Research Projects

Seventy million hectares of net sown area in India is rain-fed, which contributes 40 percent of food grain production. The crop productivity in Indian rainfed agriculture is 1.1 t ha-1. However, achievable yield in rainfed crops ranged between 0.5 to 5 t ha-1. Hence, the situation is pressing to increase crop productivity in rainfed areas. Weeds compete for water and nutrients with rainfed crops resulting in a yield reduction of 37-79 per cent. Therefore, rational weed management practices will improve crop productivity. Chemical weed control is the cheapest and most effective weed control strategy. However, there is a little scope for the use of herbicides in rainfed conditions due to variability of soil moisture, which is a prerequisite for the effective control of weeds with herbicide application. Generally, rainfed crops are sown before monsoon. Soils are dry while sowing of crops and hence lack of moisture at soil surface prevent the use of herbicides. In many cases, soils become sticky on receipt of rainfall, which also makes the situation difficult for moving into fields. Hence, the situation forces us to explore strategies for the use of herbicides in rain fed agriculture. The research proposal aims at encapsulating pre-emergence (selective) herbicides in hydrophilic polymers to achieve moisture-triggered release. The encapsulated formulation protects herbicides from volatilization and other losses and remain in the soil until the receipt of rainfall. The polymeric formulation will release herbicide on receipt of rainfall into the immediate environment for weed control. National Chemical laboratory had developed starch/cellulose nanocomposite and demonstrated moisture-induced release of dimethyl phthalate, a mosquito repellant. Leveraging this development, we propose to encapsulate herbicides in starch/cellulose nanocomposite and validate for controlling weeds. The hypothesis of the proposal is nanocellulose reinforced encapsulation system of herbicides using hydrophilic natural polymers will protect herbicides from degradation in the soil until the receipt of rainfall and release herbicides on the receipt of rainfall to control weeds in rainfed crop production. With the background, joint proposal attempt to design starch and nanocellulose based controlled release systems for the moisture-triggered delivery of atrazine, pendimethalin and oxyflorfen herbicides. The proposal will also work on the release characteristics of controlled release systems and conduct field validation studies to assess weed control efficiency of control release formulations in model crops. Encapsulation of herbicides will improve weed control efficiency by protecting active molecules from environmental degradation. The release of herbicides are also prolonged resulting in longer period of weed control. Moisture triggered release of herbicides will be of greater significance for controlling weeds in rainfed agriculture.