Rice is very important cereal in India and grown almost throughout the year depending upon altitude and climate conditions. Rice growing seasons are separated in three parts; autumn, winter and summer. Though majority of total rice is grown in winter and called “Kharif” season with contribution of 84% of country’s total rice grown.
Zinc is very essential nutrient in rice farming as it directly takes part in several biochemical processes. Chlorophyll production is directly affected by zinc content among other activities required for healthy growth of rice plants. Zinc deficiency can be easily identified by visual color difference such as dusty brown spots on upper level of zinc deficient plant leaves. It is mandatory to check nutrient levels in soil prior to sowing of rice plants for productive and healthy plant growth. Fast action is advisable after any visual symptoms of zinc deficiency is encountered like dusty brown spots on upper leaves, uneven plant growth or disturbed patches of poorly established hills. Crop maturity time may also increased under cases of sever deficiency of zinc.
Zinc deficiency is visible in about two to four weeks after transplanting and may vary depending upon climate and geographic conditions. Zinc deficiency in rice plants is easily controlled with application of zinc sulphate with various forms like heptahydrate, hexahydrate, or monohydrate as and where needed. Zinc sulphates are highly soluble in water and treatment should be applied after fields are dry in case of zinc deficiency is caused by flooding. Application of 10 – 25 kg of zinc sulphate if available in monohydrate form or 20 – 40 kg of zinc sulphate if available in heptahydrate form per hector of affected soil surface. Zinc oxide is also suitable for treatment of zinc deficiency but it is not water soluble form of zinc so it should be applied to dip roots of rice seedlings with suspension of 20 to 40 gram of zinc oxide per liter of water before plantation. Visual recovery can be noticed around 14 days on plant leaves after treatment.
Farmers should be advised and more awareness programs should be held for importance and treatment of zinc in rice plantation. Government soil testing facilities are available in different sectors of India and accessible on https://farmer.gov.in/stlrpt.aspx