Moisture content | Syrian Journal of Agricultural Research SJAR

Shady Soliman *¹ , Moussa AlSamara¹ , Mohamed Ahmed ² and Nawal Ali ³

¹Department of Environmental Protection, Higher Institute for Environmental Research, Latakia University, Latakia, Syria.

² Plant Protection Department, Faculty of Agricultural Engineering, Latakia University, Latakia, Syria.

³ Department of Biology, Faculty of Science, Latakia University, Latakia, Syria.

(*Corresponding author: Shady Soliman. E-Mail shady-sm@outlook.com).

Received: 16/ 03/ 2025 Accepted: 23/ 11/ 2025

Abstract

Trichoderma harzianum is one of the most important biological control agents. It has a high parasitic capacity against economically important soil-borne fungal pathogens. It is also characterized by its high adaptability and ability to reproduce in diverse environmental conditions. The aim of this research was to study the effects of temperature, moisture, pH, and photoperiod on conidia production and biomass of Trichoderma harzianum. The results of the morphological and microscopic characterization of the isolate studied showed that its morphological description matched that of Trichoderma harzianum. The studied isolate gave the highest number of conidia 15.02±0.18 *109 spores/g at 30°C, and the average linear growth rate reached its highest levels 22.53±0.27 mm/day at the same temperature, while the studied isolate gave the highest dry weight of biomass 32±1.15 mg/g at 25°C. When testing the optimum pH, a significant increase was observed in the growth rate, average spore number, and percentage of inhibition with increasing pH up to 5.5, where it reached its peak of 24.4 ± 0.06 mm/day, 21.7 ± 0.88 * 109 spores/g, 57.1 ± 0.92%, respectively. These indicators decreased again with increasing pH. The 16:8 photoperiod treatment significantly outperformed the other treatments with an average spore number of 10.33 ± 0.17 * 109 spores/g. The average spore number at 25% moisture content was 2 ± 0.0 * 109 spores/g compared to 94.67 ± 2.2 * 109 spores/g at 55% moisture content, i.e., about 47 times.

Keywords:Trichoderma harzianum, conidial spores, growth rate, moisture content.

Full paper in Arabic: pdf

Magda Bashir Elbeshti^*(1) Ali Ahmed Belhaj⁽¹⁾ Abeer Fayez Alkrekshe⁽¹⁾ and Siham Ibrahim Asker⁽¹⁾

(1). Soil and Water Department, Faculty of Agriculture, Tripoli University, Tripoli, Libya.

(*Corresponding author: Dr. Magda Bashir Elbeshti. E. Mail: melbeshti@yahoo.com).

Received: 03/05/2017 Accepted: 03/10/2017

Abstract

This study was conducted to measure the rates of infiltration in the soil of four different areas in use, and at different moisture levels, and to test some of the mathematical models that describe them at Research Station of the Faculty of Agriculture, University of Tripoli, Libya. The different uses of the studied lands were: land sown with cereal crop, land planted with olive trees, land used as a passageway for the passage of agricultural machinery and equipment, and land of the cowshed. The aim of this study was to describe the efficiency of some mathematical models to study the effect of different land uses and moisture content on the infiltration rates, and determine their ability to describe the infiltration process in some Libyan soils. The rate of infiltration was measured using the double ring apparatus (Measured), while Horton, Philip, and Kostiakov models were used to estimate the infiltration rates. The results showed that both land use and moisture content had an effect on the infiltration rates. This effect was evident on the estimated and measured infiltration rates. The estimated values were higher or lower than the measured values during the experiment, but the differences were not significant according to F test at (P=0.05) level pf probability, except for the infiltration rates estimated by Phillip model at the site grown with cereal crop, after rainfall. There were significant differences compared with the measured. The constants or parameters of these models also differed by changing the initial moisture content (before and after rainfall) and from site to site. When examining the effect of the initial moisture content change on the behavior of these models, the results showed that the efficiency of these models increased with the increase of the initial moisture content according to the coefficient of determination (R²) and the correlation coefficient (r).When examining the effect of land use on these models, there was a difference in the behavior of the model from one location to another as a result of different in soil construction resulting from different use. Soil samples have been taken from sites for chemical and physical analysis to determine their properties. The results showed that there were no significant differences at (P= 0.05) between the measured infiltration rates in the field, calculated using Horton model before and after rainfall in all sites despite the low in (r) between them before the rain, while (r) values after the precipitation raised up to (0.67, 0.78, 0.71, 0.65) in trees site, pathway, cereal crop and cow barn, respectively. The model constants (i₀, i_c, k) differed according to moisture content. Kostikove model behaved as Horton model in all the sites studied, whereas, the differences between the infiltration rates of this model and the double ring were non-significant at (P= 0.05) before and after rainfall, and the variability was different at different levels of moisture, also its constants (⍺, K) differed at different levels of moisture. However, the change of the constant K at the site of cereal crop after the rainfall is different from the other sites, and (r) values generally increased after the rain. While, the behavior of Philip model differed according to the different locations and levels of moisture. F test at (P= 0.05) showed significant differences between the estimated and the measured of this model in the location that grown with cereal crop after the rainfall only, while the differences were not significant in the rest of the sites before after rainfall, (r) values also decreased before and after rainfall compared with other models.

Key words: Infiltration rate, Double ring, Moisture content, Horton model, Philip model, Kostikov model.

Full paper in Arabic: PDF