Integrating cover crops and bionematicides presents a sustainable approach to managing plant-parasitic nematodes (PPN) in organic vegetable production systems. The integration of sunn hemp, Crotalaria juncea ('Crescent sun') and sorghum-sudangrass, Sorghum bicolor x S. sudanense ('Sweet Six BMR') with bionematicides was evaluated in two locations in central (Gulf Coast Research and Educational Centre-GCREC) and south (Fort Lauderdale Research and Educational Centre-FLREC) Florida for the effectiveness of PPN suppression. Field experiments were conducted with establishing cover crops in each location 3 months before planting organic zucchini on plastic beds equipped with a drip application system used to inject three commercial bionematicides (thyme oil, neem oil and azadirachtin) and the broth culture of Xenorhabdus bovienii bacteria associated with Steinernema feltiae. Cover cropping with sunn hemp and sorghum-sudangrass significantly reduced population densities of root-knot nematodes (Meloidogyne spp.) at GCREC, whereas only sunn hemp reduced the root-knot nematode population at FLREC. Galling severity on zucchini roots caused by Meloidogyne spp. was significantly lower in azadirachtin and neem oil applications integrated with sunn hemp. The impact of integrating cover crops with bionematicides on other PPN, such as Mesocriconema spp., Nanidorus minor and Hoplolaimus spp., varied among the treatments at both locations. Integrating cover crops with bionematicide applications provided additional control options for zucchini, but the efficacy of different bionematicides depended on the nematode species present in the soil and the cover crop species used. These findings underscore the importance of adaptive nematode management, where control strategies are customised to target the specific nematode populations causing economic damage in each field.

This study investigates the impact of neodymium (Nd) nanoparticle (NdNP) toxicity on the physiological and biochemical responses of sorghum ( Sorghum bicolor) and oat ( Avena sativa) plants and evaluates the potential mitigating effects of arbuscular mycorrhizal fungi (AMF). Sorghum and oat plants were grown under controlled conditions with and without AMF inoculation, and subjected to NdNPs (500 mg Nd kg- 1 soil). Results revealed that Nd nanoparticles significantly reduced biomass in both species, with a 50% decrease in sorghum and a 59% decrease in oats. However, AMF treatment ameliorated these effects, increasing biomass by 69% in oats under Nd nanoparticles toxicity compared to untreated contaminated plants. Soluble sugar metabolism was notably affected; AMF treatment led to significant increases in fructose and sucrose contents in both sorghum (+31% and +23%, respectively) and oat (+25% and +37%, respectively) plants under NdNPs toxicity. Improved sugar metabolism via enhanced activities of sucrose phosphate synthase (+29-54%) and invertase (+39-54%) enzymes resulted in higher proline (+21-81%) and polyamines (+49-52%) levels in AMF-treated plants under NdNPs toxicity, along with alterations in the biosynthesis pathways of amino acids and fatty acids, resulting in better osmoprotection and stress tolerance. Moreover, citrate (+29-55%) and oxalate (+177-312%) levels increased in both plants in response to NdNPs toxicity, which was accompanied by a positive response of isobutyric acid to AMF treatment in stressed plants, which potentially might serve as mechanisms for plants to mitigate NdNPs toxicity. These findings suggest that AMF can significantly mitigate Nd-induced damage and improve plant resilience through enhanced metabolic adjustments, highlighting a potential strategy for managing rare earth element (REE) nanoparticle toxicity in agricultural soils.

Climate change is causing significant damage to crop production in the central plateau zone of Rwanda, particularly affecting sorghum, food, and the incomes of smallholder farmers. Understanding farmers' perceptions and the factors impacting their responses is crucial for improving sorghum production policies and programs. Therefore, a study was conducted to assess sorghum farmers' perceptions of climate change and the factors determining their adaptation strategies. A multistage sampling method and a cluster random selection were utilized to select 345 respondents from five districts of the study area. The data were analyzed using descriptive statistics and a multivariate probit model. The results showed that 98.8% of farmers were aware of climate change, with deforestation being the main anthropogenic activity causing it. Consequently, 95.7% and 84.3% of farmers experienced grain yield reductions, and over 20 sorghum varieties disappeared. To address these impacts, farmers adopted five adaptation strategies: early maturing sorghum varieties (67%), adjusting planting dates (50.1%), drought-tolerant varieties (46.7%), soil conservation practices (38.3%), and crop diversification (32.8%). The multivariate probit model results showed the age and literacy level of the household head, access to extension services, access to information, access to credit, farming experience, and land size as the important factors influencing at least one of the climate change adaptation strategies. The study concluded that sorghum farmers are aware of the impacts of climate change and are acting to address its negative effects. The results suggest that the government and stakeholders should support farmers in strengthening their adaptation strategies for sustainable sorghum production.

Water scarcity, combined with low soil fertility, constitutes one of the main limiting factors in crop productivity in semi-arid regions. However, nutritional supplementation techniques with nitrogen (N) and molybdenum (Mo) can lead to positive enhancements in the production of these crops. The objective was to evaluate the effect of increasing doses of N in the presence and/or absence of Mo on the activity of antioxidant enzymes and the productive increase of forage sorghum subjected to water deficit in the semi-arid region. The experiment was conducted in the field using a randomized block design, with four replications, in a 5 x 2 x 3 factorial scheme, comprising five doses of N (urea): 0, 50, 100, 150, and 300 kg ha(-1), two doses of Mo (sodium molybdate): 0 and 160 g ha(-1), and three production cycles. The highest yields of green mass (GM) (47.98 Mg ha(-1)), dry mass (DM) (19.66 Mg ha(-1)), water use efficiency (WUE) (5.57 kg/m(3)), and N use efficiency (NUE) (0.26 kg(2)/g) occurred at the highest N dosage (300 kg ha(-1) N). The highest contents and extraction of total N, Mo, chloride (Cl), and potassium (K) were found in regrowth 2 and at the highest N dose (300 kg ha(-1)). The interaction of N and Mo resulted in higher catalase (CAT) enzyme activity. The meteorological conditions during the cycles strongly influenced the nutrient contents and extraction. The results of the study provide support for producers to use N and Mo fertilization strategies to improve crop productivity, even under water deficit conditions.

Background and Aims Infection by the hemi-parasitic plant Striga hermonthica causes severe host plant damage and seed production losses. Increased availability of essential plant nutrients reduces infection. Whether, how and to what extent it also reduces striga-induced host plant damage has not been well studied.Methods The effects of improved macro- and micronutrient supply on host plant performance under striga-free and infected conditions were investigated in glasshouse pot assays. One striga-sensitive and two striga-tolerant genotypes were compared. Plants growing in impoverished soils were supplied with (1) 25 % of optimal macro- and micronutrient quantities, (2) 25 % macro- and 100 % micronutrients, (3) 100 % macro- and 25 % micronutrients, or (4) 100 % macro- and micronutrients.Key Results Photosynthesis rates of striga-infected plants of the sensitive genotype increased with improved nutrition (from 12.2 to 22.1 mu mol m-2 s-1) but remained below striga-free levels (34.9-38.8 mu mol m-2 s-1). For the tolerant genotypes, increased macronutrient supply offset striga-induced photosynthesis losses. Striga-induced relative grain losses of 100 % for the sensitive genotype were reduced to 74 % by increased macronutrients. Grain losses of 80 % in the tolerant Ochuti genotype, incurred at low nutrient supply, were reduced to 5 % by improved nutrient supply.Conclusions Increasing macronutrient supply reduces the impact of striga on host plants but can only restore losses when applied to genotypes with a tolerant background.