India has made tremendous strides in food-grain production from 82 million tonnes in 1960-61 to 271.37 million tonnes in 2018-19. It further increased to 329.7 million tonnes in 2022-23 with agricultural exports exceeding Rs 4 lakh crore (US$ 53 B). India has the second-largest agricultural land in the world with the sector providing livelihood for nearly half of the nation’s population, contributing to about 18% of India’s GDP.

Losses due to crop diseases and pests

However, agriculture as an activity, is reliant on variables, which are often outside the control of the farmer. Climate change and erratic weather patterns, soil, water, common diseases, pests affect the crops as well as the post-harvest stock, leading to losses.

By some estimates, every year, 30% of crops worth Rs 90,000 crores are lost in India due to pests and crop diseases. Indian farmers suffer yield losses due to weeds and rodents too. These factors substantially undermine India’s agricultural productivity, further underscoring the importance of plant disease management.

Plant disease management

Common crop diseases like rust, blight, blast, powdery mildew, smut can be prevented by effective plant disease management. These methods encompass a diverse array of techniques and strategies aimed at minimising damage from pests, diseases, weeds, and other environmental factors.

Scientific management of common crop diseases has become even more important with increasing demand for organically produced food, conservation of biodiversity, unpolluted environment and sustainable agriculture.

Plant disease management include crop production practices that make the crop environment less susceptible to pests. Crop rotation, cover crop, row and plant spacing, planting and harvesting dates, destruction of old crop debris are a few examples. These practices are based on pest biology and development.

Crop disease prevention

The adage of prevention is better than cure always holds true. The first step towards common crop disease prevention is monitoring. And this starts with the soil even before the seeds are sowed. Unhealthy composition of the soil or chemical contamination incubate common crop diseases. Excessively wet or waterlogged soil also act as ‘fertile’ ground for pathogens that harm crops.

Keeping track of pests, the soil and particular environment they thrive in, and their potential damage is helpful in selecting the best possible combinations of pest management methods. This is true for all crops, whether grains, vegetables or herbs.

Most common crop diseases caused by bacteria, fungi, nematodes, and virus need focused approach to contain the damage and save crops.

Bacterial diseases

Blights and wilts are examples of bacterial common crop diseases. These affect plants when bacteria get into the culture’s tissue through damaged areas caused by agricultural tools, insects or unfavourable weather conditions. Infections may also occur when bacteria use natural holes or glands of plants.

Bacterial diseases spread fast and treating the affected area is complicated since the infection is internal and therefore not exposed to chemicals. Preventive measures include using pathogen-free seeds, hot water for seed treatment, soil solarisation or using germicidal compound of seeds.

Fungal diseases

Fungi cause widespread plant diseases which extract a huge economic cost. Fungi mainly infects plans through wounds, stomata and water pores. Wind also plays a part by spreading fungal spores.

Plant disease management is varied in the case of fungi. Crop disease control methods include destroying plant matter containing the pathogen, using healthy seeds, regular crop rotation and using chemical and biological fungicides.

Viral diseases

Viruses and viroids affect plants at a smaller scale, but agricultural diseases caused by them are difficult to contain. Virus-infected plants are almost impossible to save. Viral infections usually spread through the contact of sick plants with healthy plants, through soil apart from vegetative reproduction. Seeds, pollen and insects are also carriers of common crop diseases caused by viruses.

Agricultural disease control is paramount in cases of viral infections since they turn out to be fatal for plants. Therefore, appropriate plant disease management measures become an effective tool to counter viral infections. Most common crop disease prevention methods include cultivation of resistant crops, indexing, determining the presence or absence of viruses. Quarantine is the last resort if a large agricultural area is affected.

Integrated pest management

Parasitic plants, nematodes are other category of pests that cause widespread plant diseases.

Common crop diseases caused by various pathogens and pests need an integrated pest management approach. These include breeding of pest resistant varieties, chemical control via pesticides, mechanical control by using bird perches, installation of traps, hand picking etc.

Crop rotation, soil solarisation, soil treatment are some other methods to counter both abiotic (non-infectious) and biotic (infectious) common crop diseases.