Botanical nematicides have recently received increasing interest because of the high risks of some traditional nematicides to human health and the environment. This study evaluated the nematicidal activity of a plant volatile, trans-2-hexenal, against Meloidogyne incognita. This compound exhibited higher activity in a fumigation experiment than in the aqueous phase in vitro. Both in pot tests and in field trials, trans-2-hexenal showed significant efficacy against M. incognita while maintaining excellent plant growth, especially at doses of 1000 and 500 L ha, which were superior to that of abamectin at 180 g ha via hole application treatment but not significantly different from fumigation with 400 kg ha of dazomet. Furthermore, plants treated with 500 L ha trans-2-hexenal had fruit yields 20.2 and 45% greater than the control group. On this basis, trans-2-hexenal may be a potential alternative fumigation agent for controlling M. incognita on tomato crops.

The size of microcapsules (MCs) is an important and easily adjustable parameter; however, the function of this parameter in the movement behavior of pesticide MCs had not yet been studied. Phoxim-loaded polyurethane MCs with three various size distributions (average diameters of 1.39 μm, MC-S; 5.78 μm, MC-M; and 23.60 μm, MC-L) were obtained. In the greenhouse experiment, the insecticidal activities of MC-S and MC-M occurred mainly in the first 3 days and that of MC-L was maintained from 3 to 10 days after application. The direct and secondary distributions of a pesticide were defined and used to investigate the effects of particle size on the insecticidal activity of MCs in the field. The results indicated that the reason why MC-S had an excellent initial activity was that it was more widely distributed on the surface of the organism, was more likely to be adhered to by pests, and had greater resistance to rain washing. MC-L had excellent later-stage insecticidal activity, which was mainly because of its outstanding light stability. Then, retained phoxim was released through a crack caused by a light shining onto the shell. The increase in the size of the MCs improved the amount of pesticide swallowed by the insect and the movement distance of the pesticide within the digestive system of the insect. Thus, increasing the size of MCs helps increase the utilization rate of pesticides if a chemical group responding to alkaline conditions can be added into the capsule shell. The transfer and release behavior of pesticide MCs in the field can be regulated by simply adjusting the particle size, which is of great value to the application of pesticide MCs in agriculture and could provide a new approach for the efficient utilization of pesticide MC formulation.

The broad-spectrum and widely used fungicide pyraclostrobin is encapsulated using a coordination assembly between Fe 3+ and tannic acid to promote its efficacy and environmental safety. The deposition is confirmed by the surface zeta potential and energy dispersive spectroscopy. Optical microscopy, scanning electron microscopy, transmission electron microscopy (TEM), and atomic force microscopy (AFM) observations are integrated to characterize the pyraclostrobin-loaded microcapsules (MCs). These MCs retain a spherical shape when suspended in water but quickly deform or rupture after the water evaporates when deposited for 1 cycle. After sequential deposition of the membrane, the membrane thickness increases linearly according to TEM and AFM height analyses. These MCs show satisfactory efficacy on rice blast, resulting in significantly higher yields at doses of 120 and 180 g ha −1 . Moreover, these MCs display significantly lower toxicity to Brachydanio rerio, Daphnia magna, Xenopus laevis, and Rana nigromaculata. Overall, this novel microencapsulation strategy is capable of promoting the efficacy and environmental safety of pyraclostrobin.

The application of pesticide microcapsules (MCs) in agriculture is becoming more and more popular. In this study, the effects of different wall materials on the stomach toxicity, contact toxicity, length of efficacy, and photolysis characteristics of pesticide microcapsules were investigated. The results showed that microencapsulation reduced the stomach and contact toxicities of phoxim and prolonged the efficacy of this light-sensitive chemical in the greenhouse test. Neither of the degradation curves for microencapsulated phoxim under ultraviolet light fit a first-order model, although the emulsifiable concentrate (EC) degradation curve fit it well. The phoxim-loaded polyurea microcapsules (PUA-MCs) showed significantly increased UV-resistance ability, stomach toxicity, and contact toxicity compared with the phoxim-loaded urea-formaldehyde microcapsules (UF-MCs). These experiments indicated that it is crucial to select the appropriate wall materials for pesticide microcapsules on the basis of application sites and physicochemical properties of pesticide active ingredients.

It is desirable for a simple and universal method to synthesize stimuli‐responsive nanocarriers to targeted delivery of pesticides. In this study, a novel pH‐value and laccase dual‐responsive nanopesticide system loaded with lambda‐cyhalothrin (LC) is established by iron mineralization after electrostatic self‐assembly between sodium lignosulphonate (SL) and dodecyl dimethyl benzyl ammonium chloride (DDBAC). These nanoparticles are core–shell structures in which iron mineralization plays a key role in stabilizing the nanoparticles. This synthesis strategy is suitable for encapsulating hydrophobic and low‐volatility compounds. The encapsulation of the nanocarriers prolongs the half‐life of the LC under UV irradiation by 4.4‐fold. After irradiation, the mortality of Agrotis ipsilon treated by the LC@SL/DDBAC/Fe is approximately 39% higher than that treated by emulsifiable concentrate (EC) at the concentration of 1 mg L−1. The dual‐responsive property of lignin‐based nanoplatform to alkalinity and laccase enable cargo release on demand. Although the toxicity of EC and LC@SL/DDBAC/Fe to A. ipsilon is similar, that of LC@SL/DDBAC/Fe to Brachydanio rerio is decreased by 11.57‐fold, and the toxicity selective pressure is enhanced by 11‐fold compared with EC. The SL/DDBAC/Fe nanocarriers represent a simple preparation procedure, excellent environmental safety, and dual‐responsive release profiles and can offer a promising nanoplatform for precise pesticide delivery.

At present, it is highly important to develop a simple and compatible nano delivery system for pesticides for foliar application, which can improve their insecticidal efficacy and resistance to adverse climates while reducing the environmental risks. Polyethylene glycol and 4,4-methylenediphenyl diisocyanate are used as hydrophilic soft and hydrophobic hard segments, respectively, for polymer self-assembly and polyurethane gelation in a nanoreactor. The nanocarrier synthesis and the pesticide loading are realized by a one-step integration procedure and suited well for hydrophobic active compounds. Modifying the molecular structure of the soft segment can adjust the flexibility of the nanocarriers and result in viscosity and deformation characteristics. After foliar spray application, the foliar flattening state of the nanogels increases the foliar protection area by 2.21 times and improves both pesticide exposure area and target contact efficiency. Concurrently, the flexibility and viscosity of the nanogels increase the washing resistance and the retention rate of the pesticide by approximately 80 times under continuous washing. The encapsulation of the nanogels reduces the foliar ultraviolet (UV) degradation and aquatic pesticide exposure, which increase the security of λ-cyhalothrine by 9.33 times. Moreover, the degradability of nanogels is beneficial for pesticide exposure and reducing pollution. This system has simple preparation, good properties, and environmental friendliness, making the nanocarriers promising for delivering pesticides.

Anthracnose, caused by Colletotrichum species, can severely infect the fruits and leaves of more than 30 plants and thus results in great yield and quality losses. To identify the major Colletotrichum species infecting walnut fruits, strawberry leaves, grape fruits, and tea leaves in Shandong Province, China, 101 strains were collected and isolated. The morphological characteristics of all isolates were observed, and multilocus phylogenetic analyses (ITS, GAPDH, ACT, TUB2, CAL, CHS-1, and HIS3) were conducted on the representative isolates. The strains were identified as five Colletotrichum species, namely, C. gloeosporioides sensu stricto, C. fructicola, C. camelliae, C. acutatum sensu stricto, and C. viniferum. Among them, C. viniferum was reported for the first time from walnut fruits and strawberry leaves in Shandong Province, China. Corresponding leaves or fruits were used as a model to clarify the pathogenicity of these isolates. The results showed that C. fructicola obtained from strawberry leaves was more aggressive than C. viniferum. All of the isolates obtained from various hosts were highly sensitive to pyraclostrobin, difenoconazole, fludioxonil, tebuconazole, pyrisoxazole, and tetramycin in terms of mycelial growth inhibition (EC50 values of 0.07 to 1.63 mg/liter). The fastest mycelial growth was observed in the temperature range of 25–28°C for all isolates. In addition, anthracnose symptoms occur frequently under these conditions. Overall, this study can improve the understanding of Colletotrichum species causing anthracnose in walnut fruits, strawberry leaves, grape fruits, and tea leaves and can provide a solid foundation for the effective control of this disease in different hosts.

The southern root-knot nematode (RKN), Meloidogyne incognita, is the most disastrous and prevalent nematode threat to the production of crops, especially vegetables. In the current study, second-stage juveniles (J2) of M. incognita were collected from five regions near Tai'an, China. The toxicity of abamectin to these J2 had insignificant differences, with LC values of approximately 2 mg/L. Two pesticide application approaches (i.e., blending-of-soil and root-irrigation) were adopted in pot experiments; blending-of-soil was more beneficial for promoting the efficacy of abamectin on the RKN of tomatoes. Abamectin microcapsule suspension exhibited superiority to emulsifiable concentrate (EC) at dosages of 5 and 10 mg active ingredient per plant integrating efficacy, root length, plant height, the fresh weight of roots, and the fresh weight of stems + leaves. Adsorption, leaching, and mobility of abamectin in the soil also verified bioactivity test results. Modifying the formulation of abamectin can promote its efficacy on RKN under different application approaches.