Yield and yield components of ratoon crop of rice as influenced by harvesting at different plant height and time

In order to survey the effects of harvest time and harvest height on grain yield and yield components of rice (Taroem Hasemi variety), an experiment was done in Sari province in 2009. A split plot design within randomized complete block design with three replications was used. In this experiment, harvest time was considered as the main factor at two levels (T-1 : The first harvest on 29 August and 8 September), and harvest height was considered as sub-factor (H-1 : Level ground, H-2 : 10 cm, H-3 : 20 cm, H-4: 30 cm and H-5 : 40 cm). The effect of harvesting time was significant on the number of days from plantation until 50% of flowering, the number of fertile tillers, the number of panicles per m(2), the number of filled spikelets and grain yield. Harvesting height had significant influence on the number of tillers, the number of fertile tillers, the number of panicles per m(2) and the number of filled spikelets. The number of tillers, the number of fertile tillers, the number of panicles per m(2) and the number of filled spikelets were significantly affected by harvesting time and harvesting height interaction. The highest number of days from plantation until 50% of flowering, plant height, the number of tillers, the number of fertile tillers, the number of panicles per m(2), the number of spikelets per spike, the number of filled spikelets, 1000-grain weight and grain yield were related to plantation on 29 August. The low grain yields of the rice may be attributed to the poor management of cutting height and harvesting time during the cultivation and harvesting period. The results of the survey concluded that the harvesting at 40 cm height and harvesting on 29 August had the potential to produce higher yields.