Original Research Article

EFFECT OF DIFFERENT GROWTH MEDIA ON THE GERMINATION AND SEEDLING GROWTH OF TOMATOES (Lycopersicum esculentum Mill)

M. D. BELEL, A. G. BILKISU

Asian Journal of Plant and Soil Sciences, Volume 1, Issue 1, Page 1-8

Field study was carried out at the students main orchard farm of the Department of Agricultural Technology Federal Polytechnic Mubi, during the 2012 rainy season on the effect of different growth media (Wood sawdust, cotton lint, rice husk, and soil medium)  on the germination and seedling growth of Tomato (Lycopersicum esculentum Mill). The experiment was set out on completely randomized design (CRD), which was replicated three times. The result showed that the different growth media significantly affect plant height, number of leaves, emergence count, stem diameter, and root length of tomatoes. Cotton lint was better in both germination and growth of Tomato seedlings. Cotton lint was a better growth medium in the screen house experiment and is recommended for laboratory experiments in tomatoes.

Original Research Article

SEED PREDATORS, DRUPE PREDATION RATES AND THEIR EFFECTS ON THE REGENERATION DYNAMICS OF Olea welwitschii IN KAKAMEGA FOREST, KENYA

H. M. TSINGALIA

Asian Journal of Plant and Soil Sciences, Volume 1, Issue 1, Page 9-16

Careful scrutiny of data collected during the forest inventory in the 1960s on the undergrowth reveals absence of seedlings of Olea welwitschii. This study sought to determine why Olea welwitschii does not regenerate inside the forest and to examine the roles of predispersal and post-dispersal drupes and seed predation intensities as precipitators of lack of regeneration. Seed/drupe predation experiments were conducted at two levels. The first level examined pre-dispersal seed and drupe predation.  Rectangular seed/drupe traps made out of meshed fabric with a collecting surface of 0.25 m2were randomly placed to cover all the four quadrants under the canopy of five randomly selected Olea fruiting trees. The second level examined post-dispersal predation by sampling seeds and drupes under the crown of each of the randomly selected fruiting trees by dividing it into four quadrants. Within each quadrant, five 1m2 quadrats were established on the ground in a random fashion to cover at least 10-30 per cent of the total canopy area. Frequency- and distance- dependent seed/drupe predation were examined using 30 (l m2) quadrats with equal numbers of seeds and drupes and inspected every 12 hours for one month to determine differences in seed and drupe predation rates. Effects of density and distance were tested by setting up 50 m long transects with the base of the fruiting trees as the starting point. Two transects per tree in two different directions, north/south and east/west at five fruiting trees were established. Along each transect, eleven sampling stations were established at a five metre interval. A trapping grid was established under the crown of five fruiting Olea adults and away from the crown to determine differences in small mammal predator density. Results of predispersal drupes predation was derived from the pooled sample of all drupes collected. A total of 1386 drupes were collected. Of these, three (3) per cent had insect holes. A closer examination of size and weight of the drupes that were attacked revealed that smaller drupes (70%) were attacked more than larger ones (30%). Overall, there were more small drupes falling on the forest floor (89 per cent) than large ones (11 per cent). Drupe and seed density was a decreasing function of distance from the parent trees ad distance from the parent trees had a significant effect on drupes and seed predation rates. Regardless of density, seeds were removed at higher rates under the parent crowns, while drupes were ignored by the predators. One species of rodents, Praomys jacksoni was trapped. The majority of the captures were under fruiting Olea adults (3.71 animals per trapping night) rather than farther away from the adult trees (0.61 animals per trapping night; Z=8.724, p<0.01). A total of 18,000 seeds were examined for pathogen attacks and only 10 per cent of the intact seeds showed sign of insect/rodent attack.  Drupes density greatly influenced fungal infection rates (ᵡ2=55.867, p<0.001). Results clearly suggest that density is not an important factor in the predation of Olea drupes and drupes. The failure to find greater predation rates for drupes in large clumps suggest that either large clumps are no easier to find than small clumps for predators or these predators remove all the drupes they find regardless of clump size. Predation risk of drupes and seed appears to be influenced by patchiness in the activity patterns of drupes eaters.

Original Research Article

EFFECT OF SOME PHYSICAL AND CHEMICAL TREATMENTS AND TEMPERATURE ON THE SEEDS GERMINATION OF HAWTHORN: Crataegus monogyna Jacq.

MOKHTARIA HAMDAOUI, ZOHEIR MEHDADI, FATIHA CHALANE

Asian Journal of Plant and Soil Sciences, Volume 1, Issue 1, Page 17-26

Experiments were conducted to determine the effect of some physical (warm and cold stratification) and chemical treatments (scarification with sulphuric acid 98% at different durations) on the breaking of the double dormancy (endocarp inhibition and embryonic dormancy) affecting the seeds of oneseed hawthorn (Crataegus monogyna Jacq.) collected from shrubs grow spontaneously in the mount of Tessala (West-Algerian). The germination was tested in an oven at 20°C and 25°C. Compared to the seeds not treated with sulphuric acid, chemical scarification for 30 and 60 min by sulfuric acid combined with warm and cold stratification improves the germination capacity of seeds. Indeed, these pretreatments (stratification and scarification) have allowed to obtain maximum germination capacities 62 ± 5.38% at 25°C and 57 ± 1.65% at 20°C; while the weakest capacities are noted with seeds not treated with sulphuric acid and that are subjected only to cold stratification 24 ± 5.08% and 25 ± 0.86% respectively at 20°C and 25°C. Also the scarification works favorably by improving the velocity coefficient and shortening the time latency. The scarification entrains the deterioration of seeds when it exceeds 60 min.

Original Research Article

CHARACTERISATION OF ATTAPULGITE AND ITS COMPARISON WITH DIATOMACEOUS EARTH ON THE BASIS OF PHYSICOCHEMICAL PROPERTIES AND SORPTION BEHAVIOUR OF P AND NH4+

R. SHARMA, V. S. R. KAMBALA

Asian Journal of Plant and Soil Sciences, Volume 1, Issue 1, Page 27-34

Attapulgite is a naturally occurring crystalline hydrated magnesium alumino-silicate that gives it unique colloidal and sorptive properties, whereas diatomaceous earth is a naturally soft, siliceous sedimentary mineral with a fine white to off-white powder. The main objective of the research is to characterize the physicochemical properties and sorption behaviour of attapulgite, and its comparison with that of diatomaceous earth. Both materials were analysed for physicochemical properties such as mineralogy by XRD, pH, electrical conductivity (EC), phosphorus retention index (PRI), Exchangeable cations (Ca2+, Mg2+, Na+ and K+), cation exchange capacity (CEC) and sorption studies (NH4+ and P sorption). Mineralogy results showed that attapulgite contain major palygorskite and kaolin with trace halite (NaCl), whereas diatomaceous earth contains major quartz, minor kaolinite and halite. The lower Ca/Mg ratio (< 1) suggests that both materials are Ca deficit. Due to higher individual base saturation percentage attapulgite is weakly leached, which suggests it may be able to prevent leaching of soluble cations from sandy soils of Western Australia. Both materials have good phosphorus sorption capacity compared to the NH4+ sorption and it can be improved by treating them with other cations/anions or organic matter addition. This preliminary investigation suggests that attapulgite can be used as slow release fertilizer after treating with phosphate for sandy soils of Western Australia but it needs further investigation to assess its effect on nutrient availability to plants and leachability.

Original Research Article

ASSESSMENT OF HEAVY METALS CONCENTRATION IN ROADSIDE SOILS NEAR AN ALGERIAN NATIONAL ROAD

SOUMIA RAMDANI, AMINA AMAR, KHADIDJA BENOUIS

Asian Journal of Plant and Soil Sciences, Volume 1, Issue 1, Page 35-44

This study assesses and quantifies the contamination by heavy metals from soils near a road in western Algeria (RN35, Tlemcen). The physicochemical parameters of soils and total heavy metals concentrations were determined using standardized methods and atomic absorption spectrometry, respectively. The results showed that most of the soils were contaminated with cadmium, lead and zinc in a concentration ranges of 1.47 to 3.00 mg/kg for Cd; 8.00 to 39.75 mg/kg for Cu; 16.75 to 301.25 mg/kg for Pb and 68.00 to 1952.50 mg/kg for Zn. Pollution index of seven soils samples exceeds unity evoking significant polymetallic pollution. Monitoring measures and reduction lead content in gasoline should be taken into consideration in order to reduce concentrations of these pollutants and avoid their introduction into the environment and contamination of groundwater, wildlife and local flora.