not exceed 12.70 mg kg-1.

Conclusion: The lower and upper critical doses of Cu for xaraés grass plants cultivated in Haplic Cambisol are 62.60 and 128.92 mg kg-1, respectively.

Open Access Original Research Article

Legume and Organic Fertilizer Effects on Soil Nutrient Availability, Uptake and Kale Yields in Kabete Sub-county Kenya

C. Chepkoech, R. N. Onwonga, R. G. Wahome, H. Høgh-Jensen

Journal of Experimental Agriculture International, Page 1-21
DOI: 10.9734/JEAI/2018/30364

Declining  soil  fertility  is  the  main  constraint  to  kale  (Brassica  oleracea  var.  acephala)  a common  vegetable,  production  in  parts  of  Kiambu  County  Kenya.  A  field  experiments  to evaluate the effect of legume integration  and application of organic fertilizers on soil N and P (and OC), uptake  and kale yield was set up in Kabete field station of the University of Nairobi, in the long and short rainy season of 2014. The experimental layout was a Randomized Complete Block Design with a split plot arrangement. The main plots were; (i) sole kale, (ii) kale intercropped with lupin and chickpea (lupin/kale and chickpea/kale) and (iii) Kale succeeding lupin and chickpea (lupin-kale and chickpea-kale). The spilt plots were the organic fertilizers inputs; Minjingu rock phosphate (MRP) and Farm yard manure (FYM), and the control. the nutrients  N, P and  organic carbon, kale N, P uptake and yield were analyzed at  intervals of 1, 2 and 3 months of kale development. The plant available N was higher in the lupin/kale intercrops + FYM in both seasons.  Plant available P was significantly (P≤0.05) higher in lupin/kale intercrop + MRP across the two seasons. There were no significant changes in soil organic carbon levels with legume integration and organic fertilizers application throughout the sampling period in both short rain seasons.  In  both  seasons,  significant  higher  N  concentration  was obtained  in  a  sole  kale  +  FYM  whereas  P  concentration  was  significantly  increased  in  a lupin/kale intercrop + MRP. Lupin/kale intercrop + FYM and lupin/kale intercrop +MRP showed a positive correlation (R2=0.99) between soil N and plant N, soil P and plant P respectively in both seasons.  Higher  kale  yields  were  obtained  in  lupin-kale  rotation  +  FYM  and  MRP; chickpea-kale rotation + FYM and MRP and kale monocrop + FYM. Integration of white lupin (intercrop/rotation) + FYM and MRP in a kale production system leads to a significant improvement on soil nutrient status, kale nutrient uptake and yield. Similarly where lupin was integrated positive correlations of soil and plant N and P were recorded and this means that the nutrient supplied was able to replenish the soil as much as plant took them up.

Open Access Original Research Article

Chemical Characteristics and Bioactive Compounds in Juazeiro Fruits Collected in Different Maturation Stages

Jéssica Leite da Silva, Franciscleudo Bezerra da Costa, Ana Marinho do Nascimento, Tatiana Marinho Gadelha, Márcio Santos da Silva, Larissa de Sousa Sátiro, Maria Angélica Farias Nobre, Kalinne Passos dos Santos, Chintia Rodrigues de Araújo, Kátia Gomes da Silva

Journal of Experimental Agriculture International, Page 1-10
DOI: 10.9734/JEAI/2018/44219

Objective: The present study aims to assess the bioactive compounds found in juazeiro fruits collected during different maturation stages and kept under controlled temperature.

Experimental Design: The experiment was conducted in a completely randomized factorial design (5 x 4), in which the first factor consisted of the maturation stages and the second consisted of days of storage.

Location and Duration of Study: The experiment was conducted at the Chemistry, Biochemistry and Food Analysis Laboratory of the Agrifood Science and Technology Center of the Federal University of Campina Grande, Pombal Campus, Paraíba, Brazil, between April and May of 2017.

Methodology: Fruits were collected from juazeiro trees located in the Pombal Campus of the Federal University of Campina Grande, and were classified in five maturation stages, according to their skin color. After being classified and cleaned, the fruits were packaged in expanded polystyrene trays, wrapped with a layer of PVC film, and stored under controlled temperature (28±2°C and 55±5% RH) for 6 days. Chemical and bioactive compound analysis was conducted every other day.

Results: In the study conditions, the fruits of juazeiro of all stages of maturation remained apt for analysis and consumption only on the first day of analysis. The results of the analyzes indicate that the advancement of the maturation promotes the reduction of acidity and increase of the soluble solids content, thus providing fruits with a more pronounced sweet flavor.

Conclusion: The juazeiro fruits are potential suppliers of phenolic compounds, especially in the first stage of maturation.

Open Access Original Research Article

Endophytic Fungi Associated with the Crown-of-friar Cactus (Melocactus zehntneri Britton & Rose) in the Semiarid Region of Brazil

José Thyago Aires Souza, Rommel dos Santos Siqueira Gomes, Gabriel Ginane Barreto, Luciana Cordeiro do Nascimento

Journal of Experimental Agriculture International, Page 1-5
DOI: 10.9734/JEAI/2018/43559

Aims: The objective of this study was to identify the occurrence of endophytic fungi associated with the crown-of-friar cactus (Melocactus zehntneri Britton & Rose) in the Brazilian Semi-arid region.

Methodology: The plants were collected in the municipality of Taperoá, State of Paraíba, Brazil and sent to the Phytopathology Laboratory, belonging to the Department of Plant Science and Environmental Sciences, the Federal University of Paraíba in the city of Areia, Paraíba, Brazil. Based on the indirect isolation of the symptomatic tissue fragments, fungal structures were examined under optical microscopy and compared with specialised literature. The removal of vegetative and reproductive structures of fungi, cultivated in BDA medium was carried out at a temperature of 25 ± 2°C and a photoperiod of 12 hours of light.

Results: Fungal genera namely, Colletotrichum sp., Curvularia sp., Fusarium sp., Pestalotipsis sp.e Phomopsis sp. were identified in de crown-of-friar cactus collected in the state of Paraíba. These genera cause diverse symptomatology in this cactus, negatively affecting the crown, base and root of the plant.

Conclusion: The fungal genera Colletotrichum, Curvularia, Fusarium, Pestalotipsis and Phomopsis were found on M. zehntneri plants collected in the state of Paraíba, Brazil.

Open Access Original Research Article

Bluprins® as Alternative Bud Break Promoter for ‘Maxi Gala’ and ‘Fuji Suprema’ Apple Trees

Cristhian Leonardo Fenili, José Luiz Petri, André Amarildo Sezerino, Mariuccia Schlichting De Martin, Gentil Carneiro Gabardo, Eduardo da Silva Daniel

Journal of Experimental Agriculture International, Page 1-13
DOI: 10.9734/JEAI/2018/43649

Aims: The effect of Bluprins® at different concentrations combined with calcium nitrate and ammonium nitrate on phenology, bud break induction and fruit production of 'Maxi Gala 'and' Fuji Suprema' apple tree cultivars was evaluated in mild winter conditions.

Study Design: The experiment was designed in randomised block and replicated five times.

Place and Duration of Study: The experiment was carried out in the municipality of Caçador, Brazil, during the growing seasons of 2013/2014, 2014/2015, 2015/2016 and 2016/2017.

Methodology: The study considered ‘Maxi Gala’ and ‘Fuji Suprema’ apple trees. The treatments evaluated were as follows: 1. Control (untreated); 2. Mineral oil 3.5% + hydrogen cyanamide 0.35%; 3. Bluprins® 3.0% + calcium nitrate 3.0%; 4. Bluprins® 5.0% + calcium nitrate 3.0%; 5. Bluprins® 3.0% + calcium nitrate 5.0%; 6. Bluprins® 5.0% + calcium nitrate 5.0%; 7. Bluprins® 3.0% + calcium nitrate 3.0% + ammonium nitrate 3.0%; 8. Bluprins® 5.0% + calcium nitrate 4.0% + ammonium nitrate 4.0%. Phenology, axillary and terminal bud break, fruit set, fruit production and average fruit weight were evaluated. The phenological stage of green tip (C-C3) and the beginning of bud break and flowering were anticipated by the application of Bluprins® and hydrogen cyanamide in compared to the control. The axillary and terminal bud break was increased by the application of bud break promoters for both cultivars considering the four growing seasons studied. The average fruit weight did not show significant differences between treatments in the growing seasons of 2013/2014 and 2015/2016. Bluprins®, in combination with calcium nitrate and ammonium nitrate, proved effective in inducing bud break of ‘Maxi Gala’ and ‘Fuji Suprema’ apple tree cultivars under mild winter conditions. The phenomenon is less effective with mineral oil in combination with hydrogen cyanamide. Bluprins® in combination with calcium nitrate and ammonium nitrate anticipates the bud break and flowering period and reduces the flowering period for ‘Maxi Gala’ and ‘Fuji Suprema’ apple tree cultivars in compared to plants without application of bud break promoters. Bluprins® does not affect considerably the fruit set and fruit production of ‘Maxi Gala’ and ‘Fuji Suprema’ apple tree cultivars.