Open Access Short Research Article

Floral Biology and Pollen Viability of Passiflora edulis Sims

Ivan Sérgio da Silva Oliveira, Vênia Camelo de Souza, Sara Beatriz da Costa Santos, Jazielly Nascimento da Rocha Almeida, Josinaldo da Silva Henrique, Paulo Marks de Araújo Costa, João Henrique Constantino Sales Silva, Carlos Alberto Lins Cassimiro, Carmelita Érica Azevedo de Lucena, Thiago de Sousa Melo

Journal of Experimental Agriculture International, Page 1-9
DOI: 10.9734/jeai/2019/v41i130386

Yellow passion fruit is a native tropical fruit tree whose cultivation has evolved very rapidly in Brazil; therefore, studies on the ecology of reproduction are needed. The study of pollen viability is an important tool to observe the male potential of the species. The objective of this study was to estimate pollen viability, pollen/ovule ratio and floral biology of Passiflora edulis Sims in organic cultivation located in Bananeiras, PB, and Brazilian. The study was developed in a completely randomized design, using ten flower buds in the pre-anthesis. The analyses performed in the biology laboratory of the Center of Human, Social and Agrarian Sciences of the Federal University of Paraiba. For the pollen viability analysis, all the anthers of the ten flower buds were used, five anthers per flower, which were crushed on a glass slide and with the aid of Alexander dye, the purple pollen grains were considered viable and the green ones unviable. To measure flower morphology and biometrics, a digital pachymeter, analytical balance and ruler were used. Five stamens form the androecium; the fillets are of short length inserted below the ovary. The flowers have three stigmas with an average height of 16.5mm, an average of 32,136 viable pollens, 58 unviable pollen grains and 140 ovules per ovary, having a pollen viability of 99.8% and a pollen/ovule ratio of approximately 95/1 pollen grains per ovule. Their structures are uniform, with no biometric variations in the amount of petals, sepals, anthers and stigma length. Alexander's reactive dye was effective in staining the pollen grains of yellow passion fruit. The pollen/ovule ratio indicates that this species performs facultative autogamy as well; however, this classification alone is not sufficient to affirm its reproductive system.

Open Access Short Research Article

Risk Analysis in a Tropical Forest Wood Exploration and Processing System in Mato Grosso State, Brazil

Denise Ransolin Soranso, Luciano José Minette, Wanderson Lyrio Bermudes, Michel Picanço Oliveira, Stanley Schettino, Nilton Cesar Fiedler, Frederico Eustáquio Telles Vieira

Journal of Experimental Agriculture International, Page 1-10
DOI: 10.9734/jeai/2019/v41i130391

Forestry and logging activities in tropical regions are commonly carried out in inappropriate thermal conditions, due to the hot and humid climate, demanding from the worker high energy expenditure and physical effort. They often operate and handle machines and equipment that produce high levels of noise and vibration, and adopt postures that can be harmful to the body, given the constant lifting, handling and transport of loads above tolerable limits. The objective of this study was to evaluate the exposure of workers to risks in a rainforest harvesting and processing system in northern Mato Grosso State, Brazil. The study was conducted in two forest management areas and four processing industries. Occupational heat exposure was assessed and a qualitative analysis of noise and vibration was performed in the two study areas. Occupational exposure to heat was performed by determining the Wet Bulb Index and Globe Thermometer (IBUTG), while the qualitative analysis of noise and vibration was performed with the application of a Risk Analysis methodology. The results indicate that the values of the wet bulb index and globe thermometer (IBUTG), obtained every hour of the working day in the activities of the timber industry and wood processing, correspond to values above the tolerance limit, as standardized.  The condition most likely to be harmful to health was found in the exposure to noise by workers in the wood processing industry, especially in operations related to the logging stages, where the risk was categorized as intolerable. With respect to exposure to vibration, the risk was higher in chainsaw operations in logging. In this case, it was possible to qualitatively analyze which occupational exposure limit (OEL) would be exceeded when the machine was in operation, representing risks to workers’ health and safety. It is concluded that there is a need to adopt control measures, since the risk exposure levels were in a range that poses a risk to workers’ health.

Open Access Original Research Article

Effect of Field Treatment with Selected Soil Amendments on Bacterial Wilt Incidences in Tomatoes, Capsicum and Potatoes

E. K. Kago, Z. M. Kinyua, J. M. Maingi, P. O. Okemo

Journal of Experimental Agriculture International, Page 1-12
DOI: 10.9734/jeai/2019/v41i130387

Aims: The aim of this study was to establish the effect of field treatment with selected soil amendments on bacterial wilt incidences in Tomatoes, Capsicum and Potatoes. 

Study Design:  The study was laid out as randomized complete block design (RCBD) in split plot arrangement for two seasons in the field.

Place and Duration of Study: The experiment was conducted at the experimental plots at KARLO- NARL, Kabete Nairobi County between July, 2017- September, 2017 and between November, 2017- January, 2018.

Methodology: The three choice crops of interest (potatoes, tomatoes and capsicum) were inoculated with prepared pure bacterial isolates; 18 (2T-Kiambu-Low Land), 71(2A-Nyeri-Low Land), 67 (2A-Nyeri-High Land), 83 (2T-Kirinyaga-Highland) and MX (18/71/67/83). A plot measuring 66 m by 28.5 m was marked, cleared, ploughed, harrowed and demarcated into 150 plots each measuring 2.4 m x 3.75 m. Spacing of the host crops of interest: potato - (Tigoni variety), tomato (Caj variety) and capsicum (Califonia Wonder) was carried out at 75 cm between the rows and 30 cm within the rows. The treatments were ChalimTM, Super-hydro-grow polymer + Metham sodium, Metham sodium, Metham sodium & Orange peel, Super-hydro-grow polymer, Brassica tissues, ChalimTM + Super-hydro-grow polymer, Brassica tissue + Orange peel, Metham sodium + Super-hydro-grow polymer and Control (no amendments).

Results: Significant differences (P≤0.05) were revealed in the bacterial wilt incidences in tomatoes, capsicum and potatoes between control and all the soil amendments used in season 1 and 2 in the five R. solanacearum isolate from Kenyan highlands and lowlands. The Brassica tissue + Super-hydro-grow polymer was superior in reducing bacterial wilt incidences in tomatoes, capsicum and potatoes in the field in all the R. solanacearum isolates from Kenyan highlands and lowlands both in season 1 and 2.

Conclusion: The findings showed that organic and inorganic soil amendments could serve as a viable control of bacterial wilt in solanaceous crops caused by R. solanacearum in the field. We recommend the use of Brassica tissue + Super-hydro-grow polymer soil amendment in the control of bacterial wilt incidences in the field on solanaceous crops.

Open Access Original Research Article

Sugarcane Leaf Scald Disease in Côte d'Ivoire: Pathogenicity and Biocontrol of Xanthomonas albilineans Isolates

N’guessan Aya Carine, Kouamé Konan Didier, Kassi Koffi Fernand Jean-martial, Kouamé Koffi Gaston, Konan Dawa Richard, Yao Kouadio Jacques-Edouard, Koné Daouda

Journal of Experimental Agriculture International, Page 1-11
DOI: 10.9734/jeai/2019/v41i130388

Aims: The present investigations describes bactericidal potential of essential oil for management of Xanthomonas albilineans (Ashby. 1929) Dowson 1943, pathogen responsible for sugarcane Leaf scald disease in Côte d'Ivoire.

Study Design: the study was conducted at the Ferké 1 sugar mill and the Laboratory of Plant Physiology of Felix Houphouët BOIGNY University.

Methodology: Diseased leaves specimens showing signs of X. albilineans presence were collected from sugarcane industrial plantations in Côte d'Ivoire. Pathogenicity was confirmed by observing Koch’s postulates under semi-controlled conditions. Asymptomatic leaves, obtained after 60 days of culture, were inoculated at three points by infiltration with bacterial suspension calibrated at 108 bacteria/ml. Apparition of small tan-brown necrotic lesions on the leaf blade, parallel to the veins and prolonged to the ends by a discolored vascular bundle confirmed that disease is caused by Xanthomonas albilineans. Three essential oils of aromatic plants whose antibacterial properties are recognized were used at 100; 300; 500; 1000 and 2000 ppm in comparison with Callicuivre (56% copper oxychloride) used as reference product.

Results: The aqueous solutions based on these essential oils induced an inhibition zone of bacterial growth proportional to the dose applied and the incubation period. Thus, on day 5 of incubation, the essential oil solution of Ocimum gratissimum L. at 100 ppm induced an average inhibition zone diameter not significantly different from the one induced by the Cymbopogon citratus (DC.) Stapf solution at 300 ppm and the one of copper oxychloride at 1000 ppm. At 1000 ppm, Zingiber officinale Roscoe, Cymbopogon citratus (DC.) Stapf and Ocimum gratissimum L essential oils induced equivalent inhibition rates (6 mm) that were higher than that of the control (3.5 mm).

Conclusion: sugarcane varieties cultivated at the Ferké 1 sugar mill complex, despite the selection for resistance are threatened by Leaf Scald Disease, which is significantly expressed on variety R585. Cymbopogon citratus (DC.) Stapf and Ocimum gratissimum L oils have the strongest antibacterial activity and may be useful to control Leaf Scald Disease.

Open Access Original Research Article

The Effect of Air Dried Leaf Powder and Burnt Leaf Ash of Different Plants on Root-knot Nematode (Meloidogyne spp.) on Okra (Abelmoschus esculentus L. Moench)

O. F. Nnadi, C. C. Ononuju, E. A. Ikwunagu, C. C. Orikara

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/jeai/2019/v41i130389

The effect of air dried leaf powder and burnt leaf ash of different plants on the control of root-knot nematode (Meloidogyne spp.) on Okra was investigated in a pot experiment. The experiment was laid out in a Completely Randomized Design with nine treatments each replicated four times. The treatments included: burnt leaf ashes and air dried leaf powders of Baphia nitida, Pentaclethra macrophylla and Delonix regia, a synthetic nematicide (Carbofuran 3G) and two control which included inoculated but untreated (control 1) and un-inoculated and untreated (control 2) pots. The plants were inoculated with 1000 nematode eggs (Meloidogyne spp.), two weeks after emergence. Three days after, the treatments were applied at the rate of 30 g each, while the synthetic nematicide (Carbofuran 3G) at 3 g/per pot. Parameters recorded were: plant height, number of leaves, fresh and dry shoot weights, fresh root weight, and number and weight of pods per plant as plant growth parameters. Number of galls, number of nematode eggs in roots and number of juveniles in soil as nematode parameters. Results obtained indicated significant differences among the treatments in most parameters recorded and compared to controls. Generally, results from air dried leaf powder of Baphia nitida and burnt leaf ash of Delonix regia were better and compared favorably with the nematicide treated plants.