Realization of an indirect solar dryer: With a plan sensor for fruits and vegetables
With 2200 kW/year/m2 of sunshine (National Office of Meteorology — Algeria), Algeria enjoys favorable climatic conditions to use the sun as a source of thermal energy for drying agricultural products. Indeed drying offers the possibility of recovery of surplus fruits and vegetables by their conservation for future consumption. Indirect drying gives better results (nutritional and taste viewpoint) compared to direct drying (traditional), taking into account the quality of dried products. An indirect solar dryer, conducted at the National Institute of Agronomy, gave satisfactory results.
The Isothermal Sorption Measurement and the Isosteric Heats Determinations for the South Algerian Date Varieties
Received: 18 April 2019 Accepted: 10 July 2019 The equilibrium water content of a product to be dried is essential during a forced convection solar drying and storage operation. These values are often taken from the so-called isothermal sorption curves. The isotherms determination is an essential step to know the distribution and the intensity of the water connections in the products. They make it possible to determine the products final water content to be reached in order to optimize the drying conditions and give valuable information on the hygroscopic equilibrium. As a result, this experimental study aims to determine the physicochemical components' and the desorption isotherms curves for deferent date type L’hmira, Bamakhlouf and Tegazza from the Touat region, in South-West Algeria, using the saturated salt solution method. The experiment is carried out for three temperature values 40 ° C, 50 ° C and 60 ° C, to study the influence of the temperature on the equilibrium curves of the product and finally to describe the isothermal moisture desorption for deferent date types for three temperatures using known models of GAB, SMITH, LANGMUIR and OSWIN.
Effect of Soybean Cyst Nematode (Heterodera glycines) on Yield of Resistant and Susceptible Soybean Cultivars Grown in Ohio.
Soybean (Glycine max) producers in Ohio rarely use soybean cyst nematode (Heterodera glycines, SCN)-resistant cultivars because of concerns over limited yield potential and lack of resistance to Phytophthora sojae. A two-year study was initiated to determine grain yield and nematode population increase on soybean cyst nematode-resistant cultivars in maturity groups II and III in production fields. Sites differed in soil texture, nematode densities, and P. sojae infestation at a number of locations in Ohio. Soil was assayed for nematode densities before planting and at harvest. Yields of resistant cultivars averaged 0% to 18% higher than those of susceptible cultivars in fine-textured soils with average preplant populations ranging from 463 to 14,330 SCN eggs/100 cm(3) soil. In coarse-textured soils, yields of susceptible cultivars were 21% to 56% less than the resistant cultivars with average preplant densities ranging from 1,661 to 15,558 SCN eggs/100 cm(3) soil. The reproductive index ranged from 0.1 to 5.5 for resistant cultivars and 0.4 to 112 for susceptible cultivars. In 1993, yield of P. sojae-susceptible, nematode-resistant 'Asgrow A 3431' was as high as yield of the P. sojae-resistant, nematode-susceptible cultivar 'Resnik' in a Phytophthora-infested field. The nematode-resistant cultivars Madison Experimental 131527 and Asgrow A3431 had higher yields than AgVenture AV1341 and susceptible cultivars Resnik and Kenwood when compared over five nematode-infested sites. Nematode-resistant cultivars were found to be excellent alternatives to currently grown susceptible cultivars for managing SCN where group III cultivars are used. However, better cultivar alternatives may be needed for sites with combined Phytophthora root rot and cyst nematode problems.