Yield Components Of Maize Research Articles

Responses of plant biomass and yield component in rice, wheat, and maize to climatic warming: a meta-analysis.

Responses of plant biomass and yield components to warming are species-specific and are shifted as increased warming magnitude rises; this finding improves the results of IPCC AR5. The responses of crop yields to climatic warming have been extensively reported from experimental results, historical yield collections, and modeling research. However, an integrative report on the responses of plant biomass and yield components of three major crops to experimental warming is lacking. Here, a meta-analysis based on the most recent warming experiments was conducted to quantify the climatic warming responses of the biomass, grain yield (GY), and yield components of three staple crops. The results showed that the wheat total aboveground biomass (TAGB) increased by 6.0% with general warming, while the wheat GY did not significantly respond to warming; however, the responses shifted with increases in the mean growing season temperature (MGST). Negative effects on wheat TAGB and GY appeared when the MGSTs were above 15°C and 13°C, respectively. The wheat GY and the number of grains per panicle decreased by 8.4% and 7.5%, respectively, per degree Celsius increase. Increases in temperature significantly reduced the rice TAGB and GY by 4.3% and 16.6%, respectively, but rice straw biomass increased with increasing temperature. However, the rice grain weight and the number of panicles decreased with continuous increasing temperature (ΔTa). The maize biomass, GY, and yield components all generally decreased with climatic warming. Finally, the crop responses to climatic warming were significantly influenced by warming time, warming treatment facility, and methods. Our findings can improve the assessment of crop responses to climatic warming and are useful for ensuring food security while combating future global climate change.

The Impact of Nitrogen Fertilization and the Use of Biostimulants on the Yield of Two Maize Varieties (Zea mays L.) Cultivated for Grain

The field experiment was carried out in 2015–2017 on a family farm in Toczyski Czortki, in the Mazovia voivodeship in Poland. The experiment was set up in a split–split–plot system in three replications. The area of one plot was 30 m−2. The studied factors were: I—two maize varieties: PR38N86 (medium late hybrid cultivar 280 FAO), P8400 (medium early hybrid cultivar 240 FAO); II—four doses of nitrogen fertilization: 1. control object—without the use of nitrogen (0 kg N·ha−1), 2. nitrogen dose—80 kg N·ha−1 (applied once before sowing), 3. nitrogen dose—120 kg N·ha−1 (applied once before sowing), 4. nitrogen dose—160 kg N·ha−1 (applied once before sowing); III—four types of biostimulants used: 1. control object—without using a biostimulant, 2. Asahi®SL biostimulant: I term—four-leaf phase (BBCH 14) at a dose of 0.60 dm3∙ha−1, II term—eight-leaf phase (BBCH 18) at a dose of 0.60 dm3∙ha−1, 3. Improver® biostimulant: I term—four-leaf phase (BBCH 14) at a dose of 1.00 dm3∙ha−1, II term—eight-leaf phase (BBCH 18) at a dose of 0.60 dm3∙ha−1, 4. Zeal® biostimulant: I term—six-leaf phase (BBCH 16) at a dose of 2.00 dm3∙ha−1. The aim of the study was to determine the effect of nitrogen fertilization and the use of biostimulants on the size and quality of yield of two varieties of maize grown for grain. Based on the conducted research, it was found that nitrogen doses influenced the amount of maize grain obtained. The highest yields were obtained using 120 kg N∙ha−1. Nitrogen doses significantly affected the studied maize yield components. The dose of 120 kg N∙ha−1 increased the number of grains in the cob, while the dose—160 kg N∙ha−1 exerted the best effect on obtaining the highest values of a thousand seeds. The biostimulants used in the experiment significantly affected the mass of one thousand seeds and the number of grains in the cob. In addition, Asahi®SL, Improver® and Zeal® biostimulants increased maize yield in each growing season studied.

Effects of Integrated Use of Calliandra calothyrsus and Maize Stover with Urea on Maize Yield Components under Striga Infestation in Western Kenya

The effect of integrated use of Calliandra or maize stover with urea on Striga infestation and maize yield components was assessed in a field experiment carried out for five consecutive seasons on a clay loam Ferralsol in western Kenya. Urea and Calliandra or maize stover were combined to supply N at 75 kg ha-1 from both sources in 0:0, 100:0, 80:20, 60:40, 40:60, 20:80, 0:100 ratios. A randomized complete block design (RCBD) with 12 treatments replicated four times was used with maize hybrid (WS 502) as a test crop. All the three ear traits (ears per plant, ear length, and ear diameter), kernels per row and grain yields were significantly higher under Calliandra (45 kg N ha-1) combined with urea (30 kg N ha-1) and Calliandra (30 Kg N ha-1) combined with urea (45 kg N ha-1) or maize stover (45 kg N ha-1) combined with urea (30 kg N ha-1) and maize stover (30 kg N ha-1) combined with urea (45 kg N /ha-1). Number of ears per plant was a major yield component and accounted for (R2=0.74) of the variation in grain yield under Striga. Stepwise regression analysis showed ears per plant to be the most important yield component under Striga infestation (R2=0.58) followed by kernels per row (R2=0.38).

Short-Term Impact of Drip Irrigation Frequency on Soil Hydro-Physical Properties of an Alfisol and Performance of Two Maize Varieties

Irrigation scheduling is important for efficient use of applied water and for maximizing crop yields. Therefore, the aim of this study was to evaluate the short-term effect of drip irrigation frequency on soil hydro-physical properties of an Alfisol and performance of two maize varieties, at the Teaching and Research Farm, Faculty of Agricultural Sciences, Ekiti State University, Ado Ekiti, Southwest Nigeria. The experiment was laid out using a split-plot experiment in randomized complete block design (RCBD) and three replications. Irrigation frequency constituted the main plot namely: irrigation four times a week (I4), irrigation thrice a week (I3), and irrigation twice a week (I2) of re-filling soil to field capacity while the subplot was maize variety namely: V1: SAMMAZ-27 and V2: OBA-super-6. Plant growth parameters and soil physical properties of soil water content (SWC), bulk density (BD) and saturated hydraulic conductivity (Ksat) were monitored during the growing cycle. Water use efficiency (WUE) and yield components were determined at maturity. There were significant interactions between irrigation regime and maize variety on SWC and Ksat. The maximum bulk density (BDmax) and optimum soil water content SWCopt were 1.41 g/cm3 and 0.12 g/g, respectively. Plant height (PH) did not differ between the two maize varieties throughout the growth cycle. Drip irrigation frequency did not significantly affect plant height until growth stage V12 (12 fully opened leaves), with I4 irrigation treatment having the tallest plant. Both drip irrigation and maize variety had no significant influence on both LAI and CC, neither was there any significant interaction effect. Increasing irrigation water increased maize yield and yield components. The treatment combination of I4V1 had the highest performance indices in terms of yield components. WUE decreased with increasing frequency of irrigation water application while the WUE of SAMMAZ-27 > OBA-super-6. Therefore, irrigating four times a week and SAMAZ-27 maize variety could be a suitable irrigation-variety combination for providing sustainable irrigation agriculture for maize in this region.

Effect of Chemical and Compost Fertilizers on Yield and Oil Fatty Composition of Maize (Zea mays L.) in Delay Planting Date

ABSTRACT Changes in oil and forage quality of maize due to agronomic practices have been poorly investigated. A field experiment was carried out to determine the effect of sowing date, and organic and inorganic fertilizers on fatty acid composition, physiological traits, yield, and yield components of maize in two cropping season. Sowing date (on time and delay planting), organic fertilizers (control, fresh farmyard manure, composted cattle manure, and vermincompost), and nitrogen (urea soil application, urea water application, and nitroxin treatment) were used for treatment group. Results showed second year performed better than first year. The interaction between planting time and organic fertilizer showed that the highest grain yield, oleic, and linoleic acid percentage was achieved in on-time planting and vermicompost treatment. In addition, the interaction effect of planting time and nitrogen showed that the highest oil yield and linoleic acid percentage was observed in on-time planting time and urea soil application. Although, palmitic and linolenic acid increased by delay planting date. In two years, soil application of urea yielded higher grain weight and oil yield than water application of urea and nitroxin. Results of this research demonstrated that application of organic fertilizers yielded to higher yield and yield componentsrather than first year. Also, by delaying planting time, the percentage of palmitic, and linolenic acid increased.

Genetic Dissection of the General Combining Ability of Yield-Related Traits in Maize.

Maize yield components including row number, kernel number per row, kernel thickness, kernel width, kernel length, 100-kernel weight, and volume weight affect grain yield directly. Previous studies mainly focused on dissecting the genetic basis of per se performances for yield-related traits, but the genetic basis of general combining ability (GCA) for these traits is still unclear. In the present study, 328 RILs were crossed as males to two testers according to the NCII mating design, resulting in a hybrid panel composed of 656 hybrids. Both the hybrids and parental lines were evaluated in four environments in 2015 and 2016. Correlation analysis showed the performances of GCA effects were significantly correlated to the per se performances of RILs for all yield-related traits (0.17 ≤ r ≤ 0.64, P > 0.01). Only 17 of 95 QTL could be detected for both per se performances of RILs and GCA effects for eight yield-related traits. The QTL qKN7-1 and qHKW1-3, which could explain more than 10% of the variation in the GCA effects of KN and HKW, were also detected for per se performances for the traits. The pleiotropic loci qRN3-1 and qRN6, which together explained 14.92% of the observed variation in GCA effects for RN, were associated with the GCA effects of KW and HKW, but not with per se performances for these traits. In contrast, Incw1, which was related to seed weight in maize, was mapped to the region surrounding MK2567 at the qHKW5-2 locus, but no GCA effect was detected. The QTL identified in present study for per se performances and corresponding GCA effects for yield-related traits might be useful for maize hybrid breeding.

Evaluating the effect of in-situ rainwater harvesting techniques on maize production in moisture stress areas of humbo woreda, wolaita zone, southern Ethiopia

The study was conducted to investigate the effect of different in-situ water harvesting structures as soil moisture conservation techniques under maize crop production in Abela Sippa kebele Wolaita zone, Ethiopia where rainfall variation is affecting agriculture with prolonged dry spells during critical crop growth stages. The experiment was laid out in a Randomized Complete Block Design, with three replications and four treatments. The four treatments used in the study were; Control, Targa, Tie-ridge and Zai pits. Findings from this study revealed that maize grain yield and yield components, such as, grain yield, dry matter biomass, and cob length were highly significant (p<0.05) on Targa. Soil-moisture content over the crop growing season at dry spell periods was significantly higher in Targa and Tie ridges than the control. Maize yield of (7150 kg ha-1), (6190 kg ha-1), (4500 kg ha-1) and (4900 kg ha-1) was obtained from Targa, Tie ridge, Zai pits and Control, respectively. Targa and Tie ridge treatments recorded higher net returns (29712 and 25164 kg ha-1) than Control (20370 kg ha-1) and Zai (14350 kg ha-1) treatments. The results revealed that the in-situ rainwater harvesting techniques could play great role in improving crop yield in dry periods. However, the utilization of the technology is surrounded by various constraints. The major constraints include labour, cost, lack of knowledge and crops planted on bunds. The findings suggest that Targa structure improved water availability during the growing season, thereby protecting crops from dry periods and it needs minimum cost, less labor power ,and easily constructed by local farmers (not require complicated knowledge).
 Int. J. Agril. Res. Innov. Tech. 10(1): 71-79, June 2020

Optimizing the split of N fertilizer application over time increases grain yield of maize-pea intercropping in arid areas

Abstract Productive cropping systems like cereal-legume intercropping might contribute to feeding the ever-growing population. However, intercropping systems require adapted nitrogen (N) fertilizer management that better match temporal and spatial N supply with crop demand. On the basis of field experiment conducted in northwestern China from 2012 to 2014, the study evaluated three N management practices in maize (Zea mays L.)-pea (Pisum sativum L.) intercropping on yield performance. All three treatments (N1, N2, and N3) received the same amount of fertilizer N prior to planting and at the pre-tasseling stage of maize, while they received different ratios of fertilizer N at jointing (45, 90, and 135 kg N ha−1 for N1, N2 and N3, respectively) and at 15 d post-flowering (135, 90, and 45 kg N ha−1 for N1, N2 and N3, respectively). The N1 treatment was superior to other treatments as it achieved a mean N nutrition index (NNI) near 1 and extended the duration of N accumulation by 3.6 d for pea and 9.0 d for maize. This treatment also improved the nodulation advantage of intercropped pea, enhanced compensatory intensity of intercropped maize, and increased yield components of pea and maize, compared to N3 (current farmer practice). Consequently, grain yield of pea and maize in intercropping with N1 was increased by 6 and 14 %, respectively, compared to N3. The optimized NNI and improved grain yield allow us to conclude that the N1 treatment with jointing top-dress N at 45 kg N ha−1 and 15 d post-flowering top-dress N at 135 kg N ha−1 can be used as an efficient N management practice for maize-pea intercropping.

Evaluating the Effects of In situ Rainwater Harvesting Techniques on Maize Production in Moisture Stress Areas, Humbo Woreda, Wolaita Zone, Southern Ethiopia

This study was conducted to investigate the effect of some In-situ water harvesting techniques on production of maize with respect to soil moisture content, yield and yield components. It also aimed to assess farmers' perception of water conservation techniques. To achieve these objectives of the study, data were collected through house hold survey and field experiment. The experiment was conducted in Wolaita Zone Humbo Woreda at Abela Sippa kebele, which has an irregular rain fall distribution and has a prolonged dry season which leads to low soil moisture during critical crop growth stages. The study was conducted over a period of one growing season (2017/18) using maize as indicator crop at the farmers training center of the Abela Sippa kebele. The experiment was made in a randomized complete block design, with three replications and four treatments. The four treatments used in the study were; Control, Targa, Tieridge and Zai pits . Findings from this study revealed that maize grain yield and yield components, such as, grain yield, dry matter biomass, and cob length were significantly high (p<0.05) at Targa treatments, but plant height was not significantly different. Soil-moisture content over the crop growing season at dry spell periods was significantly higher at Targa and Tie ridges than the control. Targa treatments increased maize yield to (7.15 t/ha), Tie ridge also significantly increased maize production to (6.19t/ha). Similarly, Zai pits yielded (4.5t/ha) and Control treatment yielded (4.9 t/ha). Targa and Tie ridge treatments recorded higher net returns (29712, and 25164 ha-1) than the Control (20370ha-1) and Zai (14350 ha-1) treatments. The results revealed that the rainwater harvesting technology by the community members was a good initiative in improving agricultural practices in periods of water scarcity. However, the utilization of the technology is affected by various constraints. The major constraints include: labor cost, lack of knowledge and types of crops planted on bunds. The findings suggest that Targa structure improved water availability during the growing season, thereby protecting crops from dry periods and it needs minimum cost, less labor power, and easily constructed by local farmers (not require complicated knowledge).

Nitrogen recovery from fertilizers and cover crops by maize crop under no-tillage system

Crop rotation associated with the use of cover crops promotes the introduction of crop residues to the soil, with direct and indirect effects on the availability of plant nutrients, especially nitrogen (N). The objectives of this study were to estimate the N utilization from 15N-urea and cover crop residues (labelled with 15N) of maize crops grown in succession, and evaluate the effects of the isolated and combined use of cover crops and urea on maize plant height, yield components, and grain yield, grown under a no-tillage system. Field research was conducted in an Oxisol (Rhodic Haplustox), Cerrado (Savannah) phase. The experimental design was a randomized block with 20 treatments and four replications in a 5x4 factorial scheme. The treatments were four cover crops species: sunn hemp (Crotalaria juncea L.), pigeon pea (Cajanus cajan (L.) Millsp), green velvet bean (Mucuna prurens), and millet (Pennisetum glaucum L.) + spontaneous vegetation (fallow in the off-season), combined with four N rates: 0, 30, 90, and 150 kg ha-1, applied at the sowing and topdressing stages. The results showed that legume cover crops provided maize grain yields equivalent to the application of 80-108 kg ha-1 N as urea. The urea N utilization by the maize was at an average of 43.5 % of the applied amount. The results indicate that cover crops, particularly legume cover crops, are an important source of N to non-legume cereals. Legumes used as cover crops can replace nitrogen fertilizers of more than 80 kg ha, which is both environmentally and economically viable for corn production.

Mısır (Zea mays l.) ve Börülce (Vigna sinensis l. )’nin İkinci Ürün Olarak Birlikte Yetiştirmenin Yeşil Ot Verimi ve Bazı Tarımsal Karakterlere Etkilerinin Araştırılması

Güneydoğu Anadolu’da, hâsıl amacı olarak birlikte yetiştirilen mısır ve börülcenin farklı ekim sistemlerinde bazı tarımsal karakterler ile kalite özelliğine etkisini incelemek amacıyla yürütülen bu çalışmada, incelenen özellikler koçan oranı hariç birlikte üretim sistemlerinden önemli ölçüde etkilenmiştir. İkinci üründe börülce veriminin azaldığı, mısır yeşil ot veriminin arttığı, alan kullanım etkinliğinin bir ölçüsü olan LER’in karışım ekimlerde kaynakları daha etkin kullanmasından kaynaklanabilmektedir.

Baklagil Yem Bitkilerinden Sonra Yetiştirilen Silajlık Mısırın Verimi Üzerine Azot Uygulamalarının Etkileri

In a 2-year study, it was determined how winter planting various forage legumes (Hungarian vetch, narbon vetch and forage pea) before applying nitrogen (0, 5, 10, 15 and 20 kg N da-1) affected the yield components of silage maize grown afterward. Fallow was applied for control treatment. The results showed that among the forage legumes cultivated from October to May, forage peas afforded the highest fresh weight (4279 kg da-1) and the dry matter ratio (20.50%). However, narbon vetch affected all other yield components of silage maize except dry matter ratio more positively than the other legumes and increased the green yield by 30.3% compared yields achieved in control plots. The dry matter ratio of silage maize was higher in plots grown with Hungarian vetch and forage pea plots because of their later sowing and harvest times. Later, applying nitrogen positively affected the green yields of silage maize by up to 15 kg N da-1. Such results readily apply to cultivating crops with high nitrogen demands (e.g., maize) in soils with low organic matter content. It was concluded that narbon vetch as a previous crop should be advised for silage maize and top-dressing of 15 kg N da-1 could be beneficial for increasing green maize yield.

Yield Attributes, Yield, Competitive Ability and Economics of Summer Maize-Legume Intercropping System

Maize (Zea mays L.), the queen of cereals, is planted with wide spacing and so it offers the scope of intercropping. Considering the benefits of cereal-legume association, an experiment on maize-legume intercropping system was conducted during summer season of 2018 at Bagusala Farm of M. S. Swaminathan School of Agriculture, Centurion University of Technology and Management, Gajapati district, Odisha. The experiment was laid out in randomized complete block design and the treatments were comprised of ten cropping systems, namely, T1: sole maize, T2: sole green gram (Vigna radiata L.), T3: sole groundnut (Arachis hypogaea L.), T4: sole black gram (Vigna mungo L.), T5: maize + greengram (2: 1), T6: maize + groundnut (2: 1), T7: maize + blackgram (2: 1), T8: maize + greengram (2: 2), T9: maize + groundnut (2: 2) and T10 maize +black gram (2: 2). Paired row sowing of hybrid maize was done with a spacing of 80 cm/30 cm × 25 cm in sole maize. Pure stand of legumes i.e. green gram, groundnut and black gram were sown with 30 cm × 10 cm spacing. As per the treatments, single and double row of intercrops were taken in between two pairs of maize. The result indicated that intercropped legumes improved the yield components of maize and offered some bonus yield. The maximum maize grain yield (5669 kgha−1) was noted with sole maize, however, maize equivalent yield of 7609kg ha−1 was recorded with maize + groundnut (2: 2) and it was followed by maize + black gram with 2: 2 ratio (6902 kg ha−1). In expression of the competition functions, maize + groundnut (2: 2) recorded the highest values of area time equivalent ratio (1.70), relative yield total (1.47) and monetary advantage ( 42002 kg ha−1). The intercropping combination of maize + groundnut (2: 2) recorded the highest net return ( 47954 ha−1), with a benefit-cost ratio of 1.00, but by the treatment maize + black gram with 2: 2 ratio registered greater B: C ratio (1.11) with net return of 45499 ha−1.

Effect of Water Application Methods in Furrow Irrigation Along with Different Types of Mulches on Yield and Water Productivity of Maize (Zea mays l.) at Hawassa, Ethiopia

Water has been identified as one of the scarcest inputs, which can severely restrict agricultural production and productivity unless it is carefully conserved and managed . A field experiment was conducted under dry season conditions to investigate the effects of mulch types and water application methods in furrow irrigation system on water productivity and yield of maize (Zea maysL.) at Hawassa, Southern Nations Nationalities, and Peoples Regional State of Ethiopia. Three types of furrow irrigation methods (alternate, fixed and conventional) and two mulch types (plastic and straw mulch) and no mulch with three replications were used as two factors to evaluate the yield and yield component including water productivity of maize in split-plot design, in which furrow irrigation methods were used as the main plot together with the three mulching techniques were used as sub-plot. Results indicated that different types of furrow irrigation method had a very highly significant (p<0.001) effect on plant height, cob length, cob weight with seed, aboveground biomass, grain yield, and water use efficiency. Types of furrow irrigation method used highly significantly (p<0.01) affected thousand seed weight and harvesting index. Moreover, maize growth, yield and yield components including water productivity were highly significantly (p<0.01) influenced due to different mulch types used.However, there was no interaction effect due to the two factors studied (furrow irrigation method and mulching type).Significantly a higher growth, yield and yield component of maize was recorded due to conventional furrow irrigation method than alternate and fixed furrow irrigation method. Highest yield was scored (9003.8 kg/ha) from conventional furrow irrigation water management method. However, higher water productivity (2.43kg/m 3 ) was obtained due to alternate furrow irrigation method. Moreover, higher growth, yield and yield components including water use efficiency were obtained due to plastic mulch than no mulch and straw mulch. Maximum grain yield (8088.9 kg/ha) and water productivity (2.34kg/m 3 ) obtained at plastic mulch condition , but the partial budget analysis revealed that straw mulch was economically feasible for farmers than plastic mulch for maize at Hawassa area. Therefore the present study suggests that, for maximizing grain yield under no water stress scenario, irrigation of maize with conventional furrow irrigation methods could be used. On the other hand, under limiting irrigation water condition, irrigation of maize could be done with alternate furrow irrigation method with straw mulch application to minimize evaporation loss and maximize water productivity of maize at Hawassa and similar agro-ecology and soil type. Keywords : water productivity, yield, maize, mulching and furrow irrigation method DOI: 10.7176/JNSR/10-5-01 Publication date: March 31 st 2020

English

Field studies were conducted at the teaching and research farm of the Osun State University Ejigbo Campus, Osun State, Nigeria, during the 2015 and 2016 cropping seasons to determine the agronomic performance of low N maize varieties under two nitrogen conditions (low and high). The aim of this experiment was to determine the response of low N maize to two levels of nitrogen fertilizer. Ten low N maize varieties were used in this study. Low and high-N conditions of the soil was induced by application of urea fertilizer at the rate of 30 and 90kg ha-1 of nitrogen .The experiments were laid out in a randomized complete block design with three replications. High nitrogen application significantly improved maize vegetative growth, yield components and grain yield. The use of 90 kg ha-1 of N gave the highest maize plant height, and number of leaves per plant, as well as grain yields of 3.50 and 3.58 tha-1 was obtained with the application of 90 kg ha-1 of N in 2015 and 2016 cropping seasons, respectively. The result indicated that application rates of nitrogen (kg ha-1 of N) improved growth attributes of all the varieties with SINT MAR 20CA LARGA gave maximum grain yield that is not significantly different from 72PBPROLC3SYN. Key words: Plant height, agronomic performance, low N maize, nitrogen levels.

Influence of Intercropping Cowpea with some Maize Hybrids and N Nano-Mineral Fertilization on Productivity in Salinity Soil

A TWO-year field experiment was carried out at El-Serw Agricultural Research Station, during the 2018 and 2019 seasons to study the effect of intercropping cowpea (Vigna unguiculata L.) with three maize (Zea mays L) hybrids (SC 168, SC176 and TWC 321) and four N fertilization treatments (120kg N/fed as urea (100% N mineral), 50% N mineral + 50% N nano, 75% N mineral + 25% N nano and 3.0cm3 N nano/ L (100% N nano) on maize and cowpea productivity, land use efficiency and economic return. A split-plot design with three replicates was used. Results showed that maize hybrids had significant effect on yield and yield attributes of maize and cowpea in both seasons, with some exception. The S.C.168 hybrid gave the highest grain yield and its components, while intercropping cowpea with S.C.176 hybrid significantly increased yield and its attributes of cowpea in comparison with other hybrids. Applying 75% N mineral along with 25% N nano significantly increased growth, yield and yield components of maize and cowpea in both seasons. Significantly increase in yield and its attributes of maize and cowpea was realized by interaction between maize SC168 and 75% N mineral +25% N nano fertilization. Intercropping cowpea with maize SC168 that received 75% of the N mineral + 25% nano fertilizer recorded the highest LER 1.67 and 1.66, ATER 1.59 and 1.58, Aggressivity 0.28 and 0.23, gross return15865 and 15854 L.E./fed and net return 7983 and 7972L.E./fed in first and second seasons, respectively, as well as rationalizing the use of N mineral fertilizers.

Effect of Different Herbicides, Plant Extracts and Mulches on Yield and Yield Components of Maize

ABSTRACT: To examine the effect of pre emergence herbicides, plant extracts and mulches on yield and yield components of maize, a field experiment was carried out at New Developmental Farm, The University of Agriculture Peshawar-Pakistan during summer crop season 2016. Maize variety “Azam” was sown in Randomized Complete Block (RCB) design having four replications and ten treatments i.e. hand weeding, Dual Gold 960 EC (S-metolachlor 1 L ha-1), Stomp 330 EC (pendimethaline 2.5 L ha-1), atrazine 1.25 L ha-1, Eucalyptus camaldulensis L. extract (125 g L-1), Ammi visnaga L. extract (125 g L-1), black plastic mulch, wheat straw mulch, saw dust mulch and weedy check. The data revealed that hand weeding and herbicides significantly affected the weed density (m-2), weeds biomass (kg ha-1), plant height (cm), kernels weight (g), number of kernels ear-1, biological yield (kg ha-1) and grain yield (kg ha-1). All the significant parameters of crop were comparable among the hand weeding, atrazine, S-metolachlor and pendimethaline treated plots. However, atrazine and S-metolachlor proved to be the most economical herbicides giving maximum yield (4636.4 and 4562.8 kg ha-1), respectively. Among plant extracts, E. camaldulensis showed satisfactory results in suppressing weeds and enhancing yield of maize i.e. (3441.6 kg ha-1). Hence, the use of herbicides (atrazine and S-metolachlor) at the recommended rates and hand weeding is recommended for effective weed control and ultimately high yield of maize crop.

Effect of Planting Methods and Deficit Irrigation on Yield and Yield Components of Maize

The research was carried out at Agronomy Research Farm, The University of Agriculture Peshawar, during May 2017. The research was laid out in RCBD with split plot arrangement having 4 replications. Deficit Irrigations (Full irrigation (10 irrigations), one irrigation missing at six leaves stages, one irrigation missing at twelve leaves stage, one irrigation missing at flowering stage and one irrigation missing at grain filling stage) was allotted to main plots, while planting methods (Ridge, Flat and Broadcast) was allotted to sub plots. Deficit irrigations had significant (P ≤ 0.05) affect on all parameters excluding emergence m2, days to emergence, number of plants at harvest, ears plant–1, ears m2. Full irrigation (10 irrigations) had significantly more plant height (189.25 cm), 1000 grain weight (211.25 g), grain yield (3352.75 kg), shelling percentage (47.78). Whereas one irrigation missing at six leaves stages produced maximum Harvest index (33.99%). In case of planting methods, ridge planting had significantly higher plant height (186.10 cm), Plant at harvest (61316.60), thousand grain weight (205.90 g), grain yield (2948.35 kg). While broadcast planting produced high Shelling percentage (46.90). The interaction of planting methods and deficit irrigations, maize grow on ridge method and give full irrigations produced higher plant height (192 cm), ridge and one irrigation missing at six leaves stages had more Harvest index (35.06%)) and high Shelling percentage (49.27)was obtained on broadcast planting with full irrigation. On the basis of the above results it is recommended that in water scarce area grow maize on ridge planting method and give deficit irrigation at vegetative stage (one irrigation missing at six leaves stages) in order to increase water productivity (Efficiency).

Selection indexes in the simultaneous increment of yield components in topcross hybrids of green maize

Abstract: The objective of this work was to define the most suitable selective strategy for the simultaneous increment of yield components of green maize, by comparing three selection indexes weighted by economic weights and by the REML/BLUP method, in the assessment of predicted genetic gains for traits of interest. An experiment with 75 topcross hybrids from partially inbred S1 lines of green maize was carried out in Jataí, in the state of Goiás, Brazil, using a randomized complete block design, with four replicates. The following yield traits were evaluated: straw ears and commercial ears, grain mass, ear length, ear diameter, and number of ear rows. The selection indexes of Smith and Hazel, Williams, and Mulamba & Mock were applied and weighted for four economic weights (1, CVg, CVg/CVe, and h2). Among the tested selection indexes, those of Williams and Mulamba & Mock are the best-fit ones for the selection of topcross hybrids of green maize, as they provide positive and more balanced selection gains for all evaluated traits. The REML/BLUP method shows better predicted genetic gains than those achieved by the three selection indexes, besides being efficient for the selection of topcross hybrids of green maize.

Weed management in glyphosate-resistant maize

ABSTRACT The application of glyphosate associated with other herbicides is an important alternative for weed control in maize, to increase control spectrum and to minimize problems with resistance and tolerance from some species to the product. The objective of this work was to evaluate the efficacy, selectivity and effects on the grain yield components of glyphosate-resistant maize as a function of its application, associated or not with other pre- and postemergence herbicides. The design used was randomized blocks with four replications. Treatments consisted in the use of glyphosate combined with the herbicides: atrazine, [atrazine + simazine], [atrazine + oil], [atrazine + S-metolachlor], applied pre- and/or postemergence and [nicosulfuron + mesotrione] only postemergence, plus two controls, one weeded and one infested. The evaluated variables were maize phytotoxicity, weed control, ear insertion height, number of rows per ear, number of grains per row, one thousand grain mass and grain yield. Herbicide treatments caused low phytotoxicity to maize, less than 6%; control greater than 88, 95 and 95% for alexandergrass, turnip and sunflower, respectively, and did not affect grain yield components. The tested herbicides are selective to the hybrid Forseed 2A521 PW and effective in weed control. Weed control with weeding or herbicide increased maize Forseed 2A521 PW yield by 43%. The association of glyphosate with pre- or postemergence herbicides increased maize grain yield by approximately 14%.