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Invasive plant species (IPS) are often considered weeds that cause high yield losses in crops, negatively affect the environment, and disrupt certain ecosystem services. The negative impact of IPS on biodiversity is increasing and disturbing native vegetation. The management of plant invasions can be divided in two phases (before and after invasion). Prior to introduction it is crucial to develop the knowledge base (biology, ecology, distribution, impact, management) on IPS, prevention measures and risk assessment. After introduction if eradication fails, the monitoring and the integrated management of IPS are imperative to prevent the naturalization and further dispersal. This review uses two major invasive weed species (Amaranthus palmeri S. Wats. and Solanum elaeagnifolium Cav.) as case studies to propose a framework for early detection, rapid herbicide resistance screening, and integrated management. The holistic framework that is presented exploits recent: (i) novel detection tools, (ii) rapid tests and assays for herbicide resistance, and (iii) biology, ecology, distribution traits, and management tools for the IPS. Farmers, advisors, researchers, and policymakers need briefing on IPS growth dynamics, adaptability rates, and response to conventional and novel treatments to prevent new invasions, eradicate isolated stands, and mitigate the impact of invasive weed species in the long term. © 2022 Society of Chemical Industry.

Alien ornamental plants have the potential to become invasive and biological control is considered a promising method for managing them. Global literature was searched to reveal the potential biological control agents for 56 ornamental plants which have invasion potential in Turkey. Out of the biological agents, we compiled the list of species already in Turkey which could be utilised in managing invasive species. Moreover, succesfull biological control agents for these plants from other parts of the world have also been listed. As a result, 128 species of arthropods were found as natural enemies and 27 of them were established in the released areas in the world. In Turkey, out of these 128 species, 58 were noted as present in Turkey, however, their impacts on plants have not been studied in detail. Potential biological agents for controlling invasive plants in Turkey are: Carpomyia vesuviana (Costa) for Ziziphus mauritiana Lam., Rhizaspidiotus donacis (Leonardi) for Arundo donax L., Unaspis euonymi (Comstock) for Euonymus fortunei (Turcz.) Hand.-Mazz., Diaspis echinocacti (Bouché) for Opuntia ficus-indica (L.) Miller, Eulecanium ciliatum (Douglas), Lepidosaphes ulmi (Linnaeus), Melanaspis inopinata (Leonardi) and Phenacoccus aceris (Signoret) for Acer negundo L. There is a possibility to use these biological agents for controlling the alien ornamental plants in Turkey, although there is a need for conducting further Pest Risk Assesment to assess the invasiveness of alien plants in Turkey, and studies are also required for safe release of beneficial insects.

Amaranthus palmeri is a troublesome weed which is growing in importance worldwide. It causes serious competition in many crops. A. palmeri was introduced into Turkey 4–5 years ago and appears to adapt to different environmental conditions. Monoculture cropping systems and repeated use of the same herbicides have led to development of herbicide resistance in A. palmeri to several active ingredients including glyphosate, in USA and in South America. This study was conducted to investigate the evolution of glyphosate resistance in A. palmeri in Turkey. Seeds of 21 A. palmeri populations were collected in Turkish citrus fields where control problems with glyphosate were reported. A potentially glyphosate susceptible A. palmeri population was collected from a maize field (GS1 biotype). Seeds of putatively resistant and potentially susceptible (GS) biotypes were germinated and transplanted into large pots, and then allowed to grow in separate greenhouse chambers to obtain F2 generations. After carrying out a preliminary test experiment to exclude the most susceptible populations, a dose-response experiment was conducted in which glyphosate was applied at the 3–4 true leaf stage at 0, 332.5, 665, 1330, 2660, 5320, 10,640 and 21,280 g a.i. ha−1. Plants were harvested 21 days after treatment and dry weight was determined. Glyphosate applied at the recommended rate (1330 g a.i ha−1) controlled GS A. palmeri biotypes by more than 95% while controlling the GR biotypes at about 45%. Among those biotypes, GR1 and GR2 biotypes were confirmed to have an incipient resistance to glyphosate. The effect of glyphosate on shikimic acid accumulation was determined. Results showed that the GS2 biotype accumulated 3.1 and 1.56 times more shikimic acid than GR2 and GR1 biotypes which demonstrates that there is a lower accumulation of shikimic acid in the alleged resistant biotypes than in GS1. These findings demonstrate some increased tolerance of A. palmeri biotypes to glyphosate, which reinforces the need to implement integrated weed management to control this invasive plant in Turkey.

Combining tillage with herbicides is an economical and efficient method for weed management and yield improvement in wheat. A two-year study was conducted having three tillage levels viz. 2″ tillage (shallow tillage, ST), 4″ tillage (conventional tillage, CT) and 6″ tillage (deep tillage, DT). The weed control treatments were five including three herbicides i.e. bromoxynil + MCPA (a broad-leaf weed killer), fenoxaprop-p-ethyl (a grass killer) and isoproturon + carfentrazone (a broad-spectrum herbicide), along with a hand weeding (HW) and a weedy check (WC). Results showed that the recorded parameters were significantly affected by the varying tillage depths, herbicide applications and their interactions. The weed density and biomass were the highest in ST and the lowest in DT, while among the weed control treatments, the weed density and biomass were highest in WC and lowest in HW. On the other hand, the DT treatments resulted in highest number of spikes m−2, 1000-grain weight (TGW), biological yield and grain yield; while ST showed the lowest values. Among the weed control treatments, the number of spikes, TGW, biological and grain yields were the highest in HW and the lowest in WC treatments. The herbicide isoproturon + carfentrazone performed the best among the three applied herbicides in diminishing the weed population density and biomass, and improving the number of spikes, TGW, biological and grain yields. In conclusion, the combination of deep tillage and herbicide isoproturon + carfentrazone can prove to be the best option for optimum weed management in wheat at higher altitudes.

Global environmental changes are believed to promote the invasion of many invasive plant species, especially under nitrogen enrichment conditions. However, it is unclear, how invasive plant species respond to nitrogen enrichment along with water deficit. In this study, competition of invasive plant (Wedelia trilobata, WT) was studied with its congener native (Wedelia chinensis, WC) under three levels of nitrogen (control, additional and double additional), two levels of water (normal and deficit) and three types of culture (single, mono and mixed). The result showed that under control treatment and additional nitrogen, the growth of WT was 30% higher than WC in all cultures but under additional nitrogen along with water deficit the growth of WT was 20% lower than WC within single plant and monoculture. Under competition, biomass, specific leaf area, root-to-shoot ratio, leaf chlorophyll content and leaf nitrogen of WT were 20–40% decreased as compared to WC under water deficit along with nitrogen addition treatments. These results indicated that competitive interaction between WT and WC was altered by additional nitrogen together with water deficit. It provides exceptional evidence that vigorous invasive species become weak competitor under additional nitrogen along with water deficit.

A global rise in CO2 concentration and temperature levels can impact the living part of the earth including the plants. Stevia or candy leaf (Stevia rebaudiana Bertoni) is a medicinal aromatic plant that produces several useful chemical compounds. Studies were carried out in a fully automated greenhouse in order to determine the response of aromatic compounds of stevia leaves to different CO2 concentrations and temperature levels. This study had four treatments including (1) 26 ± 1/16 ± 1 °C day/night temperature plus 400 ± 50 ppm CO2 concentration [control], (2) 29 ± 1/19 ± 1 °C day/night temperature plus 600 ± 50 ppm CO2 concentration, (3) 32 ± 1/22 ± 1 °C day/night temperature plus 800 ± 50 ppm CO2 concentration and (4) 35 ± 1/25 ± 1 °C day/night temperature plus 1000 ± 50 ppm CO2 concentration. Results of the study showed that yield of total aromatic compounds ranged between 12.65 and 13.65 μg/g for stevia . Generally, concentrations of the compounds such as ketones, aldehydes and alcohols were decreased with increase in concentration of CO2 and temperature. Terpenes were the compounds whose concentrations were increased with increase in concentration of CO2 and temperature. The climatic conditions did not cause a significant change in the aromatic compounds of stevia.

The major challenge in sustainable rice production is to achieve the goals of increasing crop productivity, profitability, and resource use efficiency. Production systems (PS) and nitrogen (N) management patterns are two key agronomic practices influencing crop performance, profitability, water use efficiency (WUE), and N use efficiency (NUE). So, this study was conducted to check the influence of split application of N on rice productivity, NUE and profitability under dry direct-seeded rice (DDSR) and transplanted rice (TPR) systems. A field study was conducted in the summer season of 2017 and 2018 to investigate the influence of two PS (dry direct-seeded rice = DDSR and transplanted rice = TPR) and six N management treatments (N-1 = control, N-2 = 50 kg N ha(-1) as basal, N-3 = 100 kg N ha(-1) as basal, N-4 = 150 kg N ha(-1) as basal, N-5 = 100 kg N ha(-1) in three splits and N-6 = 150 kg N ha(-1) in three splits) on crop productivity, profitability, and resource use efficiency. Yield-related traits, spikelet sterility, WUE, and profitability aspects were significantly influenced by PS. All aspects of crop performance, kernel quality, N uptake, and NUE (except NUE on biomass basis = NUEB) were affected by N management pattern, while no significant interaction between PS and N management was observed for any aspect. On average, DDSR improved the productive tiller density (26%), biological yield (16%), WUE (14%), and NUEB (27%) as compared with TPR. Similarly, DDSR reduced the cost of production (31-43%), while maintaining statistically similar paddy yields and reducing total water inputs (5-17%) in comparison with TPR. Among N management pattern, 100 kg N ha(-1) in three splits increased paddy yields (44%), and WUE (42%) as compared with the basal application of 100 kg N ha(-1). Similarly, application of N at 100 kg ha(-1) in three splits improved the total N uptake (42%), agronomic NUE (146%), apparent recovery efficiency (226%) while reducing the spikelet sterility (28%) as compared with the basal application of 100 kg N ha(-1). The DDSR has the potential to maintain or increase yield, WUE, NUE, and economic returns. While, split application of N at 100 kg ha(-1) either in DDSR or TPR not only increased the SPAD-chlorophyll value, WUE, NUE, and economic returns but also reduced the spikelet sterility. WOS:000583920600002 2-s2.0-85093937443

BACKGROUND Invasive plant species present a serious threat to the environment, as well as human and animal health. An interaction may exist between the climatic changes and invasive plant species. In this 2-year study, we investigated the effects of warming, CO2 and nitrogen application on the biomass, growth and leaf tissue nitrogen concentration of three invasive weed species. Treatments were: (i) simulated (elevated) CO2 (approximately 800-900 ppm); (ii) warming or high temperature (day/night 25/15 °C); (iii) simulated (elevated) CO2 combined with high temperature (CO2 = approximately 800-900 ppm; temperature day/night 25/15 °C); and (iv) control conditions (CO2 = approximately 400-450 ppm; temperature day/night 20/10 °C). The doses of nitrogen were: (i) 0 kg ha-1 (control; low); (ii) 60 kg ha-1 (medium); and (iii) 120 kg ha-1 (high). RESULTS Elevated CO2 and elevated CO2 combined with high temperature improved biomass and the growth of the tested invasive weed species: Lactuca serriola L., Hordeum murinum L. and Bromus tectorum L. Nitrogen application had little effect on grasses, whereas the broadleaved weed mostly had a positive response to nitrogen application. Invasive weed species were generally negatively or neutrally affected by warming. CONCLUSION The results of the present study demonstrate that nitrogen fertilization under different climatic conditions improved few of the parameters, whereas elevated CO2 promoted most of the growth parameters of invasive weeds. Overall, is it concluded that these weeds will be more invasive under climate change conditions. © 2020 Society of Chemical Industry.

Weeds and their management are being affected by warming of the earth and rise in carbon dioxide (CO2) levels in the atmosphere. Evidence from the recent literature confirms that high carbon dioxide in the atmosphere will increase the growth of weeds particularly the C3 weeds. Warming on the other hand will support several weeds to expand their range and establish into new areas. Further, high levels of warming and CO2 may also have a negative effect on the efficacy of several herbicides. Under this situation, use of cultural and mechanical weed control will be important. No doubt, these and other nonchemical weed control methods can be integrated with herbicides to achieve effective control of weeds under changing climate.

Weed infestations significantly reduce the growth and yield of field crops. Herbicides are mostly used for weed management due to their quick results. However, resistant biotypes to available herbicides are rapidly increasing around the word. This situation calls for the development of alternative weed management strategies. Crop rotation and allelopathic water extracts are regarded as the most important alternative weed management strategies. Therefore, this two-year study assessed the impact of different annual crop rotations by weed management strategies’ interactions on weed infestation and productivity of wheat crop. Wheat was planted in five rotations, i.e., (i) fallow-wheat, (ii) rice-wheat, (iii) cotton-wheat, (iv) mungbean-wheat and (v) sorghum-wheat. The weed management strategies included in the study were, (i) false seedbed, (ii) application of 12 L ha−1 allelopathic plant water extracts (1:1:1:1 ratio of sorghum, sunflower, mulberry and eucalyptus), (iii) herbicide application, (iv) weed-free (weed control) and (v) weedy-check (no weed control). Herbicide application was the most effective treatment in lowering weed densities and biomass during both years followed by false seedbed, while allelopathic crop water extracts were least effective. The lowest weed infestation was noted in sorghum-wheat rotation followed by cotton-wheat and mungbean-wheat, while fallow-wheat had the highest weed infestation. Weedy-check treatment caused significant reduction in wheat growth and yield, whereas the highest grain yield was recorded from weed-free and herbicide application treatments. Grain yield of wheat planted after sorghum was suppressed, however, yield improved when wheat was planted after mungbean. Planting wheat after mungbean in a weed-free environment, achieved through chemical and/or mechanical means, is the best strategy to obtain higher wheat yields.

Planning effective weed control in cropping systems requires exact appraisal of the weed intensity and duration of their competition with the crops. This 2‐year study was carried out in order to determine the critical weed control period in sesame fields. Related and relative crop yields were monitored and analyzed using a four‐parametric log‐logistic model. We recorded data from weed‐free plots and compared these with data from different periods of weed interference. In both the study years, the longer period of weed interference decreased the relative yield of sesame, whereas the yield was increased with increasing duration of the weed‐free period. A 51–78.7% decline in sesame yield was noted if the weeds were allowed to compete with the crop from planting to harvest. In the first year, the duration of the critical period for weed control (CPWC) was 177–820 growing degree days (GDD), which corresponded to 14–64 days after crop emergence (DAE), and between 170 and 837 GDD (13–64 DAE) in the second year; this was based on a 5% acceptable yield loss. The results of this study clearly elaborated that maintaining weed‐free conditions is compulsory from as early as the second week after the emergence of sesame plants, and this should be maintained at least until the ninth week to avoid sesame yield losses by more than 5%. These findings show that growers can benefit from CPWC to improve weed control in sesame production, including the efficacy of a weed control program and its cost.

Cotton plant has been domesticated in tropical and sub‐tropical climates of the world but severe climate is not suitable for good lint yields. Globally, cotton is grown on an area of more than 30 million hectare and possesses a global production of more than 70 million tons of seed cotton. The average yield of seed cotton in the world is more than 2000 kg/ha and the largest cotton producer in the world (China) is getting an average yield that is double to the world average. China, India, the United States, and Pakistan are the largest seed cotton producers in the world. Cotton crop possesses an inevitable role in the global industries, economy, and culture. In this chapter, the history and evolution of the cotton, the global production trends of cotton, uses, and the role of biotechnology in improving cotton production have been discussed.

In cotton-wheat cropping system of Pakistan, wheat (Triticum aestivumL.) is harvested in late April; however, the optimum sowing time of Bt cotton is mid-March. This indicates a time difference of 4-6 weeks between the harvest of wheat and cotton sowing. It is hypothesized that this overlapping period may be managed by transplanting cotton seedlings (30-45 days old) in late April, after the harvest of wheat due to better performance of already established seedlings. To this end, this study was conducted to evaluate the allometric traits and fiber quality of transplanted Bt cotton after harvesting wheat in the cotton-wheat cropping system. The Bt cotton-wheat cropping systems were flat sown wheat (FSW)-conventionally tilled cotton, FSW-zero tilled cotton, ridge sown wheat-ridge transplanted cotton using 30- and 45-days-old seedlings, and bed sown wheat (BSW)-bed transplanted cotton (BTC) also using 30- and 45-days-old seedlings. The study was conducted at Vehari and Multan in Punjab, Pakistan. Bt cotton in BSW-BTC with 45-days-old seedlings showed better performance for allometric (leaf area index; (LAI), net assimilation rate; (NAR), and crop growth rate; (CGR)), seed cotton yield, and fiber traits (fiber uniformity, fiber length, fiber strength, and fiber fineness) in comparison to other treatments. Most of the fiber quality traits were positively correlated with allometric traits and biological yield (dry matter yield at maturity) at both locations, except correlations of CGR and LAI with fiber fineness and fiber length and NAR with fiber length. As plant growth and fiber quality of transplanted cotton was significantly higher than conventionally grown cotton, our data indicate transplanting is an interesting management practice for improving productivity in wheat-cotton cropping systems. Higher Education Commission of PakistanHigher Education Commission of Pakistan The authors are highly thankful to Higher Education Commission of Pakistan for providing financial support to this PhD project. WOS:000568285500003

Narrow row spacing has attracted significant attention due to its beneficial impacts on weed management in cotton. This study compared the effects of normal and ultra-narrow row spacing on critical periods of weed control in American (Gossypium hirsutum L.) and ‘Desi’ (Gossypium arboreum) cotton. Two different row spacings (i.e., recommended (75 cm) and ultra-narrow (30 cm)) and three weed control intervals (i.e., weed control at 30, 60 and 90 days after sowing (DAS)) were included in the study. Weedy-check and weed-free treatments were included in the experiment as controls for comparison. ‘Desi’ cotton grown under ultra-narrow spacing recorded the lowest weed density and individual density of Trianthema portulacastarum L., Cyperus rotundus L., Cynodon dactylon L., Echinochloa colona (L.) Link and Digera muricata (L.) Mart. Moreover, ‘Desi’ cotton sown under ultra-narrow spacing with weed-free and weed control at 30 DAS resulted in the highest leaf area index (LAI), leaf area duration (LAD), net assimilation late (NAR), root elongation rate (RER) and root growth rate (RGR) at all sampling dates. Likewise, ‘desi’ cotton sown under recommended row spacing and weed-free conditions produced the highest number of sympodial and monopodial branches, number of flowers and bolls per plant, whereas the highest seed cotton yield of ‘Desi’ cotton was noted under ultra-narrow spacing and weed-free conditions. It is concluded that sowing both cotton types in ultra-narrow row spacing and controlling weeds at 30 DAS will result in lower weed infestation and higher seed cotton yield.

Aerobic rice has been introduced during the recent past owing to higher water needs and labor requirements of the conventionally irrigated rice. Agronomic crop management of aerobic rice is still under development. Some high-yielding aerobic rice cultivars have been introduced while efforts are underway to produce more cultivars for different rice-growing areas of the world. Although, the seed rate used across the different aerobic rice ecologies varied (40–80 kg ha−1); however, it can be adjusted according to seed type and specific soil conditions. The aerobic rice can be sown manually or using drill on flat land, furrow-beds or furrow-ridges. Ground covers like plastic and straw mulch can be used to improve soil water retention in water-limited areas. Similarly, wise water management is crucial for the good harvest of aerobic rice. Sprinkler and drip irrigation can importantly be employed for growing aerobic rice in water-scarce environments. Efficient fertilizer and pest management are crucial for harvesting high aerobic rice yields. High weed infestation is the biggest pest problem in the aerobic rice. Herbicides are the salient methods to control weeds. Paddy yields similar to the conventional method can be harvested from the aerobic rice if the crop has been managed properly.

This research was done in Düzce during 2018 to study the taxa of naturally distributed Heracleum L., natural habitats of the taxa and floristic composition of the habitats. Results of the field study showed that two different taxa of Heracleum L. including Heracleum platytaenium and Heracleum sphondylium ssp. ternatum were determined in six different habitats such as agriculture, urban areas, coastal areas, forest, riparian and artificial habitats. From the samples collected from the habitats, it was determined that 150 taxa belonging to 48 families and 112 genera were present along with the Heracleum spp. The distribution of the taxa found in the study area was examined according to phytogeographical regions and as a result, regions belonging to 121 taxa (80.66%) were determined. According to this; 8 taxa belong to the Euxine province while 36 taxa (24%) are of Euro-Siberian, 17 taxa (11.33%) of Mediterranean and 1 taxon (0.66%) are of Iran-Turan origin. In addition, 67 taxa (44.66%) have a wide distribution, while 29 taxa (19.33%) are multi-regional or not known. When taxa are examined according to the Raunkiær plant life-form; 73 taxa (48.67%) are Hemicryptophytes while it is respectively followed by Therophytes (48 taxa - 32%), Phanerophytes (14 - 9.33%), Cryptophytes (10 - 6.67%) and Chamaephytes (5 - 3.33%). Finally, it is also presented that plant taxa living together with Heracleum spp. in their habitats., Düzce ilinde doğal olarak yayılış yapan Heracleum L. taksonları, taksonların bulunduğu habitat tipleri ve bu habitatların floristik kompozisyonunun araştırıldığı bu çalışma 2018 yılında yürütülmüştür. Arazi çalışmaları sonucunda Heracleum platytaenium ve Heracleum sphondylium ssp. ternatum olmak üzere Düzce’de iki farklı Heracleum L. türünün; tarımsal, şehir, kıyı, orman, riparian ve yapay habitatlar olmak üzere altı farklı habitatta yayılış yaptığı belirlenmiştir. Habitatlardan alınan örnek alanlarda ise Heracleum spp. ile birlikte yayılış yapan 48 familya ve 112 cinse ait 150 takson belirlenmiştir. Araştırma alanında tespit edilen taksonların fitocoğrafik bölgelere göre dağılımları incelenmiş ve bu inceleme sonucunda 121 taksona (%80,66) ait bölgeler belirlenmiştir. Buna göre; 8 takson Öksin kesime ait olmak üzere 36 takson (%24) Avrupa-Sibirya elementi, 17 takson (%11,33) Akdeniz ve 1 takson (%0,66) İran-Turan kökenlidir. Ayrıca 67 takson (%44,66) geniş yayılışa sahipken 29 takson (%19,33) ise çok bölgeli veya fitocoğrafik bölgesi bilinmemektedir. Raunkiaer’in yaşam biçimlerine göre taksonlar incelendiğinde; 73 takson (%48,67) Hemikriptofit iken bunu sırasıyla; Terofit (48 takson - %32), Fanerofit (14 - %9,33), Kriptofit (10 - %6,67) ve Kamefit (5 - %3,33) bitkiler takip etmiştir. Son olarak, Heracleum taksonlarının habitatlara göre hangi bitki taksonları ile bir arada yaşadıkları ayrıca sunulmuştur.

Growth behavior of different species under different habitats can be studied by comparing the production of biomass, plasticity index and relative competitive interaction. However, these functional traits of invasive species received rare consideration for determining the invasion success of invasive species at wetlands. Here, we examined the effect of water depth at 5 cm and 15 cm (static and fluctuated) with different nutrient concentrations (full-strength (n1), 1/4-strength (n2) and 1/8-strength (n3) Hoagland solution) on functional traits of invasive Wedelia trilobata and its congener native Wedelia chinensis under mono and mixed culture. Water depth of 5 cm with any of the nutrient treatments (n1, n2 and n3) significantly restrained the photosynthesis, leaf nitrogen and photosynthetic nitrogen use efficiency (PNUE) of both W. trilobata and W. chinensis. While, increase in the water depth to 15 cm with low nutrient treatment (n3) reduced more of biomass of W. chinensis under mixed culture. However, relative competition interaction (RCI) was recorded positive for W. trilobata and seemingly W. trilobata benefited more from RCI under high-fluctuated water depth at 15 cm in mixed culture. Therefore, higher PNUE, more competitive ability and higher plasticity may contribute to the invasiveness of W. trilobata in wetlands.

Agricultural practice, which includes well-established systems of cropping, pasture and forestry, represents a continual and essential dependence on healthy arable land across the globe and requires safeguarding with sustainable fertilization and pest control measures. This natural resource system must be continually protected from deliberate and inadvertent damage, in order to provide a suitable source of current and future amenities for all inhabitants of the planet. In this respect, it is morally and ethically necessary that we strive to manage the productivity and well-being of agricultural land in a way that will fulfil the necessities of the present generations and do not compromise needs of the future generations (Bruntland et al. 2012).

Cotton-wheat is an important cropping system of the world in which cotton is sown after harvest of wheat in the start of summer season. In the recent decades, Bt cotton cultivars have been introduced to better combat the bollworms. However, the Bt cotton cultivars have a growth period longer than the conventional cotton cultivars. This situation pressured the farmers to opt to grow either wheat or cotton in a single year. This not only could result in economic loss to farmers but also could threaten the food security of the cropping region. Relay cropping of cotton in wheat was suggested by an innovative solution for maintaining the productivity and sustainability of cotton-wheat cropping system. Relay cropping of cotton in wheat could be done either by inter-seeding the seeds of cotton in free space between the wheat strips (while wheat is at reproductive phase) or by transplanting the 5–7-week-old cotton seedlings between the wheat strips. Subsequent research work indicated that relay cropping could improve the resource use efficiency and overall productivity of the cotton-wheat cropping system. In a 2-year study in Punjab, Pakistan, conducted at two locations, intercropping cotton in bed−/ridge-sown wheat in early March improved the overall system productivity and cotton fiber quality as compared with conventionally tilled cotton sown after harvest of flat-sown wheat in late April. Future research may investigate the weed control and incorporation of conservation agricultural practices in the cotton-wheat relay intercropping systems.

The prevention and management of weeds have been difficult throughout the history of food production. We are now entering into a new era where new challenges are arising more rapidly due in part to the rapid population growth, which places an unprecedented demand upon both natural and agricultural ecosystems to fulfil food, fibre, and feed for at least another two billion people by 2050. Climatic change is associated with a higher frequency of extreme weather events, and it is generally agreed that this will have a drastic impact on ecosystem productivity and biodiversity. The present world atmospheric temperature has increased by 1.0 °C since 1900 with half of this rise coming in the past 30 years. Crop production is directly affected by the direct effects of climate change (temperature and water stress) and indirect effects of increased competition from weeds and other pest species. In a field situation, crop plants are inevitably surrounded by an assemblage of C3 and C4 plants, and a considerable variation in the growth response of weeds to climate change have been reported. In this chapter, we present an overview of the impact of temperature rise, carbon dioxide increase, and changed rainfall patterns on weed composition, distribution, abundance, and our current approaches to weed management. There is a high risk that some weed species will shift their range with the change in temperature and precipitation patterns. The efficacy of chemical weed control depends on the environmental conditions before, during and after the herbicide application. The changes in physiology, morphology, and anatomy of plants will result in altered weed growth, crop-weed competition, and herbicide efficacy under elevated temperature and/or carbon dioxide. Global warming may increase the risk of evolution of nontarget site resistance mechanisms against herbicides in the weed plants and thus decrease herbicide efficacy. The anticipated actions in these areas are also discussed in the end which may enhance our understanding of the impact of climate change on the practice and future of weed management and crop production.

Weed residues mixing with the soil after the death of weeds can inhibit growth and development of crop plants. A study was conducted to assess the allelopathic intrusion of Nicotiana plumbaginifolia above-ground residues on growth of selected crops (Pisum sativum, Cicer arietinum) and weeds (Cassia tora, C. sophera), nature of chemicals involved, role of nutrients and physico-chemical parameters. Growth responses of weeds and crops were analyzed for soil amended with different rates of Nicotiana residue (residue amended soil, RS) and residual extract (residue extract amended soil, RES). Likewise, the growth behaviour of test plants was also evaluated against extract of residue in hydroponics (residue extract, RE). Physiochemical screening of amended soils was conducted to look for concentration and bioavailability of essential nutrients. The soil amended with residues (RS and RES) showed inhibitory effect on test plants, however, residue extract (RE) had more inhibitory effects. The inhibition in growth (root length, shoot length and dry biomass) was concentration dependent and C. tora plants experienced the highest reduction among all test plants. A partial enrichment was observed in nutrient status and phenolic content as we increased the concentration of the soil amendment or the extract. This points out that growth inhibition occurred due to phenolic and not due to nutrient depletion. These findings indicate a role of putative phenolic allelochemicals forced allelopathic effects on C. arietinum, P. sativum, C. tora and C. sophera. © 2020, Pakistan Botanical Society. All rights reserved., Ege Üniversitesi, Authors are thankful to the Aligarah Muslim University, India; Ege University, Turkey; Hatay Mustafa Kemal University, Turkey; University of Mohaghegh Ardabili, Iran; Ni?de ?mer Halisdemir University, Turkey; for their support in the collaboration of this project.

Three distinct components of climate change in the recent times are warming of the earth, increased levels of carbon dioxide in the atmosphere and erratic changes in water availability to plants. These changes in the global climate not only impact the growth and life cycles of plants but also affect their pests. Recent research demonstrates that the effects of climate change on pests, pesticides (their efficacy and post-application chemistry) and pest management are complex. This is important to document changes in the behaviour of pests and pesticides in the wake of climate change and propose pest management strategies accordingly. Nevertheless, non-chemical methods and integrated pest management will play an important role in sustainable pest control under climate change. Further, the effects of climate change factors on crop protection and crop production are desired to be understood in order to maintain the global food supplies and global food security.

Farooq, Muhammad/0000-0003-4368-9357; Jabran, Khawar/0000-0001-8512-3330 WOS: 000457576500005 Nitrogen use efficiency (NUE) is low in cereals especially in wheat. Different wheat cultivars may vary in NUE due to inherited biological nitrification inhibition (BNI) potential. In this study, three wheat cultivars (Punjab-2011, ARRI-2011 and Millat-2011) were fertilized at the rate of 140kg ha(-1) with three N sources [nitrophos (NP), urea and calcium ammonium nitrate (CAN)]. The soil nitrate (NO3-)-N contents were significantly enhanced coupled with simultaneous decrease in ammonium (NH4+)-N contents in the rhizosphere of cultivar Punjab-2011, fertilized with NP; however, cultivar Millat-2011 receiving urea behaved in contrast. Wheat cultivar Punjab-2011 fertilized with NP had the highest grain yield and agronomic NUE than other treatments due to significant increase in chlorophyl contents, allometric and yield parameters. The highest net benefit was recorded from the cultivar Punjab-2011 fertilized with CAN. In conclusion, use of NP in Punjab-2011 enhanced the grain yield and agronomic NUE.

[EN] Allelopathy is an ecological phenomenon that involves the production and release of biomolecules from different crops, cultivated plants, and bacteria or fungi into the soil rhizosphere and impacts other organisms in the vicinity. Sorghum possesses vital allelopathic characteristics due to which it produces and releases different biomolecules from its root hairs, stems, and grains. Several studies have reported that sorghum acts as an allelopathic crop, decreasing the growth and ecophysiological attributes of surrounding plants and weeds growing simultaneously or subsequently in the field. Sorghum allelopathy has been exploited in the context of green manure, crop rotations, cover crops, and intercropping or mulching, whereas plant aqueous extracts or powder might be an alternate method of weed control. A diverse group of allelochemicals, including benzoic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, chlorogenic acid, m-coumaric acid, p-coumaric acid, gallic acid, caffeic acid, p-hydroxibenzaldehyde, dhurrin, sorgoleone, m-hydroxybenzoic acid and protocatechuic acid, have been isolated and identified from different plant tissues of sorghum and root exudates. These allelochemicals, especially sorgoleone, have been investigated in terms of their mode(s) of action, specific activity and selectivity, release in the rhizosphere and uptake and translocation in sensitive species. The present review describes the importance of sorghum allelopathy as an ecological tool in managing weeds, highlighting the most recent advances in the allelochemicals present in sorghum, their modes of action, and their fate in the ecosystem. Further research should focus on the evaluation and selection of sorghum cultivars with high allelopathic potential, so that sorghum allelopathy can be better utilized for weed control and yield enhancement

Jabran, Khawar/0000-0001-8512-3330; Rehmani, M.I.A./0000-0001-7922-1233; Rahman, Muhammad Habib ur/0000-0002-2823-9959; Amin, Asad/0000-0003-2242-8377; Ahmad, Ashfaq/0000-0002-9249-185X; Turan, Veysel/0000-0001-7805-8411; Shah, Ghulam Mustafa/0000-0003-1230-7029 WOS: 000419944100076 PubMed: 29103112 Sunflower (Helianthus annuus L.) is the leading non-conventional oilseed crop in Pakistan. Nitrogen fertilizer can affect plant growth and productivity by changing canopy size which has an effect on the radiation use efficiency (RUE) of the crop. The response of sunflower hybrids in terms of phenology, fraction of intercepted radiation (F-i), and RUE to nitrogenous rates (0, 60, 120, 180, and 240 kg ha(-1)) was studied in three field experiments conducted in three various environments: Multan (arid), Faisalabad (semi-arid), and Gujranwala (sub-humid) during spring seasons 2008 and 2009. The treatments were laid out according to a randomized complete block design with split plot arrangements, keeping the sunflower hybrids in main plots and nitrogen rates in subplots, and replicated three times. The results showed Hysun-38 took a maximum number of days to anthesis (101) as compared to Pioneer-64A93 (100) and Hysun-33 (99). The mean values of F-i were 0.850, 0.903, and 0.978, and the estimated values of RUE for total aboveground dry matter were 2.14, 2.47, and 2.65 g MJ(-1) at experimental locations of Multan, Faisalabad, and Gujranwala, respectively. The values of RUE for grain yield (RUEGY) were 0.78, 0.98, and 1.26 g MJ(-1) at experimental locations of Multan, Faisalabad, and Gujranwala, respectively. The average RUEGY values over three locations were 2.61, 2.60, 2.43, and 2.36 g MJ(-2) in N-4 (180 kg ha(-1)), N-5 (240 kg ha(-1)), N-3 (120 kg ha(-1)), and N-2 (60 kg ha-1) treatments, respectively. Increasing rates of N increased RUEGY over the standard treatment N-3 (120 kg N ha(-1)); however, the averaged values over three locations were 1.22, 1.08, 0.99, and 0.92 g MJ(-2) in N-4, N-5, N-3, and N-2 treatments, respectively. Therefore, optimum water and N doses are important for attaining higher RUE, which may enhance sunflower growth and yield. Pakistan Science Foundation (PSF); University of Agriculture, Faisalabad, Pakistan The first author is highly thankful to the Pakistan Science Foundation (PSF) for the partial funding to present this work in a second International Balkan Agriculture Congress at the Namik Kemal University, Tekirdag, Turkey (2017). Moreover, the first author is also appreciative to the Endowment Fund Secretariat, University of Agriculture, Faisalabad, Pakistan, which was highly acknowledged for the partial financial support of this study.

Jabran, Khawar/0000-0001-8512-3330; Mahajan, Gulshan/0000-0002-9423-9893; Chauhan, Bhagirath/0000-0003-1540-4668 WOS: 000397372500001 Weeds represent a significant challenge to successful crop production. Highly effective and sustainable weed control is required in order to meet global food demand. In this context, excessive use of herbicides has resulted in serious environmental and ecological issues. There are several weed control options which neither harm the environment nor require a significant increase in cost of production. Improving crop competition is particularly important and attractive among such options, which can be achieved by using crop cultivars possessing a competitive advantage over weeds, and manipulating the seed rate and direction of crop rows. Crop cultivars possessing traits such as fast germination, quick growth, high biomass, and large leaf area have a competitive advantage over weeds. Sowing such cultivars has been shown to suppress weeds in various crops. The use of high seed rates and narrow row spacing, if properly manipulated, can cause a significant decrease in weed proliferation in the crops. These techniques (cultivar, seed rate, row spacing, and row direction) are under-exploited as weed control methods, and offer considerable potential for achieving environmentally benign weed management. This special issue on "Eco-friendly Weed Management" will address the role of crop competition in managing weeds in different crops as well as in different countries. (C) 2016 Elsevier Ltd. All rights reserved.

Jabran, Khawar/0000-0001-8512-3330; Farooq, Shahid/0000-0002-6349-1404 WOS: 000401566600041 PubMed: 28391467 This 2-year field study investigates the potential of seed priming to mitigate losses caused by drought stress at different phenophases of wheat. Wheat seeds were soaked either in distilled water or in aerated solution of CaCl2 (Psi s-1.25 MPa) for 18 h to accomplish hydropriming and osmopriming, respectively. The soil moisture was maintained at 90-100% field capacity (well-watered) or 45-50% field capacity at vegetative (vegetative drought) and reproductive (terminal drought) phases. Allometric traits leaf area index, leaf area duration, and crop growth rate were initially more affected by vegetative drought; however, terminal drought was more severe at later stages. Drought at both phenophases, especially terminal drought, impaired the entire yield-related traits of wheat; however, osmopriming compensated the drought-induced losses up to a certain extent. Osmopriming improved the wheat grain yield, economic benefits, and allometric traits under vegetative and terminal drought as well as well-watered conditions. It is recommended that the physiological, biochemical, and genetic mechanisms of osmopriming must be explored to find more valuable insights for improving wheat productivity.

Invasive plant species present a serious threat to the environment, as well as human and animal health. An interaction may exist between the climatic changes and invasive plant species. In this 2-year study, we investigated the effects of warming, COElevated COThe results of the present study demonstrate that nitrogen fertilization under different climatic conditions improved few of the parameters, whereas elevated CO

Evolution of herbicide resistance in weeds is among the serious challenges that agriculture face today. In Pakistan herbicide use over last 6 decades has enabled earlier planting of short-season crops and improved weed control in wheat as well as other cropping systems. This has greatly favored the use of more and more herbicides. Conversely, this exercise increased the evolution of resistant biotypes. Wheat being Pakistan's number one staple crop faces daunting weeds problem. In order to understand the status of herbicide resistant weeds in wheat fields, survey was conducted for two consecutive years (2015-2017) in different regions of Pakistan. A questionnaire was designed to collect data from three hundred farmers randomly selected in all four provinces of Pakistan on herbicides used in wheat, history of crop cultivation regimes and weed species that have seized to respond to field rates of herbicides. Seed of suspected biotypes were collected from the survey sites and preserved in our gene pool for the confirmation of the resistance in the laboratory by bioassay and molecular level in future. Farmers (96%) perceived that Phalaris minor Retz. was the most important annual weed of wheat crop followed by Avena fatua L. (94%). Customarily, three aryloxyphenoxy propionate herbicides, clodinafop-propargyl, fenoxaprop-P-ethyl and diclofop-methyl were used to control different grass weeds such as P. minor, A. sativa L. and A. fatua. In farmers' opinion, high yield of wheat was associated with the continuous use of these herbicides. Resistance-suspicious weeds were reported from all studied areas (Punjab, KPK, Sindh, and Baluchistan provinces) in fields with the herbicide use history of five to seven years or more. This study suggests that for long-term avoidance of herbicide resistance, in our wheat growing systems we will require embracing practices that decrease selection pressures favoring resistant weeds. Achieving these goals requires an understanding of the evolution and dynamics of resistant populations. It is recommended that for the effective management of resistant populations of P. minor and A. fatua, farmers' education on ecologically sustainable weed management is critically important. This study will provide a basis for examining the questions that are relevant to understanding herbicide resistance evolution in Pakistan and that may help determine appropriate weed management strategies.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000454462900005 Weeds are among the major biotic factors that reduce rice productivity. Alternative weed control methods are required in the wake of problems, such as increasing number of herbicide-resistant weed species and environmental pollution. In this research work, we evaluated the weed-suppressive effects of water levels and rice cultivars against an important rice weed Echinochloa oryzoides (Ard.) Fritsch. The studies comprised three water levels [low (5 cm), medium (15 cm) and high (25 cm)], three medium-grain rice cultivars (Ronaldo, Nembo and, Cameo) and three weed levels [high weed density (> 30 plants m(-2)), low weed density (< 10 plants m(-2)), and weed-free]. Weed-free condition helped the rice plants achieve excellent growth and development, and resulted in the highest grain yield, while weedy condition hampered the growth and productivity of rice cultivars. Water levels had the greatest impact on weeds, rice growth, and paddy yield. A standing layer of water (high water level i.e., 25 cm in particular) not only had a highly suppressive effect against weeds, but it also helped to enhance the growth and yield of rice cultivars. Deep and shallow water levels respectively caused an increase in the leaf area, number of tillers, and dry weight of rice cultivars, particularly for Ronaldo. Ronaldo performed better than other cultivars in terms of growth and competitiveness either under weedy or weed-free conditions. This work concludes that maintaining a water layer (15-25 cm) in rice fields could produce multiple beneficial effects including improved rice growth and decreased weed growth, resulting in high rice productivity. TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TOVAG 214O446] This project has been supported by TUBITAK with number of (TOVAG 214O446).

Demand for organic food production and environmental pollution caused by the synthetic insecticides and fungicides stresses the need for non-chemical insect pest and disease pathogen control. In this chapter, the possibility to use various kinds of mulches for control disease pathogens and insect pests has been assessed. For instance, straw mulch provides an indirect control of insect pests by facilitating the living and proliferation of predators. Subsequently the increased activity or populations of predators will help eating more of the insect pests. Similarly, colored plastic mulches change the spectrum of incident light, and this negatively impacts the behavior of an insect pest. This provides a way to repel or deflect many of the insect pests particularly in the high-value crops. Straw or other mulches of organic origins are likely to enhance the activities of biocontrol agents or increase the concentration and activities of certain enzymes (such as cellulase) that could suppress disease pathogens (by dissolving cell walls of the pathogens). Mulches also modify the soil properties positively, and the soil with changed properties is more likely to express suppressive behavior against the disease pathogens.