Rainfall is not the most limiting factor to maize (Zea mays L.) production in intermediate rainfall regions of Zambia. Lessons from Choma District

2020 ◽  
Vol 3 (1) ◽  
pp. 18-40
Author(s):  
Dr. Kabwe Harnadih Mubanga ◽  
Prof. Martin Joachim Steyn
Keyword(s):  
Water Stress ◽  
Crop Yields ◽  
Potential Evapotranspiration ◽  
Actual Evapotranspiration ◽  
Limiting Factors ◽  
Stress Index ◽  
Soil Conditions ◽  
Unique Contribution ◽  
Maize Production ◽  
Significant Difference

Purpose: This study was based on the following objectives; (1) to investigate the sufficiency of rainfall received in Choma by assessing the differences in the precipitation received (PPT) against the potential evapotranspiration (PET) and actual evapotranspiration (ETa) for maize, and (2) to estimate potential for maize production in Choma under the current rainfall and temperature conditions.Methodology: The Soil Water Balance (SWB) crop growth model was used to analyze the rainfall-temperature interactions and estimate the maize stress index (SI) for analyses of crop water stress and potential yields (Yp). The relationships involving precipitation, potential and actual evapotranspiration were performed using time series auto regression and Fisher’s least significant difference (LSD).Findings: Choma was not in a state of water deficit as maize water requirements were lower than precipitation. Maize water stress was destructive when it occurred in the mid than late stages of maize development. Mean precipitation (799.29mm) was higher than mean actual evapotranspiration (719.23 mm), though the difference was insignificant (F = 1.281; p = 0.126). However, potential evapotranspiration for maize in the area was significantly higher than the actual evapotranspiration (mean = 719.23) (F = 5.621; p = 0.012). Less destructive moderately dry periods seldom occurred during the sensitive initial and mid periods of maize development.Results: Farmers in Choma can potentially increase their rain-fed maize yields from the current 1.89 t/ha/year to 4.9 t/ha/year by managing limiting factors to maize production such as reduced access to fertilizer, declining of soil nutrients, late delivery of inputs, lack of markets, pests and lack of proper nutrient management. The study also showed that management rather than climatic conditions is responsible for the low yields in Choma area. Unique contribution to theory, practice and policy: The study established a methodology for simulating potential yields of farmers given existing climatic and soil conditions. Policy should concentrate on improving crop management rather than the current concentration on mitigating impacts of climate change as these are not the factors responsible for observed reduced crop yields.

scholarly journals A global non-invasive methodology for the phenotyping of potato under water deficit conditions using imaging, physiological and molecular tools

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
M. Musse ◽  
G. Hajjar ◽  
N. Ali ◽  
B. Billiot ◽  
G. Joly ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Soil Conditions ◽  
Growth Stages ◽  
Dry Matter Content ◽  
Tuber Growth ◽  
Non Invasive ◽  
Potato Plants ◽  
Significant Difference

Abstract Background Drought is a major consequence of global heating that has negative impacts on agriculture. Potato is a drought-sensitive crop; tuber growth and dry matter content may both be impacted. Moreover, water deficit can induce physiological disorders such as glassy tubers and internal rust spots. The response of potato plants to drought is complex and can be affected by cultivar type, climatic and soil conditions, and the point at which water stress occurs during growth. The characterization of adaptive responses in plants presents a major phenotyping challenge. There is therefore a demand for the development of non-invasive analytical techniques to improve phenotyping. Results This project aimed to take advantage of innovative approaches in MRI, phenotyping and molecular biology to evaluate the effects of water stress on potato plants during growth. Plants were cultivated in pots under different water conditions. A control group of plants were cultivated under optimal water uptake conditions. Other groups were cultivated under mild and severe water deficiency conditions (40 and 20% of field capacity, respectively) applied at different tuber growth phases (initiation, filling). Water stress was evaluated by monitoring soil water potential. Two fully-equipped imaging cabinets were set up to characterize plant morphology using high definition color cameras (top and side views) and to measure plant stress using RGB cameras. The response of potato plants to water stress depended on the intensity and duration of the stress. Three-dimensional morphological images of the underground organs of potato plants in pots were recorded using a 1.5 T MRI scanner. A significant difference in growth kinetics was observed at the early growth stages between the control and stressed plants. Quantitative PCR analysis was carried out at molecular level on the expression patterns of selected drought-responsive genes. Variations in stress levels were seen to modulate ABA and drought-responsive ABA-dependent and ABA-independent genes. Conclusions This methodology, when applied to the phenotyping of potato under water deficit conditions, provides a quantitative analysis of leaves and tubers properties at microstructural and molecular levels. The approaches thus developed could therefore be effective in the multi-scale characterization of plant response to water stress, from organ development to gene expression.

scholarly journals Do Water and Nitrogen Management Practices Impact Grain Quality in Maize?

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1851
Author(s):  
Adrian A. Correndo ◽  
Javier A. Fernandez ◽  
P.V. Vara Prasad ◽  
Ignacio A. Ciampitti
Keyword(s):  
Water Stress ◽  
Grain Quality ◽  
Management Practices ◽  
Meta Analysis ◽  
Limiting Factors ◽  
Fertilizer N ◽  
Maize Production ◽  
Production Water ◽  
Oil Concentration ◽  
Protein Change

Concomitantly pursuing superior maize (Zeamays L.) productivity with grain quality is essential for food security. Therefore, this study provides a meta-analysis of 21 studies assembled from the scientific literature to tackle the effect of the two most limiting factors for maize production, water and nitrogen (N), and their impacts on grain quality composition, herein focused on protein, oil, and starch concentrations. Water stress levels resulted in erratic responses both in direction and magnitude on all the grain quality components, plausibly linked to a different duration, timing, and intensity of water stress treatments. Nitrogen fertilization more consistently affected the grain protein concentration, with a larger effect size for protein as fertilizer N levels increased (protein change of +14% for low, ≤70 kg N ha−1; +21% for medium, >70–150 kg N ha−1; and +24% for high, >150 kg N ha−1). Both starch and oil grain concentrations presented less variation to fertilizer N levels. The positive protein–oil correlation (r = 0.49) permitted to infer that although the oil concentration may reach a plateau (8%), further increases in protein are still possible. Augmented research on grain quality is warranted to sustain food production but with both high nutritional and energetic value for the global demand.

scholarly journals PECAN TREE GROWTH, PRODUCTION, AND NUT QUALITY RESPONSES TO WATER STRESS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1171f-1171
Author(s):  
D.J. Garrot ◽  
M.W. Kilby ◽  
D.D. Fangmeier ◽  
S.H. Husman
Keyword(s):  
Water Stress ◽  
Tree Growth ◽  
Stress Index ◽  
Crop Water ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Significant Difference ◽  
Stress Levels ◽  
Growth Production ◽  
Crop Water Stress

Pecan tree (cv. “Western Schley”) water stress was numerically quantified with the crop water stress index (CWSI). The CWSI was used to schedule irrigation at increasing water stress levels to correlate the effects of water strees on tree growth, production, and nut quality from 1987 to 1989. Highest growth increases, production, and nut size were attained at lower water stress levels (CWSI = 0.08 to 0.14 units). Even moderate increases in water stress (CWSI>0.20 units) decreased pecan tree growth and production, and significantly reduced nut size (P=0.01). A significant difference (P=0.05) in nut quality was measured only in 1988. Depending on yearly climatic variation, the amount of irrigation water required to maintain the CWSI below 0.14 units in the same orchard varied 44% over three years. The CWSI is a viable tool to assess pecan water stress.

FARMER’S PERCEPTION OF CLIMATE CHANGE AND ITS ASSOCIATION WITH DEMOGRAPHIC CHARACTERISTICS IN MAIZE PRODUCING AREA OF NORTHERN, NIGERIA

2021 ◽  
Vol 4 (4) ◽  
pp. 200-206
Author(s):  
Buba Adamu Ndawayo ◽  
Abdullahi Adamu
Keyword(s):  
Climate Change ◽  
Crop Yields ◽  
Northern Region ◽  
Agricultural Practice ◽  
Demographic Information ◽  
Chi Square ◽  
Maize Production ◽  
Significant Difference ◽  
Cross Tabulation ◽  
And Gender

This study was designed to found farmers’ perception on climate change and weather changeability using farmers’ demographic information to analyze gender exertion with education level in maize producing areas of the northern region, and its impacts on crop yields. Purposive sampling was used to select a sample size of 400 households. Information was composed from heads of households using a questionnaire and the data obtained were analyzed using statistical analysis. The results showed that farmers perceived climate change and weather variability correctly. The result of the independent-sample t-test on-farmers’ perception about climate change and farming status shows that there was a significant difference in perception of climate change between farmers and non-farmers. chi-square cross-tabulation also demonstrated that there is a significant association between farmers’ level of perception of climate change and gender. Lastly, the study outcome indicates that there was no significant difference in farmers’ perception based on the educational level of the farmers. These findings will be used by both institutions and government in formulating policies and funding for better maize production and agricultural practice in genera

scholarly journals Vineyard Variability Analysis through UAV-Based Vigour Maps to Assess Climate Change Impacts

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 581 ◽  
Author(s):  
Luís Pádua ◽  
Pedro Marques ◽  
Telmo Adão ◽  
Nathalie Guimarães ◽  
António Sousa ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Crop Yields ◽  
Moisture Stress ◽  
Temporal Analysis ◽  
Stress Index ◽  
Crop Water Stress Index ◽  
Multi Temporal

Climate change is projected to be a key influence on crop yields across the globe. Regarding viticulture, primary climate vectors with a significant impact include temperature, moisture stress, and radiation. Within this context, it is of foremost importance to monitor soils’ moisture levels, as well as to detect pests, diseases, and possible problems with irrigation equipment. Regular monitoring activities will enable timely measures that may trigger field interventions that are used to preserve grapevines’ phytosanitary state, saving both time and money, while assuring a more sustainable activity. This study employs unmanned aerial vehicles (UAVs) to acquire aerial imagery, using RGB, multispectral and thermal infrared sensors in a vineyard located in the Portuguese Douro wine region. Data acquired enabled the multi-temporal characterization of the vineyard development throughout a season through the computation of the normalized difference vegetation index, crop surface models, and the crop water stress index. Moreover, vigour maps were computed in three classes (high, medium, and low) with different approaches: (1) considering the whole vineyard, including inter-row vegetation and bare soil; (2) considering only automatically detected grapevine vegetation; and (3) also considering grapevine vegetation by only applying a normalization process before creating the vigour maps. Results showed that vigour maps considering only grapevine vegetation provided an accurate representation of the vineyard variability. Furthermore, significant spatial associations can be gathered through (i) a multi-temporal analysis of vigour maps, and (ii) by comparing vigour maps with both height and water stress estimation. This type of analysis can assist, in a significant way, the decision-making processes in viticulture.

scholarly journals A water stress index based on water balance modelling for discrimination of grapevine quality and yield

OENO One ◽  
2014 ◽  
Vol 48 (1) ◽  
pp. 1 ◽  
Author(s):  
Rémi Gaudin ◽  
Kamal Kansou ◽  
Jean-Christophe Payan ◽  
Anne Pellegrino ◽  
Christian Gary
Keyword(s):  
Water Stress ◽  
Water Balance ◽  
Soil Water ◽  
Water Deficit ◽  
Water Balance Model ◽  
Stress Index ◽  
Balance Model ◽  
Soil Conditions ◽  
Water Stress Index ◽  
Berry Quality

<p style="text-align: justify;"><strong>Aims</strong>: A water stress index based on a water balance model was tested as a tool for classifying the water stress paths experienced by grapevines in various French Mediterranean vineyards. The relations between the index value and grapevine yield and berry quality (sugars, organic acids, anthocyanins) at harvest were investigated.</p><p style="text-align: justify;"><strong>Methods and results</strong>: A data set of 102 situations, each combining one location, one variety, one vintage and one water regime (irrigation or, most often, no irrigation), was collected for the study. The Fraction of Transpirable Soil Water (FTSW) was simulated by a unique-soil-reservoir water balance model at a daily time step. Five classes of water deficit were delimited from specific decreasing thresholds of FTSW over four periods between flowering and harvest. These thresholds were derived from predawn leaf water potential values because over decades, grapegrowers and researchers have shared references and built expertise by using this variable throughout the Mediterranean region. A water stress index resulting from the levels of water deficit reached at each of the four periods of the cycle was calculated. This index was correlated with yield per vine, berry weight, and berry sugar and organic acid contents but not with berry anthocyanin content.</p><p style="text-align: justify;"><strong>Conclusion</strong>: A simple water stress index, based on the water balance model, exhibited significant correlations with yield and berry quality for various cultivars and pedo-climatic conditions in Mediterranean vineyards.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This water stress index is a valuable tool for explaining the variations in grape yield and quality among various locations and years because it reflects the vineyard water stress history in relation to rainfall regime and soil conditions. Improvement would come from the simulation of FTSW during winter, notably for soils of high Total Transpirable Soil Water. One potential application is the quantification of water stress change brought by irrigation in Mediterranean vineyards, and its relation to grapevine production.</p>

scholarly journals A Global Non-Invasive Methodology for the Phenotyping of Potato Under Water Deficit Conditions using Imaging, Physiological and Molecular Tools

2021 ◽  
Author(s):  
Maja Musse ◽  
Ghina Hajjar ◽  
Nusrat Ali ◽  
Bastien Billiot ◽  
Gisèle Joly ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Soil Conditions ◽  
Growth Stages ◽  
Dry Matter Content ◽  
Tuber Growth ◽  
Non Invasive ◽  
Potato Plants ◽  
Significant Difference

Abstract Background: Drought is a major consequence of global heating that has negative impacts on agriculture. Potato is a drought-sensitive crop; tuber growth and dry matter content may both be impacted. Moreover, water deficit can induce physiological disorders such as glassy tubers and internal rust spots. The response of potato plants to drought is complex and can be affected by cultivar type, climatic and soil conditions, and the point at which water stress occurs during growth. The characterization of adaptive responses in plants presents a major phenotyping challenge. There is therefore a demand for the development of non-invasive analytical techniques to improve phenotyping.Results: This project aimed to take advantage of innovative approaches in MRI, phenotyping and molecular biology to evaluate the effects of water stress on potato plants during growth. Plants were cultivated in pots under different water conditions. A control group of plants were cultivated under optimal water uptake conditions. Other groups were cultivated under mild and severe water deficiency conditions (40 and 20% of field capacity, respectively) applied at different tuber growth phases (initiation, filling). Water stress was evaluated by monitoring soil water potential. Two fully-equipped imaging cabinets were set up to characterize plant morphology using high definition color cameras (top and side views) and to measure plant stress using RGB cameras. The response of potato plants to water stress depended on the intensity and duration of the stress. Three-dimensional morphological images of the underground organs of potato plants in pots were recorded using a 1.5 T MRI scanner. A significant difference in growth kinetics was observed at the early growth stages between the control and stressed plants. Quantitative PCR analysis was carried out at molecular level on the expression patterns of selected drought-responsive genes. Variations in stress levels were seen to modulate ABA and drought-responsive ABA-dependent and ABA-independent genes.Conclusions: This methodology, when applied to the phenotyping of potato under water deficit conditions, provides a quantitative analysis of leaves and tubers properties at microstructural and molecular levels. The approaches thus developed could therefore be effective in the multi-scale characterization of plant response to water stress, from organ development to gene expression.

scholarly journals DOIS MÉTODOS DE ESTIMATIVA DA EVAPOTRANSPIRAÇÃO DE REFERÊNCIA E ÍNDICES DE ESTRESSE HÍDRICO EM CEBOLA IRRIGADA

Irriga ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 352-366
Author(s):  
Paulo José Desiderio de Oliveira ◽  
José Eduardo Pitelli Turco
Keyword(s):  
Water Stress ◽  
Reference Evapotranspiration ◽  
Sao Paulo ◽  
Estimation Methods ◽  
Stress Index ◽  
Water Volume ◽  
São Paulo ◽  
Water Stress Index ◽  
Significant Difference ◽  
E Mail

DOIS MÉTODOS DE ESTIMATIVA DA EVAPOTRANSPIRAÇÃO DE REFERÊNCIA E ÍNDICES DE ESTRESSE HÍDRICO EM CEBOLA IRRIGADA      PAULO JOSÉ DESIDÉRIO DE OLIVEIRA1 E JOSE EDUARDO PITELLI TURCO2   1Doutor em Agronomia, Programa de Pós-Graduação em Agronomia (Ciência do Solo), FCAV/UNESP - Campus de Jaboticabal, Via de acesso Prof. Paulo Donato Castellane, Km 5, CEP: 14884-900, Jaboticabal - SP, Brasil, e-mail: [email protected] 2Departamento de Engenharia Rural. FCAV/UNESP - Campus de Jaboticabal, Via de acesso Prof. Paulo Donato Castellane, Km 5, CEP: 14884-900, Jaboticabal - SP, Brasil, e-mail: [email protected]     1 RESUMO   Objetivou-se, com este trabalho, avaliar o efeito de dois métodos para cálculo da evapotranspiração de referência e a determinação do índice de estresse hídrico da cultura, sobre a produção de bulbos de cebola, irrigadas por aspersão. O experimento foi conduzido durante o período de abril a setembro de 2017, no sítio Santo Antônio, município de Monte Alto, São Paulo, Brasil. O delineamento experimental foi em blocos com repetições, constituído em dois tratamentos: T1 e T2, com irrigações baseadas na evapotranspiração de referência pelo método de Hargreaves e pelo método de Penman-Monteith, respectivamente. Cada tratamento foi dividido em quatro blocos para medições de tensão de água no solo e cada bloco com quatro repetições para medições de índice de estresse hídrico da cultura. Com os resultados concluiu-se que no T1 aplicou-se maior volume de água, mas não houve diferença significativa da produtividade. A variabilidade dos índices de estresse hídrico em todos os blocos foi de 1,9 °C a 2,4 °C, prevalecendo maiores valores no T2, onde foi aplicado menor volume de água. Para toda a área, o índice de estresse hídrico em 1,9 ºC correspondeu a 50% da capacidade de água disponível no solo.   Palavras-chaves: água e solo, termômetro infravermelho, déficit hídrico.     OLIVEIRA, P. J. D. de; TURCO, J. E. P. TWO  EVAPOTRANSPIRATION REFERENCE ESTIMATION METHODS AND WATER STRESS INDEX IN IRRIGATED ONION     2 ABSTRACT   The objective of this work was to evaluate the effect of two methods to calculate the reference evapotranspiration and the determination of water stress index of the crop on the production of onion bulbs irrigated by sprinkling. The experiment was conducted from April to September 2017, at Santo Antônio site, Monte Alto municipality, São Paulo, Brazil. The experimental design was in blocks with repetitions, consisting of two treatments: T1 and T2, with irrigations based on the reference evapotranspiration by Hargreaves method and Penman-Monteith method, respectively. Each treatment was divided into four blocks for soil water stress measurements and each block with four replicates for measurements of water stress index of the crop. With the results it was concluded that in T1, a higher water volume was applied, but there was no significant difference in productivity. The variability of water stress indices in all blocks was 1.9 ° C to 2.4 ° C, with higher values ​​prevailing in T2, where a lower volume of water was applied. For the whole area, the water stress index at 1.9 ° C corresponded to 50% of the available water capacity in the soil.   Keywords: water and soil, infrared thermometer, water deficit.

scholarly journals Estimating Actual Evapotranspiration over a Large and Complex Irrigation System of the Nile Delta in Egypt

2019 ◽  
Vol 8 (4) ◽  
pp. 2432-2439
Keyword(s):  
Water Balance ◽  
Irrigation Water ◽  
Nile Delta ◽  
Potential Evapotranspiration ◽  
Irrigation System ◽  
Relative Yield ◽  
Actual Evapotranspiration ◽  
Relative Reduction ◽  
Cropping Pattern ◽  
Significant Difference

In the Nile Delta region of Egypt, measurements of Actual Evapotranspiration (ETa) and Potential Evapotranspiration (ETp) are difficult, expensive and labor-intensive. The current paper aimed at finding the superior method for estimating the ETa and ETa/ETp in the Nile Delta governorates by comparing different methods. Three different methods were used for ETa estimates being; Remote Sensing approach by Moderate Resolution Imaging Spectroradiometer (MODIS) ETa-product (MOD16A2), FAO (33) method, and Irrigation Water Balance Calculation (IWBC) method. The three ETa methods were applied for five governorates in 2017, where the data for IWBC were available. However, only MOD16A2 was compared with FAO (33) for ETa/ETp ratio and the two selected methods were applied for all eight Nile Delta governorates for the period of 2008 -2017. The MOD16A2 product was derived from the MODIS satellite images using an improved evapotranspiration algorithm based on the Penman-Monteith equation. FAO (33) was based on the relationship between the relative yield loss of any crop to relative reduction of water consumption. The IWBC required estimation of both; the field application and conveyance water losses as the only unknown elements of irrigation water balance in Delta governorates. For comparison between applied methods, descriptive statistics, analysis of variance (ANOVA) for checking difference, and cluster analysis were applied. The results showed a significant difference values between MOD16A2 and FAO (33) for estimating ETa/ETp ratios. However, the difference for ETa estimation was insignificant between the three methods indicating a significant relationship, with a strong correlation between MOD16A2 and IWBC. It was observed that ETa values were impacted by the cropping pattern, since they were very close in governorates having the same dominant crops. In conclusion, both MOD16A2 and IWBC can be utilized for ETa estimation. Both MOD16A2 and FAO (33) are not confirmed for estimation of ETa/ETp ratio due to the significant difference between both results. FAO (33) cannot be utilized for both ETa and ETa/ETp ratio estimates. Further data collection and investigation on ETa and ETp estimates methods are recommended.

Monitoring Crop Water Status and Irrigation Needs Using Multispectral Airborne Sensors

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 905D-905
Author(s):  
Thomas R. Clarke ◽  
M. Susan Moran
Keyword(s):  
Water Stress ◽  
Near Infrared ◽  
Water Status ◽  
Canopy Cover ◽  
Stress Index ◽  
Crop Water ◽  
Vegetative Cover ◽  
Crop Water Stress Index ◽  
Water Stress Index ◽  
Subsurface Drip

Water application efficiency can be improved by directly monitoring plant water status rather than depending on soil moisture measurements or modeled ET estimates. Plants receiving sufficient water through their roots have cooler leaves than those that are water-stressed, leading to the development of the Crop Water Stress Index based on hand-held infrared thermometry. Substantial error can occur in partial canopies, however, as exposed hot soil contributes to deceptively warm temperature readings. Mathematically comparing red and near-infrared reflectances provides a measure of vegetative cover, and this information was combined with thermal radiance to give a two-dimensional index capable of detecting water stress even with a low percentage of canopy cover. Thermal, red, and near-infrared images acquired over subsurface drip-irrigated cantaloupe fields demonstrated the method's ability to detect areas with clogged emitters, insufficient irrigation rate, and system water leaks.

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