scholarly journals Effects of tillage and weed management on the vertical distribution of microclimate and grain yield in a winter wheat field  

2013 ◽  
Vol 59 (No. 5) ◽  
pp. 201-207 ◽  
Author(s):  
H. Han ◽  
T. Ning ◽  
Z. Li

This paper presents results of a field study of the influence of tillage and weed on the vertical distribution of microclimate in the upper, middle, and deeper layers of a winter wheat population and grain yield during the 2008–2009 and 2009–2010 winter wheat growing seasons. The results showed that the microclimate of the winter wheat canopy was different among the upper, middle, and deeper layers. Illumination was higher in the upper layer of the canopy than in the middle and deeper layers; under no-tillage + weed-reserving, a greater difference was found among the 3 layers. In the upper layer, illumination was the highest and lowest under no-tillage + weed-control and conventional tillage + weed-control, respectively. In the upper layer, air temperature was higher under no-tillage + weed-control than under conventional tillage + weed-control. The effects of air temperature in the middle and deeper layers were relatively low with tillage and considerably higher with weeds. Relative humidity was the highest and lowest under no-tillage + weed-reserving and conventional tillage + weed-control, respectively. During the winter wheat growing seasons, illumination and air temperature were lower at the heading stage and increased to a maximum at the filling stage, whereas the trend for relative humidity was the opposite. With weed-control, grain yield was significantly (LSD, P < 0.05) higher under conventional tillage than under no-tillage; with weed-reserving, no significant (LSD, P < 0.05) differences in grain yield were found between conventional tillage and no-tillage. The results showed that tillage and weed influenced microclimate vertical distribution in the winter wheat canopy and grain yield of winter wheat.

2008 ◽  
Vol 23 (2) ◽  
pp. 107-114
Author(s):  
Milena Simic ◽  
Nebojsa Momirovic ◽  
Zeljko Dolijanovic ◽  
Zeljko Radosevic

The effects of different herbicide combinations: control (1), alachlor+linuron (2), and alachlor+linuron+imazethapyr (3) were investigated in double-cropped soybean grown in two row spacing variants, 38 cm and 76 cm, under conventional tillage (CT) or no-tillage (NT). In trials conducted on a sandy loam soil at Zemun Polje, high weediness had a negative effect of on the yield of double-cropped soybean, especially at the higher row spacing tested and with no-tillage. Regression and correlation data revealed a dependence of weediness in double-cropped soybean on tillage system and herbicide combination, and dependence of soybean yield on tillage system.


2015 ◽  
Vol 29 (3) ◽  
pp. 367-373 ◽  
Author(s):  
Drew J. Lyon ◽  
Frank L. Young

Spring barley can be used to diversify and intensify winter wheat-based production systems in the U.S. Pacific Northwest. The objective of this study was to describe the effects of tillage system and weed management level (WML) on weed control and spring barley grain yield when grown in a winter wheat-spring barley-spring dry pea rotation. A long-term integrated pest management field study examined the effects of three WMLs (minimum, moderate, and maximum) and two tillage systems (conservation and conventional) on weed control and barley grain yield. Total weed biomass at harvest was 8.0 and 59.7 g m−2for the maximum and minimum WMLs, respectively, in the conservation tillage system, but was similar and averaged 12.2 g m−2for all three WMLs in the conventional tillage system. Despite greater weed biomass with minimum weed management in the conservation tillage system, barley grain yields averaged 5,060 and 4,780 kg ha−1for the conservation tillage and conventional tillage systems, respectively. The benefits of conservation tillage require adequate herbicide inputs.


2021 ◽  
pp. 1-14
Author(s):  
Jodie A. Crose ◽  
Misha R. Manuchehri ◽  
Todd A. Baughman

Abstract Three herbicide premixes have recently been introduced for weed control in wheat. These include: halauxifen + florasulam, thifensulfuron + fluroxypyr, and bromoxynil + bicyclopyrone. The objective of this study was to evaluate these herbicides along with older products for their control of smallseed falseflax in winter wheat in Oklahoma. Studies took place during the 2017, 2018, and 2020 winter wheat growing seasons. Weed control was visually estimated every two weeks throughout the growing season and wheat yield was collected in all three years. Smallseed falseflax size was approximately six cm in diameter at time of application in all years. Control ranged from 96 to 99% following all treatments with the exception of bicyclopyrone + bromoxynil and dicamba alone, which controlled falseflax 90%. All treatments containing an acetolactate synthase (ALS)-inhibiting herbicide achieved adequate control; therefore, resistance is not suspected in this population. Halauxifen + florasulam and thifensulfuron + fluroxypyr effectively controlled smallseed falseflax similarly to other standards recommended for broadleaf weed control in wheat in Oklahoma. Rotational use of these products allows producers flexibility in controlling smallseed falseflax and reduces the potential for development of herbicide resistance in this species.


Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


2006 ◽  
Vol 20 (3) ◽  
pp. 622-626 ◽  
Author(s):  
Patrick W. Geier ◽  
Phillip W. Stahlman ◽  
John C. Frihauf

Field experiments were conducted during 2003 and 2004 to compare the effectiveness of KIH-485 and S-metolachlor for PRE weed control in no-tillage and conventional-tillage corn. Longspine sandbur control increased as KIH-485 or S-metolachlor rates increased in conventional-tillage corn, but control did not exceed 75% when averaged over experiments. Both herbicides controlled at least 87% of green foxtail with the exception of no-tillage corn in 2004, when KIH-485 was more effective than S-metolachlor at lower rates. Palmer amaranth control ranged from 85 to 100% in 2003 and 80 to 100% in 2004, with the exception of only 57 to 76% control at the lowest two S-metolachlor rates in 2004. Puncturevine control exceeded 94% with all treatments in 2003. In 2004, KIH-485 controlled 86 to 96% of the puncturevine, whereas S-metolachlor controlled only 70 to 81%. Mixtures of atrazine with KIH-485 or S-metolachlor generally provided the most effective control of broadleaf weeds studied.


2015 ◽  
Vol 153 (8) ◽  
pp. 1353-1364 ◽  
Author(s):  
C. Y. ZHENG ◽  
J. CHEN ◽  
Z. W. SONG ◽  
A. X. DENG ◽  
L. N. JIANG ◽  
...  

SUMMARYTen leading varieties of winter wheat released during 1950–2009 in North China were tested in a free-air temperature increase (FATI) facility. The FATI facility mimicked the local air temperature pattern well, with an increase of 1·1 °C in the daily mean temperature. For all the tested varieties, warming caused a significant reduction in the total length of wheat growth period by 5 days and especially in the pre-anthesis period, where it was reduced by 9 days. However, warming increased wheat biomass production and grain yield by 8·4 and 11·4%, respectively, on an average of all the tested varieties. There was no significant difference in the warming-led reduction in the entire growth period among the tested varieties. Interestingly, the warming-led increments in biomass production and grain yield increased along with the variety release year. Significantly higher warming-led increases in post-anthesis biomass production and 1000-grain weight were found in the new varieties compared to the old ones. Meanwhile, a significant improvement in plant productivity was noted due to wheat breeding during the past six decades, while no significant difference in the length of entire growth period was found among the varieties released in different eras. The results demonstrate that historical wheat breeding might have enhanced winter wheat productivity and adaptability through exploiting the positive effects rather than mitigating the negative impacts of warming on wheat growth in North China.


2017 ◽  
Vol 35 (0) ◽  
Author(s):  
L.F. CIESLIK ◽  
R.A. VIDAL ◽  
A.B. MACHADO ◽  
M.M. TREZZI

ABSTRACT Grass weeds are common in summer crops and strongly decreases the grain yield of the common bean crop. The time of herbicide application influences the variability of environmental conditions and affects the product performance. The objectives of this work were to identify the time of fluazifop-p-butyl (fluazifop) application which gives best grass weed control in the common bean crop and to elucidate the environmental variables most important for the efficacy of this herbicide. Field experiments were conducted involving five application times (2 a.m., 6 a.m., 11 a.m., 4 p.m. and 9 p.m.) and five doses of fluazifop (80, 110, 140, 170 and 200 g ha-1), with additional no-herbicide control. At the time of the herbicide application it was determined the air temperature, relative humidity, the photosynthetically active radiation (PAR) and the leaf angle, whereas the weed control and the dry mass of the weed Urochloa plantaginea was assessed at 20 days after treatment (DAT). Efficacy on grass control with fluazifop was dependent on the herbicide dose and on the time of day that the product was applied. Spray at early morning hours (6 a.m.) showed better efficacy on weed control in relation to periods during warmer conditions of the day (11 a.m. and 4 p.m.). Nocturnal fluazifop application had better weed control when compared to herbicide sprayed in the afternoon. The air temperature, relative humidity and PAR were correlated to weed leaf angle, which correlated the most with fluazifop performance.


Author(s):  
Nguyễn Trung Hải ◽  
Trần Thanh Đức ◽  
Vi Thị Linh

Nghiên cứu này nhằm đánh giá tác động của các biện pháp làm đất và mật độ trồng khác nhau đến quá trình sinh trưởng, phát triển, năng suất và hiệu quả kinh tế của giống ngô lai HQ2000 trên đất cát nội đồng trong vụ Đông Xuân năm 2018-2019 tại Thừa Thiên Huế. Thí nghiệm thứ nhất gồm 3 công thức gồm làm đất truyền thống, làm đất tối thiểu và không làm đất trong đó thí nghiệm thứ hai gồm 4 công thức với mật độ gieo trồng lần lượt là 47.058, 53.333, 61.538 và 66.666 cây/ha. Kết quả thí nghiệm cho thấy: Thời gian hoàn thành các giai đoạn sinh trưởng và phát triển ở các biện pháp làm đất tối thiểu có xu hướng ngắn hơn các công thức làm đất truyền thống; chiều cao cây cuối cùng dao động từ 154 đến 175cm, số lá dao động từ 16 đến 18 lá, diện tích lá đóng bắp có xu hướng giảm ở các công thức làm đất tối thiểu trong khi các yếu tố khác như chiều cao đóng bắp, chiều dài bắp, đường kính bắp và đường kính lóng gốc ở các công thức thí nghiệm dao động tương đối ít. Năng suất lý thuyết dao động từ 61 đến 72 tạ/ha, năng suất thực thu đạt cao nhất là 59,8 tạ/ha ở công thức không làm đất. Đối với biện pháp canh tác truyền thống, năng suất đạt cao nhất ở mật độ 18,5 kg hạt giống/ha (63,4 tạ/ha). Ở các công thức thí nghiệm, lợi nhuận đạt cao nhất ở công thức không làm đất và ở mật độ trồng là 18,5 kg hạt giống/ha, tương đương 61.538 cây/ha.  ABSTRACT This study aims to evaluate the impact of different tillage methods and planting densities on the growth, development, grain yield and economic efficiency of hybrid maize HQ2000 on sandy soil in the 2018-2019 Winter-Spring season in Thua Thien Hue province. The first trial consisted of three treatments including conventional tillage, limited tillage and no tillage; the second trial consisted of four treatments with planting density of 47.058, 53.333, 61.538 và 66.666 plants/ha, respectively. Experimental results showed that: The completed time of the growth and development stages at the minimum tillage methods was shorter than conventional tillage treatments; final plant height varied from 154 to 175cm, the number of leaves ranged from 16 to 18 leaves, the leaf area at ​​corn position decreased in minimum tillage treatments while other factors such as ear height, ear length, ear diameter and stalk diameter at prop root position fluctuated slightly. Potential grain yield varied from 6.1 to 7.2 tons/ha, the highest actual grain yield was 5.98 tons/ha in the no-tillage treatment. For conventional tillage, the highest grain yield was at 18.5 kg seed/ha treatment (6.34 tons/ha). In the experimental treatments, the highest profit was achieved in the no-tillage treatment and in planting density of 18.5 kg seed/ha, equivalent 61,538 plants/ha.      


2019 ◽  
Vol 1 (20) ◽  
Author(s):  
Milenko Ćurčić ◽  
Dragica Milinković ◽  
Dragana Radivojević ◽  
Dijana Đurić

Vertical distribution of species and infraspecies taxa of diatoms (Bacillariophyta) on well mosses where they live epiphytically, and a relative number of individuals per surface area unit were followed in 8 open wells with shadoof. Researches were conducted during 2015-2016 through four seasons. Sampling of algae material from well mosses that cover interior of the well was conducted on every 50 cm of depth starting from the surface (O cm) to 200 cm. Considering the specificity of substrate on which diatoms live in wells, and those are mosses that are especially expressed to 1,5 m depth of well and whose leafs cover each other and have an effect on light climate of micro habitat with already existing differences in intensity and quality of light, relative humidity of air, temperature of air on different depths, density of populations of certain species Bacillariophyta is in function of such ecological occasions on different well depths. It is concluded that the most abundant populations on mosses of researched wells, during most of the year, develop four aerophilic species of diatoms: Navicula contenta Grunow, N. atomus var. atomus (Kiitzing) Grunow, Achnanthes lanceolata (Brebisson) Grunow ssp. lanceolata var. lanceolata and Amphora normanii Rabenhorst.


2018 ◽  
Vol 64 (No. 7) ◽  
pp. 310-316 ◽  
Author(s):  
Mirosavljevic Milan ◽  
Momcolovic Vojislava ◽  
Maksimovic Ivana ◽  
Putnik-Delic Marina ◽  
Pržulj Novo ◽  
...  

The aim of this study was to improve understanding of (1) the effect of genotypic and environmental factors on pre-anthesis development and leaf appearance traits of barley and wheat; (2) the relationship of these factors with grain yield, and (3) the differences between these two crops across different environments/sowing dates. Therefore, trials with six two-row winter barley and six winter wheat cultivars were carried out in two successive growing seasons on four sowing dates. Our study showed that the observed traits varied between species, cultivars and sowing dates. In both growing seasons, biomass at anthesis and grain yield declined almost linearly by delaying the sowing date. There was no clear advantage in grain yield of wheat over barley under conditions of later sowing dates. Generally, barley produced more leaf and had shorter phyllochron than wheat. Both wheat and barley showed a similar relationship between grain yield and different pre-anthesis traits.


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