Response of Sugarbeets(Beta vulgaris)to Sublethal Rates of 2,4-D

Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 629-631 ◽  
Author(s):  
E. E. Schweizer

The herbicide 2,4-D [(2,4-dichlorophenoxy)acetic acid] was applied as sublethal rates to sugarbeets(Beta vulgarisL. ‘Mono Hy D2’) in the field at different growth stages to determine its effect on growth and yield. The greatest reduction in top growth occurred when the highest rate of 2,4-D, 0.07 kg/ha, was applied to the oldest plants (12-leaf stage). All rates of 2,4-D reduced the components of sucrose yield (percentage sucrose, percentage purity, and root weight) to the extent that, together, the three components contributed to a significant reduction in recoverable sucrose. The yields of recoverable sucrose were reduced 6.8, 7.8, and 13.2% by the 0.017, 0.035, and 0.07 kg/ha rates, respectively.

Weed Science ◽  
1986 ◽  
Vol 34 (6) ◽  
pp. 953-956 ◽  
Author(s):  
Drew J. Lyon ◽  
Robert G. Wilson

The effects of the dimethylamine salt of dicamba (3,6-dichloro-2-methoxybenzoic acid) and the dimethylamine salt of 2,4-D [(2,4-dichlorophenoxy)acetic acid] on fieldbeans (Phaseolus vulgarisL. ‘Great Northern Valley’) were studied in order to assess the potential hazards of using these herbicides in areas adjoining fieldbean production. Dicamba and 2,4-D were applied to fieldbeans at three different rates (1.1, 11.2, and 112.5 g ai/ha) and four different growth stages (preemergence, second trifoliolate leaf, early bloom, and early pod). Application of 2,4-D preemergence or in the second trifoliolate leaf stage of growth did not reduce seed yield, delay maturity, or reduce germination of seed obtained from treated plants. Dicamba or 2,4-D applied at 112.5 g/ha to fieldbeans in the early bloom or early pod stages of growth consistently reduced seed yield, delayed maturity, and reduced germination percentage. Fieldbeans exhibited a greater overall sensitivity to dicamba than to 2,4-D.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1971
Author(s):  
Xingyang Song ◽  
Guangsheng Zhou ◽  
Qijin He ◽  
Huailin Zhou

Drought stress has adverse effects on crop growth and yield, and its identification and monitoring play vital roles in precision crop water management. Accurately evaluating the effect of drought stress on crop photosynthetic capacity can provide a basis for decisions related to crop drought stress identification and monitoring as well as drought stress resistance and avoidance. In this study, the effects of different degrees of persistent drought in different growth stages (3rd leaf stage, 7th leaf stage and jointing stage) on the maximum carboxylation rate at a reference temperature of 25 °C (Vcmax25) of the first fully expanded leaf and its relationship to the leaf water content (LWC) were studied in a field experiment from 2013 to 2015. The results indicated that the LWC decreased continuously as drought stress continued and that the LWC decreased faster in the treatment with more irrigation. Vcmax25 showed a decreasing trend as the drought progressed but had no clear relationship to the growth stage in which the persistent drought occurred. Vcmax25 showed a significantly parabolic relationship (R2 = 0.701, p < 0.001) with the LWC, but the different degrees of persistent drought stress occurring in different growth stages had no distinct effect on the LWC values when Vcmax25 reached its maximum value or zero. The findings of this study also suggested that the LWC was 82.5 ± 0.5% when Vcmax25 reached its maximum value (42.6 ± 3.6 μmol m−2 s−1) and 67.6 ± 1.2% (extreme drought) when Vcmax25 reached zero. These findings will help to improve crop drought management and will be an important reference for crop drought identification, classification and monitoring as well as for the development of drought monitoring and early warning systems for other crops or maize varieties.


Sugar Tech ◽  
2019 ◽  
Vol 22 (3) ◽  
pp. 504-517 ◽  
Author(s):  
Ke Shao ◽  
Zhenqing Bai ◽  
Manhong Li ◽  
Chao Yu ◽  
Jinwang Shao ◽  
...  

2021 ◽  
Author(s):  
Hang Thi Thuy Vu ◽  
Cham Thi Tuyet Le ◽  
Ly Thi Pham

Abstract Mungbean is an important pulse crop and commonly grown in Asia. Drought affects mungbean growth and yield at at different growing stages and various levels through physiological traits and gene expression. In this study, two mungbean cultivars, DX208 and Tam Thanh Hoa, were exposed to drought at the vegetative and flowering stages and assessed for various morphophysiological traits at 8, 12, 15 and 15 days post withholding water and the plant recovery 7 days after re-watering. Differential expression of VrDREB2A gene was observed in leaf and root of two mungbean cultivars under drought condition. Plants used up water more quickly at the flowering stage than the vegetative stage. Drought adversely affected the plant height, leaf number, above-ground plant biomass and root weight with relative reduction to the control by 4.0–85%. Yield components and individual yield reduced significantly by around 50–60% compared to the control. Relative expression of VrDREB2A gene was varied, with stronger expression in leaves and roots when drought imposed at the flowering and vegetative stages respectively. Increase in VrDREB2A expression occurred earlier at 8 days compared with 12 days for drought imposed at the flowering and vegetative stages respectively, resulting in more tolerance of plants to drought at the flowering stage. The results indicate that VrDREB2A functioned as an important transcriptional activator and might help increase the drought stress tolerance of the mungbean plant at various growing stages. Morphophysiological traits can also be used as indicators in screening mungbean for drought tolerance.


Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 207-209 ◽  
Author(s):  
P. H. Grabouski

Eight herbicide postemergence treatments were applied to proso millet (Panicum milaceumL.) at three growth stages. The dimethylamine salt of (2,4-dichlorophenoxy)acetic acid (2,4-D) at 0.56 kg/ha had significantly higher grain yields than the weedy check. All herbicides except the amine of 2,4-D at 0.28 kg/ha appeared to injure proso millet plants by varying degrees; however, yields were not greatly affected. All herbicides gave excellent control of redroot pigweed (Amaranthus retroflexusL.) when applied to proso millet in the 4 to 6-leaf stage. Weed control was poorer when spraying was delayed until proso millet was in pre-boot and post-flower stages.


2019 ◽  
Vol 42 (10) ◽  
pp. 1133-1141 ◽  
Author(s):  
Hasnain Waheed ◽  
Muhammad Mansoor Javaid ◽  
Adeel Shahid ◽  
Hafiz Haider Ali ◽  
Javaria Nargis ◽  
...  

Author(s):  
Magdi A.A. Mousa ◽  
Adel D. Al Qurashi

A field experiment was conducted in 2013 and 2014 at the Agriculture Experimental Station of King Abdulaziz University to study the effects of water deficit treatments at different growth stages on growth, yield and IWUE on cowpea cultivars. Four water deficit treatments were applied T0 (no water deficit), T1 (at vegetative stage), T2 (at flowering and pod setting), T3 (at pod filling), T4 (at vegetative and flowering) and T5 (at flowering and pod filling). The cultivars ‘Balady’ under water deficit T1, T3 and T4 and ‘Cream7’under T1 and T2 produced the highest yield component parameters except number of pods/plant. The highest yield of dry seeds kg/ha was produced by the cultivars ‘Cream7’ under water deficit T1 and T3 and ‘Balady’ under T2. ‘Cream7’ and ‘Balady’ revealed the highest irrigation water use efficiency (IWUE) under water deficit T1, T2 and T4. High seed yield of ‘Balady and ‘Cream7’ can be obtained by applying water deficit at vegetative stage (T1).


2021 ◽  
Vol 27 (4) ◽  
pp. 495-504
Author(s):  
Imran Khan ◽  
Muhammad Iqbal ◽  
Malik Muhammad Hashim ◽  
Muhammad Saleem Jilani ◽  
Mohammad Safdar Baloch ◽  
...  

Weed infestation is a major problem and matter of concern as it reduces yield as well as quality of many crops including sugar beet. Manual weeding is very tedious, costly, time consuming and most probably non-availability of trained and skillful labor is another issue. Keeping in view these facts, an experiment was performed to evaluate the efficacy of dual gold on the weed biomass (gm-2) and on the growth and yield components of sugar beet (Beta vulgaris L.) cv. California-KWS during 2013-14 and 2014-15. The study was performed using RCBD having five treatments and three replications. The treatments included different application times (pre-emergence application and application after 15, 30 and 45 days after emergence) of dual gold (s-Metolachlor) and a control (weedy check). Data were recorded on fresh and dry weed biomasses (g m-2), number of leaves plant-1, leaf area plant-1 (cm2), leaf and root weights plant-1 (g), sucrose%, TSS%, root and sugar yields (t ha-1). The results showed significant variation among the treatments for all parameters during both years of study. Among the treatments the dual gold (s-Metolachlor) applied as pre-emergence reduced weed fresh and dry biomasses (g m-2) and also enhanced number of leaves plant-1, leaf area (cm2), leaf and root weight plant-1, sucrose%, TSS%, root and sugar yields (t ha-1) during both years. Hence it is concluded that dual gold (s-Metolachlor) applied as pre-emergence is best for eradicating weeds at early stages of growth and hence improving yield and quality of sugar beet under Dera Ismail Khan Conditions.


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