Botrytis cinerea Pers., the causal agent of gray mold, is an airborne pathogen that causes significant damage to tomato crops worldwide at all development stages and post-harvest. In this study, the aqueous extract of Capsicum annuum seeds was screened for its phytochemical constituents and assessed at various concentrations (10, 20, 30, and 60%) for antifungal activity in vitro. Selected biochemical, pathological, agronomical, physicochemical, and morphometrical traits were investigated to determine the effectiveness of applying the aqueous seed extract and salicylic acid either separately or in combination to tomato seeds and fruits in vivo. Phytochemical screening of the aqueous seed extract showed the presence of 2, 2-diphenyl-1-picrylhydrazyl, phenolic and flavonoid contents, quinic acid, protocatechuic acid, syringic acid, p-coumaric acid, trans-ferulic acid, rutin, quercetin-3-o-rhamonosic, kaempferol, naringenin, and apigenin at various concentrations. The findings suggested that the aqueous extract at a concentration of 60% was most efficient in vitro where mycelial growth was < 3.8 mm, mycelial growth inhibition was > 52%, and mycelial growth rate of < 1.05 mm/h. In vivo, the combined treatments of tomato seeds produced the greatest reduction in gray mold damage (disease severity index 8.67%) and the most favorable growth parameters of seedlings were chlorophyll a > 1.50 mg/g.f.Wt.; chlorophyll b > 1.76 mg/g.f. Wt.; total chlorophyll content > 3.26 mg/g.f.Wt.; seedling fresh weight > 0.43 g; seedling length > 12.43 cm, respectively. Combined preventive treatment applied to tomato fruits inoculated with B. cinerea resulted in the lowest disease severity (percentage of fruit area covered by gray mold < 33.33%; disease severity index < 46.67%) and the most favorable physicochemical attributes (water content < 98.28%; juice yield > 53.35%; pH < 3.59; titratable acidity > 1.37 g/10 ml juice; Brix degree > 4.73; nitrate content < 383.33 mg/kg; electrical conductivity < 2.47 mS/cm) and morphometrical attributes (fruit firmness > 3.03). The combined treatments resulted in the strongest activity of peroxidase (> 4.162 units/mg/min), ascorbate peroxidase (> 31.66 µmol/mg/min), and malondialdehyde (> 3.90 µmol/g) on the tomato fruits. The aqueous extract of C. annuum seeds combined with salicylic acid had positive effects in terms of inhibiting B. cinerea and is thus a promising and environmentally friendly alternative substitute for chemical fungicides towards sustainable agriculture under climate change.

The focus of this study is to compare salt stress response among pearl millet genotypes, based on agronomical traits. A field experimental complete randomized design (CRD) was conducted during the summer-winter season (July-December) of 2010, at the Agricultural Experimental Station of Nabeul. Nine pearl millet Pennisetum Glaucum L genotypes (IP 22269; IP 13151; MC 94C2; IP 19612; SVDANPOL III; ICMV 1550; IP 7704; HHVBCTAB2; IP 19586) were irrigated with saline water (8.57 dS.m-1 EC). Plant height, biomass accumulation and morphological measures of clusters (weight, length, diameter) were determined. Based on plant height and fresh biomass accumulation, we could classify the genotype IP22269 as more tolerant to salinity, while MC94C2 as sensitive genotype. MC94C2 was once more identified as sensitive genotype, based on less clusters weight. Highest values of clusters weight and diameter were recorded for IP19586 and IP19612. Thus, a noticeable variability in salt tolerance was observed among studied genotypes.

Botrytis cinerea, a causal agent of gray mold disease, is one of the most destructive fungal pathogens that leads to substantial global economic crop losses, especially for tomato plants. The present study aims to investigate the inhibitory effect of two microbial culture filtrates (BCA filtrate alone and combined with salicylic acid) of Trichoderma longibrachiatum and Pseudomonas sp. against the phytopathogenic fungus B. cinerea on tomato plants. The biochemical modifications, gray mold disease incidence, and fruit quality parameters of the tomatoes were determined according to tested treatments. The results showed that both fungi and bacteria were able to solubilize phosphate and produce IAA and HCN. T. longibrachiatum could produce hydrolytic enzymes (chitinase, protease, and glucanase). Otherwise, Pseudomonas sp. showed the capacity to produce catalase and amylase enzymes. Both microbial culture filtrates inhibited the hyphae growth of B. cinerea. The biocontrol efficacy, in vitro, was significant: up to 50% in terms of the growth inhibition rate at a concentration of 40%. The tomato seedlings’ growth was promoted by the separate preventive treatments of each micro-organism culture filtrate. In addition, disease severity in the tomato seedlings and fruit was significantly reduced. Furthermore, the combined treatment of tomato fruit with culture filtrates and salicylic acid induced significant biochemical and physiological changes in fruit firmness, juice yield, total protein, and ROS enzyme activities. The culture filtrates of T. longibrachiatum and Pseudomonas sp. can be recommended as an effective microbial biofungicide to control gray mold disease under storage conditions.