EVALUATION OF NUTRIENT MANAGEMENT OPTIONS FOR POTATO PROCESSING CULTIVARS

The indigenous potato processing cultivars Kufri Chipsona-1 and Kufri Chipsona-2 were evaluated under eight nutrient management strategies (related with substitution of inorganic fertilizer with organic manure and supplementation of secondary/micro nutrients like Mg, Zn and Fe) during two seasons (2003-04 and 2004-05) in west-central plains. Year to year variations were observed in most of the variables studied. Plant growth parameters (plant height and number of compound leaves) remained unaffected up to 50 percent replacement of inorganics by organic source (FYM). However, 100 percent organic fertilization showed significantly poor plant growth, whereas stem number was not influenced by various nutrient management treatments. The processing grade and total tuber yields remained unaffected up to 25 percent substitution of inorganics by organics. However, the yield decreased significantly at 50 percent replacement or more. Similar trends were observed with mean tuber weight (36.6-56.4 g) and mean process grade tuber weight (64.4-90.6 g). Neither substitution of inorganic fertilizers with organic source (FYM) nor supplementation of micro nutrients (Zn, Fe and Mg) with inorganic fertilizers affected the processing quality traits, such as specific gravity, tuber dry matter content, chip colour score and reducing sugars content. Across the nutrient management options cv. Kufri Chipsona-1 had significantly higher tuber number and yield than Kufri Chipsona-2. Keeping the soil health and sustainability of production system in view, the integrated use of inorganic fertilizers and organic manure i.e. 75 percent of recommended NPK through inorganic source and 25 percent from FYM (on N basis) is suggested.