Applicability of plastic mulch and conservation strip tillage for potato production in Bangladesh

<p>Application of plastic mulches in potato production is rarely used by farmers in Bangladesh although it has a good prospect for saving irrigation water, weed control, maintaining tuber quality, and increasing yield. A study was conducted in experimental farm at Rural Development Academy (RDA), Bogura, Bangladesh to evaluate the precision of irrigation water for potato production using different colored plastic mulches i.e, black and blue in combination with conservation strip tillage and control (no-mulch). Four different treatments were prepared where some of the phenological characteristics of plants as well as yield of potato were compared among treatments by applying the same amount of irrigation water. The results showed that treatment with black plastic mulch had the highest tuber growth as well as yield of 25.1 t ha^-1 compared to other treatments while other treatments such as blue plastic mulch, control, and strip tillage had a yield of 16.37, 13.75, and 15.75 t ha^-1, respectively. Potato plants having black plastic mulch took less time to mature in comparison to other treatments. Black plastic mulch restricts soil moisture evaporation and keeps the soil warm. In conclusion, potato production with various mulches has a great scope in a semi-arid region like Bangladesh and present experimental results will help to improve the understanding of potato growers for adopting best mulch management practices.</p>

Effects of Different Irrigation Management Practices on Potato (Solanum tuberosum L.)

Decisions in irrigation management can greatly impact the overall sustainability of potato production. A field study was conducted in 2018 and 2019 to evaluate the impacts of different irrigation regimes on yield and quality of three russet potato varieties. For Russet Burbank, fry quality at harvest and at 4 and 8 months after harvest was assessed. During early growth stages, the standard practice of irrigating to maintain 60–80% soil moisture was employed. The irrigation treatments were applied during the late tuber bulking and maturation growth stages, and consisted of irrigation at 125%, 100%, 75%, and 50% of daily evapotranspiration (ET). We found that 125%ET provided no increase in total yield and marketable yield compared to other treatments in 2018, and it produced similar marketable yield to 100%ET in 2019. Total yield, but not marketable yield, of 125%ET and 100%ET was significantly higher than the number under 50%ET in 2019. In both years, increasing irrigation rate led to a decrease in irrigation efficiency and water-use efficiency. Irrigation rate had no significant effects on tuber quality at harvest and during storage. This study indicated that over-irrigation at 125%ET was not beneficial to profitable potato production in the Upper Midwest of the US, and deficit irrigation at 75%ET during late tuber bulking and tuber maturation could potentially result in more sustainable water use while not jeopardizing tuber growth. The results support the possibility of adopting late-season deficit irrigation for growing potatoes in the region, though more years of research would allow for a better understanding of the impacts of this practice.

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

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.

Role of Tuber Developmental Processes in Response of Potato to High Temperature and Elevated CO2

Potato is adapted to cool environments, and there is concern that its performance may be diminished considerably due to global warming and more frequent episodes of heat stress. Our objectives were to determine the response of potato plants to elevated CO2 (700 μmol/mol) and high temperature (35/25 °C) at tuber initiation and tuber bulking, and to elucidate effects on sink developmental processes. Potato plants were grown in controlled environments with treatments at: Tuber initiation (TI), during the first two weeks after initiating short-day photoperiods, and Tuber bulking (TB). At TI, and 25 °C, elevated CO2 increased tuber growth rate, while leaves and stems were not affected. Whole-plant dry matter accumulation rate, was inhibited by high temperature about twice as much at TI than at TB. Elevated CO2 partially ameliorated high temperature inhibition of sink organs. At TI, with 25 °C, elevated CO2 primarily affected tuber cell proliferation. In contrast, tuber cell volume and endoreduplication were unaffected. These findings indicate that the TI stage and cell division is particularly responsive to elevated CO2 and high temperature stress, supporting the view that attention should be paid to the timing of high-temperature stress episodes with respect to this stage.

X-Ray CT Phenotyping Reveals Bi-Phasic Growth Phases of Potato Tubers Exposed to Combined Abiotic Stress

As a consequence of climate change, heat waves in combination with extended drought periods will be an increasing threat to crop yield. Therefore, breeding stress tolerant crop plants is an urgent need. Breeding for stress tolerance has benefited from large scale phenotyping, enabling non-invasive, continuous monitoring of plant growth. In case of potato, this is compromised by the fact that tubers grow belowground, making phenotyping of tuber development a challenging task. To determine the growth dynamics of tubers before, during and after stress treatment is nearly impossible with traditional destructive harvesting approaches. In contrast, X-ray Computed Tomography (CT) offers the opportunity to access belowground growth processes. In this study, potato tuber development from initiation until harvest was monitored by CT analysis for five different genotypes under stress conditions. Tuber growth was monitored three times per week via CT analysis. Stress treatment was started when all plants exhibited detectable tubers. Combined heat and drought stress was applied by increasing growth temperature for 2 weeks and simultaneously decreasing daily water supply. CT analysis revealed that tuber growth is inhibited under stress within a week and can resume after the stress has been terminated. After cessation of stress, tubers started growing again and were only slightly and insignificantly smaller than control tubers at the end of the experimental period. These growth characteristics were accompanied by corresponding changes in gene expression and activity of enzymes relevant for starch metabolism which is the driving force for tuber growth. Gene expression and activity of Sucrose Synthase (SuSy) reaffirmed the detrimental impact of the stress on starch biosynthesis. Perception of the stress treatment by the tubers was confirmed by gene expression analysis of potential stress marker genes whose applicability for potato tubers is further discussed. We established a semi-automatic imaging pipeline to analyze potato tuber delevopment in a medium thoughput (5 min per pot). The imaging pipeline presented here can be scaled up to be used in high-throughput phenotyping systems. However, the combination with automated data processing is the key to generate objective data accelerating breeding efforts to improve abiotic stress tolerance of potato genotypes.

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

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.