Fuzzy effective shortest spanning tree algorithm

Abstract :

Trials were conducted at Horticultural College and Research Institute, Coimbatore and Krishi Vigyan Kendra, Kundrakudi to study the effects of different spacing and nutrient levels on Allium cepa L. var. aggregatum Don. With respect to phenotypic characters such as plant height, number of leaves and number of shoots, days taken for flower initiation, days to 50 per cent flowering, shape index, bulb diameter and bulb length. Three spacing viz., 45 x 5 cm (M1), 45 x 10 cm (M2) and 45 x 15 cm (M3) formed as main plot (M) treatments. The sub plot treatments (S) consisted of 10 combinations involving three levels of Nitrogen and Phosphorus (20, 40 and 60 kg ha-1), constant level of K (30 kg ha-1) along with FYM (Farm Yard Maure) at  25 t ha-1 , Azospirillum at 2 kg ha-1 and Phosphobactria at 2 kg ha-1. A control without nutrients was also adopted. The experiment was laid out in split plot design with 10 treatments replicated thrice. The maximum plant height showed on increased trend with increasing level of nutrients. Interaction effect recorded the higher plant height (48.5 cm) at 100th and 135th day of showing with the application of 60:60:30 Kg NPK ha-1 along with FYM at 25 t ha-1, Azospirillum at 2 kg  ha-1 and Phosphobactria at 2 kg ha-1 with the closet spacing of 45 x 5 cm. The increase in length of bulb and shape index was higher at closet spacing of 45 x 5 cm, whereas, the wider spacing of 45 x 15 cm registered the greater bulb diameter. The treatments had significant influence on the bulb characters, which increased with increasing level of nutrients. Spacing and nutrients had no influence on the days taken for flower initiation and days to 50 per cent flowering. Higher bulb length (5.70 cm) and shape index (1.09 %) was recorded from the application of 60:60:30 kg NPK ha-1, FYM @ t ha-1,  Azospirillum @2 kg ha-1 and Phosphobactria @ 2 kg ha-1  along with the closet spacing of 45 x 5xcm.