Does continuous cropping of maize contribute to infestation with Johnsongrass (Sorghum halepense (L.) Pers.)?

Johnsongrass (Sorghum halepense (L.) Pers.) is a very common weed in maize fields in Serbia. Dense Johnsongrass infestations severely limit maize production, especially under continuous maize cropping. The key tool to manage this weed is to implement multiple control strategies when Johnsongrass is first observed and not to wait until it is firmly established. Experiments were conducted in the Maize Research Institute (MRI), Zemun Polje, Belgrade, in order to examine how economically driven continuous cropping of maize influences weed infestation, especially the distribution and abundance of Jonhsongrass, as well as maize productivity. The maize hybrid ZP 606 was grown in continuous cropping from 2009 to 2018 at a density of 59,500 plants ha-1. The experimental field was split into a part treated with the pre-emergence herbicide isoxaflutole + metolachlor (750 + 960 g a.i.) and untreated control. The level of complete weed infestation was evaluated 4-5 weeks after herbicide application by determining the number of weed individuals per species (NI), total fresh biomass (TB) and total dry weight (TDW) of all weeds and Johnsongrass fresh biomass (JB) and dry weight (JDW). Maize harvest index (HI) and grain yield (GY) were determined at the end of each growing period. All measured weed parameters were highly dependent on agro-meteorological conditions of the year, herbicide application and their interaction. On average, TDW was 760.7 g m-2 in the control plot, and 142.2 g m-2 in the treated plot, while Johnsongrass participated with 34.8% and 48.7%, respectively. Herbicide application reduced JDW by 77.6% on average, even though its biomass increased over the years. A regression analysis revealed that GY was negatively influenced by JDW (R2= - 0.094) in untreated control, while GY was higher with a lower JDW under herbicide treatment (R2=-0.4439). Continuous cropping of maize should be replaced with crop rotation in order to prevent Johnsongrass prevalence and to obtain higher crop productivity.Divlji siriak (Sorghum halepense (L.) Pers.) je vrlo čest korov na poljima u Srbiji. Intenzivna zakorovljenost divljim sirkom ozbiljno ograničava proizvodnju kukuruza, naročito kada se on gaji u monokulturi. Suština borbe protiv ovog korova je pravovremena primena više mera suzbijanja čim se divlji sirak uoči i pre nego što razvije veliku masu rizoma i dobro se ukoreni. Poljski ogled je izveden u Institutu za kukuruz Zemun Polje, sa ciljem da se utvrdi kako profitom dirigovano gajenje kukuruza u monokulturi utiče na zakorovljenost, naročito na rasprostranjenost i brojnost divljeg sirka, kao i na produktivnost kukuruza. Hibrid ZP 606 je gajen u monokulturi u periodu 2009-2018. godine u gustini od 59.500 biljaka ha-1. Polje pod kukuruzom u monokulturi je podeljeno na deo na kome je primenjivan herbicid pre nicanja useva (isoksaflutol + metolahlor (750 + 960 g am) i deo koji nije bio tretiran - kontrola. Intenzitet zakorovljenosti je određen 4-5 nedelja nakon primene herbicida merenjem broja jedinki vrsta (NI), ukupne sveže biomase (TB) i ukupne suve mase (TDW) svih korova i sveže biomase divljeg sirka (SB) i njegove suve mase (JDW). Žetveni indeks (HI) i prinos zrna (GY) određeni su na kraju vegetacionog perioda kukuruza. Svi parametri korova u velikoj meri su zavisili od agro-meteorološkoh uslova godine, primene herbicida i njihove interakcije. U proseku, TDW je iznosila 760,7 g m-2 u kontroli i 142,2 g m-2 na tretiranoj parceli, od čega je udeo suve mase divljeg sirka bio 34,8% u kontroli i 48.7% na tretiranoj parceli. Primena herbicida smanjila je suvu masu divljeg sirka prosečno za 77.6%, iako se ona sa godinima povećavala. Prema regresionoj analizi, JDW je negativno uticala na GY (R2= - 0,094) u kontroli, dok se GY povećavao sa smanjenjem JDW u varijanti sa primenjenim herbicidom (R2=-0,4439). Monokulturu kukuruza bi trebalo zameniti plodoredom da bi se sprečilo zakorovljavanje divljim sirkom i postigla veća produktivnost useva

Variability in antioxidants in yellow, white, and red coloured maize grain in response to different fertilizers

Maize (Zea mays L.) grain is an important source of nutrients in human diet. The differences in content and relations between certain components of maize grain impact grain colour and its nutritional quality. The objective of the Study was to examine effects of different fertilization systems: mineral fertilizer (urea), organic fertilizer, and bio-fertilizer on white, yellow, and red coloured maize hybrids, regarding grain yield and variations in content of antioxidants: phytate, phenolic compounds, glutathione, carotenoids (yellow pigment), and reduction capacity of DPPH radical. Two-fold higher average grain yield and double fold lower concentration of phenols and carotenoids were present in 2018, in comparison to drier 2017. The lowest phytate content and the highest values of phenols and DPPH reduction capacity were present in red maize kernel, as a hybrid with the highest yield, while in yellow maize kernel, the highest values of yellow pigment and glutathione occurred. The bio-fertilizer expressed the positive impact on reduction of phytate concentration and increase of phenols concentration in maize grain, while urea increased concentration of yellow pigment and glutathione. Correlation analysis showed that reduction in phytate and carotenoids was significant and positive related with grain yield increase, while phenols showed positive correlation with reduction capacity of DPPH radical. Thus, it was shown that changes in fertilization methods could affect antioxidants status in maize grain, particularly in red coloured maize, which besides high yield potential, possess remarkable higher antioxidant capacity in regard to yellow and white coloured maize

Variability in antioxidants in yellow, white, and red coloured maize grain in response to different fertilizers

Maize (Zea mays L.) grain is an important source of nutrients in human diet. The differences in content and relations between certain components of maize grain impact grain colour and its nutritional quality. The objective of the Study was to examine effects of different fertilization systems: mineral fertilizer (urea), organic fertilizer, and bio-fertilizer on white, yellow, and red coloured maize hybrids, regarding grain yield and variations in content of antioxidants: phytate, phenolic compounds, glutathione, carotenoids (yellow pigment), and reduction capacity of DPPH radical. Two-fold higher average grain yield and double fold lower concentration of phenols and carotenoids were present in 2018, in comparison to drier 2017. The lowest phytate content and the highest values of phenols and DPPH reduction capacity were present in red maize kernel, as a hybrid with the highest yield, while in yellow maize kernel, the highest values of yellow pigment and glutathione occurred. The bio-fertilizer expressed the positive impact on reduction of phytate concentration and increase of phenols concentration in maize grain, while urea increased concentration of yellow pigment and glutathione. Correlation analysis showed that reduction in phytate and carotenoids was significant and positive related with grain yield increase, while phenols showed positive correlation with reduction capacity of DPPH radical. Thus, it was shown that changes in fertilization methods could affect antioxidants status in maize grain, particularly in red coloured maize, which besides high yield potential, possess remarkable higher antioxidant capacity in regard to yellow and white coloured maize

Common millet and soybean intercropping with bio-fertilizer as sustainable practice for managing grain yield and quality

Climate changes are one of the biggest threats to food security. Sustainable agriculture, focused on eco-friendly practices for highly efficient food production, enables greater resilience and safety. This study experimented on intercropping and bio-fertilizer application as convenient ecological solutions for crop yield stability and quality. The experiment was conducted during 2018 and 2020 with soybean and common millet sown in three sowing patterns: alternating rows, alternating strips 1 (2 rows of soybean + 2 rows of millet), and alternating strips 2 (2 rows of soybean + 4 rows of millet), as well as sole crops (control), with or without a bio-fertilizer Coveron. Grain yield and nutrient grain yield response were calculated through land equivalent ratio (LER) and element-LER (E-LER), while quality was estimated based on the concentration of antioxidants (phytate phosphorus, total phenolic compounds, and yellow pigment) and elements in grains, including potential bio-availability of essential elements. Results revealed LER values to be >1 for all sowing patterns, with the highest one achieved in alternating strips 1 (1.38) together with a greater level of all antioxidants in millet grain. Intercropping significantly enhanced Fe and Mn accumulation in both crops and simultaneously decreased the concentration of potentially toxic elements (Al, Cr) in millet grain. Potential bio-availability of essential elements, expressed through the ratio between phytic acid and Ca, Mg, Fe, and Zn revealed smaller values in intercropped soybean and millet with the bio-fertilizer. The bio-fertilizer also increased the concentration of some micro-elements in millet grain, classifying it as a highly dependent plant to microbial inoculation. Interaction of intercropping and bio-fertilizer was most pronounced for LER, E-LER, and accumulation of Fe and Mn in grains. These results highlighted the benefits of soybean–common millet intercropping, especially in combination with the bio-fertilizer, in light of enhanced land utilization and nutrient absorption, thus increasing the resilience of soybean and millet under dry land conditions and low-input systems toward stability and food security

Adjuvants and nozzles effects in Johnsongrass (Sorghum halepense (L.) Pers.) control using nicosulfuron

Johnsongrass is one of the most troublesome weed species to control, since it belongs to the same family as maize. The sulfonylureas have been the first selective herbicides for Johnsongrass control in maize. Non-proper use of sulfonylureas had led to herbicide resistance development, and weed control failures. However, an optimization of herbicide performance through different adjuvants and spraying nozzles application can improve Johnsongrass control. Adjuvants are able to change physico-chemical properties of herbicide solution, while nozzles influence coverage rate and potential drift. A field trial regarding the influence of adjuvants and nozzles on Johnsongrass control started 2020 at the experimental field of the Maize Research Institute “Zemun Polje”. Nicosulfuron (OD formulation) was applied at 5-6-leaf stage, tank-mixed with NIS (non-ionic surfactant) or AMS (ammonium-sulphate) using XR11002 or TTI11002 nozzles. Sprayings were done when maize developed 5-6 leaves (15-16 BBCH) using CO2 backpack sprayer calibrated to deliver a spray volume of 140 l ha-1 of solution at 275.8 kPa. Following applications, weed density and biomass were evaluated on the 28th day. After harvest, maize grain yield was measured. According to obtained data, the highest Johnsongrass suppression was obtained using XN nozzle when nicosulfuron was tank-mixed with NIS adjuvant. Spraying with XR nozzle provided 96.3% of the biomass reduction compared to the untreated check, while spaying with TTI nozzle provided 87.5% of biomass reduction. Addition of AMS as adjuvant reduced to 70% of biomass, as it was noticed in the treatment without adjuvant. Consequently, the highest grain yield of 12.3 t ha-1 was recorded when nicosulfuron was tank-mixed with NIS adjuvant and sprayed with XR nozzle, while the yield of 11.7 t ha-1 was recorded when the TTI nozzle was used. The lowest yield, ranging from 10.6 to 11.4 t ha-1 , was recorded in treatments without adjuvants

Intercropping of soybean-common millet in combination with bio-fertilizer as an ecological method for increasing productivity

Због интезивне примене минералних ђубрива и пестицида, који повољно утичу на повећање продуктивности али штетно на животну средину, све већи изазов у свету представља проналажење еколошки прихватљивог начина гајења усева, који ће обезбедити одрживи и задовољавајући принос. Једна од алтернативних метода која се успешно користи у ту сврху јесте гајење два или више усева истовремено на истом пољу. Циљ овог истраживања био је да се процени агрономска вредност, тј. принос соје и проса комбинованих на различите начине (наизменични редови и наизменичне траке) и упореди са самостално гајеним усевима. Експеримент је постављен на огледном пољу Института за кукуруз “Земун Поље”, током 2018. и 2020. године. Соја (сорта Селена) и просо (сорта Бисерка) су посејани у три различите комбинације (С-П, СС-ПП, СС-ПППП), као и контролни усеви, док је истовремено испитиван и утицај био-ђубрива Coveron (садржи микоризне гљиве и ризосферне бактерије). Добијени приноси су изражени преко односа еквивалента земљишта (ЛЕР), док је компетиција између соје и проса описана помоћу компетитивне способности (ЦР) и агресивности (А). Резултати су показали да све три испитиване комбинације здруживања повољно утичу на продуктивност. Просечне ЛЕР вредности су у свим комбинацијама веће од 1, указујући на већу продуктивност соје и проса у здруженим у односу на чисте усеве. Највише ЛЕР вредности су постигнуте у СС-ММ комбинацијама (1.48 и 1.28 са и без Coveron-а, респективно). Разматрајући компетицију, соја се истакла као компетитивнија и доминантнија врста, посебно у комбинацијама наизменичних трака, где је у СС-ММММ комбинацији са био-ђубривом забележена ЦР вредност од 3.19 и А вредност од 1.34. На основу наведених резултата може се закључити да је изражена компетитивност соје у односу на просо повољна за здруживање наведених врста и има агрономску вредност у одрживој пољопривреди.Due to the intensive application of mineral fertilizers and pesticides, which have a favorable effect on increasing productivity but are harmful to the environment, finding an ecological way of growing crops, which will provide a sustainable and satisfactory yield, is a growing challenge in the world. One of alternative methods that is successfully used for this purpose is growing two or more crops simultaneously in the same field. The aim of this study was to assess the agronomic value, ie. yield of soybean and common millet intercropped in different ways (alternating rows and alternating strips) and compare with monocrops. The experiment was set up on the experimental field of the Maize Research Institute "Zemun Polje", during 2018 and 2020. Soybean (var. Selena) and common millet (var. Biserka) were sown in three different combinations (SP, SS-PP, SS-PPPP), as well as control crops, while at the same time the influence of bio-fertilizer Coveron (containing mycorrhizal fungi and rhizosphere bacteria) was examined. The obtained yields are expressed through the land equivalent ratio (LER), while the competition between soybean and millet is described by competitive ratio (CR) and aggressivity (A). The results showed that all three examined combinations have favorable effect on productivity. The average LER values in all intercrops are greater than 1, indicating higher productivity of soybean and millet in intercropping compared to pure crops. The highest LER values were achieved in SS-MM combinations (1.48 and 1.28 with and without Coveron, respectively). Considering competition, the soybean stood out as more competitive and dominant specie, especially in the combinations of alternating strips, where CR value of 3.19 and A value of 1.34 were calculated for SS-MMMM combination treated with bio-fertilizer. Based on the above results, it can be concluded that expressed competitiveness of soybean in relation to millet is favorable for intercropping of these species and has agronomic value in sustainable agriculture

The evaluation of the influence of biological treatments of maize seeds on the morphological characteristics of seedlings and seed germination

Све већи проблем у семенској и комерцијалној производњи кукуруза представња недостатак воде у сетви. У систему гајења усева без наводњавања сушни период проузрокује велике штете смањењем броја биљака по хектару, што директно утиче на висину приноса. У овим истраживањима метаболички процеси клијања и ницања стимулисани су хидропрајмингом семена. Постављен је двофакторијални оглед, са четири линије кукуруза Л-1, Л-2, Л-3, Л-4 и четири третмана хидропрајминга. Третмани укључују различиту дужину времена потапања семена у води, 8 (Х1) и 16 (Х2) сати, као и различиту температуру воде, 25°C (Т1) и 30°C(Т2). Након хидропрајминга, семе је сушено ваздушно сувим третманом на 35°C 24 сата. Клијавост, дужина стабаоцета, дужина коренка, маса стабаоцета и маса коренка одређени су након седам дана наклијавања семена у клијалишту стандардном методом. Семе коришћено у огледима било је различиток квалитета. Клијавост се кретала од 69-92%, дужина корена од 89-129 cm, дужина клијанца од 70-84 cm, маса клијанца од 0,5-08 g и маса корена од 0,47-0,67 g. Применом сва четири третмана хидропрајминга имало је позитиван ефекат на дужину стабаоцета, дужину коренка и њихову масу. Третман Т1 утицао је на масу коренка, а Т2 на дужину коренка. Применом третмана Т2, у комбинацији са два временска третмана (Х1, Х2) дужина коренка била је значајно дужа у односу на контролу. Најдужи коренак, 137 mm одређен је код Л2 у комбинацији третмана Т2Х1. Најдуже стабаоце клијанца било је 98,11 mm применом Т1Х2. Такође третмани су деловали и на повећање масе стабаоцета, највећу масу стабаоцета 0,93 g имала је комбинација Л3Т1Х2. Побољшање морфолошких особина садница, применом биолошког третмана, помаже семену да буде отпорније на тешке временске прилике.A growing problem in seed and commercial maize production is the lack of water at sowing. In the cropping system without irrigation, drought causes great damage by reducing the number of plants per hectare, which directly affects yield. In these studies, the metabolic processes of germination and emergence were stimulated by hydropriming the seeds. A two-factor experiment was set up with four maize lines L-1, L-2, L-3, L-4 and four hydropriming treatments. The treatments included different times of seed immersion in water, 8 (H1) and 16 (H2) hours, and different water temperatures, 25°C (Т1) и 30°C(Т2). (T2). After hydropriming, seeds were air-dried at 35°C for 24 hours. Germination, stem length, root length, stem weight, and root weight were determined after seven days of seed germination in the germination chamber using the standard method. The seeds used for the experiments were of different quality. Germination ranged from 69-92%, root length ranged from 89-129 cm, seedling length ranged from 70-84 cm; stem weight ranged from 0.5-08 g, and root weight ranged from 0.47-0.67. The application of all four hydropriming treatments had a positive effect on stem length, root length, and root weight. Treatment T1 had an effect on root weight and T2 on root length. When treatment T2 was applied in combination with two time treatments (H1, H2), root length was significantly greater compared to the control. The longest root, 137 mm, was obtained at L2 in the combination of treatment T2H1. The longest stem of the seedling was 98.11 mm in treatment T1H2. The treatments also affected the increase in stem weight, with the highest stem weight of 0.93 g obtained in the combination L3T1H2. Improving the morphological characteristics of seedlings through biological treatment helps to make the seed more resistant to harsh weather conditions

Influence of intercropping and bio-fertilizer on the level of antioxidants in soybean and common millet grains

While climate change severely affects food production and its security, each practice which boost yield and quality of crops in an eco-friendly way is required. Soybean (S) and common millet (M) present valuable crops regarding nutritive quality of grains, and their intercropping (IC) can be used to enhance performance of both crops in a sustainable way. Field experiment was performed during 2018 and 2020, as completely randomized block design. Three combinations of intercrops: S-M, SS-MM and SS-MMMM, as well as sole crops were included in trial. Additionally, the influence of bio-fertilizer Coveron (containing Glomus sp., Trichoderma atroviride and plant growth-promoting rhizobacteria) was also investigated. The quality of grains was determined by measuring the level of three important antioxidants: yellow pigment - YP, total phenolic compounds - TPC and phytic phosphorus - PPhy. In terms of soybean, IC was insignificant for variability in concentration of antioxidants, while in millet grains, concentrations of Pphy, TPC and YP were significantly affected by IC. Pphy and TPC levels were mainly increased by IC, but not YP level. The only combination that influenced simultaneous increase of all three parameters was SS-MM combination. Consequently, this planting pattern is suggested as an effective for increasing antioxidants level in millet grain. On the other side, BF significantly affected only Pphy in soybean, increasing its concentration, which proved positive effect of BF on enhanced phosphorus availability and accumulation in grain. These findings indicate the importance of planting pattern in managing nutritive quality of grains, emphasizing 1:1 ratio set as alternating strips in soybean-common millet intercropping

The role of sustainable agriculture in production of nutrient dense food

Industrialization of agriculture, as the main food source, resolved the problem of food quantity, but other problems, present in environment degradation and hidden malnutrition (deficiency in essential minerals and vitamins) were upraised. The situation is aggravating when climate change was taken into account, whereas conventional agriculture is highly contributing to climate change. Thus, a shift to sustainability paradigm and systems are a necessary solution. Sustainable systems combine various measures to achieve a high and nutrient dense yield of agricultural crops and to preserve or improve agro ecosystem. Soil recovery could be realized by increasing soil organic matter, diversity of soil microbiota and other organisms, as a part of the agro ecosystem balance, thus contributing to the increased productivity and food quality. Together, sustainable agriculture and sustainable food systems, have an important role in the health enhancement of humankind and the agro ecosystem

Role of soybean - millet intercropping and bio-fertilizer in managing potential bio-availability of essential elements

The potential bio-availability of minerals from food, i.e. agricultural products, is mainly subjected to the concentration of anti-nutrients, due to its high affinity to bind elements and make them unavailable for humans from digestive tract. Thus, increasing the mineral concentration in grain is just one point in the string that can improve food quality, but reduction in concentration of anti-nutrients, such as phytates, is of great importance, too. [1,2] As intercropping and use of bio-fertilizer represent integrative part of sustainable agriculture which influence nutrient use efficiency [3,4], their combination seems to be a good way to manage nutrients uptake and accumulation, and anti-nutrients concentration in grain. Therefore, this research aimed to examine the impact of soybean - common millet arrangement in intercropping, together with bio-fertilizer, on potential bioavailability of essential elements in grain. A two-year field experiment was conducted with soybean and common millet. Mono-crops (T1 - soybean, T2 - millet), as well as three planting patterns of intercrop (T3 - alternating rows of soybean and common millet; T4 - alternating strips of two rows of soybean and two rows of millet and T5 - alternating strips of two rows of soybean and four rows of millet) were set up in 2018 and 2020. The bio-fertilizer Coveron (BF) (containing mycorrhizal fungi, Trichoderma and plant growth-promoting rhizobacteria) was also included in same combinations, as a subplots, as well as variant without BF (BFƟ). After determination of concentrations in grains, the molar ratios between phytic acid (Phy) and magnesium (Mg), calcium (Ca), iron (Fe) and zinc (Zn) were evaluated. Results showed that intercropping and bio-fertilizer significantly affected molar ratios between phytic acid and essential elements. Regarding to the soybean, all 4 ratios showed smaller values in intercropping comparing with mono-crops (both in plots with and without fertilizer). Intercrops + BFƟ decreased Phy/Ca, Phy/Mg and Phy/Fe ratios down to the 0.31 (T4 and T5), 0.16 (T4) and 14.03 (T4), respectively, while intercrops + BF decreased Phy/Zn ratio down to the 25.25 in T3 + BF. These lowest values could be related to lower accumulation of Phy and greater accumulation of minerals in intercropped soybean, due to the presence of cereal (millet) and its ability to excrete phytosiderophores, which promotes mineral uptake [5]. Nevertheless, situation for common millet was different. Ratios of Phy/Ca, Phy/Mg and Phy/Zn had the lowest values in mono-crops (both in BF and BFƟ variants), while the value of Phy/Fe was the lowest in T3 + BF (23.88). Such results suggest soybean - common millet intercropping as a good sustainable agricultural practice to enhance bio-availability of essential elements in grain of soybean. On the other side, positive impact of BF was pronounced in millet, enhancing potential bio-availability of examined minerals in grain by lowering values of all 4 ratios. These findings can be connected to beneficial effect of microbes on nutrients uptake by cereals [6], highlighting the tested combination of fungi and plant growth-promoting rhizobacteria as a sustainable strategy to increase grain quality. However, although this research proved positive effects of soybean - common millet intercropping and bio-fertilizer on potential bio-availability of essential elements, further research is needed to determine the most suitable combination for increased quality of both crops