Weather swings, monsoon risks, and the growing threat to mango, apple crops

Indian farming is approaching a phase where weather uncertainty is emerging as one of the biggest risks for a farmer. Extreme heat waves, unseasonal rains, heavy windstorms, hailstorms, and long dry spells have stopped being sporadic; they have become a common phenomenon and are being increasingly erratic. The fluctuations in weather can have a direct effect on the flower initiation, fruit set, fruit quality, and production yield of horticultural crops, such as mango and apple. The fruit farmers across the country are growing anxious with the onset of the Southwest monsoon. Though timely rainfall is a boon for Indian agriculture, uneven distribution of rains, increased moisture levels, and sudden storms can become a cause of concern for orchards and the production of both mangoes and apples, which are extremely susceptible to climate fluctuations. Weather disruptions, even for a brief spell, can cause huge losses. In the aftermath of such routine climatic aberrations, farmers now have to continuously combat the increased incidence of insect pests and diseases, resulting in poor quality of fruits and enhanced production costs.

Monsoon variability and the rising crop risk:
The influence of the southwest monsoon on fruit production is paramount. But variation in rain has turned the operation more unpredictable for the growers all over India. Excessive rain during flowering and fruit set can interfere with the pollinator activities and fruit-setting capabilities. Disproportionately high moisture and humidity predispose the plants to a higher vulnerability to biotic stresses. A short-term intense shower with strong wind and unseasonal hail can drastically reduce fruit set and cause fruit drop/damage. During monsoon months, high humidity levels coupled with warm temperatures result in a higher incidence of diseases, such as anthracnose and powdery mildew, in mango orchards. A similar problem is being reported by the apple growers of the Himalayan belt, with highly erratic rainfall and unusual temperatures disrupting the crop cycle. Apple scab and fruit rot are directly related to high moisture content. Waterlogging in the orchards during heavy rain reduces the efficiency of the roots for nutrient uptake and disturbs the rhizosphere microbiome as a result of asphyxiation and reduced metabolism. A prolonged gap between the rain spells may also cause additional stress by changing the moisture balance of the soil.

Impact on fruit quality and farmer income:
In addition to production, weather stress also affects the quality, shelf life, and market price of the fruit. The growers also look for uniformity in the colour, sweetness, and shelf life of the fruit, as well as quality. The sweetness of the fruits can be affected by fluctuations in temperature and improper moisture regimes; water stress can induce cracking and fungal infection, thereby adversely affecting the storage life. Horticulture farming is input-intensive, demanding large expenditures on irrigation, pruning, nutrition, labour, and crop protection across the season. Without cost rationalisation through precision technologies like micro-irrigation, fertigation, and artificial intelligence (AI), cultivation of high-value perennial crops such as mango and apple will continue to deliver diminishing returns to the farmers.

Prevention strategies that farmers can adopt:

“Come Clean and Go Clean” should guide horticultural cultivation. Provision for orchard fencing with a single entry/exit point equipped with a disinfectant mat or shallow disinfectant trench can help prevent the movement of infection propagules. Only certified, pest- and disease-free planting material should be used. Orchard hygiene is critical for sustainability; regular pruning of diseased branches and removal of fallen leaves and plant debris should be carried out immediately after the season, as these act as sources of carryover infection. In apples, effective leaf litter management (burning, burial, or a 5% urea spray to hasten decomposition) can reduce scab/blotch incidence by 50-60% by limiting primary inoculum for the next season.

Balanced nutrition application also plays a great role in building plant immunity. During the humid period, a heavy dose of nitrogen should not be applied, as it increases disease proneness. Balanced nutrients improve the stress tolerance of the crop. Water stress should also be overcome; drip irrigation can effectively reduce water losses and can manage soil moisture in a controlled manner. Mulch should be used for soil moisture conservation and for protection from extreme temperatures during dry spells. Weather advisories on a local level would also enable the farmers to adjust their irrigation and spraying schedules in time to improve crop quality. The above cultural and strategic methods can cut the incidence of pests and diseases by at least 50% with strict adherence.

Crop protection and modern agriculture methods:
Besides cultural and agronomic measures, host resistance and judicious use of biological and chemical interventions serve as important components of IPM. Use of pheromones and semiochemicals can prove highly effective for the management of fruit flies, the major pest of mangoes. Timely and ETL-based sprays rather than the calendar-based application and an adequate drainage system in the orchard will help to minimise the spread of diseases and manage residues. The application of biostimulants, mineral/horticultural oils, botanicals, and plant growth promoters can play a vital role in climate-resilient agriculture.

The major diseases and insect pests that affect mango during the monsoon season are anthracnose, powdery mildew, bacterial canker, dieback, fruit flies, and stem borers. Whereas scab, leaf blotch, powdery mildew, collar rot, leaf blotch miner, and European red mites are the major causes of concern in apples. The prophylactic application of suitable fungicides, insecticides, and other agrochemicals during the prolonged rainfall period proves largely effective for the management of the above-mentioned insect pests and diseases, thereby reducing the cost of therapeutic management later in the season. Adoption of integrated pest management practices in combination with scientific monitoring and need-based application of pesticides should be widely practiced for better crop sustainability.

Establishing climate-resilient horticulture for tomorrow:
Climate change is not a challenge for Indian horticulture in the future but is already in vogue not only for the mango and apple growers but for all horticultural crops at large. Precise weather-based horticulture is yet to be realised in India, making science-based farming paramount for sustainable horticulture development. Advanced crop advisory services, climate-resilient varieties, modern irrigation practices, and advanced crop protection technologies would play a vital role in safeguarding horticulture from changing climatic conditions. The agriculture industry has evolved historically through adaptation and resilience, and now it is time to speed up this transformation, empowering Indian fruit growers to be more enterprising to produce quality horticultural crops against mounting climatic aberrations.

The author is Chairman Emeritus, Dhanuka Agritech Limited. Views are personal