Soil salinity is a major agricultural constraint in many countries. Plants’ response to salinity depends on the species and the salt concentration in the soil. The objective of this study was to test the resistance of three leguminous plants - common bean (variety ‘El-Jadida’), broad bean (variety ‘Claro de Luna’), and alfalfa (variety ‘Diamon’) - to several salinity rates and to show which one was more resistant to salt stress. This study was carried out under controlled conditions, with six NaCl concentrations (0, 1, 3, 6, and 9 g/kg) added to a mixture of potting soil and sand. A completely randomised design was used, where the three legumes were cultivated with different salt concentrations to determine the effect of these doses on fresh biomass, dry mass, and physiological parameters (sodium and proline content). The results showed the negative effect of salinity on fresh biomass and dry mass of shoots and roots. Claro de Luna, the broad bean variety, was more adapted to salinity than alfalfa and common bean. The amount of sodium in the shoots and roots of the three species increased with increasing salinity. Alfalfa may play a role in soil desalination; at 53.33 mM NaCl, 100 mg alfalfa dry mass absorbed 4.5 mg Na per pot, which corresponded to the uptake of about 0.6 kg Na per hectare of soil. Proline content increased with increasing salt concentrations.

In response to alerts from farmers in Bejaia region (central-north Algeria) about the decline of their fig trees, a survey was conducted between 2019 and 2021 in the main localities known for fig crops. Hypocryphalus scabricollis (Eichhoff) (Coleoptera, Curculionidae: Scolytinae) was identified as the causal agent of fig tree decline in the region. This species is reported for the first time in Algeria. Here, a morphological description and main biological traits of this species are given. Distribution of H. scabricollis in the Bejaia region is illustred, and an overview of its behaviour, symptoms and damage caused to the host plant, and their potential impact in commercial fig production is discussed. This work aims to provide a preliminary database to the scientific community about this xylophagous pest of fig trees and to alert regional and national policy makers to take it seriously and address emerging bark beetle problems before it is too late.

Globally, thrips pest of agro-ecosystems are well studied. Nevertheless, in Algeria this insect group remains poorly known. The research was conducted to determine thrips composition and population changes of F. occidentalis on three melon cultivar. The study highlighted six thrips species on three melon cultivars (Star plus, DRM and Mimosa), including two of economic importance pests, namely Frankliniella occidentalis and Thrips tabaci. The remaining species are: Odontothrips loti, Aeolothrips intermedius, T. minutissimus and Melanthrips fuscus. The western flowers thrips (WFT) F. occidentalis was eudominant species, while T. tabaci was subrecedent. Blue sticky traps allow detecting thrips early for monitoring and from crop development starting. A positive and significant relationship was observed between thrips abundance in traps and WFT recovered from flowers and leaves on all cultivars. The highest numbers of WFT were recorded on DRM flowers and Star plus leaves while the least numbers were noticed on Mimosa flowers and leaves. F. occidentalis flight activity was observed early in the growing season. Similar trend of thrips population changes was recorded during crop season. Nevertheless, one to two peaks of F. occidentalis population were registered on flowers and leaves on all cultivars. They were mainly observed in April when temperatures were high and humidity low, their numbers were not considerable. No fruits damage was observed in situ on all cultivars. This work allowed to improve knowledge about thrips linked to some melon cultivars the most used in greenhouse in the region of Biskra. The presence of these pests can be a source of concern for farmers. Extending monitoring to other crops and localities to know their status and distribution remains a priority due to direct damage caused and virus transmission hazard.

No abstract

Foliar spraying of infradoses of sugars (glucose, fructose or sucrose) induces plant resistance to pests that are particularly difficult to combat. These include thrips, which can cause flower abortion, stunting and deformation of olives, resulting in significant crop losses. Randomised block trials were conducted during three years (2017 to 2019), on two cultivars Chemlal and Sigoise, in an olive grove in Batna province (Algeria), with the aim of determining the most effective dose and type of sugar on thrips populations, and to evaluate the effectiveness of combining sugar with chemical treatment, as well as the possibility of reducing the dose of the latter. The results showed that sucrose at a concentration of 100 ppm was the most effective and that the efficacy of sucrose was higher than that of glucose and fructose, on both cultivars tested. The combination of sucrose with insecticide resulted in a synergistic effect and a higher efficacy gain than sucrose alone, and that the efficacy of the combination sucrose + insecticide at low dose D1 was identical to the combination sucrose + insecticide at recommended dose D2. It is therefore possible to reduce the chemical insecticide dose while maintaining good treatment efficacy for the control of these pests.