Heat unit and photoperiod on growth and development of banana

Heat unit requirement of banana cultivars

Abstract

Field experiment was conducted to identify the growing degree days (GDD), helio-thermal unit (HTU), Photo-thermal unit (PTU) and heat use efficiency (HUE) of eleven banana varieties namely cooking (Monthan, Saba), dessert (Grand Naine, Pachanadan, Ney Poovan, Poovan, Rasthali, Karpuravalli, Udhayam) and dualpurpose (Popoulu and Nendran) varieties. Crop duration was maximum in Udhayam (470 days) followed by Karpuravalli (415 days). The yield recorded in Udhayam (95 t/ha) was significantly higher than other varieties. Highest GDD of 8011°C day was recorded for Udhayam during the entire growth period. Similarly, Karpuravalli (7114°C days) and Rasthali (6975°C days) required more GDD than other varieties. Whereas Nendran (5338°C days) needed the least GDD. However, estimation of degree days requirement from flowering to fruiting indicated that var. Ney Poovan required more GDD (2031.50°C days) whereas var. Popoulu required lesser GDD (1125.50°days). HTU requirement of different varieties ranged from 22219.07 to 41519°C days for days taken for flowering. Accumulated PTU was also maximum in Udhayam and minimum in Nendran and Popoulu. The HUE was significantly higher for Grand Naine (16.92) followed by Udhayam (11.80) whereas, the least HUE was observed in Rasthali (4.03) and Poovan (4.90).