EFFECT OF SOLARIZATION, ORGANIC AND BIOFERTILIZER ON GROWTH AND YIELD OF BABY AND MATURE SPINACH LEAF ( Spinacia oleracea)

In a field naturally infested with weeds and soilborne pathogen, field experiments were conducted in the vegetable farm at Faculty of Agriculture, Ain Shams University in clay soil, to study the effect of seed-bed solarization of organic production on growth and yield of spinach plant. Well prepared and pre-irrigated seed-bed plots with and without organic manure were covered on 1st August with transparent polyethylene mulch of 50 μM thick, for six weeks prior to spinach sowing in early October of 2006 and 2007. Solarization raised the average maximum soil surface temperature to 58.5°C with organic manure and 56°C without organic manure. Solarization increased soil surface temperature by 4.5°C and 3.5°C degrees over the non-solarized soil in the first and second season, respectively. Soil solarization significantly reduced total fungal and bacterial count. The treatment of organic ma- nure In non-solarized soil increased the density of soil pathogens by 45% for total fungi and 72% for total bacteria in both seasons. Emerged weeds recorded the lowest number in solarized soil compared with non-solarized soil. Biofertilizer application to solarized soil improved baby leaf and mature spinach leaf growth, increased yield, and are attractive to users as environment friendly.