Hot Water Seed Treatment: A Review

*Suryapal Singh, Harshita Singh and Narender K. Bharat*

## **Abstract**

In present day agriculture, use of chemicals for crop production is discouraged. Hence, other alternative treatments for disease control must be developed, and hot water treatment is one of them. It is a feasible practice, both financially and time wise. Hot water soaking is a very age-old practice, efficient in destroying pathogens borne both outside the testa and inside the seed testa by using temperature hot enough to kill the organism but not quite hot enough to kill the seed. Extensive research work has been reported on hot water treatment in vegetables. Therefore, an attempt has been made to review the information available regarding the effect of hot water treatment on growth, disease incidence and yield of vegetables.

**Keywords:** hot water treatment, capsicum, seed-borne disease

#### **1. Introduction**

In the present age when the crop production is protected by chemicals and threat of disease due to exposure to these chemicals is at a rise, organic farming is getting momentum. This organic farming is regulated by certain certifications including chemical-free state of agriculture farm. In this condition use of chemicals will not help farmers for these certifications; rather, there is rejection of the produce. Here it becomes pertinent to involve those practices which are natural and can help control diseases naturally. Priming and pelleting are commonly used practices for seed treatment to enhance the production of *Capsicum*, but some chemicals are involved in it. *Capsicum* is in great demand as it is a vegetable with very rich contents of vitamins and minerals and is cooked in combination and individually as per the taste of consumers. Rejections of pesticide, insecticide and chemical sprayed crop attracted the attention for the present review where hot water seed treatment is controlling the diseases in bell pepper. Pepper (*Capsicum annuum* L. var. *grossum*) is commonly known as *Capsicum*, *Shimla Mirch*, green pepper, cherry pepper or bell pepper, and it belongs to the solanaceous group of vegetables. *Capsicum* is one of the most important vegetable crops grown extensively throughout the world especially in the temperate countries [1] and has attained a status of high value crop in recent years because of its delicacy and pleasant flavour coupled with rich content of ascorbic acid and other vitamins and minerals [2]. Fruits of sweet pepper are either used as salad or cooked as vegetable or processed and is appreciated worldwide for its flavour, aroma and colour. It contains several bioactive substances like capsaicin, vitamin E, pro-vitamin A, carotenoids, flavonoids and other secondary metabolites with antioxidant properties [3]. In the states of Arunachal Pradesh, Himachal Pradesh, Jammu and Kashmir, Darjeeling District of West Bengal and hills of UP,

bell pepper is grown in summer, whereas in the states of Karnataka, Tamil Nadu, Bihar and Maharashtra, it is grown in the autumn season [4]. In India, bell pepper covers an area of 29,800 ha with 171,370 tonnes production and productivity of 5.75 tonnes/ha [5]. Sweet pepper is a warm-season crop, which grows well under an extended frost-free season, with the capability of producing high yields of exceptional quality. The best temperature range for sweet pepper growth is 20–25°C, whereas the best germination temperature is 29°C. A temperature of less than 29°C reduces the growth of seedling, leading to increased exposure of seedlings to insects, diseases or salts, resulting in damaged or dead seedlings [6]. High temperatures adversely affect the productivity of many plant species of which sweet pepper is of no exception.

High humidity in the environment and moist soil together with optimum temperature result in high incidence of various diseases. Diseases like bacterial spot (*Xanthomonas campestris* pv*. vesicatoria*), *Cercospora* leaf spot (*C. capsici*), anthracnose (*Colletotrichum capsici*) and virus diseases are seed borne in nature. To avoid the occurrence of such diseases, seed treatment with various chemicals has been recommended from time to time [7]. But in present day agriculture, use of chemicals for crop production is discouraged. Hence, other alternative treatments for disease control must be developed. One such treatment is with hot water which is economically as well as temporally feasible. Farmers, along with a little technical assistance, can easily adopt this treatment. This treatment is also successful for destroying viruses like *mosaic virus* that affect bell pepper. It is very efficient in destroying pathogens borne both outside the testa and inside the seed testa. In this area no such work has been done in the case of bell pepper.
