scholarly journals Quantitative Response of Maize Vcmax25 to Persistent Drought Stress at Different Growth Stages

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.

2019 ◽  
Vol 6 (1) ◽  
pp. 57-67
Author(s):  
Md Shahriar Kobir ◽  
Md Rashedur Rahman ◽  
AKM Mominul Islam ◽  
Suchana Paul ◽  
Md Monirul Islam ◽  
...  

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, during the period from December 2017 to April 2018 to study the yield performance of some maize varieties as influenced by irrigation management at different growth stages. The experiment was laid out in a split plot design with three replications where factor (A) irrigation stages were allocated in main plots and factor (B) varieties were distributed in sub plots. In factor A five irrigation management viz. I0 = (No irrigation), I1= (Four leaf stage + eight leaf stage + tasselling stage+ grain filling stage), I2= (Four leaf stage+ eight leaf stage + tasselling stage), I3= (Eight leaf stage + tasselling stage +grain filling stage), I4=(Four leaf stage + tasselling stage+ grain filling stage), I5=(Four leaf stage+ eight leaf stage+ grain filling stage) and in factor B three varieties viz. V1= (BARI hybrid vutta-9), V2= (BARI hybrid vutta-13), V3= (pacific-559) were included as treatments in the experiment. Data were collected on yield and yield contributing characters. The highest grain yield (5.88 t/ha) was obtained with the water management treatment I1(Four leaf stage + eight leaf stage + tasselling stage+ grain filling stage) which is statistically similar to treatment I4(Four leaf stage + tasselling stage+ grain filling stage) and highest grain yield (5.87 t/ha) obtained due to the varietal factor V3 (pacific-559). Interaction between I1 irrigation treatment and V3 varietal factor (I1V3) were found to be the best combination which is statistically similar to I4V3 interaction. As I4 treatment and I4V3 interaction are cost effective than I1 treatment and I1V3 interaction, respectively, irrigation should be given at four leaf stage, tasselling stage, and grain filling stage with variety pacific-559 for better performance in maize production. Res. Agric., Livest. Fish.6(1): 57-67, April 2019


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.


2020 ◽  
Vol 12 (4) ◽  
pp. 884-900
Author(s):  
Okechukwu S. EZEH ◽  
Sifau A. ADEJUMO

Okra growth and yield are adversely affected by drought at different growth stages. This is aggravated by poor soil fertility. In this study, the roles of compost applied at 0, 5 and 10 t/ha on the tolerance and morpho-physiological response of okra (NHAe 47-4) exposed to varying levels of water stress (25%, 50%, 75% and 100% field capacity, FC), at different growth stages (vegetative, reproductive and vegetative-reproductive stages) for ten days duration were assessed. Data were collected on okra growth and yield, leaf relative water content (LRWC), leaf photosynthetic pigments (LPG) and proline accumulation. Results showed that drought stress reduced LRWC, LPG, growth and yield of Okra. This reduction was more evident in okra plants exposed to severe stress for 10 days and at the reproductive stage. Soil amendment with compost however, had cushioning effect on drought stressed okra. Compared to control, it increased the LRWC, LPG, growth and yield of okra. The ameliorative roles of compost were however, dependent on stress intensity, compost dosage, okra growth stage and stress duration. Though, okra plants stressed at 25% FC were more affected by drought stress, but compared to the un-amended soil, those grown on amended soil were more tolerant. Higher compost rate was superior to lower rates. Whereas, higher proline accumulation was recorded in plant exposed to 25% field capacity without amendment, proline accumulation was reduced in the plants grown on compost amended soil and exposed to drought which was an indication of stress reduction. Generally, okra stressed at vegetative growth stage only was able to recover rapidly and had better yield compared to those stressed at reproductive growth stage. It is concluded that addition of compost to soil could reduce the drought stress effect on okra.


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.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0259585
Author(s):  
Gull Mehak ◽  
Nudrat Aisha Akram ◽  
Muhammad Ashraf ◽  
Prashant Kaushik ◽  
Mohamed A. El-Sheikh ◽  
...  

Optimum water availability at different growth stages is one the major prerequisites of best growth and yield production of plants. Exogenous application of plant growth regulators considered effective for normal functioning of plants under water-deficit conditions. A study was conducted to examine the influence of exogenously applied L-methionine on sunflower (Helianthus annuus L.) plants grown under water-deficit conditions. Twenty-five-day old seedlings of four sunflower cultivars, FH331, FH572, FH652 and FH623 were exposed to control (100% F.C.) and drought stress (60% F.C.) conditions. After 30-day of drought stress, L-methionine (Met; 20 mg/L) was applied as a foliar spray to control and drought stressed plants. Water deficit stress significantly reduced shoot fresh and dry weights shoot and root lengths, and chlorophyll a content in all four cultivars. While a significant increase was observed due to water deficiency in relative membrane permeability (RMP), malondialdehyde (MDA), total soluble proteins (TSP), total soluble sugars (TSS), ascorbic acid (AsA) and activity of peroxidase (POD). Although, exogenously applied Met was effective in decreasing RMP, MDA and H2O2 contents, it increased the shoot fresh weight, shoot length, chlorophyll a, chlorophyll a/b ratio, proline contents and the activities of SOD, POD and CAT enzymes in all four cultivars under water deficit stress. No change in AsA and total phenolics was observed due to foliar-applied Met under water stress conditions. Of all sunflower cultivars, cv. FH-572 was the highest and cv. FH-652 the lowest of all four cultivars in shoot fresh and dry weights as well as shoot length under drought stress conditions. Overall, foliar applied L-methionine was effective in improving the drought stress tolerance of sunflower plants that was found to be positively associated with Met induced improved growth attributes and reduced RMP, MDA and H2O2 contents under water deficit conditions.


Agronomy ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 97 ◽  
Author(s):  
Yanqi Wei ◽  
Juliang Jin ◽  
Shangming Jiang ◽  
Shaowei Ning ◽  
Li Liu

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).


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