Ayusha Gupta, (ph.D Research scholar) Department of vegetable Science
Suresh Kumar Wakre, (ph.D Research scholar) Department of vegetable Science
Dr. Narottam Atree, Department of Agriculture Economic
Dr. Devendra Kurre (Assistant Professor) College of Agriculture Narayanpur

Abstract
Vegetable crops are essential for human nutrition and rural incomes, but they are facing growing threats from climate change. Rising temperatures, unpredictable rainfall, prolonged droughts, waterlogging, soil salinity, higher CO₂ levels, and ozone pollution are causing major losses in both yield and quality across India’s vegetable-growing areas. To address these challenges, several practical measures have been developed and put into action. Climate-resilient varieties, grafting techniques, and seed priming improve plant tolerance to stress. Using plant growth regulators and plant growth-promoting rhizobacteria supports physiological resilience in tough conditions. Climate-smart farming practices like drip irrigation, mulching, and adjusted sowing dates help use resources efficiently and avoid peak stress times. Protected farming through polyhouses and net houses protects crops from extreme weather and allows for off-season production. Incorporating these adaptive methods into vegetable production systems is crucial for reducing climate-related risks, boosting crop resilience, and ensuring nutritional and economic security in a changing climate.

Keywords: Abiotic stress, Adaptive strategies, Climate change, Protected cultivation, Vegetable crops

1. Introduction
Vegetables play a crucial role in our diet, offering a variety of essential vitamins, minerals, and antioxidants that our bodies need. They also represent an important source of income for millions of small-scale farmers across India. However, this critical part of our agricultural landscape is facing serious challenges due to climate change. Issues like frequent droughts, extreme weather fluctuations, unpredictable rainfall, rising soil salinity, and higher concentrations of CO₂ and ozone in the air are all taking a toll on vegetable production, affecting both the quantity and quality of what we grow. This article looks into how climate change is impacting vegetable farming and shares effective strategies, backed by real-life examples, to help strengthen this essential sector against these challenges.

2. Climate Change and Its Impact on Vegetable Crops

2.1 Heat Stress: An Invisible Scorcher
Heat stress stands out as one of the most harmful abiotic pressures faced by vegetable crops. Take Punjab, for example: during the summer months, the cultivation of tomatoes takes a hit when temperatures soar beyond 38°C. This rise in heat has a detrimental effect, leading to a significant drop in pollen viability. Consequently, the fruit set becomes poor, resulting in yield losses that can reach as high as 40%. Similarly, in Bihar, the high temperatures that occur during the flowering phase of bottle gourd also create challenges. Here, the heat tends to favor the development of male flowers over female flowers, which ultimately impacts fruit set negatively.

2.2 Cold Stress: A Silent Killer
Cold stress during the early stages of crops can significantly delay germination and hinder growth. In Himachal Pradesh, when night temperatures drop below 8°C, crops like capsicum and cucumber that are grown in open fields during early spring are severely impacted. This chilling injury results in softening, water-soaked spots, and eventually decay during transport and storage. In Uttarakhand, crops such as peas and French beans often face challenges like flower drop and seed abortion when caught off guard by unexpected cold waves in February.

2.3 Water Stress: Both Scarcity and Excess Harm
In Bundelkhand, farmers growing tomatoes and okra face a significant challenge due to a lack of adequate irrigation. When water is scarce during the flowering stage, tomato yields can plummet by as much as 60%. Meanwhile, in eastern Uttar Pradesh, onion crops frequently suffer from waterlogging during the monsoon season. A study on the onion variety Arka Kalyan revealed that just a week of standing water could slash bulb yields by nearly 50%. This happens because of oxygen shortages in the roots and the emergence of foliar diseases, such as purple blotch.

2.4 Salinity Stress: A Growing Threat in Coastal and Canal Areas
In regions like Gujarat and Tamil Nadu, excessive irrigation and saline groundwater are causing serious salinization issues for vegetable fields. In the Kutch area, crops like okra and carrots are showing signs of distress—leaf tip burn and stunted growth—due to high soil electrical conductivity, exceeding 6 dS/m. Pea plants exposed to salinity levels of 8 dS/m faced a dramatic 50% decrease in both seed germination and plant height when compared to the control group.

2.5 Elevated CO₂: Quantity vs Quality Dilemma
While boosting CO₂ levels can enhance biomass and yields, it often comes at the cost of nutritional quality. For instance, in controlled experiments at IIHR Bengaluru with elevated CO₂ levels of 550 ppm, tomato plants did indeed produce more fruits and larger sizes. However, this increase was accompanied by a decrease in flavonoids and vitamin C, ultimately impacting both taste and nutrition.

2.6 Ozone Pollution: A Hidden Crop Destroyer
Ozone (O₃), a harmful air pollutant, infiltrates leaves through stomata, leading to oxidative damage. Research conducted in the Delhi-NCR region revealed that Palak (Beta vulgaris) plants exposed to 60 ppb of ozone experienced yield losses of up to 25%. Additionally, tomato crops suffered from diminished fruit size and premature yellowing when they were subjected to high levels of ambient O₃ during the months of April and May.


(Source: Bose et al., 2023)
The relationship between atmospheric CO2 levels and temperature plays a significant role in determining how plants grow and produce yields.


3. Adaptive Strategies: From Labs to Land
To tackle the challenges posed by climate change, a variety of strategies have been explored and effectively implemented both in India and around the world.

3.1 Climate-Resilient Varieties: Genetic Insurance
Among the most commonly embraced stress-tolerant varieties are:

Crop

Variety

Stress Tolerance

Tomato

Arka Vikas, Pusa Sheetal

Drought, Cold

Onion

Arka Kalyan

Waterlogging

Okra

Pusa Sawani

Salinity

Chilli

Arka Lohit, G4

Drought

Bottle Gourd

Pusa Santushti

Heat & Cold

Cowpea

Arka Garima

Drought


Farmers in Rajasthan who grow Arka Meghali tomatoes have noticed that their crops perform better and yield more consistently, even when faced with dry conditions and rising temperatures above 35°C.

3.2 Grafting for Resilience
By grafting sensitive scions onto more tolerant rootstocks, we can enhance a plant's ability to withstand flooding, diseases, and salinity. For instance, in Eastern India, when tomatoes are grafted onto brinjal rootstock like Arka Neelkanth, they show remarkable resilience to waterlogged soils during the monsoon season. Interestingly, in countries such as Korea, over 95% of watermelon crops are cultivated using grafted seedlings.

3.3 Seed Priming: A Simple But Powerful Tool
Priming seeds with gentle chemicals like potassium nitrate (KNO₃) or thiourea can significantly boost seedling establishment even in tough conditions. A notable example comes from trials at Punjab Agricultural University, where capsicum seeds treated with hydrogen peroxide and abscisic acid (ABA) achieved a remarkable 100% survival rate under salt stress.

3.4 Plant Growth Regulators (PGRs)
The application of plant growth regulators like brassinosteroids, melatonin, or salicylic acid can help crops cope better with drought and salinity. For example, research from CAZRI in Jodhpur revealed that applying melatonin to watermelon improved photosynthetic activity and biomass even when faced with salt stress.

3.5 PGPR (Plant Growth Promoting Rhizobacteria)
Plant growth-promoting rhizobacteria (PGPR) such as Trichoderma harzianum and Bradyrhizobium play a crucial role in enhancing root growth and nutrient uptake under stress conditions. In Karnataka, tomato plants treated with Trichoderma outperformed untreated ones in terms of survival during periods of heat and drought.

3.6 Climate-Smart Agronomic Practices
In Maharashtra, drip irrigation has become a popular solution for growing tomatoes and capsicum, helping address water scarcity issues. Meanwhile, farmers in Odisha and West Bengal often use black plastic or paddy straw for mulching to retain moisture and control weeds. Additionally, in Jharkhand, shifting sowing dates to avoid the peak heat or monsoon stress has proven beneficial for protecting cauliflower and brinjal crops.

3.7 Protected Cultivation
Utilizing polyhouses, net houses, or tunnels provides valuable protection for crops against extreme weather, ultimately enhancing quality. For example, in Sikkim, the cultivation of capsicum and tomatoes in polyhouses has led to income increases of two to three times compared to traditional open-field methods. Furthermore, protected farming has enabled the production of off-season vegetables.

4. Conclusion
Climate change isn't just a looming threat anymore; it's a pressing issue we face today. Vegetable crops are bearing the brunt of this shift. Farmers all over India are grappling with lower yields, pest problems, and financial setbacks, largely due to heatwaves sweeping through the plains and unexpected rain hitting the hills. Farmers have the chance to turn these hurdles into stepping stones. By embracing climate-resilient crop varieties, making use of advanced farming tools, practicing grafting, utilizing beneficial bacteria, engaging in protected cultivation, and adopting smart irrigation techniques, they can navigate through these tough times.

References

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Atayee, A. R., & Noori, M. S. (2020). Alleviation of cold stress in vegetable crops. Journal of Science and Agriculture, 4, 38–44. https://doi.org/10.25081/jsa.2020.v4.6110

Ayyogari, K., Sidhya, P., & Pandit, M. (2014). Impact of climate change on vegetable cultivation-a review. International Journal of Agricultural and Environmental Biotechnology, 7, 145. https://doi.org/10.5958/j.2230-732X.7.1.020

Bhardwaj, M. (2012). Effect of climate change on vegetable production in India. In Vegetable production under changing climate scenario (pp. 1–12).

Bisbis, M. B., Gruda, N., & Blanke, M. (2018). Potential impacts of climate change on vegetable production and product quality – A review. Journal of Cleaner Production, 170, 1602–1620. https://doi.org/10.1016/j.jclepro.2017.09.224.

Bose, B., & Pal, H. (2023). Impact of Climate Change on Vegetable Production. In M. Hasanuzzaman (Ed.), Climate-Resilient Agriculture, Vol 1. Springer. https://doi.org/10.1007/978-3-031-37424-1_4.