Current Science

Dibyendu Chatterjee ¹, Rakesh Kumar ¹, Rukuosietuo Kuotsu ¹, Bidyut C. Deka ¹

Affiliations
1 Indian Council of Agriculture Research, Research Complex for North Eastern Hill Region, Nagaland centre, Jharnapani, Medziphema 797 106, IN

Abstract

Traditionally, common salt (NaCl) is applied to control broadleaved weeds under shifting cultivation in Nagaland. The aim of the present study was to find out whether such practice is harmful to the soil. For this, an experiment was conducted on upland rice with 12 treatments, viz. control, weedy check and different doses of NaCl from 20 to 200 kg ha^-1. Soil samples were collected at several phases of shifting cultivation and analysed for organic carbon, available N, P, K, pH, electrical conductivity (EC), cation exchange capacity, exchangeable sodium percentage and sodium adsorption ratio. Yield and yield attributing characters were measured and economics was computed. The results revealed that soil organic carbon (SOC) increased after harvest, but decreased after one year. In contrast, available N, P and K decreased during the crop growth and post harvest period. Weedy check followed by an application of 100 kg NaCl ha^-1 realized the highest gross and net returns. It was observed that NaCl did not exert an undesirable influence on pH, SOC and available NPK; however, EC increased for a short time. The results were confirmed by the verification trial. The yield of rice was highest in 100 kg NaCl ha^-1 treatment among the treated plots. Hence, this may be recommended to control weeds under shifting cultivation.

Keywords

Common Salt, Direct-Seeded Rice, Indigenous Technical Knowledge, Shifting Cultivation, Weed Control.

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A. Thirugnanavel ¹, Bidyut C. Deka ², Tasvina R. Borah ³, G. Rajesha ⁴, Lily Rangnamei ⁵, Naksungla Walling ⁶

Affiliations
1 ICAR-Central Citrus Research Institute, Nagpur 440 033, IN
2 Assam Agricultural University, Jorhat 785 013, IN
3 ICAR-Research Complex for NEH Region, Umiam 793 103, IN
4 ICAR-Indian Institute of Millets Research, Hyderabad 500 030, IN
5 Krishi Vigyan Kendra-Imphal West, Manipur 795 004, IN
6 School of Agricultural Sciences and Rural Development, Medziphema Campus, Nagaland University, Medziphema, Nagaland 797 106, IN

Abstract

In this study, 110 taro landraces were characterized using 19 quantitative traits. Statistical tools like descriptive statistics, Shannon–Wiener diversity index, principal component analysis (PCA) and cluster analysis were used to evaluate diversity. Descriptive statistics showed significant variation among the landraces for the 19 quantitative traits studied. The highest coefficient of variation was found in the yield, number of suckers, leaf width and total oxalate. The corm length (H′ – 1.06) and starch content (H′ – 1.20) had the highest Shannon–Wiener diversity index. PCA resulted in seven principal components (PCs), which explain 70.65% of the total variation. PC1 was mainly associated with plant height, leaf length, leaf width, petiole length and plant spread. PC2 was associated with yield, moisture content, corm length and total oxalate. PC3 was associated with dry matter content and disease index. The cluster analysis using the weighted neighbor-joining method resulted in five major clusters based on geographical location. Cluster IV had a maximum of 54 landraces, and cluster III had a minimum of five landraces. The present study, which identified high genetic diversity and plant height, number of suckers, leaf length, leaf width, corm length, yield, total oxalate content and disease index, can be useful in taro varietal improvement programmes.

Keywords

Colocasia esculenta, Correlation, Descriptive Statistics, Genetic Diversity, Landraces.

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