Hail's Impact on Plants: Morphology, Vulnerability & Strategies

Analysis of Mechanical Damage to Plant Tissues from Hail Impact

Hail, an increasingly frequent and severe meteorological phenomenon in various regions, including parts of Argentina and Latin America, poses a significant threat to agriculture and horticulture. Its impact transcends mere physical destruction, affecting crop viability and the aesthetic appeal of green spaces. Understanding how this climatic event influences different plant types is fundamental for implementing effective protection and recovery strategies, adapting to a changing climate landscape.

Hail interaction with plants causes direct mechanical damage, the severity of which varies depending on the size of the ice particles, storm intensity, and the inherent structure of each plant species. Common injuries include leaf tears, perforations, bruising on stems and fruits, and the fracture of young branches.

Plants with large, tender leaves, such as lettuce (Lactuca sativa), Swiss chard (Beta vulgaris var. cicla), or cabbage (Brassica oleracea var. capitata), are particularly susceptible. A hail event can cause extensive tears and perforations that severely compromise the plant’s photosynthetic capacity, drastically reducing its yield and commercial value. The edges of these lesions act as entry points for fungal and bacterial pathogens, exacerbating the initial damage.

For plants with more flexible, herbaceous stems, like tomatoes (Solanum lycopersicum) or peppers (Capsicum annuum), hail can cause bruising and breakage that disrupt sap flow, weakening the plant’s structure and anchorage. Developing fruits suffer contusions that, while not always destroying them immediately, result in scars that make them unmarketable and predispose them to rot.

In the case of trees and shrubs, damage is concentrated on young shoots, leaves, and bark. Growing shoots are essential for future fruit and wood production, and their destruction can significantly reduce the following year’s harvest. Wounds on the bark, even superficial ones, can serve as infection points for diseases or pests, especially in fruit species like peaches (Prunus persica) or apples (Malus domestica).

Differential Vulnerability of Horticultural and Field Crops

The response to hail impact is not uniform; each crop type exhibits differentiated vulnerability, demanding specific approaches for its protection and management.

Fruiting vegetables (tomatoes, peppers, squash, eggplants) are extremely sensitive. Hail can cause direct damage to the fruits, resulting in scars, deformities, or complete destruction. A recent study by INTA in the Pampas region highlighted how the severity of damage to these vegetables can lead to total crop loss, severely impacting the economy of small producers. Furthermore, damaged plants require a recovery period that delays production and makes them more vulnerable to new adversities.

Field crops such as corn (Zea mays), soybeans (Glycine max), or wheat (Triticum aestivum) also suffer significant losses. Hail can defoliate plants, break stems, and damage ears or pods, reducing the plant’s ability to photosynthesize and ultimately diminishing grain yield. The crop’s phenological stage at the time of the event is crucial: hail during grain filling is devastating.

In fruit orchards, the impact is multifaceted. Early-season hail can destroy flowers or newly set fruits, nullifying the harvest. If it occurs later, it can damage the skin of developing fruits, affecting their aesthetic and commercial quality. Wounds on branches and trunks may require intensive pruning, which stresses the tree and exposes it to pathogens. Innovations in genetic breeding aim to develop fruit varieties with greater mechanical resistance in their tissues and enhanced healing capabilities.

Prevention and rapid response are crucial to minimize losses and ensure production continuity.

Implementation of Physical Barriers and Resistant Genotypes

Active Prevention

The installation of hail netting is one of the most effective solutions, especially for intensive and fruit crops. The nets, made of high-density polyethylene, dissipate the hail’s energy, physically protecting the plants. Technological advancements have led to the development of lighter, more durable nets with varying shade levels, adaptable to diverse needs. In Patagonia, for example, cherry and apple producers have widely adopted these systems to protect their valuable harvests.

Selecting plant varieties with greater natural resistance to mechanical damage, or those that can recover more quickly, is another strategy. Research in plant biotechnology is exploring genes associated with tissue toughness and cellular regeneration capacity, offering a promising future for more hail-resilient crops.

Post-Event Management

After a hail event, sanitary pruning is an essential practice. Removing damaged plant tissue (torn leaves, broken branches) not only helps the plant redirect its energy to recovery but also prevents disease entry. It is vital to make clean cuts and disinfect tools to avoid pathogen spread. The application of contact fungicides and bactericides may be necessary in the hours following hail to protect open wounds from secondary infections.

Recovery Protocols and Post-Event Nutritional Management

Similarly, proper nutritional and irrigation management supports recovery. Providing balanced nutrients and ensuring optimal hydration helps the plant generate new tissue and strengthen its immune system. Constant monitoring of affected plants is key to detecting signs of stress or disease in a timely manner.

The increasing frequency of extreme weather events, driven by climate change, highlights the importance of adopting more resilient gardening and agricultural practices. Permaculture and regenerative agriculture offer principles that promote biodiversity and soil health, creating more robust ecosystems capable of withstanding disturbances. Species diversity within the same space, for instance, can reduce the overall impact of a hail event by not concentrating vulnerability in a single crop type.

Smart farming technologies also play a growing role. Advanced climate sensors and early warning systems allow farmers to prepare for hail events in advance, activating automated protection systems or mobilizing resources to mitigate damage. Collecting data on hail incidence and its effects enables the development of more accurate predictive models and improves regional adaptation strategies. The future of horticulture and agriculture requires a combination of traditional knowledge, technological innovation, and a deep respect for ecological principles to thrive in an unpredictable climate.

In summary, a detailed understanding of how hail affects each plant type is the first step in protecting our crops and gardens. By implementing preventive measures such as hail netting and selecting resilient varieties, and by applying diligent post-event management, gardeners and producers can significantly mitigate losses. Continuous adaptation and the incorporation of sustainable practices are essential for building agricultural and horticultural systems that not only survive but thrive in the face of current climate challenges.