Aims: Today, the use of nanoparticles has been studied in various fields of science. One of the sectors that is perhaps less dealt with is the physiology of medicinal plants. The present study is aimed at investigating the phytotoxicity or beneficial effects of titanium dioxide (TiO2) and titanium dioxide nanoparticle (NP-TiO2) treatments on seed germination, root and shoot length, photosynthetic pigments and possible inhibitory effects particularly NP-TiO2 on Mentha piperita. This study was evaluated in 2012-2013 in the Islamic Azad University of Falavarjan, Isfahan, Iran, research Laboratory. Methodology: Seeds were treated with TiO2 and NP-TiO2. Each treatment was conducted with four replicates, and the results were presented as mean ±SE (standard error of the mean). Germination percentage, root and shoot length and photosynthetic pigments were analysed using the SPSS 18. Results: The different concentrations of NP-TiO2 and TiO2 had a negative significant effect on germination percentage and shoot length. However, root length was significantly influenced by 100mg L-1 concentration of NP-TiO2 rather than nonNP-TiO2 concentrations. Pronounced effect on photosynthetic pigments (chlorophyll a and b and carotenoids) was found in 200mg L-1 concentration of TiO2 and 100mg L-1 concentration of NP-TiO2. Conclusion: The results of this experiment showed that TiO2 in higher concentration had pronounced effects on photosynthetic pigments while lower concentration of NP-TiO2 had significantly increased root length.
Sterculia setigera is a multipurpose savanna tree with socio-economic importance due to its gum and cultural importance in sub-Saharan Africa. The present study was carried out in Togo’s Sudanian area to characterize the structure and regeneration potential of S. Setigera in order to define a sustainable management plan associated to its valorization as gum species. Data were collected during May and April 2010. The methodological approach was based on forest inventory oriented by the presence of S. Setigera. Total height and stem diameter at breast height (dbh) greater than 10 cm of all trees species were measured in 97 plots. In each plot, ecological parameters were recorded and the seedling and suckers (dbh<10cm) of S. Setigera were counted. Forty six woody species belonging to 42 genera and 22 families were listed. Fabaceae, Combretaceae, Malvaceae and Moraceae were the dominated families. The prominent species were S. Setigera, Balanites aegyptiaca, Lannea acida and Diospyros mespiliformis. Presence/absence data of the overall species recorded in each plot was subjected to multidimensional scaling and results showed 5 plants communities: fallows, croplands, low side savannas, mean side and tablelands savannas and uplands savannas. The structure adjusted by 3-parameter Weibull showed reverse “J” shape for class diameter distribution with shape parameter varies between 1 and 3.6 showing a predominance of individuals with small diameter within the overall study area. The height structure showed a bell-shape and left dissymmetric distribution. The regeneration rate is very low (5.21 to 16.15). It is necessary to define a sustainable program for the conservation and valorization of this gum species.
This article studied soil samples from the various rice-based environments of the inland valleys of Cote d’Ivoire to evaluate their native capacity of mineralization of N. Soil N, is subject to intense chemical and microbiological transformation processes (hydrolysis, oxidations, reduction). All these transformation processes are subject to water availability and therefore show a strong variability related to soil grains size and vegetative cover. In order to applied appropriate technical strategies aiming at conserving soil N or using it for food crop, it is important to evaluate its mineralization potential in the concerned soils. In this paper, the nitrogen supplying potential of soils from the ten major rice-based production systems of Côte d’Ivoire was determined by incubation experiments in 1997. The net N mineralization potential (N supplying capacity during 6 weeks of anaerobic incubation) from soils of the various rice-based systems of Côte d’Ivoire varied between 4 and 16 mg N kg-1 of soil. It was generally less in the savanna than in forest upland soils and intensified land use reduced soil N supplying capacity more in savanna than in forest ecosystems. It may be concluded that N mineralization from soils of the various rice-based systems of Côte d’Ivoire strongly varied. Soil N supply was generally less in the sandy than in clay soils. Land use intensification affected N release more in the savanna than in the forest and tended to reduce the N supplying capacity more in lowland than in upland soils. As soil nutrient mineralization rates are also controlled by the specific character of the vegetation occupying a site, plant-soil-plant feedback loops in agricultural systems will influence the N dynamics over time.
The application of fertilizers derived from agroindustrial by-products, represents an interesting opportunity in organic farming. The composition of such inputs includes complex molecules, which strongly influence their effectiveness in providing the optimal nutrient availability and improving crop performances. The aim of the present study was to determine the nutrient release rate of different organic fertilizers and amendments and their effects on shoot growth, fruit production, leaf nutritional status, root biomass and morphology. In a two-years pot trial, two organic fertilizers produced with dried fungal biomass (DFB) and vinasse of sugar beet pulp (VN) and two amendments obtained from fermented animal sewage (SE) and composted olive husks plus grapevine waste (OG), were applied on apple rooted cuttings. One set of plant were not fertilised and acted as Control. The application of DFB, VN and SE increased nitrogen concentration in the soil and in the leaves, supported higher fruit number and enhanced plant growth above and below ground compared to OG and Control. The effect on root growth was positively correlated with nitrogen mineralization rate. For OG treatment, soil electric conductivity negatively influenced root branching frequency, indicating a potential risk of stress due to salinity excess.
Impact of environmental factors (temperature and relative humidity) on phenology and reproductive biology of a medicinal plant Sida cordifolia L. growing at district Agra was studied. The study revealed that phenological events (leaf fall, leaf renewal, flowering and fruiting) varied considerably with the fluctuations in temperature and relative humidity. Flowering was observed throughout the year with maximum in the months of February-April (11.8 – 38.3ºC) and August-September (24.4- 33.9ºC). Floral biology studies showed that pollen viability, pollen-ovule ratio and fruit-set percentage was greatly reduced with rise or fall in temperature and relative humidity. The maximum pollen fertility (71%), fruit-set (70- 90%) and pollen-ovule ratio (190:1) was recorded in the month of March when temperature was ranging between 15.1-32.6ºC with 22- 76% RH. With the fall in temperature in the month of January (6.8 - 17.9ºC) the pollen fertility was reduced to 52%. At the end of April 32.5- 45.3ºC with 16- 43% RH, the plants under observation exhibited a gradual decline in fruit-set percentage (45- 55%). The anthesis, anther dehiscence and stigma receptivity also varied during the entire flowering period. As the temperature rises, the anthesis takes place earlier and the time of anther dehiscence and stigma receptivity changed accordingly. In this investigation it was found that the changes in temperature and relative humidity during the entire flowering period was associated with the variation in different phenological and reproductive events in the Sida cordifolia plant.
The aim of this study was to develop a simple and quantitative system for coffee yield estimation and nutrient input advice, so as to address the problem of declining annual coffee production in Tanzania (particularly in its Northern coffee zone), which is related to declining soil fertility. The study was conducted between 2010 and 2013 at TaCRI Lyamungu, with source data taken from Hai and Lushoto districts, Northern Tanzania. An earlier model QUEFTS, developed for maize but under similar conditions as those of Arabica coffee (Coffea arabica) in the study areas was used as a benchmark. Secondary fertilizer trial data were used in model calibration for coffee, while adding two more steps related to balanced nutrition and the economics of integrated soil fertility management (ISFM). Primary soil analytical data and calculated yields on basis of tree number were used for model testing. The result was a new model which we hereby call SAFERNAC (Soil Analysis for Fertility Evaluation and Recommendation on Nutrient Application to Coffee). The model consists of three modules: SOIL (the soil properties of interest), PLANT (all the crop and crop management parameters such as physiological nutrient use efficiency, plant density, maximum yields per tree) and INPUT (nutrient inputs – organic and inorganic). It consists of two subsequent parts – a baseline approach (no input) for coffee land evaluation; and an integrated soil fertility management (ISFM) approach that involves application of nutrient inputs, for ISFM planning and design of fertilizer experiments. The model was checked for accuracy of the adjusted equations, and found to be capable of reproducing the actual yields by 80-100%. The new model is a useful tool for use in coffee farms.
On average Malawi is losing of 40 kg N ha-1 and 6.6 kg P ha-1 annually. Additionally, nutrient use efficiency (NUE) is low as a result of declining levels of soil organic matter (SOM) and associated deficiencies of other macro and micronutrients. This is usually below 20 kg maize grain kg-1 of nutrients applied. To investigate on the possibility of improving NUE a study was initiated in the 2011/12 cropping season with a parallel trial mounted along side in the second season, both were laid in a randomized complete block design replicated three times. The trials involved planting of pigeon pea as monocultures or as intercrops. The main trial had eight treatments while the parallel trial had ten treatments. After the first season legume biomass in some plots of the main trial was buried into the soil. Soil characterization was conducted before treatment application in the first and second year. Data were analyzed using genstat and subjected to analysis of variance at 5% level of confidence. Means were separated using the least significant difference. Generally, the soil chemical characteristics for soil samples collected in all the treatment plots both in the main and parallel trial indicate that the soil has low fertility. The organic carbon (OC), cation exchange capacity CEC (NH4OAc), and total N (%) was low, and was at 1.4 %, 3.5-3.6 cmol (+)/kg soil, 0.12%, while available phosphorus (Mehlich 3) was marginally adequate (mean=21.5 mg kg-1 and 22.1 mg kg-1). The soil texture which was predominantly sandy clay loam to sandy clay coupled to the low CEC suggest potential high leacheability of nutrient elements more especially nitrogen as nitrate. Inevitably, if the soil is not properly managed crop yield could be reduced drastically.
The aim of this study was to establish the nutrient release potential of different organic materials and assess their role in integrated soil fertility management for coffee using the new coffee yield model SAFERNAC. It involved an incubation experiment conducted at TaCRI Lyamungu Screenhouse for 180 days between April and September 2011. Cattle manure, coffee leaves, pulp and husks, Albizzia leaves and four green manure plants – Mucuna pruriens, Lupinus albus, Canavalia ensiformis and Crotalaria ochroleuca were mixed with two soil types – Eutric Nitisols from Lyamungu, Hai district and Humi-Umbric Acrisols from Yoghoi, Lushoto district. The mixing ratio was 5% organic to soil, the mixture was moistened to FC and incubated in 10 litre plastic containers arranged in RCBD (10 treatments and 3 replications) at room temperature. Duplicate soil samples were taken at day 0, 3, 8, 15, 26, 45, 74, 112 and 180 and analyzed for NH4+-N, NO3-N, available P and exchangeable K. The cumulative Nmin, P and K values resulting from the treatments were used to estimate their relative contribution to the soil nutrient pool and later exposed to the new model SAFERNAC for yield estimation under different nutrient management options (1 to 10 tons organics per ha alone on one hand and supplemented with 160 kg N, 60 kg P and 160 kg K). The tested organics differed significantly (P<0.001) in their Nmin, P and K release in the two soil types. They also differed in their substitution values and therefore the amounts of nutrients each one can contribute to the soil nutrient pools. Green manures showed about ten times higher potential as compared to cattle manure. Four of them (Crotalaria, Mucuna, Canavalia and Lupine) were picked as best bets for inclusion in the coffee ISFM programme. SAFERNAC recommended a number of nutrient management options involving the test organics and the two soil types under organic and conventional coffee farming.