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Drought and water shortages have always been great challenges for agricultural production in the North China Plain. To explore appropriate irrigation regimes and planting patterns in this area, a field experiment was conducted for winter wheat (Triticum aestivum L.) from 2014 to 2016. Three irrigation treatments of 50 mm irrigation at growth stage of jointing (GS34) and heading (GS48, W1), 100 mm irrigation at GS34 (W2) and 100 mm irrigation at GS34 and GS48 (W3) combined with uniform (U), double-double (DD) and furrow-ridge (F) planting patterns were designed. The tillers number, leaf water status, spike characteristics and radiation use efficiency (RUE) were measured. Results showed that compared with W2, W3 significantly reduced leaf abscisic acid (ABA) content and increased tillers number, spikelets spike −1 , yield components and RUE, while W1 produced more tillers number, leaf relative water content (LRWC) and water potential (Lψ) only in the late growth stage, yield components and RUE. The DD significantly increased tillers number, LRWC, Lψ, leaf osmotic potential, spike length, spikes m −2 , grains spike −1 and RUE, and reduced the ABA content compared with U. Considering the serious water shortage in the North China Plain, 50 mm irrigation at jointing and heading stages combined with DD is a worthy cultivation measure for sustainable agriculture at water-deficit condition.

The root-knot nematode is one of the most damaging plant-parasitic nematodes worldwide, and the ecofriendly alternative approach of biological control has been used to suppress nematode populations. Here the nematicidal activity of Aspergillus japonicus ZW1 fermentation filtrate against Meloidogyne incognita was evaluated in vitro and in greenhouse, and the effects of A. japonicus ZW1 fermentation filtrate on seed germination and the active compound of A. japonicus ZW1 fermentation filtrate were determined. The 2-week fermentation filtrate (2-WF) of A. japonicus ZW1 exhibited markedly inhibitory effects on egg hatching, and 5% 2-WF showed potential nematicidal activities on second-stage juveniles (J2s); the mortality of J2s was 100% after 24 h exposure. The internal contents of nematodes were degraded and remarkable protruded wrinkles were present on the body surface of J2s. The nematicidal activity of the fermentation was stable after boiling and was not affected by storage time. A germination assay revealed that 2-WF did not have a negative effect on the viability and germination of corn, wheat, rice, cowpeas, cucumbers, soybeans, or tomato seeds. The pot-grown study confirmed that a 20% fermentation broth solution significantly reduced root galls and egg numbers on tomatoes, and decreased galls and eggs by 47.3% and 51.8% respectively, over Czapek medium and water controls. The active compound from the A. japonicus ZW1 fermentation filtrate was isolated and identified as 1,5-Dimethyl Citrate hydrochloride ester on the basis of nuclear magnetic resonance (NMR) and LC-MS (liquid chromatograph-mass spectrometer) techniques. Thus, fermentation of A. japonicus ZW1 could be considered a potential new biological nematicide for the control of M. incognita.

The soil-borne fungus Fusarium oxysporum (Fo) and the nematode Meloidogyne incognita (Mi) are destructive pathogens that cause substantial yield losses to tomato (Solanum lycopersicum L.) crops worldwide. The present study sought to elucidate the physiological, biochemical, and cytological responses of tomato cultivars (Gailing maofen 802 and Zhongza 09) by root invasion of Fo (1 × 105 CFUmL−1) and Mi (1500 second-stage juveniles (J2) alone and in combination after 14 days. Results revealed that combined inoculation of Fo and Mi significantly increased disease intensity, electrolyte leakage, and hydrogen peroxide and malondialdehyde contents; and decreased photosynthetic capacity and enzyme activity in both cultivars as compared to their solo inoculation. Increasing the disease intensity reduced the maximum morphological traits, such as shoot length, total dry weight, and total chlorophyll contents, in G. maofen 802 (by 32%, 54.2%, and 52.3%, respectively) and Zhongza 09 (by 18%, 32%, and 21%, respectively) as compared to the control. Others factors were also reduced in G. maofen 802 and Zhongza 09, such as photosynthetic capacity (by 70% and 57%, respectively), stomatal conductance (by 86% and 70%, respectively), photochemical quantum yield of photosystem II (YII) (by 36.6% and 29%, respectively), and electron transport rate (by 17.7% and 10%, respectively), after combined inoculation of Fo and Mi. Furthermore, the combined infestation of Fo and Mi resulted in reduced activity of plant-defense-related antioxidants in G. maofen 802 compared with their single application or control. However, these antioxidants were highly up-regulated in Zhongza 09 (by 59%–93%), revealing the induction of tolerance against studied pathogens. The transmission electron microscopy (TEM) results further demonstrated that root cells of Zhongza 09 had unique tetrahedral crystal-like structures in the membrane close to mitochondria under all treatments except control. Therefore, it is concluded that Mi caused severe root damage, suppressed plant growth, depleted antioxidants, and caused high generation of ROS in the presence of Fo as compared to its solo inoculation. Tolerant cultivars adopted different mechanistic strategies at the structural and cellular levels to tolerate the Mi and Fo stresses.

Low water availability coupled with poor planting method has posed a great challenge to winter wheat (Triticum aestivum L.) productivity. To improve productivity and water use efficiency (WUE) under deficit irrigation, an effective water-saving technology that is characterized by three planting modes has been developed (uniform with 30-cm row spacing (U), double-double row spacing of 5 cm (DD), and furrow-ridge row spacing of alternated 20 cm and 40 cm (F)) combined with three irrigation regimes (50 mm water each at growth stage 34 (GS34) and GS48 (W1), and 100 mm water at GS48 (W2), or 100 mm each water at GS34 and GS48 (W3)). Results showed that DD increased yield by 9.7% and WUE by 12.6% due to higher soil water status and less soil water depletion and evapotranspiration compared with U. Although the soil water status, soil water depletion, evapotranspiration, and yield increased with increasing irrigation amount, more soil water depletion and evapotranspiration resulted in low WUE. The deficit irrigation was beneficial for improving WUE as W1 had significantly increased yield by 5.4% and WUE by 7.1% compared with W2. Yield and evapotranspiration showed a quadratic dynamic equation indicating that yield increased with increasing evapotranspiration. Considering WUE and relatively higher yield under deficit water, W1 combined with DD is suggested to be a good management strategy to be applied in winter wheat of water-scarce regions.

Root-knot nematodes (Meloidogyne spp.) are the most destructive group of plant-parasitic nematodes. Plants infected by Meloidogyne spp. develop above-ground symptoms, stunting, yellowing, nutrient deficiencies, and gall formations with typical hook-shaped root tips. Infected plants experience yield losses. During 2018-2019 survey, leaf chlorosis rice plants were found in 206 fields of 67 counties in Guangxi, China, around 30 days after transplanting. Galls and hooked tips on the roots and pear-shaped females were observed. About 32.04% of fields were infested with the nematode. The nematodes were identified as Meloidogyne graminicola base on morphological and molecular analysis. To the best of our knowledge, this is the first report of M. graminicola on rice plants in Guangxi, China. The results of this study urge the discovery of resistant cultivars and the development of management strategies.

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the most notorious insect pest of potato globally. Injudicious use of insecticides for management of this pest has resulted in resistance to all major groups of insecticides along with many human, animal health, and environmental concerns. Additionally, the input cost of insecticide development/discovery is markedly increasing because each year thousands of chemicals are produced and tested for their insecticidal properties, requiring billions of dollars. For the management of resistance in insect pests, synergists can play a pivotal role by reducing the application dose of most insecticides. These eco-friendly synergists can be classified into two types: plant-based synergists and RNAi-based synergists. The use of plant-based and RNAi-based synergists in resistance management of insect pests can give promising results with lesser environmental side effects. This review summarizes the resistance status of CPB and discusses the potential advantage of plant-based and RNAi-based synergists for CPB resistance management. It will motivate researchers to further investigate the techniques of using plant- and RNAi-based synergists in combination with insecticides.

With the passage of time and indiscreet usage of insecticides on crops, aphids are becoming resistant to their effect. The different classes of insecticides, including organophosphates, carbamates, pyrethroids and neonicotinoids, have varied effects on insects. Furthermore, the molecular effects of these insecticides in aphids, including effects on the enzymatic machinery and gene mutation, are resulting in aphid resistance to the insecticides. In this review, we will discuss how aphids are affected by the overuse of pesticides, how resistance appears, and which mechanisms participate in the resistance mechanisms in various aphid species as significant crop pests. Gene expression studies were analyzed using the RNA-Seq technique. The stress-responsive genes were analyzed, and their expression in response to insecticide administration was determined. Putative insecticide resistance-related genes, cytochrome P450, glutathione S-transferase, carboxylesterase CarEs, ABC transporters, cuticle protein genes, and trypsin-related genes were studied. The review concluded that if insecticide-susceptible aphids interact with ample dosages of insecticides with sublethal effects, this will result in the upregulation of genes whose primary role is to detoxify insecticides. In the past decade, certain advancements have been observed regarding insecticide resistance on a molecular basis. Even so, not much is known about how aphids detoxify the insecticides at molecular level. Thus, to attain equilibrium, it is important to observe the manipulation of pest and insect species with the aim of restoring susceptibility to insecticides. For this purpose, this review has included critical insights into insecticide resistance in aphids.