To clarify the impact of sod-cultural practices on the soil physico-chemical properties in Macadamia orchards, suitable local grass cultivation models were selected. Five common grass species in orchards (Vicia villosa, Trifolium repens, Lolium multiflorum, Vulpia myuros, and Raphanus sativus) were selected in the study with clear tillage as the control to analyze the differences in soil moisture content, temperature, physical properties, nutrients, and fertility among different treatments in orchards. The membership function method was used for comprehensive evaluation. Sod-cultural practices could effectively increase the surface soil moisture content, which was 8.7%~24.0% higher than that of the clear tillage control. Meanwhile, sod-cultural practices could reduce the surface soil temperature of orchards by 7.6% to 16.8%. Compared with tillage, the average soil bulk density in the sod-cultural practice areas decreased by 11.7%. In terms of soil nutrients, sod-cultural practice areas significantly increased the soil organic matter content, with T. repens having the highest soil organic matter content, reaching 32.0 g/kg. Leguminous and cruciferous grass species could significantly increase the soil available nutrient content, while poaceae grass species showed no significant improvement. The soil comprehensive fertility coefficient of the cultivation modes of V. villosa, T. repens, and R. sativus showed the best performance, increased by 51.5%, 49.2%, and 45.4% respectively compared to the clear tillage control. The evaluation of orchard soil fertility could reach a fertile level. The optimal grass cultivation mode obtained using the membership function method was V. villosa. Comprehensive evaluation of the four physical and chemical indicators of soil moisture content, bulk density, temperature, and fertility in each treated orchard by the membership function method revealed the cultivation mode of V. villosa performed the best.

Gibberellic acid is a typical plant growth regulator, which has the efficacy of increasing yield and fruit preservation for crops. The preparation process of gibberellic acid dry flowable is still lacking systematic exploration, and the fruit preservation test of this preparation on citrus still needs to be verified. The study was aimed to investigate the effect of the wet grinding process of sand mill on the performance of gibberellic acid suspension slurry and to determine the performance of dry flowable prepared by spray drying. The 3% gibberellic acid dry flowable was prepared by the wet sand mill and pressure spray drying equipment, and the final process was screened according to the determination of particle size, viscosity, the retention rate of gibberellic acid content, and other performance indexes of the suspension concentrate through the optimization of the number of wet grinding times, the wet grinding speed, and the size of the diameter of zirconia beads used for wet grinding. The effect of 3% gibberellic acid dry flowable on citrus fruit set, fruit thickness, single fruit weight and soluble solids were tested in field efficacy test. The results showed that the optimal grinding process was 1 mm in diameter of the zirconium beads used for grinding, the grinding speed was 2500 r/min and grould twice. The viscosity of the suspension concentrate before spraying was lower than 200 mPa/s, and the particle size was about 2 µm, and the particle size of the suspension concentrate after spraying was about 3 µm after rehydration, and the retention rate of gibberellic acid was more than 90% after this grinding process, and the low viscosity of the slurry could meet the production requirements. The 3% gibberellic acid dry flowable produced by this process has high suspension rate (>90%), fast wetting speed (10 s), high retention rate of gibberellic acid, and the performance indexes are in accordance with the regulations, and there is no precipitation of suspension slurry during the production process. The results of the field trial showed that the spraying of gibberellic acid dry flowable increased the transverse and longitudinal diameter of the citrus single fruit, the thickness of the peel decreased, the weight of the single fruit increased, the soluble solids increased, and the fruiting rate of the planting area increased. The results provide theoretical support for the industrial production of gibberellic acid dry flowable, and the field trial of gibberellic acid dry flowable prepared in this study in citrus trees can provide reference for the application of gibberellic acid in citrus fruit trees.

Xyleborus affinis, a main pest of rubber trees, is effectively monitored and controlled using semiochemicals, a key method in rubber pest management. Chemosensory proteins (CSPs) are believed to play an important role in the process of binding and transporting odorants in insect. To elucidate the role of chemosensory proteins in semiochemicals recognizing by X. affinis, the XaffCSP1~XaffCSP5 genes were cloned and identified in this study. The characteristics of nucleotide and deduced amino acid sequences of the genes were analyzed using bioinformatics methods. The binding mode and ability with 15 different ligands (14 host plant volatiles and 1 aggregation pheromone) was analyzed using molecular docking technology. Results revealed that the length of the open reading frame (ORF) of the five XaffCSPs genes was 366-417 bp, encoding 121-138 amino acids. The predicted protein molecular weight was 13.95-16.08 kDa and all five XaffCSPs contained signal peptide composed of 17-20 amino acid residues at N-terminal. The secondary structure of the proteins was mainly composed of α-helix. All five XaffCSPs possessed four conserved cysteine residues, conforming to the typical characteristics of insect chemosensory proteins. Phylogenetic tree anaylsis indicated that except for XaffCSP5, XaffCSP1 to XaffCSP4 were clustered with CSPs of other bark beetle species. The three-dimensional models of the the five XaffCSPs were with good model quality according to model assessment results, and the models of the five XaffCSPs were composed of six α-helices. Molecular docking results demonstrated all five XaffCSPs had a strong binding affinity with (-)-α-copaene and (+)-longifolene. Additionally, XaffCSP4 showed strong binding to terpinolene and limonene, while XaffCSP5 showed strong binding to camphene, α-pinene, and β-pinene. The binding ability of the five XaffCSPs to (S)-cis-verbenol was relatively weak. The results demonstrated that the five XaffCSPs had good affinity with host volatiles and may be participated in the process of recognizing host plant volatiles by X. affinis. This study would provide a theoretical basis for elucidating the molecular mechanism of X. affinis in recognizing semiochemicals and is of great significance for the control of X. affinis.

The study was aimed to provide technical support for risk management, risk analysis and risk assessment of pests carried by banana seedlings in China. By consulting domestic and foreign literature (mainly including China’s National Pest Quarantine Information System, etc.), a total of 68 species of pests that may be transmitted to bananas exported to China were identified, including 32 species of insects, 19 species of fungi, 9 species of nematodes, 4 species of bacteria, 1 species of mollusca, and 3 species of mites (including spiders). Based on the distribution in China (undistributed or not widely distributed), whether they are officially controlled, and the possibility of being carried with banana seedlings, 9 potential quarantine pests were identified that require further evaluation, including 7 species of fungi and 2 species of bacteria. The 9 potential quarantine pests were qualitatively and quantitatively analyzed one by one in terms of entry, colonization, diffusion possibility, economic impact and multi-index comprehensive evaluation, and 5 species of medium-risk pests and 4 species of high-risk pests were identified. Finally, it was determined that the nine pests including Botryotinia fuckeliana were quarantine pests that require attention when banana seedlings were exported to China, and the corresponding risk management measures were put forward.

Plant protection unmanned aerial vehicle (UAVs) operational parameters have remarkable effects on droplet distribution in UAVs spraying, which significantly affects pesticide utilization rate and treatment effectiveness. The study was aimed to explore the effects of operating parameters of electric UAVs on droplet deposition distribution in mango trees canopy and to enhance the efficiency of targeted deposition by UAVs. The DJI T40 multi-rotor electric plant protection UAV was used and the main operational parameters including droplet sizes (80, 100, 120 μm), flight height (2.0, 2.5, 3.0 m) and flight speed (3.0, 4.0, 5.0 m/s) were optimized by an orthogonal test. When the droplet size was 80 μm with 2.0 m of flight height and 3.0 m/s of flight speed, the droplet deposition density, coverage rate and uniformity in each canopy of mango trees were significantly larger than those of the other groups. There was a negative correlation between droplet deposition density, coverage rate and flight height, flight speed. The results of range analysis showed that droplet size was the main factor affecting the deposition density of droplet in mango canopy. The flight height was the main factor affecting the coverage rate of spray droplets on the front side of the lower canopy leaves and the back side of the inner canopy leaves of mango trees. The flight speed was the main factor affecting the coverage rate of spray droplets on the back side of the upper canopy leaves of mango trees. The spray diameter of the front and back of the leaves of the other layers was the main factor affecting the droplet coverage rate. The droplet distribution within mango canopy exhibited significant variation, with droplet size being the primary factor determining uniformity, followed by flight speed and flight height. In our current study, according to the droplet deposition density, coverage rate and uniformity in mango canopy, the best operating parameters of T40 multi-rotor electric plant protection UAV were obtained as follows: droplet size of 80 μm, operation height of 2.0 m, and operation speed of 3.0 m/s. It could provide fundamental guidance of the operation of small UAVs for the aerial spraying of mango trees and other similar orchards.

Meloidogyne enterolobii is one of the most devastating pathogens in tomato (Solanum lycopersicum) production. Grafting with resistant rootstocks could help superior cultivars gain root-knot nematode resistance straightly. Previously, we identified a medium-resistant tomato rootstock cultivar Guizhen 1. In order to deepen the understanding to its resistance mechanism, we inoculated Guizhen 1 and susceptible cultivar Yala with M. enterolobii, and measured the proportion of root knots and nematode numbers in roots once every four days within 28 days. The root knot proportion of Yala reached 71.7%, which was kept under 36.0% in Guizhen 1. The root knot proportions between resistant and susceptible cultivars were significantly different on day 12, 16, 20, 24 and 28 after inoculation. Whereas the differences of nematode numbers between resistant and susceptible cultivars were not significant except on day 20. Thus it can be seen that the resistance of Guizhen 1 was not reflected by limiting the invasion of nematodes. The LC-MS based non-targeted metabolome of resistant and susceptible roots on 5th day after inoculation were measured. With the threshold of VIP>1 and P<0.05, 415 significantly different metabolites were gained, among which 280 were up-regulated and 135 were down-regulated. The top 8 classes of metabolites with largest number of metabolites were amino acid and its metabolites, heterocyclic compounds, benzene and its derivatives, organic acid and its derivatives, aldehyde, ketone and ester, fatty acyls, glycerol phospholipids, alcohol and amines. KEGG dataset were employed to do the metabolite pathway enrichment analysis. Glycerophospholipid metabolism, ascorbate and aldarate metabolism, nicotinate and nicotinamide metabolism, betalain biosynthesis and flavonoid biosynthesis pathways had relatively high level of enrichment, with the glycerophospholipid metabolism having the highest enrichment level. In glycerophospholipid metabolism pathway, there were several metabolites with significant differences between resistant and susceptible cultivars, which were phosphocholine, phosphatidylcholine, lysophosphatidylcholine, sn-glycero-3-phosphocholine, triethanolamine and diethanolamine. It was speculated that glycerophospholipid metabolism pathway might enhance the M. enterolobii resistance of Guizhen 1 at certain level. In this study, the histological and metabolomic fundamentals of M. enterolobii resistance were explored in tomato rootstock cultivar Guizhen 1, which would provide certain basis for the in-depth study on resistance mechanism in the future.

The purpose of the study was to explore the relationship between Lvnonglin^® 41 compound microbial fertilizer (LNL41) and the occurrence of tomato Fusarium wilt and soil fungal communities and to provide theoretical basis for the prevention and control of tomato Fusarium wilt and the rational application of nitrogen fertilizers. Using plots with severe occurrence of tomato Fusarium wilt in previous years as experimental plots, four treatments were designed in field: water control (CK), LNL41, bacterial fertilizer nutrient substrate (NS), compound microbial (CM). The effects of different treatments on the concentrations of main soil nutrients of rhizosphere soil, plant growth, soil respiration rate, incidence of Fusarium wit disease were analyzed. Using 18S rDNA sequencing technology, the differences in the occurrence of tomato Fusarium wilt and the fungal community structure in rhizosphere soil under LNL41 were investigated. Compared with other treatments, the LNL41 treatment is the best. The treatments with LNL41 and CM had higher contents of organic matter and available phosphorus in tomato rhizosphere soil than other two treatments. Compared with the control, the plant height, stem circumference, leaf area, photosynthesis, chlorophyll, yield and water-soluble sugar treated by LNL41, CM and NS all increased by 8.87%-34.71%, 15.93%-67.62%, 13.37%-52.88%,3.17%-12.55%, 3.20%-20.49%, 4.38%-19.53%, 0.46%-8.79% respectively. The soil respiration rate increased by 59.52% in LNL41. The incidence and control effect of tomato Fusarium wilt disease in different growth stages reached 2.33%-16.33% and 80.50%-90.83% in LNL41, respectively. The Ace index and Chao1 index at the fungal genus level in the rhizosphere soil increased by 26.97%-57.71% and 24.89%-56.00%, respectively. The diversity indicators of the Simpson index and Shannon index of the CM treatment increased by 25.75%-29.45% and 39.04%-49.13%, while the diversity indicators of the NS treatment decreased. Hypocreaceae and Trichoderma treated with LNL41 were among the top five dominant families and genera (both abundances were 8.56%); Trichoderma was similar to Cladosporium, Uwebraunia, Aureobasidium and Fusarium in the four treatments, and was positively correlated with Aspergillus, Uwebraunia and Alternaria respectively. Chao1 index treated with LNL41 was significantly positively correlated with organic matter, available phosphorus, available potassium and soil respiration rate, and was significantly negatively correlated with salinity and disease incidence. The abundance of saprophytic functional groups treated with microbial fertilizer increased by 0.92-11.15 percentage, plant pathogen decreased by 2.55 percentage, and endophyte decreased by 7.95 percentage, while only two functional groups treated with NS and CM increased in abundance. LNL41 can significantly improve the ratio of soil nutrients, thereby improving the structure and functional characteristics of soil fungal communities, stimulating saprophytic functions of the fungal communities, promoting tomato growth, and reducing the rate of blight.

UV-C treatment is an emerging and abiotic stress technology, and is a non-ionizing and non-thermal physi-caltechnology. By using proper dose of UV-C treatment, it can be used to inactivate microbes on the surfaces of food, reduce the decay rate, maintain phytonutrients content and organoleptic quality. According to the research, the application of UV-C treatment is effective in increasing the levels of antioxidants content and the antioxidant capacity of fruits, then it can enhance resistance ability of some fruits, and which makes storage qualities better and extend the shelf life. Combining UV-C treatment with other technologies, such as 1-methylcyclopropene (1-MCP), and coating with all kinds of active compositions, and different packaging so on, it can form a hurdle technique which is a combination by two or more treatment, it can result in synergistic or additive interactions when compared to any single preservation technique in some horticulture. In addition, UV-C treatment is an eco-friendly and a cost effective technology which can be carried out easily without complex equipment on post-harvest and logistics and transportation for their commercialization. This critical review aims to summarize the research conducted on the effects of UV-C treatment on postharvest fruits in the past five years, the review draws the current challenges as well as future perspectives. It is hoped to provide valuable insights for the widespread adoption of UV-C treatment technology.

Species of Diaporthe have broad host ranges and are widely distributed in ecosystems, occurring as plant pathogens, endophytes or saprobes. In this study, the ingredients and contents of phytohormones, organic acids, and fatty acids in 16 strains of Diporthe fungi, collected and identified from Xisha islands, were detected by LC-MS and GC-MS methods. Cluster analysis by Ward method of Euclid Distance was used to classify the quality types of different strains. The results showed that four phytohormones, three organic acids, and five fatty acids could be detected. The phytohormones included abscisic acid (ABA, average yield 125.36 µg/kg), indole-3-acetic acid (IAA, average yield 40.28 µg/kg), salicylic acid (SA, average yield 6.63 µg/kg) and jasmonic acid (JA, average yield 4.95 µg/kg). the yield of ABA was significantly higher than other plant hormones, and the four phytohormones contents of different strains varied greatly. Organic acids were succinic acid (average yield 336.04 µg/g), succinic acid (Vc, average yield 10.03 µg/g), shikimic acid (average yield 0.58 µg/g). The succinic acid production of Diporthe fungus was significantly higher than those of other organic acids. The yield of organic acids varied greatly among the 16 strains. The fatty acids were trans linoleic acid (average yield 58.99 µg/g), linolenic acid (average yield 28.15 µg/g), stearic acid (average yield 21.35 µg/g), palmitic acid (average yield 17.07 µg/g) and oleic acid (average yield 15.22 µg/g). The production of trans linoleic acid were the highest, while the production of oleic acid the lowest, and the five organic acids contents of different strains varied remarkably. Cluster analysis using plant hormones, organic acids, and fatty acids of the 16 strains revealed D. biconispora D43 was independent group. The strain showed the highest production of ABA (average yield 443.86µg/kg), succinic acid (average yield 1115.98 µg/g), shikimic acid (average yield 1.21 µg/g), and oleic acid (average yield 60.75 µg/g), while the lowest production of linoleic acid (average yield 7.08 µg/g). Comprehensive analysis suggests that D. biconispora D43 had certain potential for the development and utilization of microbial derived succinic acid. This study would provide information for the research and appication of Diaporthe resources in the field of food, chemical industry, and other related fields.

Biogenic volatile organic compounds (BVOCs) serve as a critical link between the biosphere and the atmosphere, playing a vital role in atmospheric chemistry, ozone formation, and the creation of secondary organic aerosols. Volatile emissions from urban forest parks and greenery can have a significant impact on local and regional air quality. In this study, two common Ficus spp. plants with a high planting rate in Haikou were selected, and the BVOCs emissions of F. elastica and F. altissima were measured using the dynamic headspace bagging collection method and identification and analysis by gas chromatograph. The chemical components and emission characteristics of the BVOCs were also investigated. Meanwhile, the experiment continuously monitored environmental factors [temperature (T), photosynthetically active radiation (PAR)] and physiological parameters [stomatal conductance (G_s), intercellular CO₂ concentration (C_i), transpiration rate (T_r)] to further analyze the driving factors of BVOCs emissions in Ficus spp. The results showed 19 and 12 compounds identified for F. elastica and F. altissima. BVOCs emissions from Ficus spp. were dominated by isoprene and terpenoids. Among them, the relative content of isoprene emission from F. elastica increased by 1.82 times in the rainy season compared to the dry season, indicating that F. elastica has a significant potential for isoprene emission. The terpene compounds α-pinene and Caryophyllene made significant contribution. The daily variation of BVOCs in Ficus spp. showed a single-peak emission pattern of “low in the morning and low in the evening, high in the middle of the day”, with the maximum emission of BVOCs occurring at 12：00 or 14：00 noon, when the temperature or photosynthetically active radiation was the highest. BVOCs emissions from Ficus spp. were significantly higher in the rainy season than they were in the dry season. In addition, the BVOCs emissions of Ficus spp. were positively correlated with the temperature and with the photosynthetically active radiation. BVOCs emissions were positively correlated with the physiological parameters, T_r and G_s, and negatively correlated with C_i. This study expands the research field by investigating the emission characteristics of BVOCs from tropical Ficus spp. It provides essential data for enriching the database of BVOCs emission inventories in tropical and subtropical regions and for assessing their environmental impact.