scholarly journals Multispecies weed competition and their economic threshold on the wheat crop

2010 ◽  
Vol 28 (2) ◽  
pp. 239-246 ◽  
Author(s):  
J. Gherekhloo ◽  
S. Noroozi ◽  
D. Mazaheri ◽  
A. Ghanbari ◽  
M.R. Ghannadha ◽  
...  

Two field experiments were conducted to evaluate the effects of multispecies weed competition on wheat grain yield and to determine their economic threshold on the crop. The experiments were conducted in 2002, on two sites in Iran: at the Agricultural Research Station on Ferdowsi University of Mashhad (E1) and on the fields of Shirvan's Agricultural College (E2). A 15 x 50 m area of a 15 ha wheat field in E1 and a 15 x 50 m area of a 28 ha wheat field in E2 were selected as experimental sites. These areas were managed like other parts of the fields, except for the use of herbicides. At the beginning of the shooting stage, 30 points were randomly selected by dropping a 50 x 50 cm square marker on each site. The weeds present in E1 were: Avena ludoviciana, Chenopodium album, Solanum nigrum, Stellaria holostea, Convolvulus spp., Fumaria spp., Sonchus spp., and Polygonum aviculare. In E2 the weeds were A. ludoviciana, Erysimum sp., P. aviculare, Rapistrum rugosum, C. album, Salsola kali, and Sonchus sp. The data obtained within the sampled squares were submitted to regression equations and weeds densities were calculated in terms of TCL (Total Competitive Load). The regression analysis model indicated that only A. ludoviciana, Convolvulus spp. and C. album, in E1; and A. ludoviciana, S. kali, and R. rugosum, in E2 had a significant effect on the wheat yield reduction. Weed economic thresholds were 5.23 TCL in E1 and 6.16 TCL in E2; which were equivalent to 5 plants m-2 of A. ludoviciana or 12 plants m-2 of Convolvulus spp. or 19 plants m-2 of C. album in E1; and 6 plants m-2 A. ludoviciana, 13 plants m-2 S. kali and 27 plants m-2 R. rugosum in E2. Simulations of economic weed thresholds using several wheat grain prices and weed control costs allowed a better comparison of the experiments, suggesting that a more competitive crop at location E1 than at E2 was the cause of a lower weed competitive ability at the first location.

1970 ◽  
Vol 33 (4) ◽  
pp. 623-629 ◽  
Author(s):  
MSA Khan ◽  
MA Hossain ◽  
M Nurul Islam ◽  
SN Mahfuza ◽  
MK Uddin

Field experiments were conducted at the research farm of Bangladesh Agricultural Research Institute, Joydebpur during kharif-1 (March to July) seasons of 2005 and 2006 to identify the critical period of crop-weed competition for Indian spinach. Major weed species were Paspalurn commersoni, Echinochlaa crusgalli. Lie nv/nc india. Cyanotis axillaris and Cyperus rotundus. The lowest weed dry matter was 76.3 g m-2 in 2005 and l01.60 g m-2 in 2006 from the plots weeded up to 40 days after transplanting (DAT). The highest yields were obtained (74.82 t ha in 2005 and 48.48 t ha in 2006) from the weed free plots. The fresh yield of Indian spinach did not vary among no weeding upto 20, 30 and 40 DAT in 2006. But weeded plot upto 30 and 40 DAT produced identical yield in 2005. Maximum BCR (4.52) was obtained from weeded plots upto 30 DAT in 2005 but BCR (2.60) was same from weeded upto 30 and 40 DA F in 2006. On an average, highest BCR (3.55) was recorded from weeding upto 30 DAT. Results revealed that the critical period of crop weed competition lies between 20 and 30 DAT and two times hand weeding would be necessary within 30 DAT for maximum benefit. Key Words: Crop-weed competitions, critical period, weed management and Indian spinach. doi: 10.3329/bjar.v33i4.2306 Bangladesh J. Agril. Res. 33(4) : 623-629, December 2008


Author(s):  
Kasthuri Rajamani ◽  
A. Madhavi ◽  
T. Srijaya ◽  
P. Surendra Babu ◽  
Pradip Dey

Field experiments were conducted from 2015-16 to 2017-18 on a Typic Rhodustalfs (Alfisol) soils of Telangana at Regional Agricultural Research Station, Palem, Nagarkurnool, Southern Telangana Zone, India to validate targeted yield based fertilizer prescription equations which developed for hybrid castor by adopting eight treatments viz., Blanket recommendation (100% RDF:80:40:30 kg N, P2O5 and K2O ha-1), Blanket+5 t ha-1 of vermin-compost (VC), STCR-Target yield with NPK alone at 25q ha-1, STCR-Target yield with IPNS at 25q ha-1, STCR-Target yield with NPK alone at 30q ha-1, STCR-Target yield with IPNS at 30q ha-1, Farmer’s practice (40:20:0kg N, P2O5 and K2O ha-1) and Absolute control (without inorganic and organic fertilizers). The findings of these test verification trials clearly revealed that the percent achievement of the aimed yield target was within + 10 percent variation confirming the validity of the equations. Using STCR-NPK@25 and 30q ha-1 recorded significantly higher seed (20.74 and 22.30q ha-1) and stalk (24.63 and 26.36q ha-1) yield over blanket recommendation (19.40 and 23.13 q ha-1), while STCR-IPNS at 25 and 30 q ha-1recorde relatively higher seed (20.98 and 22.69q ha-1) and stalk (25.88 and 27.13q ha-1) yield over STCR-NPK alone treatments. The magnitude of built-up was higher with STCR-IPNS treatments as compared to STCR-NPK alone, blanket recommendations, farmer’s practice and absolute control.


Author(s):  
Elsayed Omer ◽  
Saber Hendawy ◽  
Abdel Nasser ElGendy ◽  
Alberto Mannu ◽  
Giacomo L. Petretto ◽  
...  

A relevant improvement of the cultivar conditions of Rosmarinus officinalis L. in desert areas was achieved by a specific combination between irrigation system and soil conditioner. A drastic reduction of water employment was obtained without affect the quality of the plants, determined by monitoring growth parameters and essential oil characteristics. In particular, the effect of surface and subsurface drip irrigation systems and different soil conditioners on growth parameters, yield, and essential oil constituents of rosemary plant was assessed. Field experiments at the Agricultural Research Station (Al-Adlya farm), SEKEM group Company, El-Sharkiya Governorate, Egypt, conducted over the two seasons revealed the effectiveness of the subsurface irrigation system in obtaining better performances, especially in terms of water saving. The combination of subsurface irrigation and the conditioner Hundz soil with bentonite showed the maximum mean values of growth characters compared with other soil amendments during both seasons. The possibility to employ a water-saving irrigation system as the subsurface one without any drawback in the resulting plants was also explored in terms of molecular composition. GC-MS analysis of the essential oil extracted from plants growth under different irrigation conditions revealed a comparable composition in both cases. The goodness of the most performing system was also confirmed by the comparable yield of the essential oil.


2020 ◽  
Vol 12 (8) ◽  
pp. 212
Author(s):  
A. M. Sheha ◽  
Haytham Mostafa El-Shahed ◽  
Abd El Nabi Hamed Mohamed Diab

Two field experiments were carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Agricultural Research Center (ARC), Egypt after 2018 and 2019 summer growing seasons to determine the effect of intercropping pattern of yellow maize hybrid (single cross 168: “SC 168”) with watermelon pulp at three plant distributions (20 cm between hills and one plant/hill, 40 cm between hills and two plants/hill and 60 cm between hills and three plants/hill) and different levels of nitrogen fertilizer (25, 50, 75 and 100% of the recommended dose “120 kg N fad-1”) as well as their interactions on maize and watermelon pulp growth, yield and its attributes as well as competitive relationships and yield advantages. The experiments were carried out in split-plot design with four replicates. The main-plots were assigned to plant distributions of maize, the sub-plots were allocated to levels of nitrogen fertilizer for maize. The obtained results showed that planting maize plants on one side of terraces of 140 cm width with 20 cm between hills and leaving one plant/hill and planting watermelon pulp on the other side of the terraces produced the highest values of plant height, ear height, number of kernels row-1, 100-kernel weight and grain yield fad-1, at the same time the lowest values of ear leaf area, ear length, ear diameter and number of rows ear-1 of maize as well as the lowest values of growth, yield and its attributes of watermelon pulp during the both seasons. Mineral fertilizing maize plants with 75% of the recommended dose (90 kg N/fad) and watermelon pulp with the recommended dose produced the highest values of all studied growth characters, yield and its attributes of maize and watermelon pulp in both seasons. The highest values of land equivalent ratio (LER), relative crowding coefficient (RCC), area time equivalent ratio (ATER), land equivalent coefficient (LEC), aggressivity index (AI), monetary advantage index (MAI), actual yield (L.E.) of watermelon, Total income (L.E.) and economic return (L.E.) were obtained from planting maize plants on one side of terraces of 140 cm width with 60 cm between hills and leaving three plants/hill and planting watermelon pulp on the other side of the terraces besides fertilizing maize plants with 75% of the recommended dose (90 kg N/fad) and watermelon pulp with the recommended dose in both seasons. It can be recommended that planting maize on 60 cm between hills and leaving three plants/hill and planting watermelon pulp on the other side of the terraces besides fertilizing maize plants with 90 kg N/fad and watermelon pulp with the recommended dose to obtain the maximum values growth, yield and its attributes of watermelon pulp and competitive relationships and yield advantages of both crops under the climates conditions of Middle Delta, Egypt.


2020 ◽  
Vol 15 (1) ◽  
pp. 79-88
Author(s):  
Yu. A. Gulyanov ◽  
A. A. Chibilyov ◽  
A. A. Chibilyov Jr.

Aim. Verification of scientific concepts regarding the spatial heterogeneity of field agrocenoses. Identification of the variability of phytometric and structural crop ndicators and determination of the degree of their influence on the yield and quality of winter wheat grain in the steppe zone of the Orenburg Urals.Material and Methods. Establishment of field experiments, related observations and counts in accordance with the methodology of state variety crops testing and B.A.Dospekhov's guidelin. Monitoring of winter wheat crops was carried by measuring the vegetation index (NDVI) with a Green Seeker Handheld Crop Sensor, Model HCS‐100 (Trimble, USA). Determination of grain quality indicators was conducted according to GOST 9353‐2016 Wheat – Technical Conditions. Microsoft Office Excel was employed for the correlation and regression analysis of experimental data. Results. Analysis of the intra‐field heterogeneity of winter wheat agrocenoses in terms of yield and grain quality was conducted. The dependences of yield and grain quality on the principal crop phytometric and structural parameters were defined and expressed in the form of regression equations.Сonclusion. The results of the studies attest to the growth of reserves of grain yield to 3.0 t/ha and grain quality to class I‐II class in zonal climatic conditions of optimization of environmental factors to the level of the best basic plots by levelling out field soil heterogeneity. This is possible by restoring the fertility of anthropogenically‐degraded soil through the introduction of landscape‐adaptive and resource saving farming systems, soil protective and soil restorative crop rotation, differentiated application of organic and mineral fertilizers and selection of the most adaptive varieties. We also advise the introduction of intelligent ‘digital technologies’ aimed at fuller implementation of the genetic potential of cultivated varieties with careful consideration of natural resources and the preservation of biological diversity.


Author(s):  
M. Sreekanth ◽  
M. Seshamahalakshmi ◽  
M. V. Ramana

Background: Pod fly, Melanagromyza obtusa is one of the most obnoxious pest causing grain damage ranging from 10-80% with a monitory loss of US$ 256 million annually. Being an internal feeder, infested pods do not show any external symptoms of damage until the fully grown maggots chew the pod wall, leaving a thin papery membrane intact called as window, through which adults exit from the pod. Several field studies were conducted to determine the efficacy of insecticides for the control of pod fly. However, these findings did not find acceptability and led to partial success. Insecticides that should leave lesser residues and pose lesser environmental threat have become imperative. The present study aimed to evaluate the efficacy of certain new insecticide molecules against pod fly in pigeonpea ecosystem. Methods: Two field experiments were conducted at Regional Agricultural Research Station, Lam, Guntur during Kharif, 2012 and 2013 in a randomized block design (RBD) using pigeonpea cv. ICPL 85063 (Lakshmi) with 17 treatments including untreated control and 3 replications. Two sprays were given at 10 days interval starting from pod initiation stage. At maturity, number of pods showing pod fly damage were recorded and expressed as percentage. Grain yield was recorded and cost–benefit ratio was worked out. Result: Among different insecticides, thiacloprid 21.7 SC, followed by diafenthiuron 50 WP, flubendiamide 480 SC and dimethoate 30 EC were very effective against pod fly with more grain yield and registered highest incremental cost benefit ratio (ICBR). It was further suggested that effective insecticides may be alternated in order to avoid development of resistance to pod fly in pigeonpea.


2000 ◽  
Vol 48 (1) ◽  
pp. 83-88
Author(s):  
C. Lourduraj

Field experiments were conducted at the Agricultural Research Station, Aliyar Nagar, Tamil Nadu, India during summer 1994 and 1995 on groundnut, adopting a split plot design. Two irrigation regimes based on Irrigation Water/Cumulative Pan Evaporation (IW/CPE) ratios of 0.60 (I1) and 0.75 (I2) were allotted to the main plot. Twelve treatments involving combinations of organic manure with mineral fertilizer were assigned to the subplots. Irrigation scheduled at IW/CPE 0.75 led to higher plant height, number of branches plant –1, dry matter production and leaf area index, resulting in higher yield than IW/CPE 0.60. All the growth attributes and the yield increased in response to a higher level of mineral fertilizer application and organic manure application. The combined application of inorganic and organic manures significantly enhanced the growth attributes and yield of groundnut compared to the sole application of either of them.


2015 ◽  
Vol 29 (3) ◽  
pp. 544-549 ◽  
Author(s):  
Mohsen Mohseni-Moghadam ◽  
Douglas Doohan

Field experiments were conducted at the North Central Agricultural Research Station in Fremont, OH, in 2006 and 2007, to evaluate tolerance of banana pepper to S-metolachlor and clomazone, and the efficacy of these herbicides on green and giant foxtail, common lambsquarters, and common purslane. The crop was machine-transplanted in late spring of each year. Pretransplant (PRETP) herbicide treatments included two S-metolachlor rates (534 and 1,070 g ai ha−1), two clomazone rates (560 and 1,120 g ai ha−1), and four tank mixes of S-metolachlor plus clomazone (534 + 560 g ha−1, 1,070 + 560 g ha−1, 534 + 1,120 g ha−1, and 1,070 + 1,120 g ha−1). Crop injury and weed control data were collected at 2 and 4 wk after treatment (WAT). The crop was harvested two times from August to September. Minor crop injury was observed at 2 WAT only in 2006 and in plots treated with S-metolachlor, alone or in combination with clomazone. In 2007, slight crop injury at 6 WAT in most herbicide-treated plots was mostly related to weeds that grew regardless of herbicide treatment. In general, S-metolachlor provided less weed control than did clomazone or tank mixes of S-metolachlor plus clomazone. Clomazone did not reduce yield of banana pepper. Registration of clomazone would provide banana pepper growers an opportunity to control weeds caused by late emergence or poor initial control following a burndown herbicide application.


1991 ◽  
Vol 71 (3) ◽  
pp. 821-829 ◽  
Author(s):  
K. N. Harker ◽  
P. A. O'Sullivan

Field experiments were conducted at the Lacombe Research Station to determine the influence of growth stage on the control of wild oat (Avena fatua L.) and Tartary buckwheat (Fagopyrum tartaricum (L.) Gaertn.) with imazamethabenz in wheat (Triticum aestivum L.). In greenhouse experiments, the effct of imazamethabenz on canola (Brassica campestris L.) or green foxtail (Setaria viridis L. Beauv.) at two growth stages was also studied. Canola and wild oat were highly susceptible, Tartary buckwheat was somewhat less susceptible, and green foxtail was rather tolerant to imazamethabenz. Imazamethabenz was much more effective on early growth stages of wild oat (2 leaf) and Tartary buckwheat (1–2 leaf), whereas the control of canola and the suppression of green foxtail was much less dependent on growth stage. Linear regression equations were developed to describe the response of the above species to the imazamethabenz treatments. Key words: AC 222, 293; phenology; regression; Setaria viridis; Fagopyrum tartaricum; Avena fatua


Horticulturae ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 565
Author(s):  
Mohammad Rafiqul Islam ◽  
Mohd. Mostofa Kamal ◽  
Mohammad Ashraful Alam ◽  
Jamil Hossain ◽  
Walid Soufan ◽  
...  

Mungbean is one of the most powerful pulses providing substantial protein for human diets and fixing N to the soil, improving nutritional food security and agricultural sustainability. The production of summer mungbean in the tropics and subtropics is adversely affected by drought due to water scarcity caused by various factors as well as lack of rainfall. Irrigation at different growth phases is not a suitable solution. An environmentally friendly and economically viable answer is a convenient irrigation management option that will be available to farmers together with drought-tolerant genotypes. The study considered to determine the effect of differences between drought-tolerant and drought susceptible genotypes on water productivity response and physiological traits in mung beans. To quantify seed yield-related to irrigation at different growth stages eventually to quickly determine the most appropriate irrigation stage. One water stress tolerant mung bean genotype (BMX-08010-2) and one sensitive genotype (BARI Mung-1) were grown in the field with four different irrigation schedules along with water stress conditions (no irrigation) under rain shelter at Regional Agricultural Research Station, BARI, Ishwardi, Pabna, Bangladesh. The experiment was laid out in split plots with three replications, with irrigation schedules assigned in the main plot and mung bean genotypes assigned in the side plots. Water use efficiency ranged from 3.79 to 4.68 kg ha−1 mm−1 depending on irrigation regime, and mung bean seed yield of mung bean Water stress decreased plant water status, photosynthetic pigment and membrane stability index, and increased proline soluble sugar content. Treatments that received irrigation during two or three phases (I3 or I4) gave significantly higher yields than those that received irrigation during only one stage (I1 and I2) with the lowest yield. While the yield obtained ranged between 1145.44 kg ha−1 with seasonal irrigation of 277 mm (I4) and 555.14 kg ha−1 without irrigation (I0). The flowering stage (I3) was recorded as the most sensitive growth stage with an 18.15% yield reduction compared to the treatment with triple irrigation (I4). Also, depending on the irrigation sources, at least two irrigation phases should be provided at the triple leaf stage (I2, i.e., 20 DAS) and at the flowering stage (I3, i.e., 35 DAS) to achieve the highest yield. Genotypes that maintained the higher performance of physicochemical traits under water stress provided higher seed yield and promoted drought tolerance. Therefore, these parameters can be used as physiological and biochemical markers to identify and develop superior genotypes suitable for drought-prone environments.


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