scholarly journals Critical time for weed removal in dicamba tolerant soybean as influenced by pre emergence herbicides

2020 ◽  
Vol 29 (1) ◽  
pp. 55-62
Author(s):  
Darko Jovanović ◽  
Ivan Cuvaca ◽  
Jon Scott ◽  
Stevan Knežević
Keyword(s):  
Field Experiment ◽  
Growth Stage ◽  
Critical Time ◽  
Split Plot ◽  
Main Plot ◽  
Plot Design ◽  
Weed Removal

Field experiment was conducted in 2019 at Haskell Agriculture Laboratory, Concord, NE, USA. Goal of the study was to test the influence of PRE-EM herbicides on the Critical Time for Weed Removal (CTWR) in dicamba-tolerant soybean. The study was arranged in a split-plot design which consisted of four herbicide regimes as main plot treatments and seven weed removal timings as subplot treatments, with four replications. The herbicide regimes included: (1) no PRE and glyphosate, (2) acetochlor and dicamba as PRE and glyphosate as POST, (3) acetochlor and dicamba as PRE and glyphosate and dicamba as POST, and (4) acetochlor and fomesafen as PRE and acetochlor, glyphosate and dicamba as POST. The five weed removal times included the V1, V3, V6, R2 and R5, and there were also weedy and weed-free season long plots. By utilizing herbicide regimes, the CTWR was delayed to 632 GDD (until V4 soybean growth stage, 28 days after emergence) for acetochlor and dicamba as PRE and glyphosate as POST, 861 GDD (until V6 soybean growth stage, 32 days after emergence) for acetochlor and dicamba as PRE and glyphosate and dicamba as POST, and 1060 GDD (until R1 soybean growth stage, 42 days after emergence) for acetochlor and fomesafen as PRE and acetochlor, glyphosate and dicamba as POST.

PRE herbicides influence critical time of weed removal in glyphosate-resistant corn

2020 ◽  
pp. 1-8
Author(s):  
Ayse Nur Ulusoy ◽  
O. Adewale Osipitan ◽  
Jon Scott ◽  
Amit J. Jhala ◽  
Nevin C. Lawrence ◽  
...  
Keyword(s):  
Weed Management ◽  
Growth Stage ◽  
Critical Time ◽  
Maximum Growth ◽  
Field Studies ◽  
Growth Stages ◽  
Herbicide Resistant ◽  
Main Plot ◽  
Sites Of Action ◽  
Weed Removal

Abstract Residual herbicides applied PRE provide early season weed control, potentially avoid the need for multiple POST herbicides, and can provide additional control of herbicide-resistant weeds. Thus, field studies were conducted in 2017 and 2018 at Concord, NE, to evaluate the influence of PRE herbicides on critical time for postemergence weed removal (CTWR) in corn. The studies were arranged in a split-plot design that consisted of three herbicide regimes as main plot treatments and seven weed removal timings as subplot treatments in four replications. The herbicide regimes included no PRE herbicide, atrazine, and a premix of saflufenacil/dimethenamid-P mixed with pyroxasulfone. The weed removal timings were at V3, V6, V9, V12, and V15 corn growth stages and then plots were kept weed-free until harvest. A weed-free and nontreated control were included for comparison. The relationship between corn growth or yield, and weed removal timings in growing degree days (GDD) was described by a four-parameter log-logistic model. This model was used to estimate the critical time for weed removal based on 5% crop yield loss threshold. A delay in weed removal until the V2 to V3 corn growth stage (91 to 126 GDD) reduced corn biomass by 5% without PRE herbicide application. The CTWR started at V3 without PRE herbicide in both years. Atrazine delayed the CTWR up to V5 in both years, whereas saflufenacil/dimethenamid-P plus pyroxasulfone further delayed the CTWR up to the V10 and V8 corn growth stages in 2017 and 2018, respectively. Herbicide applied PRE particularly with multiple sites of action can delay the CTWR in corn up to a maximum growth stage of V10, and delay or reduce the need for POST weed management.

Thermal energy utilization in mungbean (Vigna radiata L.) as influenced by sowing times and genotypes

2019 ◽  
Author(s):  
A.K. Dhaka ◽  
Karmal Singh ◽  
Satish Kumar ◽  
Bhagat Singh ◽  
J.K. Bhatia ◽  
...  
Keyword(s):  
Field Experiment ◽  
Thermal Energy ◽  
Vigna Radiata ◽  
Energy Use ◽  
Energy Utilization ◽  
Yield Attributes ◽  
Kharif Season ◽  
Split Plot ◽  
Main Plot ◽  
Plot Design

Field experiment was conducted to study the thermal energy utilization in mungbean as influenced by sowing times and genotypes during Kharif season of 2014 and 2016 at Research farm of CCS Haryana Agricultural University, Hisar, India. Experiment was laid out in split plot design with four main-plot treatments of sowing times (2nd fortnight of June, 1st fortnight of July, 2nd fortnight of July and 1st fortnight of August) and four sub-plot treatments comprised of genotypes (MH 421, Basanti, Sattya and MH 318). The results indicated that yield and yield attributes, phenology, agro-meteorological indices (GDD, HTV, HYTV, PTU and PAR) and yield based thermal energy use efficiencies (HUE, HTUE, HYTUE, PTUE and RUE) were significantly influenced by sowing times and genotypes. Early sowing (2nd fortnight of June) of mungbean was found more suitable and recorded significantly higher yield and thermal energy use efficiencies. Among the genotypes MH 318 was recorded with maximum thermal use efficiencies followed by MH 421.

Preemergence herbicide delays the critical time of weed removal in popcorn

2019 ◽  
Vol 33 (6) ◽  
pp. 785-793 ◽  
Author(s):  
Ethann R. Barnes ◽  
Stevan Z. Knezevic ◽  
Nevin C. Lawrence ◽  
Suat Irmak ◽  
Oscar Rodriguez ◽  
...  
Keyword(s):  
Growth Stage ◽  
Yield Loss ◽  
Critical Time ◽  
Yield Reduction ◽  
Growth Stages ◽  
Growing Degree Days ◽  
Degree Days ◽  
South Central ◽  
Main Plot ◽  
Weed Removal

AbstractUnderstanding the critical time of weed removal (CTWR) is necessary for designing effective weed management programs in popcorn production that do not result in yield reduction. The objective of this study was to determine the CTWR in popcorn with and without a premix of atrazine and S-metolachlor applied PRE. Field experiments were conducted at the University of Nebraska–Lincoln, South Central Agricultural Laboratory near Clay Center, NE in 2017 and 2018. The experiment was laid out in a split-plot design with PRE herbicide as the main plot and weed removal timing as the subplot. Main plots included no herbicide or atrazine/S-metolachlor applied PRE. Subplot treatments included a weed-free control, a non-treated control, and weed removal timing at V3, V6, V9, V15, and R1 popcorn growth stages and then kept weed free throughout the season. A four-parameter log-logistic function was fitted to percentage popcorn yield loss and growing degree days separately to each main plot. The number of growing degree days, when 5% yield loss was achieved, was extracted from the model and compared between main plots. The CTWR was from the V4 to V5 popcorn growth stage in absence of PRE herbicide. With atrazine/S-metolachlor applied PRE, the CTWR was delayed until V10 to V15. It is concluded that, to avoid yield loss, weeds must be controlled before the V4 popcorn growth stage when no PRE herbicide is applied, and PRE herbicide, such as atrazine/S-metolachlor in this study, can delay the CTWR until the V10 growth stage.

Critical time for weed removal in glyphosate-resistant soybean as influenced by preemergence herbicides

2019 ◽  
Vol 33 (03) ◽  
pp. 393-399 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Pavle Pavlovic ◽  
O. Adewale Osipitan ◽  
Ethann R. Barnes ◽  
Clint Beiermann ◽  
...  
Keyword(s):  
Field Experiments ◽  
Critical Time ◽  
Growing Season ◽  
Control Programs ◽  
Main Plot ◽  
Repeated Use ◽  
Sites Of Action ◽  
Alternative Sites ◽  
Preemergence Herbicides ◽  
Weed Removal

AbstractWidespread and repeated use of glyphosate resulted in an increase in glyphosate-resistant (GR) weeds. This led to an urgent need for diversification of weed control programs and use of PRE herbicides with alternative sites of action. Field experiments were conducted over a 4-yr period (2015 to 2018) across three locations in Nebraska to evaluate the effects of PRE-applied herbicides on critical time for weed removal (CTWR) in GR soybean. The studies were laid out in a split-plot arrangement with herbicide regime as the main plot and weed removal timing as the subplot. The herbicide regimes used were either no PRE or premix of either sulfentrazone plus imazethapyr (350 + 70 g ai ha−1) or saflufenacil plus imazethapyr plus pyroxasulfone (26 + 70 + 120 g ai ha−1). The weed removal timings were at V1, V3, V6, R2, and R5 soybean stages, with weed-free and weedy season-long checks. Weeds were removed by application of glyphosate (1,400 g ae ha−1) or by hoeing. The results across all years and locations suggested that the use of PRE herbicides delayed CTWR in soybean. In particular, the CTWR without PRE herbicides was determined to be around the V1 to V2 (14 to 21 d after emergence [DAE]) growth stage, depending on the location and weed pressure. The use of PRE-applied herbicides delayed CTWR from about the V4 (28 DAE) stage up to the R5 (66 DAE) stage. These results suggest that the use of PRE herbicides in GR soybean could delay the need for POST application of glyphosate by 2 to 5 wk, thereby reducing the need for multiple applications of glyphosate during the growing season. Additionally, the use of PRE herbicides could provide additional modes of action needed to manage GR weeds in GR soybean.

Effect of varieties and weeding regimes on weed and performance of

2011 ◽  
Vol 1 (3) ◽  
pp. 121-130
Author(s):  
U. Ismaila ◽  
M. G. Kolo ◽  
A. U. Gbanguba
Keyword(s):  
Oryza Sativa ◽  
Active Ingredient ◽  
Oryza Sativa L ◽  
Weed Suppression ◽  
Dichlorophenoxyacetic Acid ◽  
Aerobic Rice ◽  
Split Plot ◽  
Main Plot ◽  
And Performance ◽  
Plot Design

A Field trial was conducted at the aerobic rice experimental field of the NationalCereals Research Institute (NCRI), Badeggi, Nigeria (9 ° 04 N and 6° 7 E)in 2007 and 2008 wet seasons to determine the weed competitiveness andperformance of inter Ã¢â‚¬Â and intra‐specific aerobic rice (Oryza sativa L.) varietiesunder seven weeding regimes. The trial was laid out in a split plot designwith the two varieties of rice (NERICA 1 as inter Ã¢â‚¬Âspecific and FARO 46 asintra Ã¢â‚¬Âspecific) assigned to the main plot while seven weeding regimes (hoeweeding at 25, 45, and 65 days after sowing (DAS), 25 DAS, 45 DAS, 25 and45 DAS, application of 3’,3’ Ã¢â‚¬Â dichloropropionanilide /2, 4 – Dichlorophenoxyacetic acid (orizo plus R) by Candel Company Ltd. at 3.5 kg active ingredient(ai )ha Ã¢â‚¬Â1 at 25 DAS, hoe weeding at 25 DAS followed by orizo plus at 3.5 kg aiat 45 DAS and weedy check) constituted the sub – plots. The treatmentswere replicated three times in a split plot design. From the results, interspecificvariety (NERICA1) had better weed suppression ability with highergrain yield of 3.1 t ha Ã¢â‚¬Â1 than the intra‐specific variety (FARO 46). Weed controlwas better when hoe weeding was done at 25, 45 and 65 DAS or 25 and45 DAS and at 25 DAS followed by orizo plus at 45 DAS than in other treatments.However, hoe weeding at 25, 45 and 65 DAS gave significantlygreater grain yield than other treatments. Although economic yield was obtainedfrom hoe weeding at 25 DAS followed by orizo plus at 45 DAS.

scholarly journals PENGARUH FREKUENSI DAN PERIODE PEMBERIAN PAKAN TERHADAP POTONGAN KOMERSIAL KARKAS AYAM BURAS SUPER

2017 ◽  
Vol 20 (3) ◽  
pp. 118
Author(s):  
OKTAWANTARI E. F. ◽  
E. SUPRIJATNA ◽  
W. SARENGAT
Keyword(s):  
Split Plot ◽  
Main Plot ◽  
Plot Design

Penelitian ini bertujuan untuk mengetahui pengaruh frekuensi dan periode pemberian pakan terhadap potongankomersial karkas. Materi yang digunakan yaitu anak ayam buras super 252 ekor (unsexed) umur sehari dengan bobotawal 37,88 ±1,89 gram. Kandang digunakan berupa tipe litter yang dibagi menjadi 36 unit dengan masing-masingunit berisi 7 ekor ayam. Rancangan percobaan yang digunakan adalah Split Plot Design dengan 4 ulangan yangterdiri dari main plot yaitu 3 taraf frekuensi pemberian pakan dan sub plot yaitu 3 taraf periode pemberian pakan.Data yang diperoleh dianalisis ragam dengan uji F taraf 5%. Hasil penelitian menunjukkan bahwa interaksi antarafrekuensi dengan periode pemberian pakan tidak berpengaruh nyata (p>0,05), dan masing-masing perlakuan tidakmenunjukan pengaruh yang nyata (p>0,05) terhadap potongan komersial ayam buras super. Kesimpulan daripenelitian ini adalah meskipun tidak ada pengaruh perlakuan terhadap potongan komersial karkas tetapi frekuensi1 kali dan periode 14 jam (F1P3) merupakan perlakuan paling efisien untuk diaplikasikan.

Response of rice varieties to different sowing windows under Konkan conditions

2017 ◽  
Author(s):  
D. N. Jagtap ◽  
U. V. Mahadkar ◽  
S. A. Chavan
Keyword(s):  
Field Experiment ◽  
Grain Yield ◽  
Rice Variety ◽  
Rice Crop ◽  
Economic Returns ◽  
Rice Varieties ◽  
Straw Yield ◽  
Long Duration ◽  
Main Plot ◽  
Plot Design

A field experiment was conducted during kharif season 2015-16 to study the response of rice varieties to different sowing windows under Konkan conditions. The experiment was laid out in split plot design with three replications. The main plot treatments were three sowing windows, viz., 23rd Met Week, 24th Met Week, 25thMet Week. The sub plot treatments comprised five rice varietiesviz., Karjat-5, Palghar-1, Jaya, Swarna and Karjat-2. Thus there were 45 treatment combinations. Results revealed that rice crop sown on 23rd Met. Week recorded significantly higher grain yield (5782 kg ha-1) and straw yield (6462 kg ha-1). Long duration rice variety Swarna recorded the maximum grain yield (5782 kg ha-1) as well as straw yield (6462 kg ha-1), which was significantly higher over all other varieties under study except variety Jaya which was at par. From the present investigation it can be concluded that kharif rice in Konkan be sown during 23rd meteorological week with rice variety Swarna followed by conventional variety Jaya, so as to obtain higher yield and economic returns

scholarly journals KADAR AIR, pH DAN TOTAL MIKROBA DAGING AYAM YANG DITAMBAHKAN KUNYIT PUTIH (Curcuma mangga Val.)

ZOOTEC ◽  
2016 ◽  
Vol 36 (2) ◽  
pp. 405
Author(s):  
John Wala ◽  
Tiltje Ransaleleh ◽  
Indyah Wahyuni ◽  
Merri Rotinsulu
Keyword(s):  
Water Content ◽  
Cold Storage ◽  
Storage Time ◽  
Chicken Meat ◽  
Randomized Design ◽  
Split Plot ◽  
Main Plot ◽  
Completely Randomized Design ◽  
Plot Design

THE EFFECT OF WHITE TURMERIC (Curcuma mangga Val.) ADDITION ON CHICKEN MEAT AGAINST WATER CONTENT, pH AND MICROORGANISM NUMBERS. The purpose of this research was to determine the effect of the addition of white turmeric (Curcuma manggaVal.) on chicken meat at cold storage (4oC). This research used Split Plot Design with 2 treatment factors based on completely randomized design. The Main Plot contains of 4 treatments (A0 = without storage, A1 = 3 days storage, A2 = 6 days storage, A3 = 9 days storage) and the Sub Plot contains of 4 treatments (B0 = without white turmeric, B1 = 4% grating of white turmeric, B2 = 8% grating of white turmeric, B3 = 12% grating of white turmeric). The variable that observed are water content, pH and microorganism number. The result showed that the addition of white turmeric was not significant affected (P > 0.05) against water contentof chicken meat, however it was highly significant affected (P < 0.01) against pH and microorganism numbers of chicken meat. Storage time was highly significant affected (P <0.01) against water content, pH and microorganism numbers of chicken meat. The interaction between both of treatment factors was given highly significant affected (P < 0.01) against water content, pH and microorganism numbers of chicken meat. As a conclusion, the addition of white turmeric on chicken meat was not affected against water content, however it can decrease pH and obstruct microorganism activity. Keywords : chicken meat, white turmeric, pH, water content, microorganism numbers

scholarly journals Pemanfaatan Sluri Gas Bio yang Diperkaya Urin Kambing Fermentasi Terhadap Kecepatan Tumbuh, Produksi Daun dan Komposisi Nutrisi Pada Indigofera Zolliengeriana

2018 ◽  
Vol 1 (2) ◽  
pp. 188-193
Author(s):  
Rudini Arif ◽  
N Ginting ◽  
I Sembiring
Keyword(s):  
Animal Feed ◽  
Nutrient Composition ◽  
Growth Speed ◽  
Research Station ◽  
Leaf Production ◽  
Split Plot ◽  
Main Plot ◽  
Indigofera Zollingeriana ◽  
North Sumatra ◽  
Plot Design

Karakteristik pakan ternak adalah tersedia dalam jumlah besar, murah dengan kualitas baik. Leguminosa seperti Indigofera zollingeriana adalah salah satu tanaman yang memenuhi karakteristik tersebut. Penelitian ini bertujuan untuk mengetahui pemanfaatan sluri gas bio yang diperkaya urin kambing fermentasi terhadap kecepatan tumbuh, produksi daun dan komposisi nutrisi pada Indigofera zollingeriana. Penelitian dilaksanakan di Lahan Loka Penelitian Kambing Potong Sei Putih, Kecamatan Galang Lubuk Pakam Sumatera Utara, pada bulan Maret sampai dengan Agustus 2015 menggunakan 24 buah bibit tanaman Indigofera zollingeriana. Rancangan yang dipakai dalam penelitian ini adalah rancangan split plot design (petak terbagi) dengan tiga dosis pemupukan yang berbeda pada petak utama yaitu R0 (75 ml/plot), R1 (150 ml/plot) dan R2 (225 ml/plot) dan dua jenis pupuk varisi sluri gas bio yang berbeda yaitu S1 (sluri) dan S2 (sluri yang diperkaya dengan urin kambing fermentasi) dengan 4 ulangan. Parameter yang diteliti adalah tinggi tanaman, produksi daun dan komposisi nutrisi. Hasil penelitian menunjukkan bahwa dosis pemupukan sluri dan sluri diperkaya urin kambing fermentasi tidak berpengaruh terhadap kecepatan tumbuh, produksi daun dan lemak kasar. Tidak terdapat perbedaan nyata antara jenis pupuk variasi sluri gas bio pada kecepatan tumbuh, namun terdapat pengaruh yang nyata (P<0,05) pada produksi daun dan komposisi nutrisi. Kesimpulan dari penelitian ini adalah penggunaan sluri dengan diperkaya urin kambing meningkatkan produktivitas Indigofera zolleingeriana.. Characteristics of animal feed are its availability in large quantities, low price, and good quality. Legumes such as Indigofera zollingeriana are one of the plants that meet these characteristics. This study aimed to determine the utilization of bio-gas slurry enriched with fermented goat urine on growth speed, leaf production and nutrient composition in Indigofera zollingeriana. The research was conducted at the Sei Putih Goat Cut Research Station, North Sumatra, Galang Lubuk Pakam District, from March to August 2015 using 24 Indigofera zollingeriana seedlings. The design used in this study was a split plot design with three different fertilization doses in the main plot, namely R0 (75 ml/plot), R1 (150 ml/plot) and R2 (225 ml/plot) and two different types of bio-gas slurry fertilizers namely S1 (slurry) and S2 (slurry enriched with fermented goat urine) with 4 replications. The parameters studied were plant height, leaf production and nutrient composition. The results showed that the dose of fertilizing slurry and slurry enriched with fermented goat urine did not affect growth speed, leaf production and crude fat. There were no significant differences between the types of bio gas slurry fertilizers at growth speed, but there was a significant effect (P <0.05) on leaf production and nutrient composition. The conclusion of this study was the use of slurry with enriched goat urine increased the productivity of Indigofera zollingeriana.

scholarly journals Pengaruh Frekuensi Pemberian Pakan dan Awal Pemberian Pakan terhadap Performa Ayam Buras Super

2017 ◽  
Vol 12 (2) ◽  
pp. 152-164
Author(s):  
E. Rahmawati ◽  
E. Suprijatna ◽  
D. Sunarti
Keyword(s):  
Split Plot ◽  
Main Plot ◽  
Plot Design

Penelitian ini bertujuan untuk mengetahui pengaruh interaksi frekuensi pemberian pakan dengan awal pemberian pakan terhadap performa ayam buras super. Materi yang digunakan adalah 252 ekor anak ayam buras super unsex umur 1 hari dengan rata-rata bobot badan awal 37,88 ± 1,89 g (CV = 5,02%). Pakan yang digunakan adalah pakan komersial. Rancangan percobaan yang digunakan adalah Split Plot Design dengan main plot yaitu 3 taraf frekuensi pemberian pakan (F1 = frekuensi pemberian pakan 1 kali, F2 = frekuensi pemberian pakan 2 kali, F3 = frekuensi pemberian pakan 3 kali) dan sub plot yaitu 3 taraf awal pemberian pakan (A1 = awal pemberian pakan pukul 04:00 WIB, A2 = awal pemberian pakan pukul 06:00 WIB, A3 = awal pemberian pakan pukul 08:00 WIB) dalam 4 ulangan sehingga terdapat 36 unit percobaan, tiap unit percobaan terdiri dari 7 ekor ayam. Data yang diperoleh dianalisis menggunakan analisis ragam dan uji F pada taraf 5%. Hasil penelitian menunjukkan bahwa pengaruh interaksi antara frekuensi pemberian pakan dengan awal pemberian pakan tidak nyata (p>0,05), demikin pula masing-masing perlakuan tidak menimbulkan pengaruh yang nyata (p>0,05) terhadap performa ayam buras super, tetapi  jika dilihat dari keuntungan ekonomis berdasarkan selisih antara total penjualan dan biaya pakan, kombinasi perlakuan F3A1 (frekuensi pemberian pakan 3 kali dengan awal pemberian pakan pukul 04:00 WIB) menunjukkan hasil terbaik. Kata kunci : ayam buras super, performa, pemberian pakan, frekuensi, awal

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