Water is a major limiting factor in world agriculture and most crop plants are highly sensitive to even a mild water stress.The beneficial effects of diatomite is characterized by helping plants to overcome various biotic and abiotic stresses. Thus , this experiment was performed to study the ameliorative effect of diatomite (10g/kg) on each of growth, productivity, gas exchange , biochemical contents and polymorphic DNA of Lupinus albus L. plants grown in either well watered or two different soil water regimes (1 and 4 days withdrawal). Results showed that diatomite was able to alleviate the deteriorative effect of water stress on almost all measured criteria specially in plants grown under mild water stress (1+D).Soil fertilization by diatomite significantly increased all measured growth parameters expressed as shoot and root length, fresh and dry weight of shoot, root and pods and number of pods/plant above both untreated and water stress-free diatomite treated plants. Diatomite application improved the rate of photosynthesis, stomatal conductance, the contents of each of total soluble sugars (TSS), total soluble protein (TSP) , total phenols, auxins, gibberellins, cytokinins and ABA and the activity of four antioxidant enzymes namely, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and polyphenol oxidase (PPO) as compared to both control and stressed plants maintained at both levels of water regime. On the contrary, diatomite treatment markedly reduced transpiration rate and lipid peroxidation level to a minimum. Moreover, diatomite application either alone or combined with stress induced a distinctive protein electrophoratic band (92KD) which was absent in either the control or stressed plants. Three distinctive protein bands were also induced in stressed white lupin, two (65 and 25 KD) under one day drought and one (143K) under four day drought. Finally, diatomite induced several distinguished polymorphic DNA fragments using PCR-RAPD analysis.

Moringa oleifera is a highly valued plant, distributed in many countries of the tropics and subtropics. It has an impressive range of medicinal uses and high nutritional value. Accordingly, rocket (Eruca vesicaria subsp. sativa) plants were foliar sprayed with the aqueous extracts of leaves and twigs of M. oleifera at rates of 1, 2 and 3%. Among these concentrations, fertilization of rocket plants with 2% leaf and 3% twig extracts potentially increased all measured growth criteria (plant height, fresh and dry herb weight), photosynthetic rates, stomatal conductance, the amounts of each of chlorophyll a and b, carotenoids, total sugars, total protein, phenols, ascorbic acid, N, P, K, Ca, Mg, Fe as well as growth promoting hormones (auxins, gibberellins and cytokinins). Besides, bio-organic manuring with both kinds of Moringa extracts at all concentrations applied negatively reduced the levels of each of lipid peroxidation and abscisic acid as well as the activities of the antioxidant enzymes (catalase, peroxidase and superoxide dismutase). Thus, it is concluded that M. oleifera leaf and twig extracts can be recommended to be used effectively by farmers as a bio-organic fertilizer for various crops due to its high productivity, high nutritive value, antioxidant effect, easy preparation, low cost and environmentally friendly nature.

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Recent scientific findings proved that silicon feeding will provide benefits to plant growth and yield depending on the source of Si, the mode of application , the concentration used, the plant species , the mode of action and the biotic or abiotic factor involved. To better understand the intrinsic properties of Si , this work was conducted using a series of diatomite (diatomaceous earth)at rates of 0,2.5, 5 and 10 g/kg soil, to look into the most subtle changes in the growth , yield, metabolism, electropharetic protein and isozyme pattern of faba bean ( Vicia faba) plant. Indeed, diatomite-treated plants displayed an over all better morphological increments expressed as shoot and root length , number of leaves and pods/ plant, fresh and dry weights of shoots and roots and physiological activity expressed as chlorophyll a,b and total pigments , total soluble sugars (TSS) and total sugars (TS), photosynthetic rate, leaf stomatal conductance, % of leaf relative humidity ( %LRH), net intercellular carbon dioxide (∆CO 2 ), total nitrogen (TN) and total soluble nitrogen (TSN) and the concentrations of phosphorus (P), potassium (K), calcium(Ca) and magnesium (Mg) than non-treated faba bean plants . Furthermore, diatomites (86-89 % SiO 2 ) induced and restored ten electrophoretic protein bands which confirmed their significance as an algal manure in accelarating the gene functions to perform, in an elevated rate, new silence genes to operate thus expressing new protein profiles. Soil fertilization by diatomites induced four esterase ( EST), three peroxidase (POD), two catalase (CAT) and three acid phosphatase (ACP) isozyme polymorphic bands which were absent in the control plants .The intensity and density of these bands were significantly increased in response to diatomite treatment. The impact of diatomite is time-dependent as it became more effective while the experiment continued and increased in a dose-related manner . Reversibly, diatomites application showed negative response in the transpiration rate and the values of both carotenoids, sodium and iron. This study highlighted the fact that diatomites are important component of the production system and should not be ignored when attempting to attribute causes for below optimum production

Lead is one of the hazardous heavy metal pollutants of the environment that originates from various sources. Soil contamination by lead reduces the quality of both soil and cultivated plants which often limits the production of some food products and animal feed. Thus, this study was undertaken to evaluate the effect of a bio-organic fertilizer, namely Acadian, a red algal extract, at recommended dose (RD) in alleviating the deteriorative effect of Pb at 0, 50, 100, 200 and 400 mg/l on tomato (Lycopersicum esculentum) plants. Accordingly, Pb-treated plants showed marked reductions in growth measurements as root and shoot length, fresh and dry weights of shoots,roots and fruits as well as number of leaves and fruits; in photosynthetic rates, stomatal conductance, net intercellular CO? rates (?CO?) and in the contents of each of chlorophyll a, b and total chlorophyll.In addition, with the increase in level of Pb treatment in situ, total sugars, total nitrogen, catalase activity and major nutrient elements (P, K, Ca and Mg) were proportionally declined in both shoots and roots as well as proline of roots. At the other side, Pb treatment raised the levels of each of carotenoids, total soluble sugars, amino nitrogen, total soluble nitrogen, peroxidase, superoxide dismutase, phenols, lipid peroxidation, sodium, lead and iron in both roots and shoots of tomato plants as well as proline of shoots and transpiration rates. When tomato plants were supplemented with the recommended dose of Acadian solely or combined with Pb at all rates, significant increases in all measured growth parameters (shoot and root length, fresh and dry weights of shoots, roots and fruits, number of leaves and fruits), photosynthetic rates, stomatal conductance, ?CO?, the contents of each of chlorophyll a, b, total chlorophyll as well as the contents of total sugars, total soluble sugars, total nitrogen, total soluble nitrogen, amino-N, P, K, Ca and Mg in tomato shoots and roots were obtained. Conversely, Acadian fertilization negatively reduced the carotenoid values, the activity of antioxidant enzymes(catalase, peroxidase and superoxide dismutase), the amounts of phenol, Pb, Na, Fe and the level of lipid peroxidation in both shoots and roots of tomato plants, whereas, it positively affected transpiration rates. On the otherside, when Acadian where added to lead at different rates there were either synergistic increases in the activities of these antioxidant enzymes and the level of phenol and lipid peroxidation or decreases in the carotenoid, Na, Fe and Pb contents as well as transpiration rates. Thus, it is manifested that Acadian can be used to improve the safety, quality and productivity of lead polluted plants.