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"The experiment aimed to examine the growth and some physiological parameters of five metal-accumulator weed species in response to mercury (Hg) and lead (Pb) treatment. Five weed species (Branchiaria mutica, Cyperus kyllingia, Ipomea aquatica, Mikania micrantha, and Paspalum conjugatum) were grown in water culture using half strength Hoagland’s solution and subjected to Hg(NO3)2 and PB(NO3)2 at 0,  0.25 and 0.5 mM for 3 weeks. The growth, photosynthesis, lipid peroxidation and proline content were observed during the treatments. The result showed that both Hg and Pb decreased growth significantly, but the decrease was far higher in Hg than in Pb treatments. Hg treatment reduced photosynthetic rate dramatically under different photosynthetic photon flux density suggesting that heavy metal Hg until 0.5 mM caused the damage of photosynthetic apparatus almost all species except in I. aquatica. Hg and Pb treatment caused dramatic increase in leaf MDA content, which was associated with the decrease of chlorophyll content significantly. Almost all the species were tolerant to Pb treatment up to 0.5 mM except M. micrantha, while only C. kyllingia and I. aquatica were tolerant to Hg treatment up to 0.5 mM. Only Hg treatment and not Pb that induced higher proline content in the leaves of threated plants without clear pattern of the increment among the species suggesting that proline may have a role as alarm stress rather than tolerant indicator."

"The development of methods in measuring the photosynthesis process is now increasingly widespread, especially to get a more efficient method and fast. Photosynthesis efficiency of micro-algae periphytic has been estimated under the influence of light intensity and temperature by using the fluorescence monitoring system. the measurement on a colonized substrate by the saturation pulse method has been conducted using a FMSI(Fluorescence Monitoring Systems,Hansatech). Measurement of the fluorescence parameters was conducted every week on algal periphyton which was cultivated on the articial substrate during for 5 weeks under light and temperature conditions. The results show that fluorecence maximal value (Fm) increase linearly with chlorophyll a concentrations. For 20 derajat C (experiment where the biomass reached higher values),up to 100 mg chlorophyll a.m min 2 the change in Fm is approximately linear. After,the response of Fm is hyperbolic, sugesstting a measure in vivo chlorophyll a flurescence of periphyton in laboratory conditions. The instrument is simple to use, with convenient software control, especially when used in PC mode. "

"The analysis of daily curves of dissolved oxygen in the Garonne, downstream of Toulouse, shows that the river is generally heterotrophic. It appears in contradiction with the fact that the river bed is covered with a thick periphytic biofilm. From the data obtained in-vitro and in-situ, we developed a model to calculate the net production, integrated over the section. This model makes it possible to simulate various environmental situations: variations of the wet cross section, seasons and turbidity. The simulations show that some zones of the section are highly productive. For the majority of the cases, the daily balance photosynthesis/respiration remains less than one. This negative daily balance is equilibrated by the re-aeration rate associated with the turbulent flow of the Garonne. This work shows, however, that the oxygen level in the river is strongly dependent on the total rate of respiration, so that a weak increase (pollution for example) could quickly induce a reduction in the dissolved oxygen"

"The concept of periphyton growth is globally regarded as a functional unit, without considering the dynamics of various components as have been reported by earlier scholars, and is used as references to the algal periphyton growth modelling conducted in this study. Experimental data on the growth of periphyton biomass versus time was used to test two basic hypotheses to account for feedback effects on periphyton growth."

"Mulsa plastik telah banyak digunakan oleh petani di Indonesia dalam budidaya tanaman tomat. Penggunaan mulsa plastik dinilai efektif dalam meningkatkan pertumbuhan tanaman dan menghambat gulma. Namun, penggunaan mulsa plastik dalam jangka panjang dapat mencemari lingkungan karena mulsa plastik sulit terurai. Penggunaan mulsa organik dapat menjadi alternatif dalam menghambat gulma, salah satunya mulsa daun bambu. Mulsa daun bambu diketahui dapat menghasilkan senyawa alelokimia untuk menghambat gulma. Tujuan dari penelitian adalah untuk menganalisis efektivitas penggunaan mulsa daun bambu dalam menghambat gulma dan meningkatkan pertumbuhan tanaman tomat. Penelitian ini dilakukan menggunakan 3 perlakuan yaitu tanpa mulsa, mulsa plastik dan mulsa daun bambu. Setiap perlakuan terdiri atas 4 plot penanaman dan masing-masing plot terdiri dari 2 tanaman tomat. Berdasarkan analisis statistik pertumbuhan tanaman tomat menunjukkan bahwa tidak ada perbedaan secara signifikan pada setiap perlakuan. Sebaliknya, berdasarkan rata-rata pertumbuhan tanaman menunjukkan bahwa mulsa plastik memiliki pengaruh yang lebih baik daripada tanpa mulsa dan mulsa daun bambu. Berdasarkan analisis statistik berat basah buah dan diameter buah menunjukkan adanya perbedaan secara signifikan pada setiap perlakuan. Sedangkan, untuk parameter gulma menunjukkan bahwa pemberian mulsa memiliki rata-rata jumlah dan kerapatan gulma yang lebih rendah daripada tanpa mulsa.

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Plastic mulch has been widely used by farmers in Indonesia in cultivating tomato plants. The use of plastic mulch is considered effective in increasing plant growth and inhibiting weeds. However, the long-term use of plastic mulch can pollute the environment because plastic mulch is difficult to decompose. The use of organic mulch can be an alternative in inhibiting weeds, one of which is bamboo leaf mulch. Bamboo leaf mulch is known to produce allelochemical compounds to inhibit weeds. The purpose of this study was to analyze the effectiveness of using bamboo leaf mulch in inhibiting weeds and increasing the growth of tomato plants. This research was conducted using 3 treatments, namely without mulch, plastic mulch and bamboo leaf mulch. Each treatment consisted of 4 planting plots and each plot consisted of 2 tomato plants. Based on the statistical analysis of tomato plant growth, the results showed no significant difference in each treatment. On the other hand, based on the growth rate of plants, it shows that plastic mulch has a better effect than without mulch and bamboo leaf mulch. Based on the statistical analysis of fruit wet weight and fruit diameter, there were significant differences in each treatment. Meanwhile, weed parameters showed that mulching had an average number and density of weeds lower than without mulch."