Rice harvest index: Effect of planting methods
1997
Rangsan Apakupakul (Prince of Songkla Univ., Songkhla (Thailand). Faculty of Natural Resources. Dept. of Plant Science)
Results indicated that HI increased lineraly during the grain filling period for wet sown rice and transplanted rice. The rates of HI increase were not statistically significantly different between planting methods with a rate of 6.0*10*[-4)/Cd (0.011/d) of pooled data. Due to the absence of transplanting shock, estimtions of accumulated thermal time at oneset and at completion of HI formation in wet sown rice were earlier than that for tranplanted rice. A shotter duration of HI formacion in wet sown rice was due to unfavorable growing conditions during the grain filling period, such as a greater culm number/area, a lower tiller number/plant, less types of tillers developed, lodging, weed infestation, etc. At harvest maturity, HI and GY, but not TDM recordings, were significantly lower in wet sown rice than that in transplanted rice. A nagative correlation between HI and TDM, and a postitive correlation between HI and GY were found in wet sown rice and in transplanted rice, respectively. However, the GY of both planting methods increased linearly with increasing TDM. The comparison between observed and predicted GY indicated that the linear regression between GY and TDM is applicable only for grain yield prediction and HI assessment in wet sown rice due to unfavorable growing conditions during the grain filling period. In contrast, under the favorable growing conditions as in the case of transplanted rice, either linear regression or a simple equation from the product of HI and TDM can be used for GY prediction. Thus, accuracy in grain yield predicition through HI must be used with care, especially when the environmental conditions of plant growth is unfavorable during the grain filling period. The estimations of HI from the linear regression for wet sown rice and transplanted rice for Chieng Phatthalung cultivar were 0.226 and 0.374 , respectively.
Mostrar más [+] Menos [-]Palabras clave de AGROVOC
Información bibliográfica
Este registro bibliográfico ha sido proporcionado por Kasetsart University