Brown leaf spot disease and fertilizer interaction in irrigated rice growing on different soil types
Studies have been undertaken in a 1000 ha area of irrigated rice (Oryzica sativa) at Caroni (1975) Limited to determine the effect of the fertilizer programme on the incidence of important diseases. Over a period of three years higher levels of brown leaf spot (Cochliobolus miyabeanus) on rice varieties Oryzica 1 and Oryzica 5 on three different soil types were associated with increasing levels of leaf P, from a low of 0.149% of dry matter (DM) to a high of 0.396% DM. On the Washington silty clay loam series (Inceptisol) brown leaf spot incidence was lowest when leaf P was between 0.135% and 0.149% of DM. However, disease incidence was higher when leaf P levels fell to 0.133% of DM or rose above 0.149%, under conditions where N was more than adequate. The moderate levels of the disease experienced over the period had no effect on yield, as grain infection was minimal. The results support the conclusion that the incidence of brown leaf spot on irrigated rice at Caroni is influenced by sub-optimal levels paticularly of P. Careful monitoring and managememt of P nutrition is seen as an important part in the overall strategy for controlling the disease.
Observations on the incidence of rice brown spot, leaf scald and leaf smut diseases in a tidal mangrove swamp at Rokupr, Northwestern Sierra Leone
Abstract The ecological behaviour of Cochliobolus miyabeanus (Ito et Kurib.) Drechsl. ex Dast. (Bipolaris oryzae (Breda de Haan) Shoem.), causal agent of brown spot of rice (Oryza sativa L.), was investigated in a tidal mangrove swamp at Rokupr Experimental Farm, northwestern Sierra Leone. Disease increased where transplanting was delayed. This was probably due to the coincidence of flowering with favourable environmental conditions for disease development from November to February. Nitrogen fertilization at 40kg N ha−1 significantly (P = 0.05) reduced C. miyabeanus incidence in 1983, but not in 1984 and 1985 cropping seasons at the same site. Grain yields of ROK 5, a medium‐duration improved rice cultivar (ca. 150 days) were significantly reduced in late‐transplanted rice crops (September to November) in spite of adequate N fertilization. Mangrove mud was not an important source of C. miyabeanus propagules. Incidence of leaf scald caused by Monographella albescens (Thum) Parkinson, Sivanesan and Booth (M...
Concept design of solar cell satellite dish
Solar panels are devices that consist of solar cells that convert light into electricity. They are called solar on the Sun or “sol” because the Sun is the strongest light source that can be utilized. Solar panels are often called photovoltaic cells, photovoltaic can be interpreted as “light-electricity”. Solar cells or PV cells depend on the photovoltaic effect to absorb the Sun’s energy and cause currents to flow between two opposing charged layers. The purpose of this study is to analyze the satellite dish using solar panels, so this tool is a signal search tool that uses solar energy to run to carry out its functions. As we know that many places or areas that are still often experiencing power outages so that it can hamper and interfere with community activities. Therefore, this research wants to facilitate the public, especially the current generation who need electricity every day so that when there is a power outage, the satellite dish will utilize solar energy as its main source. This research uses a satellite dish as an intermediary to produce electrical energy with the help of solar energy and is collected into a high-voltage battery in the form of electricity, so that it becomes a source of electricity.