Studies were initiated for two consecutive years to find out the effect of time of transplanting and seedlings hill(-1) on the productivity of rice in Dera Ismail Khan district of North West Frontier Province (NWFP), Pakistan. The experiment was laid out in a randomized complete block design with split plot arrangements. Main plots consisted of four transplanting dates viz. 20th and 27th of June and 4th and 11th of July while sub-plots contained 1, 2, 3 or 4 seedlings hill(-1). Among transplanting dates, June 20th planted crop gave highest paddy yield and net return with 1 seedling hill(-1). It explains that the use of more seedlings hill(-1) not only adds to cost but is also a mere wastage of natural resources. Based on research findings, we conclude that the use of 1 seedling hill(-1) is most appropriate for timely sowing otherwise 4 seedlings hill(-1) should be used to compensate for the yield gap in late transplanted rice.
Agriculture ; methods ; Oryza ; growth & development ; Pakistan ; Seasons ; Seeds ; growth & development ; Temperature

To study the effect of high temperature, rice seedlings 20, 30, 40 and 50 d were kept at 5, 10, 15 and 20 cm water depth in a water pool. Meteorological findings indicated that water temperature varied up to 10 cm but became stable below this depth. Deep water inflicted higher tiller mortality, minimal increase in dry weight of aerial parts and leaf area, decrease in root length, and decrease in root dry weight especially at 20 cm water depth and produced an unbalanced T/R ratio (top versus root dry weight). However, deep water tended to increase plant length. These parameters, however, excel in shallow water. Older seedlings, with the exception of root dry weight, could not perform well compared to young seedlings in all physiological and morphological aspects. The study revealed that seedlings, particularly young ones, stand well in shallow water and can cope with high temperature.
Desiccation ; Organ Size ; Oryza ; anatomy & histology ; cytology ; growth & development ; physiology ; Plant Components, Aerial ; anatomy & histology ; growth & development ; Plant Leaves ; anatomy & histology ; growth & development ; Plant Roots ; anatomy & histology ; growth & development ; Seedlings ; cytology ; growth & development ; Temperature ; Time Factors ; Water ; analysis