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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.

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

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.

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

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.

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.

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.

Excessive tillage in conventional agriculture systems may cause plough pan, which alters soil physical properties, and thus adversely affects the crop growth and productivity. This study was conducted to monitor the effect of different tillage practices in wheat-based cropping systems on soil physical properties, allometry and grain yield of wheat. Wheat was planted in different cropping systems (viz. fallow-wheat, rice-wheat, cotton-wheat, mungbean-wheat and sorghum-wheat with zero tillage, conventional tillage, deep tillage and on two types of beds (60/30 cm with four rows) and (90/45 cm with six rows). Interaction between different tillage practices and cropping systems had significant effect on soil bulk density and total porosity, wheat allometry and grain yield. Minimum bulk density tied with higher total porosity was recorded in both types of bed sowing followed by deep tillage. This improvement in soil physical properties caused improvement in leaf area index and duration, specific leaf area, crop growth, and net assimilation rates. As a result, the productivity of bed sown wheat was better; however, grain yield of zero tilled wheat was low due to poor crop growth and net assimilation rate. Wheat productivity was substantially low when planted after sorghum; nonetheless, and was quite high when sown after mungbean. In crux, wheat planting on beds after mungbean is the best option considering the long-term environmental sustainability of wheat-based cropping systems. © 2016 Friends Science Publishers

SUMMARYThis study was conducted to improve wheat production under vegetative (early season) drought stress. Hydroprimed and osmoprimed (with CaCl2) seeds of wheat cultivars Lasani-2008 (LS-2008) and Triple Dwarf-1 (TD-1), were sown in 20 (narrow), 25 (medium), and 30 cm (wider) spaced rows. Crop was grown under well-watered conditions till physiological maturity or was subjected to drought stress (50% field capacity) during vegetative phase and then grown under well-watered conditions. Drought stress caused substantial reduction in grain and biological yields, related traits, harvest index (HI) and water use efficiency (WUE). Nonetheless, planting osmoprimed seeds in narrowly spaced rows significantly improved the grain yield, HI and WUE. However, wheat planted in wider rows had bold grains. Furthermore, wheat cultivar LS-2008 produced better yield, even under drought stress, than cultivar TD-1. Economic analysis indicated that planting osmoprimed seeds of wheat cultivar LS-2008 in narrowly spaced rows under early season drought yielded maximum economic benefits. In conclusion, planting osmoprimed seeds of cultivar LS-2008 in narrowly spaced rows is a good agronomic option to improve the wheat performance under early season drought stress.

This review provides an overview on the most common rice weed species of the world. It shows that a few generalists have established in rice independent from sites, crop management systems, and local climatic conditions. Cosmopolitan weeds are even constant elements where rice cultivation started just a century ago. Local differences may be explained by cultivation methods, growing seasons, or special weed management. Some general changes in weed spectra have been observed globally in recent years. Weedy rice ( Oryza sativa L.) and herbicide resistance have become general global problems within the last decades. Some global key weed genera such as Echinochloa , Cyperus , Scirpus , or Fimbristylis species are, however, still dominating rice fields despite the decade long use of well performing herbicides. On the other side, general species shifts as a result of resistance have not been observed yet. Leptochloa species started to become major problems in Asia in the end of the last century and now in Europe also. Several modern herbicides allow the control of perennial weeds, such as Cyperus rotundus L. or Eleocharis kuroguwai Ohwi which makes them no longer serious threats. Some genera in rice such as Echinochloa and Oryza (weedy rice) are characterized by an enormous germplasm variability which makes species definitions difficult. The fact that weeds in rice have to adapt to wet or aquatic conditions reduces the biodiversity range in comparison to other arable crops. Water management has a considerable impact on weed spectra. The increase of rice acreages with reduced irrigation may end up in higher weed infestations. Long term results of weed surveys in rice as they exist for other crops are, however, not available. This makes predictions on biodiversity changes in this crop quite difficult.

Vegetables are a substantial part of our lives and possess great commercial and nutritional value. Weeds not only decrease vegetable yield but also reduce their quality. Non-chemical weed control is important both for the organic production of vegetables and achieving ecologically sustainable weed management. Estimates have shown that the yield of vegetables may be decreased by 45%–95% in the case of weed–vegetable competition. Non-chemical weed control in vegetables is desired for several reasons. For example, there are greater chances of contamination of vegetables by herbicide residue compared to cereals or pulse crops. Non-chemical weed control in vegetables is also needed due to environmental pollution, the evolution of herbicide resistance in weeds and a strong desire for organic vegetable cultivation. Although there are several ways to control weeds without the use of herbicides, cover crops are an attractive choice because these have a number of additional benefits (such as soil and water conservation) along with the provision of satisfactory and sustainable weed control. Several cover crops are available that may provide excellent weed control in vegetable production systems. Cover crops such as rye, vetch, or Brassicaceae plants can suppress weeds in rotations, including vegetables crops such as tomato, cabbage, or pumpkin. Growers should also consider the negative effects of using cover crops for weed control, such as the negative allelopathic effects of some cover crop residues on the main vegetable crop.

Jabran, Khawar/0000-0001-8512-3330; WOS: 000436879200076 PubMed: 29691745 Plants in Brassica genus have been found to possess strong allelopathic potential. They may inhibit seed germination and emergence of subsequent crops following them in a rotation system. Series of laboratory and greenhouse experiments were conducted to determine the allelopathic impacts of Brassica napus L. against mung bean. We studied (1) the effects of aqueous extract (5%) of different plant parts (root, stem, leaf, flower, and whole plant) of B. napus, (2) the effects of leaf and flower extracts of B. napus at 0, 1, 2, 3, and 4% concentrations, and (3) the effect of residues of different B. napus plant parts and decomposition periods (0, 7, 14, and 21 days) on germination and seedling growth of mung bean. Various types of phenolics including quercitin, chlorogenic acid, p-coumeric acid, m-coumaric acid, benzoic acid, caffeic acid, syringic acid, vanillic acid, ferulic acid, cinamic acid, and gallic acid were identified in plant parts of B. napus. Among aqueous extracts of various plant parts, leaf and flower were found to have stronger inhibitory effects on germination and seedling growth traits of mung bean, higher concentrations were more toxic. The decomposition period changed the phtotoxic effect of residues, more inhibitory effect was shown at 14 days decomposition while decomposition for 21 days reduced inhibitory effect. The more total water-soluble phenolic was found in 5% (w/v) aqueous extract and 5% (w/w) residues of B. napus flowers at 14 days of decomposition (89.80 and 10.47 mg L-1), respectively. The strong inhibitory effects of B. napus should be managed when followed in rotation.

Use of ground-cover systems (GCSs) is gaining popularity owing to several of their benefits. Other than benefits such as improved soil protection and water retention, the GCS also help to suppress weeds under various agricultural systems. Most important among the GCS may include polyethylene (plastic) mulch, straw mulch, paper mulch, carpet mulch, woodchip mulch, and use of cloth and mats for weed control. Such GCS have been found to provide satisfactory to effective weed control in a variety of agricultural systems. The GCS inhibit weed germination by stopping the sunlight to reach the soil surface, exert a physical pressure to suppress the germinating/emerging weeds, and cause a slight rise in soil temperature that impacts weeds negatively. Negative impacts of plastic mulches on the environment and the organisms in an agricultural ecosystem have been noted. In addition to disposal and degradation issues, remains of plastic sheet in the field may cause hindrances in field operations. Such issues may be resolved with site-specific agronomic management. For instance, biodegradable mulches have been suggested to replace the plastic ones owing to environmental damage caused by polyethylene. Use of paper mulches from renewable stuff is the other option to replace plastic mulches. GCS are particularly important for weed control in vegetables (grown in either closed or open environments) and horticultural fruit crops (such as watermelon and muskmelon). GCS may play an important role as a non-chemical weed control in the wake of demand for pesticide-free foods. © 2018 Elsevier Inc. All rights reserved.

Olesen, Jorgen E/0000-0002-6639-1273; Jabran, Khawar/0000-0001-8512-3330; De Notaris, Chiara/0000-0002-3764-012X; Melander, Bo/0000-0002-5183-3278 WOS: 000452942600006 Inter-row hoeing has become increasingly important for weed control in organic spring cereals since the introduction of automatic steering systems. The technology requires a widening of current inter-row spacing for spring cereals in order to provide sufficient room for accurate operation of a hoe share between crop rows. However, there is considerable uncertainty about the optimal combination of inter-row hoeing, inter-row spacing and nitrogen (N) rate in terms of weeding effectiveness and crop yield. The aim of this study was to investigate the effect on weed and crop growth of the interaction between five inter-row spacings (125, 150, 200, 250, and 300 mm) and two N rates (50 and 100 kg NH4-N ha(-1)). Three field experiments were conducted in spring barley and two in spring wheat. One hoeing pass was applied for each inter-row spacing using a share width that worked 15-47 mm from the crop row. The immediate effect on weed numbers following hoeing was a 80-90% reduction in barley and a 63-80% reduction in wheat, but with no significant differences between spacings and N rates. However, the effect on weed biomass at crop anthesis was minor in barley because the crop itself substantially suppressed weed growth. Spring wheat was less competitive and inter-row hoeing reduced weed biomass by 60-70% compared to the standard 125 mm spacing without hoeing. The widening of inter-row spacing appeared not to reduce crop yield or grain quality. Prerequisites for successful inter-row hoeing in spring cereals include retained crop stands when increasing inter-row spacing and the avoidance of crop injuries from inaccurate steering. Ministry of Environment and Food of Denmark; International Centre for Research in Organic Food Systems We acknowledge the Ministry of Environment and Food of Denmark and the International Centre for Research in Organic Food Systems for funding this research, which was part of the RowCrop project under the Organic RDD2 programme. We would like to thank technicians Eugene Driessen and Karen Bjorn Heinager for their skilful technical assistance and Agrolntelli (www.agrointelli.com) for delivering the equipment for sowing and inter-row hoeing.

Jabran, Khawar/0000-0001-8512-3330; WOS: 000443245000022 Apricot fruits provide important health, economic, and nutritional benefits. Weeds damage apricot production directly and host the pests that cause damages to apricot trees. However, very few studies are available on weed control in apricot orchards. This research work was aimed at evaluating five cover crops for weed suppression in apricot orchard. The effect of living, mowed, and soil-incorporated cover corps on weeds was recorded and compared with glyphosate application and mechanical weed control. The cover crops were Vicia villosa Roth., Vicia pannonica Crantz, Triticale + V. pannonica, Phacelia tanacetifolia Benth., and Fagopyrum esculentum Moench. Five major weed species in the experimental area were Amaranthus retroflexus L., Convolvulus arvensis L., Tribulus terrestris L., Sisymbrium officinale (L.) Scop., and Sorghum halepense (L.) Per. The highest biomass production was noted for Triticale + V. pannonica in 2015 and for P. tanacetifolia in 2016. Living cover crops were effective in decreasing the weed biomass compared with the control. Both mowing and soil incorporation of cover crops were effective in decreasing weed richness and density over control. Mowed or soil-incorporated cover crops were more effective than herbicide or mechanical weed control, while F. esculentum was the least effective cover crop for suppressing weeds in apricot orchard. The results of our studies implied that cover crops could be used for weed control in apricot, and their mowing or soil incorporation could enhance their efficacy. Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [213 O 109] This research was funded by the Scientific and Technological Research Council of Turkey grant number (Project No. 213 O 109).

Evolution of herbicide resistance in weeds has increased the importance and scope of mechanical weed control. In many parts of the world, the efficacy of mechanical weed control has been reevaluated. Tillage (used for soil preparation for planting), although among the oldest methods of weed control, is still the preferred method of weed control for many farmers. Similarly, subsequent weeding (weed removal through manual or mechanical means) after the crop emergence is also a successful tool for effective weed management. Wise use of mechanical weeding can provide effective weed control in vegetables, fruits, and field crops. The use/choice of mechanical weeding method depends upon technical and economic factors. Weeds evolving herbicide resistance ultimately required either tillage, weeding, or other non-chemical methods; nevertheless, tillage has been considered the most effective among all non-chemical weed control methods. Development of intelligent weeders or automatic weeding tools may revolutionize mechanical weed control through the selective use of weeders in crops. However, a great deal of research work and investment is needed to develop robotic weeders, which are capable of functioning without human intervention for automated weed control in the future. © 2018 Elsevier Inc. All rights reserved.

Weeds are among the most important pests of agricultural crops that not only decrease the crop yields but also severely damage the quality of produce. Herbicides are usually effective in suppressing weeds occasionally supplemented with other weed control methods. During recent times, a number of factors have increased the importance of non-chemical weed control methods. Some of these are environmental concerns arising by overuse of pesticides, rising demands for organic food, and an evolution of herbicide resistance in weeds. This chapter discusses «why non-chemical weed control is needed?» and also provides an overview of currently available non-chemical weed control techniques. © 2018 Elsevier Inc. All rights reserved.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000423777600029 PubMed: 29120078 BACKGROUNDGlobal climate changes may impact the growth and management of weed species. The aim of this work was to evaluate the impact of recent climate changes on the growth of weeds and herbicide efficacy. The effects of temperature, carbon dioxide (CO2), and herbicide on growth and control of Bromus tectorum L., Hordeum murinum L., and Lactuca serriola L. were studied. Treatments included: control or ambient environment (CO2 concentration 400-450 ppm; temperature 20/10 degrees C day/night); elevated temperature (CO2 concentration 400-450 ppm; temperature 25/15 degrees C day/night); high CO2 and elevated temperature (CO2 concentration 800-900 ppm; temperature 25/15 degrees C day/night); high CO2 (CO2 concentration 800-900 ppm; temperature 20/10 degrees C day/night). Glyphosate rates (active ingredient) used in the experiment were: 0 g ha(-1) (untreated control); 360 g ha(-1); 720 g ha(-1); 1080 g ha(-1); 1440 g ha(-1) (recommended rate), and 2880 g ha(-1). RESULTSHigh CO2 concentration and high CO2 concentration plus high temperature improved the biomass and growth parameters of weeds in the studies. In general, high temperature had a neutral, negative or slightly positive effect on the growth of weed species. Climatic conditions did not affect the activity of glyphosate; its application provided equal and effective weed control under both CO2 and temperature levels and their combinations. CONCLUSIONThe positive effect of high CO2 concentration on the growth of weeds does not impact the activity of glyphosate. (c) 2017 Society of Chemical Industry Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); Scientific Research Projects of Adnan Menderes University, Turkey [ZRF-14015] The authors thank the Scientific and Technological Research Council of Turkey (TUBITAK) and Scientific Research Projects of Adnan Menderes University, Turkey (ZRF-14015) for supporting the PhD studies of Khawar Jabran. The authors acknowledge the input and support of Dr. Ozkan Eren and Prof. Ozhan Boz. Finally, we are grateful to anonymous reviewers and the Editor (Dr. Jerry Green) for their critical and useful comments on the manuscript.

Jabran, Khawar/0000-0001-8512-3330; Chauhan, Bhagirath/0000-0003-1540-4668 WOS: 000400765900046 PubMed: 28378305 Growing rice with less water is direly needed due to declining water sources worldwide, but using methods that require less water inputs can have an impact on grain characteristics and recovery. A 2-year field study was conducted to evaluate the impact of conventionally sown flooded rice and low-water-input rice systems on the grain characteristics and recovery of fine rice. Three fine grain rice cultivars-Super Basmati, Basmati 2000, and Shaheen Basmati-were grown under conventional flooded transplanted rice (CFTR), alternate wetting and drying (AWD), and aerobic rice systems. Grain characteristics and rice recovery were significantly influenced by different water regimes (production systems). Poor milling, including the lowest percentage of brown (head) rice (65.3%) and polished (white) rice (64.2-66.9%) and the highest percentage of broken brown rice (10.2%), husk (24.5%-26.3%), polished broken rice (24.7%), and bran (11.0-12.5%), were recorded in the aerobic rice system sown with Shaheen Basmati. With a few exceptions, cultivars sown in CFTR were found to possess a higher percentage of brown (head) and polished (white) rice and they had incurred the least losses in the form of brown broken rice, husk, polished broken rice, and bran. In conclusion, better grain quality and recovery of rice can be attained by growing Super Basmati under the CFTR system. Growing Shaheen Basmati under low-water-input systems, the aerobic rice system in particular, resulted in poor grain characteristics tied with less rice recovery.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900003 Wheat (Triticum aestivum L.) is among the most important crops of the world and provides food, feed, and several by-products. Other than this, wheat is among the crops that express a strong allelopathic activity. Benzoxazinoids and phenolic compounds are the most important allelochemicals reported in wheat. Allelopathic cultivars of wheat may be grown to suppress weeds in the wheat crop. Allelopathic mulch of wheat can be applied for suppressing weeds both in wheat and other field crops. Several cultivars of wheat with an allelopathic potential have been reported from various countries of the world. Research work conducted to improve the allelopathic potential of wheat has been insufficient. Future research should focus on improving the allelopathic potential of wheat cultivars through conventional and molecular breeding as well as biotechnology.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900007 Rye (Secale cereale L.) is a multipurpose crop that is grown for its fodder, grains, or as a cover crop. Rye when grown as cover crop suppresses the weeds through either of shading, physical interference, or allelopathy, or all of these. Rye is a potent allelopathic crop; benzoxazinoids and phenolic compounds being the important allelochemicals in its plants. Cover crops and mulches are the extensively used methods where allelopathic potential of rye can be employed to control weeds. Another way is to grow rye cultivars (when rye is grown as sole crop). Nevertheless, cover crops may be the most important way of utilizing rye allelopathy for controlling weeds.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900004 Several members of Brassicaceae family possess an allelopathic activity. A number of members of this family (particularly the ones belonging to genus Brassica) are grown as vegetables, herbs, or oilseed crops. Another important characteristic of plant species in family Brassicaceae is their allelopathic activity. Glucosinolates and phenolic compounds are the most important allelochemicals synthesized by the plants in Brassicaceae family. The glucosinolates are converted into several isothiocyanates through enzymatic (myrosinase) activity and express an allelopathic activity. Allelopathic potential of Brassicaceae crops (particularly, Brassica spp., Sinapis alba L. and Raphanus sativus L.) can be used for weed control in agricultural fields. Allelopathic potential of crops from family Brassicaceae may be exploited for weed control by using these as cover crops, growing their cultivars with allelopathic activity, including allelopathic crops of this family in a crop rotation and employing the allelopathic mulch from Brassicaceae crops in agricultural fields.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900008 Barley (Hordeum vulgare L.) is ranked as the fourth most important (area under cultivation and production-wise) among the cereals following maize, wheat, and rice. Barley is among the crops possessing a strong allelopathic activity. Important allelochemicals in barley may include phenolic compounds and alkaloids (e.g., hordenine, gramine). Weeds infesting the barley crop can be suppressed by growing barley cultivars expressing a high allelopathic activity. Similarly, allelopathic mulch material from barley can be applied for controlling weeds in barley and other crops. Breeding efforts can help to improve the allelopathic potential of barley cultivars for an effective and environment-friendly weed control.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900006 Rice (Oryza sativa L.) is among the most important grain crops of the world. This is grown in all parts of the world. Weeds are the most important biological constraint that interfere the rice growth and decrease its productivity. Most important rice weeds include Echinochloa spp., Cyperus spp., Leptochloa spp., Paspalum spp., etc. Rice with an allelopathic potential has been reported from various parts of the world. Momilactones and phenolic compounds are the important allelochemicals reported in rice. Biological activities of momilactones against weeds and other plant species have been observed consistently. Allelopathic potential of rice can play an important role in improving the efficacy and sustainability of weed control, particularly in rice and generally in other crops. For example, growing rice cultivars possessing an allelopathic potential can help suppress the weeds in rice. Similarly, the residues of rice can be applied in rice and other crops as well for achieving a non-herbicidal weed control. This chapter discusses the allelopathic potential of rice and opportunities to utilize this for weed control in the form of allelopathic rice cultivars and allelopathic rice mulch.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900005 Several natural compounds (allelochemicals) are produced in maize (Zea mays L.), which help its plants gain competitive ability and defense against the pests. Benzoxazinoids are most important of these compounds. Phenolic compounds are the other important allelochemicals found in maize. Allelopathic potential of maize can be used to suppress weeds in maize and other crops. Most important technique in this regard may be the growing of maize cultivars that possess an allelopathic potential and are capable to suppress the weeds. Two other important methods that may be employed to control weeds through maize allelopathy include the use of allelopathic plant parts of maize as mulch and intercropping of allelopathic maize plants in non-allelopathic crops. Allelopathic mulch from maize may be applied to control weeds in maize itself, or other crops. Future research should be focused on improving the allelopathic potential of maize cultivars and conversion of the allelopathic maize residues in the form of a weed control product.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900010 The allelopathic potential of sunflower (Helianthus annuus L.) can be used for controlling weeds in sunflower and other crops. Terpenes and phenolic compounds comprise the important allelochemicals in sunflower. Residues from sunflower plants possess a strong allelopathic activity and can be used to suppress the weeds under various agricultural settings by either scattering it in the form of a layer over the soil surface or mixing it in the soil. Weeds growing in sunflower can be suppressed by cultivating sunflower genotypes that could express an allelopathic activity.

Wheat is among the most important cereal and food crops of world and is grown in almost all parts of the world. It is a staple for a large part of the world population. Any decline in wheat yield by biotic or abiotic factors may affect global food security adversely. Weeds are the most damaging pest of wheat causing in total 24% losses in wheat grain yield. In this chapter, we discuss the (i) weed flora in different wheat growing regions of world; (ii) the yield losses caused by weeds in wheat; (iii) the preventive and cultural options for weed management; (iv) physical weed control;(v) chemical weed control; and (vi) integrated weed management strategy in wheat. A critical analysis of recent literature indicated that broadleaved weeds are the most common group of weeds in wheat fields followed by grass weeds, while sedges were rarely noted in wheat fields. Across the globe, the most important weeds in wheat fields were Avena fatua L., Chenopodium album L., Phalaris minor Retz., Galium aparine L., Stellaria media (L.) Vill., and Veronica persica Poir., respectively. Adoption of wise weed management strategies may help control weeds and avoid yield losses. Both preventive measures and cultural practices have proved their significance for improving weed control in wheat; physical and chemical tools are the other options. Moreover, site-specific herbicide application may help to make weed control economical and reduce the herbicide input. Nonetheless, integrated strategies should be opted for effective and ecofriendly weed management in wheat.

Jabran, Khawar/0000-0001-8512-3330; Farooq, Shahid/0000-0002-6349-1404; Farooq, Muhammad/0000-0003-4368-9357 WOS: 000413649700051 PubMed: 28913583 Wheat productivity and profitability is low under conventional tillage systems as they increase the production cost, soil compaction, and the weed infestation. Conservation tillage could be a pragmatic option to sustain the wheat productivity and enhance the profitability on long term basis. This study was aimed to evaluate the economics of different wheat-based cropping systems viz. fallow-wheat, rice-wheat, cotton-wheat, mung bean-wheat, and sorghum-wheat, with zero tillage, conventional tillage, deep tillage, bed sowing (60/30 cm beds and four rows), and bed sowing (90/45 cm beds and six rows). Results indicated that the bed sown wheat had the maximum production cost than other tillage systems. Although both bed sowing treatments incurred the highest production cost, they generated the highest net benefits and benefit: cost ratio (BCR). Rice-wheat cropping system with bed sown wheat (90/45 cm beds with six rows) had the highest net income (4129.7 US$ ha(-1)), BCR (2.87), and marginal rate of return compared with rest of the cropping systems. In contrast, fallow-wheat cropping system incurred the lowest input cost, but had the least economic return. In crux, rice-wheat cropping system with bed sown wheat (90/45 cm beds with six rows) was the best option for getting the higher economic returns. Moreover, double cropping systems within a year are more profitable than sole planting of wheat under all tillage practices. Higher Education Commission of PakistanHigher Education Commission of Pakistan Authors are grateful to Higher Education Commission of Pakistan for financial support for this study.

Jabran, Khawar/0000-0001-8512-3330 WOS: 000406709500072 Different furrow openers are required to be evaluated for their suitability to manage rice straw for direct planting of wheat in paddy fields. This study was carried out to assess the straw-cutting ability and draft requirements of four different disc-type furrow openers (notched, toothed, smooth-edge single disc, and double disc) in no-till paddy fields. The openers were attached to an in-field traction rig equipped with S-type load cells, and tested using three operating depths of 30, 60, and 90 mm, and three traveling speeds of 0.1, 0.2, and 0.3 m s(-1). Vertical and horizontal forces acting on the openers were observed using LabVIEW software based data acquisition system. The results of this study indicated that the furrow opener type, operating depth, and speed significantly influenced the horizontal and vertical forces, as well as straw-cutting ability of the furrow openers. The highest draft and vertical force were noted for double disc-type furrow openers. The mean straw-cutting efficiency of notched, toothed, and smooth-edge single disc and double disc furrow openers were 12.4, 46.2, 11.4, and 78.5%, respectively. The double disc furrow opener (DD) produced the lowest level of hair-pinned straw and had the highest straw-cutting efficiency with a value of 88.6% at 90 mm operating depth, and therefore had the best performance in comparison with other furrow openers. HEC, PakistanHigher Education Commission of Pakistan; National Science and Technology [2013BAD08B04]; State Key Special Program of Soil Fertility Improvement and Cropping Innovation for High-Yield Efficiency in Rice Cropping Areas [2016YFD0300900] This manuscript represents a portion of Ph.D. research by the first author. Thanks to the HEC, Pakistan for providing Ph.D. Scholarship to the first author. Additionally, work was sponsored by the National Science and Technology Support Program (2013BAD08B04) and the State Key Special Program of Soil Fertility Improvement and Cropping Innovation for High-Yield Efficiency in Rice Cropping Areas (2016YFD0300900).

Jabran, Khawar/0000-0001-8512-3330 WOS: 000461930900009 Sorghum (Sorghum bicolor (L.) Moench) is most important among the crops possessing a strong allelopathic potential. A good deal of scientific literature has been devoted to explain the allelopathic potential of this crop. Sorgoleone is the most important allelochemical that is synthesized in the sorghum roots. Aerial plant tissues of sorghum mostly contain phenolic compounds as allelochemicals. There are several ways to exploit the allelopathic activity of sorghum for controlling weeds under field conditions. These are not limited to growing of allelopathic sorghum cultivars, use of allelopathic sorghum mulch and cover crop, intercropping allelopathic sorghum with other crops, and inclusion of allelopathic sorghum in a crop rotation.

Conventionally flooded rice (CFR) requires enormous water and labor inputs. Water scarcity aspires for cultivation of water-saving rice. Growth response and physiology of basmati rice genotypes under the water-saving production systems has not been reported yet. Studies were conducted for 2 years to compare the growth and physiology of three rice cultivars (Super Basmati, Basmati-2000 and Shaheen Basmati), under high (CFR), medium (alternate wetting and drying [AWD]) and low water input (aerobic rice [AR]) systems. Leaf area index, crop growth rate, leaf area duration and dry matter accumulation were higher for AR followed by AWD and CFR, respectively. Shaheen Basmati had a lower growth and relative water contents than Super Basmati and Basmati-2000, probably due to its shorter stature and shorter life cycle. Photosynthetic rate and stomatal conductance of rice cultivars in the different production were affected only at reproductive stage. Basmati-2000 grown as AR had the highest photosynthetic rate followed by the same cultivar under AWD. The results of this study provide us an idea that basmati cultivars can attain a high growth and development with low water input. This would be helpful to grow rice successfully under water-short rice-growing environments. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Rahman, Muhammad Habib ur/0000-0002-2823-9959; Jabran, Khawar/0000-0001-8512-3330; Hakeem, Khalid Rehman/0000-0001-7824-4695; Amin, Asad/0000-0003-2242-8377; Ata-Ul-Karim, Syed Tahir/0000-0001-5233-4502; Jatoi, Ghulam Hussain/0000-0002-7266-1567; Rehmani, M.I.A./0000-0001-7922-1233; Bajwa, Ali/0000-0002-7171-3118; Nadeem, Muhammad/0000-0002-7426-1196; Ata-Ul-Karim, Syed Tahir/0000-0001-5233-4502; Ameen, Asif/0000-0002-3982-7000; Islam, Faisal/0000-0002-1471-1570 WOS: 000397013000067 PubMed: 28054268 Crop nutrient management is an essential component of any cropping system. With increasing concerns over environmental protection, improvement in fertilizer use efficiencies has become a prime goal in global agriculture system. Phosphorus (P) is one of the most important nutrients, and strategies are required to optimize its use in important arable crops like cotton (Gossypium hirsutum L.) that has great significance. Sustainable P use in crop production could significantly avoid environmental hazards resulting from over-P fertilization. Crop growth modeling has emerged as an effective tool to assess and predict the optimal nutrient requirements for different crops. In present study, Decision Support System for Agro-technology Transfer (DSSAT) sub-model CSM-CROPGRO- Cotton-P was evaluated to estimate the observed and simulated P use in two cotton cultivars grown at three P application rates under the semi-arid climate of southern Punjab, Pakistan. The results revealed that both the cultivars performed best at medium rate of P application (57 kg ha(-1)) in terms of days to anthesis, days to maturity, seed cotton yield, total dry matter production, and harvest index during 2013 and 2014. Cultivar FH-142 performed better than MNH-886 in terms of different yield components. There was a good agreement between observed and simulated days to anthesis (0 to 1 day), days to maturity (0 to 2 days), seed cotton yield, total dry matter, and harvest index with an error of -4.4 to 15%, 12-7.5%, and 13-9.5% in MNH-886 and for FH-142, 4-16%, 19-11%, and 16-8.3% for growing years 2013 and 2014, respectively. CROPGRO-Cotton-P would be a useful tool to forecast cotton yield under different levels of P in cotton production system of the semi-arid climate of Southern Punjab. Government of Australia [4915_2015]; Higher Education Commission (HEC) of PakistanHigher Education Commission of Pakistan The first author is grateful to the International Global Change Institute (IGCI) Hamilton, New Zealand, for providing the software (SimCLIM2013) and the required climatic dataset for future projections with for southern Punjab, Pakistan. The first author is thankful to Prof. Dr. Gerrit Hoogenboom (Ex-Director, AgWeatherNet, Washington State University, USA; Currently: University of Florida-USA), for his technical guidance and support during the entire period of study and modeling work. Furthermore, first author is highly thankful from NASA for weather data of respective years (which was obtained from website http://power.larc.nasa.gov/cgi-bin/cgiwrap). The corresponding author (Wajid NASIM) is highly thankful to Government of Australia, for Endeavor Research Award/Fellowship (No. 4915_2015) to The Commonwealth Scientific and Industrial Research Organization (CSIRO), Sustainable Agriculture, National Research Flagship, Toowoomba-QLD 4350, Australia. Furthermore, co-authors (Wajid NASIM and Shakeel AHMAD) are highly thankful for Higher Education Commission (HEC) of Pakistan for partial funding.

Jabran, Khawar/0000-0001-8512-3330; Farooq, Muhammad/0000-0003-4368-9357; WOS: 000383826400022 Crop rotation and tillage systems have important implications for weed infestation and crop productivity. In this study, five tillage systems viz. zero tillage (ZT), conventional tillage (CT), deep tillage (DT), bed sowing (60/30 cm with four rows; BS1) and bed sowing (90/45 cm with six rows; BS2) were evaluated in five different crop rotations viz. fallow-wheat (FW), rice-wheat (RW), cotton-wheat (CW), mungbean-wheat (MW) and sorghum-wheat (SW) for their effect on weed infestation and productivity of bread wheat. Interaction between different tillage practices and cropping systems had significant effect on density and dry biomass of total, broadleaved and grass weeds, agronomic and yield-related traits, and grain yield of bread wheat. The un-disturbed soils (ZT) under fallow-wheat or mungbean-wheat rotations favoured the weed prevalence (a total weed dry biomass of 72.4-109.6 and 105.6-112.1 g m(-2) in first and second year, respectively). Contrary to this, the disturbed soils (CT, DT, BSI and BS2) had less weed infestation with either of the rotations (a total weed biomass of 0.4-7.1 and 1.1-5.4 g m(-2) in first and second year, respectively). Sorghum-wheat rotation had strong suppressive effect on weed infestation in all tillage systems. The impact of crop rotation was more visible during second year of experimentation. Bed sown wheat (BS1 and BS2) in mungbean-wheat rotation had the highest wheat grain yield (6.30-6.47 t ha(-1)) compared to other tillage systems in different crop rotation combinations. (C) 2016 Elsevier Ltd. All rights reserved. Higher Education Commission of PakistanHigher Education Commission of Pakistan Authors are grateful to Higher Education Commission of Pakistan for financial support to accomplish this research project.

Water-saving rice production systems including alternate wetting and drying (AWD) and aerobic rice (AR) are being increasingly adopted by growers due to global water crises. Application of natural and artificial mulches may further improve water economy of water-saving rice production systems. Conventionally flooded rice (CFR) system has been rarely compared with AWD and AR in terms of economic returns. In this 2-year field study, we compared CFR with AWD and AR (with and without straw and plastic mulches) for the cost of production and economic benefits. Results indicated that CFR had a higher production cost than AWD and AR. However, application of mulches increased the cost of production of AWD and AR production systems where plastic mulch was expensive than straw mulch. Although the mulching increased the cost of production for AWD and AR, the gross income of these systems was also improved significantly. The gross income from mulched plots of AWD and AR was higher than non-mulched plots of the same systems. In conclusion, AWD and AR effectively reduce cost of production by economizing the water use. However, the use of natural and artificial mulches in such water-saving environments further increased the economic returns. The maximized economic returns by using straw mulch in water-saving rice production systems definitely have pragmatic implications for sustainable agriculture.