Every 1°C increase above the average temperature of 23°C reduces wheat yields by about 10%. More than 40% of the total wheat acreage worldwide is affected by heat stress.
As climate change adversely affects agriculture. Wheat, which is the main crop of Pakistan, has also been greatly damaged by climate change.
Weather patterns and temperatures have been changed over a long period of time by climate change. The dominant cause of climate change since the 1800s has been human activity, even if some of these changes may be considered natural. Fossil fuels like coal, oil, and gases, which retain heat, are mostly to blame for this.
People, agriculture, and wild animals all face new threats because climate change is responsible for our existence. Dry spells, thunderstorms, heat waves, ablation, warmer oceans, and more frequent and severe droughts may all directly injure animals, devastate the habitats on which they depend for survival, and have a disastrous impact on people’s way of life and communities.
85% of people on the planet are already feeling the consequences of climate change that is driven by humans. The model was developed under drought conditions, and the results showed that global warming is leading to severe droughts in 60% of the world’s wheat growing areas.
Currently, drought affects 15% of grain productivity. Heat stress is the main environmental factor limiting grain yield. Every 1°C increase above the average temperature of 23°C reduces wheat yields by about 10%. More than 40% of the total wheat acreage worldwide is affected by heat stress.
For humans, wheat is a crucial cereal crop. With billions of people depending on it for food, it is one of the most commonly grown and consumed crops in the world. In many nations, including Pakistan, a crop of wheat is a staple meal that is used to manufacture a wide range of goods, including bread, pasta, noodles, crumpets, and muffins. Moreover, it is utilized in the creation of biofuels and as animal feed.
Wheat is an excellent source of nutrients such as vitamins, minerals, dietary fiber, and carbs. It is especially high in iron, which is necessary for the production of red blood cells, and B vitamins, which are crucial for energy metabolisms.
Consuming foods made from whole grain wheat has been associated with a decreased chance of contracting long-term illnesses like heart disease, type 2 diabetes, and certain cancers. Overall, wheat is a crucial crop for the world’s economy as well as human nourishment.
Temperature increases have a variety of effects on wheat crop production in Pakistan. Wheat grain quality declines as a result of climate change because it disrupts the distribution of vital nutrients and photoassimilates.
The high temperature causes an increase in transpiration that causes drought, resulting in low productivity. The heat stress disrupts the integrity of chloroplasts, leaf senescence, and ultimately the photosynthesis of grain. The ageing of leaves during grain filling reduces the chlorophyll content of leaves.
Wheat development and growth are greatly hampered by high temperatures. High temperature stress reduces photosynthetic activity. Heat stress decreases the molar proportion of more unsaturated lipids during the grain filling stage, while high temperature stress increases the percentage of less unsaturated lipids throughout the blooming and grain filling stages.
As we discussed above, high temperatures have a significant impact on crop growth and development, leading to decreased yield and quality. Agronomic practices can help mitigate the effects of high temperatures in several ways. Here are some examples:
Crop selection: Choose heat tolerant varieties that are adapted to high temperatures can help reduce the impact of heat stress on wheat. These varieties have traits that include a deeper root system, better use efficiency, and the ability to maintain photosynthesis under high temperature conditions.
Planting date: Planting wheat earlier in the season will avoid the severe hot period of the season and reduce the impact of high temperatures because the crop can attain the required growing degree days for optimum or maximum yield.
Soil management: Proper soil management practices such as soil tillage, soil organic matter management, and soil nutrients management can help to improve soil water retention capacity and soil structure, which can reduce the effect of high temperatures on crop yield and growth.
Irrigation management: Proper irrigation management can help minimize the effect of heat stress by providing crops with adequate water to cool themselves through transpiration. Ensuring that plants receive enough water during the heading and grain filling stages is critical to minimizing the effect of high temperature stress.
Mulching: Mulch can help maintain soil temperatures and preserve soil moisture. Mulch can be made from a variety of materials, including straws, leaves, or other organic matter. It can help reduce water loss from the soil, which can help maintain soil moisture levels and reduce the effects of high temperature stress on the plant.
Fertilization: Proper fertilization can improve crop growth and development, minimizing the effects of extreme heat on crop growth, yield, and quality.
Plant density: Adjusting plant density (the optimum plant population) can help to reduce the competition for resources among plants and improve the efficiency of water and nutrient uptake, which ultimately helps the crop better cope with high temperatures.
Harvest management: Harvesting during cooler parts of the day can reduce the impact of high temperature stress on crops by reducing the risk of moisture loss and wilting.
Provide shade: Provide temporary shade for the wheat plants during the hottest part of the day. This can be done with shade cloth or by planting crops that provide shade. Providing shade can help reduce the amount of direct sunlight that reaches the wheat plants, which can lower the temperature of the plant and reduce water loss through transpiration.
Apply foliar sprays: Foliar sprays containing plant growth regulators or nutrients can help mitigate the negative effects of high temperature stress on wheat plants. These sprays can help to improve photosynthesis, reduce water loss through transpiration, and improve the plant’s ability to withstand heat stress.
Manage pests and diseases: Manage pests and diseases that can decrease the plant’s tolerance to high temperature stress is important. Pests and diseases can weaken the plant and reduce its ability to overcome stress, so it is important to maintain good pest and disease management practices.
Overall, a combination of these agronomic practices can help to mitigate the impact of high temperatures on wheat crop and increase their resilience to changing climate conditions in Pakistan as well. We must be adopting some of these strategies to secure our staple food crop and our basic needs, which are fulfilled by the wheat crop.