Response of greenhouse cucumber to mineral fertilizers on a high phosphorus and potassium soil

The response of greenhouse cucumber (Cucumis sativus L. cv. Lolita) to nitrogen (N), phosphorus (P) and potassium (K) fertilizers on a soil high in available P and K was studied during 1986. The greenhouses were located in the Beqa Valley, central Lebanon, and their soil chemical properties before planting were: NO₃‐N = 52 ppm, P(NaHCO₃ ext.) = 100 ppm, K (ammonium acetate ext.) = 650 ppm, ECe = 1.6 dS/m, pH = 7.5. Nitrogen at 200 kg/ha, P at 85 kg/ha and K at 150 kg/ha were applied in the following combinations: N, N+K, N+P+K and an unfertilized control. The rates were split into four equal weekly applications starting on the fourth week after transplanting the seedlings to the greenhouse. The treatments were applied through the drip irrigation system of the greenhouses. Fruit yield over the two months of harvest was highest in plants receiving N alone, which yielded 57 ton/ha. Yields of the plots receiving N+K, N+P+K and the control were 55.0, 54.0 and 39.5 ton/ha, respectively. Yield during the first month of harvest was comparable in all fertilized treatments and was substantially higher than the control.     

Differential allelopathic potential of sunflower (Helianthus annuus L.) genotypes on weeds and wheat (Triticum aestivum L.) crop

Studies were conducted to screen eight sunflower (Helianthus annuus L.) genotypes for their allelopathic potential against weeds and wheat crop, which customarily follows sunflower in Iraq. All sunflower genotypes significantly inhibited the total number and biomass of companion weeds and the magnitude of inhibition was genotype dependent. Among the eight genotypes tested, Sin-Altheeb and Coupon were the most weed-suppressing cultivars, and Euroflor and Shumoos were the least. A subsequent field experiment indicated that sunflower residues incorporated into the field soil significantly inhibited the total number and biomass of weeds growing in the wheat field. Sunflower genotypes Sin-Altheeb and Coupon appeared to inhibit total weed number and biomass more and significantly increased wheat yield compared with the least-suppressive genotypes (Euroflor and Shumoos). Chromatographic analyses by HPLC revealed the presence of 13 secondary metabolites in residues of the tested sunflower genotypes. All the isolated compounds appeared to be phenolic, with the exception of terpinol, which is a terpenoid derivative. The total concentration of Phytotoxins (phenolic compounds) was found to be higher in the most-suppressive potential genotypes compared with the least-suppressive genotypes.     

Aloe vera long-term saline irrigation increases contents of hydrogen peroxide,lipid peroxidation and phenolic compounds

Salt stress is more and more becoming a serious problem in the world especially if we consider its damaging effect on the plant growth and yield. The cultivation of medicinal plants, such as Aloe vera, might be an alternative for the saline water use and salt-affected soils occupation. Aloe vera, commonly known as aloe, is one of the primary medicinal plants with multipurpose applications going from pharmaceutical to cosmetic aspects with a promising economic return. Aloe plants were cultivated and irrigated, for 14 months, with drinking water (C0) and with two levels of salt (C1 and C2). Changes in growth, hydrogen peroxide (H₂O₂), lipid peroxidation and phenolic compounds were examined in leaves at harvest. Depressive effects of salt irrigation on the plant growth parameters and a perturbation in inorganic ion contents were found especially with a high level of salt in the irrigation water. The intracellular oxidative stress was evaluated with the H₂O₂ production. Our results showed that the H₂O₂ content increased with the accumulation of the toxic ion (Na) in the leaf tissues. In addition, lipid peroxidation, measured by the malondialdehyde (MDA) level, increased as well with salt augmentation in the irrigation water. In response to salt stress, Aloe leaves showed a significant increase in the levels of phenolic compounds too. These results suggest that Aloe can be planted in soils affected by salinity and irrigated with salt water at least at a moderate concentration used in the present study.     

Various Mycorrhizal Fungi Enhance Dry Weights,P and Zn Uptake of Four Pistacia Species

Pistacia is a common wild plant in the Southeast Anatolia part of Turkey. The experiment was planned to screen and select the most suitable arbuscular mycorrhizae (AM) for enhancing Pistacia species seedling growth by improving phosphorus (P) and zinc (Zn) uptake. This study was carried out under greenhouse condition at the Department of Soil Science, Çukurova University, Adana, Turkey. Two genotypes from each of P. vera (cvs ‘Siirt’ and ‘Kirmizi’), P. eurycarpa, P. atlantica, and P. terebinthus species were tested with ten different mycorrhizal species. Plants were grown in a growth medium with a mixture of sand, soil and compost with 6:3:1 ratio, respectively. Seedling plants were harvested after eight months and transplanted to pots. There were significant differences between Pistacia species in growth, nutrient uptake and the percentage of mycorrhizal infection. Also mycorrhizal species were different in terms of enhancing plant growth and nutrient uptake. The results were that Siirt, Genotype 08, 11, 13, and 14 gave a high response to the mycorrhizal inoculation and Glomus clarium gave the best improvements in growth and nutrition, resulting in greater plant biomass and Zn and P uptake. Following this, G. etunicatum, G. intraradices, G. caledonium, and G. mosseae species were effective species. In general, G. mosseae and G. fasciculatum mycorrhizae enhanced plant growth; G. clarium was the most efficient species in terms of P and Zn uptake.

It has been concluded that these mycorrhizae species significantly enhance the Pistacia plant growth and nutrient uptake. Also using AM fungi in the pistachio nursery should be taken into consideration for better seedling production. Further work needs to be done to determine how much inoculum is needed for sufficient inoculation and how the mycorrhizal seedlings can be adapted under field conditions especially under drought and high calcareous marginal soil conditions.     

Chemical changes during the fermentation of African locust-bean (Parkia filicoidea Welw) seeds for production of ‘Daddawa’

African locust-bean (Parkia filicoidea Welw) seeds were allowed to ferment under natural conditions and the chemical changes occurring during the fermentation were studied. Chemical analysis of fermented and unfermented beans showed a marked decrease in the total sugar content; crude and true protein levels all increased. The results of the chemical analyses indicate that fermentation resulted in protein enrichment of the fermented locust bean (daddaw). Fermentation also imparts a characteristic flavour and odour to the beans.     

Assessment of compost and three biochars associated with Ailanthus altissima (Miller) Swingle for lead and arsenic stabilization in a post-mining Technosol

The elevated presence of metal(loid)s in the environment significantly impacts ecosystems and human health and is generally largely due to industrial and mining activities. Thus, in the current study, we investigated and proposed an environmentally friendly method (phytomanagement) aimed at reducing the negative impacts associated with metal(loid) pollution through the use of soil amendments (biochar and compost) to permit Ailanthus altissima growth on a highly contaminated mining Technosol, with arsenic (As) and lead (Pb) contents of 539.06 and 11 453 mg kg^-1, respectively. The objective was to examine the impacts of three biochars and compost on i) the physicochemical characteristics of soil, ii) metal(loid) immobilization in soil, and iii) A. altissima growth. We revealed that the application of biochar as a soil amendment improved soil conditions by increasing soil electrical conductivity, pH, and water-holding capacity. Moreover, concomitantly, we observed a large reduction (99%) in Pb mobility and availability following application of the hardwood biochar in combination with compost (HBCP). Thus, this combined soil amendment was most effective in promoting A. altissima growth. In addition, the HBCP treatment prevented As translocation in the upper parts of plants, although soil pore water As concentration was not diminished by amendment application.     

Genetic diversity studies and screening for rice stem borer (Chilo Agamemnon) resistance in six Egyptian rice cultivars (Oryza sativa L.) using DNA based-markers

Genetic Resources and Crop Evolution - In order to assess the genetic diversity among six Egyptian rice cultivars and developing cultivars resistant to different rice stem borers, random amplified...     

Contribution of Erythrina protein banks and rejected bananas for improving cattle production in the humid tropics

In view of the low pasture productivity in the Central American humid tropics where cattle rearing is a major land-use activity, it is important to examine the potential of alternate feed sources for ruminant feeding. Erythrina berteroana Uban, locally known as poro, and green banana (Musa AAA) fruits have been identified as two such potential sources. The effects of feeding poro as a grazing supplement and diet supplementation with green banana fruits on cattle productivity were evaluated in a long-term trial in Costa Rica. Daily liveweight (LW) gains were measured and samples of all feed material were analyzed for crude protein and in vitro dry matter (DM) digestibility. Pasture availability was high, averaging 0.17 t DM ha day^–1 over the grazing period. The main grass species were Paspalum fasciculatium Poiret, Axonopus compressus Swartz and to a lesser extent African star grass (Cynodon nlemfluensis Vanderyst). DM yields of poro declined significantly with time (> 50%) when it was managed with a two-month resting period but remained higher when subsequently managed with a three-month resting period. Average daily LW gain of animals was 21% to 26% higher with two hours daily browsing of poro than for animals only grazing pasture. Highest liveweight gain was achieved when diets were supplemented with banana and there was no additional benefit when poro was fed in addition to banana. This suggests that fodder banks of poro or supplements with green banana can improve cattle nutrition in the humid tropics.This revised version was published online in November 2005 with corrections to the Cover Date.     

Effects of introducing ducks into fish ponds on water quality, natural productivity and fish production together with the economic evaluation of the integrated and non-integrated systems

Raising ducks on fish ponds (fish-duck culture) on a commercial scale is a new practice in Egypt, therefore, a study was undertaken to evaluate this practice from production, carcass composition and economic viewpoints.Five earthern ponds were used in the non-integrated system (no ducks) whereas four earthen ponds, in which each pond was supplied with 125 Pecking ducks per 0.42 ha, were used for the Integrated system. In both systems, each pond was stocked with four species of fish (common carp Cyprinus carpio, silver carp Hypophthalmichthys molitrix, Grey mullet Mugil cephalus and tilapias Oreochromis niloticusand O. aureus) at the same densities.There were no differences in temperature or pH in any of the ponds but dissolved oxygen levels were lower in integrated ponds concomitant with increasing levels of ammonia, phosphate and nitrate. Water in integrated ponds was richer in natural productivity (phytoplankton and zooplankton) either in species or density when compared with those variables in non-integrated ponds.Fish species reared in integrated ponds exhibited better body weight, food conversion and protein efficiency ratios compared with those of fish species in the non-integrated ponds. Fish yield per 0.42 ha produced from the integrated ponds was significantly higher than that obtained from non-integrated ones. Also, body composition of fish species was affected by the type of farming. Carcass crude protein of grey mullet, silver carp and tilapia was improved in the integrated system. The data on return on sales, return on costs, return on equity, pay-back period and break-even point showed that the integrated system was more profitable than the non-integrated system.     

Evaluating the curriculum of the veterinary school of Firat University, Turkey, in terms of professional and technical skills

A significant portion of the problems faced by veterinarians is related to communication. These problems are intensely experienced between veterinary practitioners and animal owners; yet no lectures or courses aiming to improve professional skills are available in the curriculum of veterinary schools in Turkey. In this study, all students currently enrolled at, and 1992 and 1998 graduates of, the Veterinary School of Firat University (VSFU), Turkey, were surveyed to evaluate the attitudes of veterinary students and graduates toward technical and professional skills. Data were collected from 581 students and 61 recent graduates via personal interviews with students and questionnaires mailed to graduates; information was obtained about participants' technical and professional skills. The overall response rate was 85%. The results show that learning about technical and professional skills is highly valued; competence and comfort in skill sets are associated with comfort in establishing communication with instructors. Positive correlations were also noted between feeling comfortable with and feeling competent in both skill sets. In conclusion, it appears to be essential to introduce courses addressing improvement of professional skills to the curriculum of veterinary schools in Turkey, given that a successful veterinarian profile requires feeling competent in and comfortable with both technical and professional skills.