Mitigation and Adaptation Strategies of Plants against Hailstorm under Changing Climate

Abstract

The growth, development and yield of crops as well as animal and fishery are depending on the prevailing extreme weather events. Vulnerability of agriculture to climate change is becoming increasingly apparent in recent years. During 2014 and 2020, India experienced episodes of abnormally widespread and untimely hailstorm events. The conversion of number of thunderstorms into hail storm events in India shows increasing trend day by day. And the type and level of hailstorm stress must be properly quantified through proper scientific planning for present as well as future references for finding mitigation and adaptation solutions. Keeping above in view, this review paper has been prepared. This study includes aspects covering atmospheric stress (hailstorm), their challenges and coping strategies in various agricultural enterprises including crops and livestock. This review paper will ignite the minds of all stakeholders including students and researchers to explore more in finding proper adaptation and mitigation measures. This study will pave the way for developing food and livelihood systems that will have greater economic and environmental resilience to risk. Therefore, the available information has been reviewed on formation of hailstorms, its characteristics and damage potential, forecasting and control mechanisms, mitigation and adaptions through different innovations and interventions.

1. Introduction

The agricultural commodities include field crops, horticultural crops, livestock, poultry and fisheries. The basic principle of agriculture lies with how crop/livestock interacts with atmosphere and soil/food as a growing medium. The system acts as pathway which regulates the intake of water/feed, nutrients and gas exchanges. Thus, any change in the quality and quantity of atmospheric variables will certainly affect the pathway through changes in atmospheric and edaphic/feed factors. Besides these, climate change is also adding salt to the wound by aggravating the extreme weather events [1].

Agricultural production in India is becoming increasingly vulnerable to climate variability and change characterised by altered frequency, timing and magnitude of precipitation and temperature. High rates of snow and glacial melting, frequent floods and droughts, heat waves, hailstorms, heavy frost and increased incidences of the pests and diseases cause widespread damage and losses to agricultural sector in India. With warmer climate, frequency and severity of extreme weather events would increase as indicated by incidences of heat waves, extreme rains, hailstorm, etc. during recent years. India’s average annual economic loss due to natural disasters is estimated to be 10 billion dollars in which cyclone and flood accounts for 0.5 and 7.5%, respectively [2]. And other atmospheric stresses like hailstorm, heat wave, cold wave, frost, etc. cause huge losses to Indian agriculture. Since agriculture makes up roughly 14% of India’s GDP, a 4.5–9% negative impact on production implies a cost of climate change to be roughly up to 1.5% of GDP per year [3]. And the impact may be of direct (mechanical) or indirect (physiological) depending on the type of stress, type of crop, stage of crop and mode of action of the stress on the commodity. However, there have been extreme weather events in the recent past including extended dry periods, floods, hailstorms, cyclonic rains and winds etc., which caused damage to standing crops and ultimately poor yield of crops. While, 11 states (viz., Karnataka, Chhattisgarh, Madhya Pradesh, Maharashtra, Odisha, Telangana, Uttar Pradesh, Andhra Pradesh, Jharkhand, Rajasthan and Uttarakhand) had submitted memoranda reporting crop loss due to natural calamities like drought, hailstorm, pest attack and cold wave/frost [4].

Hail is a solid, frozen form of precipitation that causes extensive damage to properties and growing crops. Hot, humid afternoon hours during the summer are the most congenial for development of hailstorms. These usually form over a relatively small area and pass over within a very short period, however, causes havoc even from a few minutes spell. Though hailstorm can occur in any part of the world, temperate zones are the most vulnerable. Among the countries, hail related losses are most prevalent in USA [5]. The damage with hails is determined by the size ranges and the number of hailstones that fall per unit area during a hail fall, wind force during the event and the property of the target. The extent of crop-hail damages also varies depending on the stage of occurrence of hail during the crop growing season. Even a short episode of hail can cause severe injury to crops, fruit trees, both downgrading the quality and causing subsequent losses due to diseases like blight, mould, canker and fruit rots. The hailstorms in a region often follow a definite pattern. However, the recent events in the country have surprised farmers and fruit growers when hail moved in from unexpected directions. Widespread unseasonal rainy spells accompanied by hail occurred in several states of India during February–March, 2014. It caused a large scale destruction of crops in Uttar Pradesh, Rajasthan, Madhya Pradesh, Maharashtra, Punjab, Gujarat, Uttarakhand, Haryana, Andhra Pradesh and Karnataka with central India (Maharashtra and Madhya Pradesh) being the worst hit. The country did not witness such a severe weather aberration since a long time [6].

However, hailstorm is a most divisive climatic hazard to Indian agriculture and it may be a product of changing climate. Hail being a very short term and localised phenomena, its prediction well in advance to inform all stakeholders for adequate preventive measures is a major challenge for even the most technologically advanced and hail affected countries like as USA. India, being situated in the tropical and subtropical region, the frequency of hail events is less than mid latitude and temperate countries. However, with climate change, the instances of severe weather aberrations are increasing the demand for strong institutional arrangements to combat such challenges. While occurrence, losses and post disaster management have been discussed extensively for the other climatic hazards such as excess rainfall, drought and flood, little attention has been given to hailstorm. The following sections elaborate on various aspects of hails for better hail preparedness and post hail management measures [7].

2. Hail storm, causes, forecasting and control mechanism

2.1 The science behind hailstorm and causes of recently observed hailstorms in India

2.1.1 Hail

Precipitation of small pieces of ice, with diameter ranging from 5 to 50 mm or something more, is known as hail, and hailstorm is the most dreaded and destructive form of precipitation produced during thunderstorms or from cumulonimbus clouds. These usually form over a relatively small area and pass over within a very short period, however, causes havoc even from a few minutes spell [8].

2.1.2 Science and causes of hailstorm

Hailstorms are the result of four atmospheric factors; strong convective instability creating strong updrafts, abundant moisture at low levels feeding into the updrafts, strong wind shear aloft, usually veering with height and enhancing updrafts. Some dynamical mechanisms that can assist the release of instability such as air flow over mountain ridges [8]. Hail is often associated with thunderstorm activity and changing weather fronts. Thunderstorm is a meso-scale system with space scale of few kilometres to a couple of 100 km and time scale of less than an hour to several hours. This is formed in huge cumulonimbus clouds, commonly known as thunderheads.

Hailstorms are the result of four atmospheric factors which are characterised as: (i) strong convective instability creating strong updrafts, (ii) abundant moisture at low levels feeding into the updrafts, (iii) strong wind shear aloft, usually veering with height, enhancing updrafts and (iv) some dynamical mechanisms that can assist the release of instability such as air flow over mountain ridges [8]. The worst hailstorms events have been reported in USA were mostly due to the squall lines and low pressure centres at the intersections of warm and cold fronts (41), cold fronts (21), warm fronts (14), stationary fronts (12) and unstable air mass (12) [9].

2.1.3 Causes of recently observed episode of hailstorm

In India unseasonal rain and widespread hailstorm during February–March, 2014 was prevailed due to the shifting of polar jet stream from its regular trajectory. It has been observed that due to the melting of Arctic ice, polar jet is shifting southwards, triggering extreme weather events all across the globe. It has pushed down the cold westerlies in India that usually flow over 30 latitude to 15° latitude, causing unprecedented hailstorms and rainfall [10]. The extended hailstorms in the non-conventional areas were resulted due to collision of winds from Bay of Bengal and Arabian Sea over Central India. Madhya Pradesh, Maharashtra (barring coastal districts) and also parts of interior peninsula such as north of Andhra Pradesh had witnessed such events during the aforesaid period. Clouds measuring up to 22 km in height and sub-freezing temperatures have been February–May 2014 and 2015 in northern, central and southern India was observed due to more convective activities following rise in temperature as the season progressed from winter to spring [11], and a agrometeorologist of the Vasantrao Naik Marathwada Krishi Vidyapeeth (VNMKV), Parbhani (India) attributed the extreme events such as hailstorm instances experienced mainly due to conditional instability and such instabilities are commonly observed every year at isolated places in Maharashtra [12].

2.1.4 Climate change and hail events

The agricultural production, allied agribusiness and small scale agricultural business is sensitive to changing weather. Changing climate impacts on agriculture production is complex to understand. However, there is high level of agreement across studies that the impact in all probability is going to be negative for most crop categories. It is well established that there has been an increase in extreme weather events. Only 20% of these are due to natural causes; 80% are human-induced changes. India being mainly an agricultural country the economy and further its growth purely depends on the vagaries of the weather and in particular the extreme weather events [13]. Climate change implies higher frequency of extreme weather events such as hail to name a few—causing reduced crop yields and plant production and threatening the provision of other ecosystem services [14]. While, Intergovernmental Panel on Climate Change (IPCC) has predicted that in peninsular India, rainfall patterns will become more and more erratic, with a possible decrease in overall rainfall, but an increase in extreme weather events. What we are witnessing is certainly an extreme weather event [15]. While, at regional level, contradictory report was given by the Ministry of Earth Science, Government of India and in which clearly stated that there is no evidence of change in weather pattern over the country [4]. Extreme and unprecedented weather events have to be accepted as climate change phenomenon regardless of their frequency [16, 17]. However, such argument needs to be supported by more scientific evidences and a detailed analysis of past and recent events is the need of the hour.

2.1.4.1 Are the recent hail events a symptom of climate change?

Indian climatologist’s majority opine that the unprecedented and untimely weather events were yet another sequence in the chain of freak weather events India has been witnessing in the last few decades. But many shy away from attributing it to climate change. As per Climate Change Centre, Indian Institute of Tropical Meteorology (IITM), Pune (India) it is premature to attribute it to climate change. More samples are required for the attribution. Temperatures are rising in the world everywhere and every year, so it is a symptom of climate change. But the current event of 2014 was an isolated one and has not been witnessed in the last 25–30 years. So, it is difficult to link it to climate change. It may be a part of natural variability of weather conditions.

While, hails or thunderstorms are extreme forms of weather events and deserve special attention in view of climate change. However, the homogeneity of existing reporting and data quality in many instances are questionable [18]. And due to this there is low confidence in observed trends so far in small-scale, however, few studies indicate that a strong positive relation exists between hailstorm activity and global warming. Fifth assessment report (AR5) of IPCC highlighted some studies with regard to trends of hailstorm occurrence over the years in different parts of the world [19]. A strong positive relation exists between hailstorm activity and subsequent hailstorm damage which is likely to be aggravated by global warming. By 2050, the estimated annual hailstorm damage to unprotected farming could increase from 25 to 50% [20].

2.1.5 Hail forecasting and control mechanisms

Radioactive Detection and Ranging (RADAR) technology in hail forecasting found most expedient and it is difficult to forecast all a hailstorm, since its occurrence is sporadic and confined to very limited areas in a thunderstorm. While hail formation continues to elude scientists, sophisticated RADAR has been developed that can detect the presence of hail before it falls to the ground. Eventually, warnings may be issued as about 15 minutes before hail strikes, thus allowing pilots to avoid threatening air space, people to seek shelter, and property to be protected [9].

While, artificial hail control is an important measure in disaster prevention and mitigation. With the development of atmospheric science and related science and techniques, the ability of hail cloud identification and subsequent hail suppression technique has been improving continuously. There are two techniques available for suppression or control of hail, but mercy is that no one can able to prove it confidently on ground of validation still today.

1. Cloud seeding: This process of seeding of condensation nuclei into the system on or before the start of hail formation process can be done using either specialised aircrafts or anti-hail rockets.

2. Creating shockwaves: The creation of shock waves can prevent the formation and growth of hail by melting altogether. Shockwaves are produced using hail guns/cannons.

3. Hail observations and monitoring

The data on temporal and spatial distribution of hailstorms as well as size of hailstones with the consequent damage have to be documented systematically which facilitates identification of vulnerable areas more scientifically. The size and density of hailstones that fall per unit area are being measured. The hailstone size and intensity are measured by using hail-pads and hailstone size measured by different ways; vernier scale, metric scale ruler, metric scale tape or by comparing with different shapes (e.g., grain, pea, mango, ball, coin, etc.) [9, 21, 22, 23, 24, 25].

3.1 Hail characteristics and damage potential

Usually, the extent of damage by hail is determined by the size and density of hailstones that fall per unit area and wind force during the hail fall event. There are three types of hail classified according to the occurrence and nature: (1) soft hail (less than 5 mm ice mixture when falling on the earth surface breaks into small pieces is called as soft hail), (2) small hail (small ice crystals falling on the earth along with rainfall but do not break down into small pieces is called as small hail) and (3) severe hail (hard hails having diameter of 5.5 μm commonly known as severe hail). Secondly, according to size, shape and nature, hailstones are classified into different classes with photographs and its damaging potential [9, 23, 24, 25]. However, in agriculture, hail is considered an extreme event of great destructive potential and a single hailstorm event in an orchard could result in the total loss of fruit production and would damage the trees [26]. The damage with hails is determined by the size ranges and the number of hailstones that fall per unit area during a hail fall, wind force during the event and the property of the target. The extent of crop-hail damages also varies depending on the stage of occurrence of hail during the crop growing season. Different crops are damaged in varying ways by hail. Tea, tobacco, broccoli, tomato, spinach and soybeans leaves are delicate and subject to serious damage even when 6.4 mm diameter hailstones fall. Fruit crops, such as apples and peaches, can be easily bruised by small- to moderate-sized hail and can lose great value because of reduced quality.

3.2 Indian hailstorm scenario

Hailstorm hazard is not new to the Indians and it was recorded from the British emperor; one of the deadliest hailstorms of all time killed at least 230 people, and over 1600 sheep’s and goats in Uttar Pradesh (India) on 30 April, 1888. The hailstones were reportedly as big as oranges, and in some places were as high as 600 gm. In 1898 Sir John Eliot first time in the Indian History complied hail storm record. Thereafter, Ramdas in 1938, hailstorm data of the period 1898–1935 analysed and published first time centimetres [9] and there after India Meteorological Department (IMD) as well as another all institutes and organisations were continued it through proper scientific planning with greater efforts till today. Regarding highest size of hail stones, the largest size hailstone occurred in association with a thunderstorm in April, 1888 at Moradabad a town near Delhi [13]. The hailstorm frequencies are highest in the Assam valley, followed by hills of Uttar Pradesh now known as Uttaranchal, South Bihar (now known as Jharkhand) and Vidarbha in the eastern parts of Maharashtra [27]. Whereas, the coconut size hailstones were recorded at Kondhwa in Pune, during 1908–1909. Further, during 1986, the hailstones of cricket ball size showered in Pune with observed mango size (750 gm) hails at Motala, Dist. Yevatmal (Maharashtra). The hailstone measured size of a pigeons egg in diameter (IMD 1888) [23, 28].

In some of the worst disasters associated with hailstorms, eight persons were killed in Kanpur (Uttar Pradesh) on 28 February 1992, and nine persons died near Nagpur (Maharashtra) in February 1979. Thunderstorm and squally winds killed 19 people in Patna on 29 May 1997, while in Kolkata nine people died on 26 March 1993 due to thunderstorm and lightning. Cataloguing of Disastrous Weather Events by the India Meteorological Department started in 1967. Prior to 1967, reports of deaths (loss of life) in association with thunderstorms are many [29].

The current history of hailstorm enlightens the devastative nature of hailstorm and which was clearly seen from last two decades; the affected area and losses of agriculture were documented by different workers and revealed that it was spreading on more no. of states increasing continuously in India from 1994–1995 to 1998–1999, 2014 and 2015 (0.46, 0.74, 1.2, 2.9, 1.8 and 6.3 m ha, respectively) [20, 22, 30].

3.3 Recent hailstorm episodes and damage

In India, an unprecedented 20 days was prevailed in different states, during February 24 to March, 2014, has left millions of farmers in a state of shock; surprisingly in 2014, almost 28 out of 35 districts in Maharashtra were severely affected by unseasonal rains and heavy hailstorm causing widespread damage to the agriculture (Table 1). The heavy damage to agriculture sector due to hailstorm in most of the affected villages of Maharashtra was experienced first time by elder and older peoples in their life during last 60 years [27]. Usually, hailstorm activity occurs during the months of April and May [30]. But this time it has occurred during February–March which is a severe weather aberration. Over 1.24 lac hectare (l ha) of farmland spread over 1086 villages in Maharashtra have been adversely affected in the on-going spell of unseasonal rain and hailstorm (February 10–13, 2018) which started on 10 February and at most affect 4–5% of the crop. Eleven districts mainly in Marathwada and Vidharba regions have reported hailstorm. The districts of Buldhana, Amavati, Akola and Washim in Vidharba have also got light showers. Two deaths were reported from Buldhana where farmers had taken shelter under trees to avoid the hailstones [31]. The comprehensively recent worst affected area by hailstorm events in India were reported by different organisations, media and personals are presented in Table 1 [32, 33, 34].

Period of hailstorm aberration	Affected states of India	Damage to agricultural crops and losses
February 24–March 14	Punjab, Haryana, UP, Rajasthan, MP, Maharashtra, Karnataka and AP	Ready to harvest rabi crops such as wheat, pulses, potato, sugarcane, maize, groundnut and mustard and horticultural crops like grapes, papaya, mango, banana, onion and other vegetables damaged partially or completely. 4.65 million ha of standing crops were ravaged in the worst-hit Maharashtra and Madhya Pradesh alone.
February 11–13, 2014	Maharashtra	Over 3 lakh ha in Maharashtra were affected by thunderstorms and hailstorms. Overall, the crops of wheat, gram, sorghum, onion, grapes, oranges and cotton have been affected in 19 districts of the state. State Government, released nearly Rs. 313 crores from the state disaster response fund.
End of February 2014	Marathwada, Vidarbha, Northern Maharashtra and parts of Western Maharashtra	Absolutely destroying the farmer. Rabi crops like wheat, gram, cotton, sorghum, summer onion were lost, horticultural crops like papaya, sweet lime, grapes are battered and orchards which took years to grow are ridden to the ground. Turmeric was drying in the sun, grapes were waiting to be graded, and wheat was harvested and lying in the fields. A preliminary estimate and news reports, crops over 12 lakh ha thousands of livestock, animals and birds have succumbed to injuries and diseases, which threaten to spread. Around 21 people have lost their lives to the disaster.
March 14–16, 2016	Marathwada and Vidarbha region of Maharashtra State	Flattening rabi crops over 85,000 ha area.
February 11, 2018 at 09:15 am	Wakod Village, Resod, Washim District, Maharashtra	The mostly damaged of crops the area was horticultural and Rabi crops (viz., sorghum, cotton, pigeon pea, sunflower, etc.) and allied agribusiness was also partially damaged intensively.

Table 1.

Recent hailstorm episodes and damaged to agricultural sectors.

3.4 Hail storm frequency in India

Considering the resent hailstorm events, few of the scientists kept their views without data and they believe on some part of the Maharashtra may convert into hail prone area. Therefore, hail storm data are reviewed that the average number of days with hail is about 6–7 per year over Himachal Pradesh and its neighbourhood, but it decreases sharply to 1 in 2 per years over the adjoining plains. Over Bengal, Bihar, Uttar Pradesh and in central Indian states of Madhya Pradesh and Maharashtra hailstorm occurs on an average once a year. In the interior parts of southern peninsula, only one hail event may be expected once in 5 years. Hailstorms are comparatively rare over the coastal tracts of the Peninsula [9, 17]. However, similar observations were reported by another worker that the total number of thunderstorm and hail storm events in India during the period of 1967–2006 observed 1123 and 934, respectively with increasing trend of 1.90 and 1.00 per year, respectively [6]. While, hail is an extreme event out of the 10 selected key climate extreme events and recent past spatio-temporal pattern over India showed that highly significant increasing trend in the total number of events was observed [3]. While, hailstorm data for 38 years have been used for frequency analysis (1972–2011; excluding 1977 and 1984, for which data are not available). More than 61% of districts have experienced at least one hail event in this 38-year period. The highest frequency was noticed over districts in the northern parts of the Vidarbha region of Maharashtra adjoining the state of Madhya Pradesh. Vulnerability of agriculture to climate change is becoming increasingly apparent in recent years [29]. Regarding the frequency and trend of hailstorm in India, hailstorm data for 38 years have been used for frequency analysis (1972–2011; excluding 1977 and 1984, for which data are not available). More than 61% of districts have experienced at least one hail event in this 38-year period. The highest frequency was noticed over districts in the northern parts of the Vidarbha region of Maharashtra adjoining the state of Madhya Pradesh [22, 35].

4. Hail damage to agriculture

Optimal growth of the plant found under a certain quantity of each of the environmental factors, and any deviation from such optimal conditions adversely affects its productivity through plant growth and development. Effect of hailstorm on the plant depends on their intensity and duration of act. These stress factors hailstorm highly impacted on crop, thereafter on livestock and least on fisheries. Once hailstorm hazard prevailed, its impacts may be direct or indirect; due to direct impact causes mechanical damage or injuries, it may be total loss (e.g., death of human, animals and birds, lodging of plants, uprooted trees and crop, etc.) and partial loss (e.g., causality of human, animals and birds, heavy defoliation, shredding of leaf blades, breaking of branches and tender stems, peeling of bark, stem lesions, cracking of fruits, heavy flower and fruit drop in crops and plants, etc.). And due to indirect impact causes injuries or physiological disorder (depending on the type of stress, type of crop/animal/birds, stage of crop/animal/birds), it is based on stage of occurrence (damages in mature produce quickly become focal points for diseases like brown/grey rot smut); primary injuries (like dieback or wilting of damaged plant parts) and discoloration of damaged parts (like leaves and fruits affecting their quality and rotting of damaged fruits and/or tender stems and branches due to fungal and bacterial infections), etc.

Based on Post-Disaster Needs Assessment (PDNA) report of Food and Agriculture Origination (FAO), damage and loss in agriculture by agricultural sub-sector, percentage share of total (2006–2016) was highest 49% in crop and thereafter in decreasing order in livestock (36%), unspecified sectors (8%), forestry (4%) and fishery (3%) were observed. The type of the damages recorded during recently prevailed continues episodes of hailstorms (2013–2014–2017–2018) are given in Table 1 [9, 36].

4.1 Hail damage to agricultural production and allied agribusiness

Hailstorm causes primary injuries due to direct impact of hails which causes heavy defoliation, shredding of leaf blades, breaking of branches and tender stems, lodging of plants, peeling of bark, stem lesions, cracking of fruits, heavy flower and fruit drop, etc. This is followed by secondary injuries which are nothing but the manifestations of primary injuries like dieback or wilting of damaged plant parts, loss of plant height, staining, bruises, discoloration of damaged parts like leaves and fruits affecting their quality and rotting of damaged fruits and/or tender stems and branches due to fungal and bacterial infections [9, 37]. While, heavy rain, hail and strong wind affect crop yield in different ways, especially depending on the development stage. Whereas roots may lose their contact and anchorage in soil when heavy either rain, hailstorm or in combination of both, decreases soil strength and increases the load which the plant must bear.

For rice, mainly reduced translocation of mineral nutrients and carbon for grain filling, increased respiration, reduced carbon assimilation within the canopy, rapid chlorosis and greater susceptibility to pests and diseases are reported as main mechanisms. Lodging reduces the yield of rice by self-shading and reducing canopy photosynthesis. Additionally, lodging of cereals provides a favourable environment for leaf diseases and causes harvesting losses. Lodging also adversely affects grain quality, for example lodging inhibits grain drying due to reduced air circulation and increased humidity. In addition to the type of crop, stage of growth, weather conditions and susceptibility to disease also determine the impact. Prolonged hot and wet conditions after the storm enhance losses by increase in incidences of diseases, particularly those caused by bacteria [20, 38, 39, 40].

An overview on yield reductions due to lodging are 31–80% in wheat, 4–65% in barley, 37–40% in oats, 5–20% in maize, and 5–84% in rice [41]. While, the huge loss of winter, rabi and annual as well as perennial crops was generated in 2014 due to fallen hailstorm during the month of February and March in India and crop wise affected area in 1000 ha of gram, wheat, sorghum, maize, summer rice, vegetables, banana and other crops are 149, 119, 20, 10, 9.0 0.6, 0.2 and 357, respectively in 2014 due to hailstorm in India were [27]. Similarly, recorded damaged area and entity due to hailstorm episode or hailstone events during the year 2014–2018 [9, 21, 30, 31, 33, 42, 43] and which is given in Table 1.

Though variation was observed in between official and the media reports of hailstorm damage in the February and March, 2014, a divisive nature of hail storm in one report uttered, nearly 20 L ha crops was under risk, death of poultry birds and animals observed around 39,000 and 4096, respectively. Whereas, 30,000 villages were affected from 28 districts of Maharashtra and economical loss was estimated 250 crores. While, due this episode of hailstorm, destroyed 1.45 L ha grape crop (a dollar crop) at maturity stage in Maharashtra state and district wise distribution was 0.65, 0.50, 0.20 and 0.10 L ha of Nasik, Sangli, Solapur and Pune, respectively [43]. Since, 2013–2014, hailstorms are striking the state every year during spring (February, March, April) when the rabi crops are getting ready for harvest. In March 2015, hailstorm damaged in general 7.5 L ha area and out of which 6.1 L ha comes under agriculture crops and 1.4 L ha under horticulture crops [32]. Whereas, the intensity and divisive nature of hailstorm uttered that the 4.55 l ha area of Marathwada region of Maharashtra state was affected by prevailed hailstorm during March–April, 2016, Which was perished partially or completely rabi crops and vegetables, and horticultural crops [36].

4.2 Damage to livestock and poultry

The basic principle of agriculture lies with how livestock interacts with atmosphere. Thus, any deviation of external optimal atmospheric conditions affects the pathway through changes in atmospheric and feed factors for animal growth, development and/or productivity. The quantum of impact on livestock and poultry mainly depends on the type of stress and animal, its age and mode of action of the stress [22]. Hailstorms can cause seriously injury to livestock, poultry. Livestock, mostly cattle and sheep, grazing in the open become the first victim of the hail. Poultry sector was another allied sector that was badly hit birds housed in temporary or semi-temporary sheds were the first casualty [34]. While, 1075 cattle have perished and 38,512 houses have been damaged due to a hailstone event [21]. In the year 2014–2017, according to a preliminary estimate and news reports, thousands of livestock, animals and birds have succumbed to injuries and diseases, which threaten to spread due to severe hailstorm [33].

4.3 Damage to biodiversity

Hailstorms causes severe damage or mortality of people and wildlife and it is not a new phenomenon, though the incidence may be growing in new areas. The deaths of 460 parrots due to hailstorm at Tumsar in Bhandara district of Maharashtra state, on 13 February 2018 [34]. The hailstorm events occurred from the end of February into May 2014 which were caused mortality of roosting birds such as rosy starling (Pastor roseus), house sparrow (Passer domesticus) and rose-ringed parakeet (Psittacula krameri). Mammals residing in open areas were also killed. During this period major events were occurred especially during 3–10 March, resulting in a huge loss to the wildlife and agriculture sector; Vidarbha and Marathwada regions of Maharashtra (2,00,000 km²), owing to unusual hailstorms, 35 species of birds and nine species of mammals were found dead, totalling at least 62,000 birds and hundreds of mammals, in India, during 2014 and hail stones were up to 5 cm in diameter [44]. The unseasonal excessive rains along with hailstorms and lightning have also caused losses, 1075 of cattle have been perished [21].

Extreme weather events such as hailstorm in Cedar Rim in Fremont County, Wyoming, USA, was destroyed eggs and injure or kill juvenile and adult birds at the nest. Seventeen-percent of 128 nests failed due to the hailstorm; however, all failed nests were located where the hailstorm was most intense, and 45% of all nests on those plots failed due to hail. Mortality rates varied by species, nest architecture, and nest placement. Nests with more robust architecture and those more likely to survive the hailstorm, that natural history traits may modulate mortality risk due to hailstorms [45].

4.4 Damage to socioeconomics

Hailstorms can cause severe damage to farm structures apart from seriously injuring to humans and mortality of people due to intense hailstorms is not a new phenomenon, though the incidence may be growing in new areas [34]. And in the year 2014–2017, according to a preliminary estimate and news reports around 21 people have lost their lives to the disaster [33]. While, it was estimated that more than 20 lakh farmers of Madhya Pradesh are badly affected due to hailstorm calamity prevailed in 2014. Whereas, the survey reports show that there has been a loss of eight human lives and 38,512 houses have been damaged [21]. The number of farmers has committed suicide on account of failure/damage of agricultural crops, vegetables and fruits due to natural calamities including unseasonal rains and hailstorms during the year 2014–2015. And the amount of compensation/relief sought by the affected States and the amount of assistance provided by the Union Government during the said period; Uttar Pradesh, Rajasthan and Haryana demanding Rs. 744.48 crores, Rs. 8252 crores and Rs. 1135.91 crores from National Disaster Response Fund (NDRF), respectively. Assistance from NDRF for Natural Calamities (Drought) in the States from 2013 to 2014 to 2015–2016 was provided (Rs. in cores) and Assistance sought by the State Government are 39,180.41 and central assistance approved under NDRF are 7108.06. Whereas, the reports of State Government of Maharashtra confirm three cases of farmers suicide due to untimely rains and hailstorm during the period January–March, 2015 [46].

5. Hailstorm management/coping management

The substantial impact of hailstorm is mainly depending on the type of stress and crop/animal/fish, its stage/age and way of action of the stress. Management strategies for mitigation and adaptation of these stresses require both application of current interdisciplinary knowledge, development of a range of technological innovations and timely interventions. Considering its divisive nature this is a high time to update our knowledge regarding existing. However, the increased frequency of hailstorm events, especially in vulnerable ecosystem of Deccan Plateau region of India demanded appropriate measures to minimise adverse impact on agricultural crops. Hence, some of the pre hail, during hail and post hail possible management and adaptations revived.

Make use of location specific recommendations given in Agromet Advisory Bulletin (AAB) during pre/post hail disaster to maximise advantages and minimise losses in agricultural production. AAB is a most useful weather smart agriculture technological tool that can minimise climatic risks and build a resilient agricultural production [47] and the Maharashtra State Agricultural Department were aware and warned to the farmers through AAB in the year 2014–2015 about the prevailed hailstorms. But little that can be done to save the standing crops from hailstorms because of ignorance regarding alert message given in AAB [12], and the farmers, who followed the AAB are able to reduce the livestock rearing cost and increasing the net profit as compared to the non AAB farmers [47].

5.1 Pre hail management

It’s high time to update our knowledge regarding existing technologies and side by side explores new avenues for managing atmospheric stresses in agriculture. As hail is the sudden event, and highly unpredictable, it is always better to take some precautions to minimise the hail damage.

5.1.1 Forewarning

Dissemination of forecast of thunderstorm/hailstorm through multimedia, special AAB/regular AAB are essential and it was found useful during the worst hailstorm of 2014–2015 [12, 47]. While, the state of affairs with regard to forecasting by RADAR technology, vulnerability zonation tools have been included [48].

5.1.2 Precautions

Prepare mind set of farmers for adaptation of hailstorm or fight against it and they need not be panic if the damage is less severe. Wait till the next sprout to decide whether totally abandon orchards or replacement of trees will suffer. While, plantations of tree shelterbelts can markedly reduce hail damage in their immediate vicinity since hails are usually associated with strong winds. Protective screens termed as anti-hail nets above the crop can be appropriately utilised especially for high value crops. These anti-hail nets are not effective against strong hail storms. While, shade nets can be a good option especially for high value crops in areas with higher probability of hailstorm occurrence. A range of anti-hail nets used to protect the apple orchards in Himachal Pradesh and similar suggestions are reported by [48], nylon nets intended for protection against birds actually gave good result towards protection against hail. Cropping pattern required to change of the hailstorm prone area and which are another way to abatement of hailstorm in regions with high frequency is to grow those crops that are less subject to hail damage. Some region-specific hailstorm resistance cropping pattern for Marathwada region are suggested [48]. Another approach to minimise the hail losses to the farmers is through insurance. Insurance is the most widely used adjustment tool on the economic front to crops and property damages due to hail and now it is supported by the government though it requires easier process to get relief [46].

Adaptations of farmer’s innovative interventions to fight against hailstorm in Maharashtra (cost effective technology to protect crop from hailstorm) viz., protecting young fruit seedlings and small horticultural tree by straw thatching/polythene tunnels, protecting grape fruits by silver coated hard board (Figure 1a and b), protecting banana fruits by using skirting’s bag, which is manufactured from polythene (Figure 2) were found useful up to some extent. However, it requires validation for auditing exact protection efficiency and monitory benefit; through systematic documentation and conformation based on research in view of wide adaptability [36].

Figure 1.

(a and b) Protecting grape fruits by silver coated hard board.

Figure 2.

Protecting banana fruits Skirting’s by polythene bags.

5.2 Precautions during hailstorm

5.2.1 Precautions for human beings

To avoid the casualty/damage/mortality, human being should be inside house or a covered shelter, avoid going outside unless absolutely necessary, listen to a local radio or television station or perceive authorised message from government institutes to see when it is safe to come out of cover, stay off of phones and other appliances during a hail storm, etc.

5.2.2 Precautions for crops

For the cash crop and horticultural farmer’s mitigation of hailstorm through weather modification science viz., cloud seeding by using aircraft (Figure 3) and anti-hail rocket (Figure 4); creating shock waves through anti hail canon/hail gun (Figure 5) is possible up to some extent though it is very costly, but its reliability till today is not widely accepted. Therefore, it may be possible to commercial crop growers either on co-operative base or government provides this technology on subsidy/free of cost through relief fund provision.

Figure 3.

Cloud seeding aircraft. Source: https://images.app.goo.gl/not4sup9oBuQSoAP9.

Figure 4.

Anti-hail rocket. Source: https://images.app.goo.gl/TxEq1jzHaALvfg498 Ref. [9].

Figure 5.

Anti-hail cannon or hail gun installed in apple garden. Source: file:///C:/Users/user/Desktop/Hailstorm/Seminar_PRJ_2018_ROUGH/USED/improved%20hailgun/hagelkanon_en.pdf.

5.2.3 Precautions for poultry and animals

5.2.3.1 Pre hail storm precautions

Hailstone creates abrupt high frequency sound; which have scaring birds and animals, such scaring condition are responsible to create depression of them. These depressions are caused damage to nervous system and finally its converted into death of such hazards birds and animals. To avoiding such disaster, if animal and poultry birds shed roof are of tin sheet, then which have covered by straw of sugar cane trash/rice/sorghum/Bajara/cotton/red gram/jute straw during the hailstone time. While, it was observed that the mortality and health problems of poultry birds and animals (especially kids of goat and sheep) reduced on large scale due adaptation of aforesaid technique at the time of hailstorm and post hailstorm disaster [36].

5.2.3.2 Post hail storm precautions

Take medical treatment/take care as per advice of veterinary doctors.

5.3 Post hail management

In fact, forewarning and preparedness for hailstorm is constrained mainly by the speed with which it occurs. Once damage occurs, specific management strategies are necessary in formulating the relief strategies for recovery, thus minimising the hailstorm impacts [49].

5.3.1 Coping strategies (in general)

Though, little information is available on measures for hastening recovery in hail damaged crops. These studies indicate the potential of technological interventions to cope with hailstorms. Therefore, some of the post-hail measures including nutritional supplement, plant bio-regulators and canopy management were revealed. Among these, pruning of the hardy and indeterminate eggplant crop induced effective branches, which produced more flowers and fruits. Nitrogen supplemented with urea drenching and stress alleviating effects of salicylic acid promoted recovery in maize while drenching with humic acid along with spraying of potassium nitrate improved productivity of onion. While, little information is available on measures for faster recovery in hail-damaged plants, application of additional nitrogen encourages new growth [50, 51].

To control of secondary damage due to insect pests and diseases, remove the fallen fruit to reduce the spread of disease and pests during their decay. Large wounds on trunks and branches should be covered with a water-based paint to avoid desiccation and disease infection. Fruit thinning by removal of hail-damaged fruits improves yield and quality of remaining fruit. Bud-breaking chemicals and growth/bio regulators may be applied to induce the vegetative growth in orchard crop along with fertilisers [9, 52]. Proper drainage facilities are to be provided to avoid waterlogging and to avoid secondary infection of diseases; near-maturity bulb crops like onion and garlic may be harvested to avoid rotting. In horticultural crops provide support to the bent/damaged tress with bamboo sticks and earthling up Provide light irrigation to soften the fields that are hardened/compacted due to hailstorm [36]. Select the proper contingent crops to take the advantage of soil moisture and to recover part of losses and pruning may be necessary to retain young trees and optimise new growth [9, 36, 48].

Hailstorm app to assess crop damage developed by Indian Space Research Organisation (ISRO) is one of another technique, it is not useful direct mitigation of hailstorm but it provides help to proper assessment through scientific way of hailstorm nature of damage and intensity, which provides base for agro technically advice to the farmers for adaptation and help in relief provision implementing by government [53].

5.3.2 Crop specific management

The certain crop specific management strategies that need to be followed for long term management of hailstorm damaged crops. In order to prevent further losses due to flower and fruit drop because of hailstorm, unseasonal rains and high winds, the mango orchards spraying with potassium nitrate (KNO₃) 1.0% was found beneficial. While, incidence of powdery mildew and insect pests like mango hoppers, thrips are very high due to hailstorm created favourable microclimatic condition (i.e., persistence of cloudy weather, increased humidity and wet conditions on foliage). Hence, affected orchards sprayed with fipronil (5% EC) @ 1.5 ml/L or spinosad (45% SC) @ 0.3 ml/L for aforesaid pest control and with hexaconazole @ 1.0 ml/L for powdery mildew disease control [9].

After hailstorm, (i) the chemicals used for foliar spray/drenching on onion crop at bulb initiation stage, improved the bulb yield of the onion when compared to water spray. The maximum benefit of about 40% higher yield was observed in case of drenching with humic acid (HA; 2 ml/L) and spray of KNO3 (1.5%) where the bulb yields were 23.4 mg/ha against 16.3 mg/ha when the crop was raised as such. (ii) Application of salicylic acid (SA), KNO₃ and urea drenching led to considerable improvement in grain weight of major cobs in maize especially when damage to cob was <20%. Recovery was not significant in case crop damage was more than 20%. Grain weight per cob was improved with application of plant bio-regulators (PBRs) compared to control plot in the range of 7–26.5% and 2.2–14.7% when damage of cob was <20% and > 20 (20–80)%, respectively, and among all treatments urea drenching and SA performed better. The yield improvement ranged between 14 and 26% with urea drenching being most effective. (iii) Pruning at 20 cm of two-month-old transplanted brinjal crop affected by hail had greater advantage than the same at 30 cm due to higher number of branches from basal nodes resulting in higher biomass/plant. It was noticed that deep pruning delayed flower bud formation only by 3–4 days in case of plants pruned at 20 cm height when compared to unpruned plants. It was also observed that timely removal of damaged fruits and dried twigs/branches from plants helped in faster recovery of the crop and also facilitated picking of fruits and other operations. Foliar spray of nitrogenous fertilisers such as urea (2%), KNO₃ (2%) and thiourea (10 μM) also resulted in improved plant growth and development that was monitored in terms of plant height, branch and chlorophyll index [20].

5.3.3 Provision of immediate rehabilitation and relief

After the hailstorm disaster, immediately needs rehabilitation and relief to the affected community. Therefore, at government level efforts has been made to post hailstorm disaster management and rehabilitation; and relief provided to the sufferers through NDRF and State Disaster Response Fund (SDRF) and by some non-government originations (NGO’s) time to time. However, it was not sufficient and it is strongly supporting statements are available in public domain, which had discussed in both the both parliament of India [43]. In connection to this it is suggested that it is proposed to provide relief in the interest rate to be given on conversion of medium-term loans, exempted school and college fees to students from the affected families, another approach to minimise the hail losses to the farmers are through improvement in insurance rules, regulations and process. While, the households severely affected due to calamity should get the benefit of subsidised food grains, salt, sugar, gas and kerosene under Targeted Public Distribution System in the State under the National Food Security Act (NFSA)-2013 the Government of India, electricity bills for permanent agricultural pump consumers should be exempted, central government should make plain for start modified ‘Kanyadan Yojna’ to affected farmers and provide affordable amount of rupees for the marriage of the daughters of calamity affected farmers and conformity to this statement reports are mentioned in [46].

6. Conclusion

Climatic reason of hailstorm, its classification or characteristics and damage potential, control measures complemented with photographs are reviewed. It is concluded that the hailstorm events frequency increased in India and its cause is of climate change is not defined concretely. Causes of recent unseasonal hailstorm events have been discussed. The management techniques for recovery of different field and fruit crops have been reviewed. The crop specific management strategies discussed which should help in formulating the plans and strategies for minimising the impacts of such vagaries if these happen in future. Enlightened the need of research, relief and financial support to the hailstorm affected farming community.

7. Future scope

Thus, greater efforts are needed to improve the forecast skill and use these better forecasts in disaster management [13]. There is a need for formulation a pilot project involving IMD, SAUs, AICRPAM and progressive farmers to undertake studies on suppression of hailstorms and to explore economically viable protection strategies to minimise the losses from hailstorms; there is a need for adequate RADAR network in the country to forecast the occurrence of hailstorms over larger area [36, 48]. Other essentialities are the data on temporal and spatial distribution of hailstorms as well as size of hailstones with the consequent damage have to be documented systematically which facilitates identification of vulnerable areas more scientifically. As a way forward, suggesting to have very targeted and well-designed experiments on the regionally specific crop impacts of a hailstorm at the level of SAU’s and ICAER institutes and usable recommendations make it available to the farmers for cope up hailstorm through adoption of agro techniques and mechanisms.

Acknowledgments

I am here taking opportunity to gratefully acknowledge the various publications and media sources (referred above) from which valuable materials were drawn for this topic.