Compact plant type rice has higher lodging and N resistance under machine transplanting

To identify the major factors that contribute to the difference in lodging among different rice varieties under machine transplanting and their responses to nitrogen(N),field experiments were conducted at Danyang County(a representative eco-site of the Lower Yangtze River)in Jiangsu Province,China in 2017 and 2018,22 hybrid indica varieties(HIs),22 inbred japonica varieties(IJs)and two indica japonica hybrid varieties(IJHs)were transplanted by machine with three N rates(N0,N150 and N300,0,150 and 300 kg ha–1,respectively).Lodging-related physical parameters,morphological characteristics and apparent transport rates of dry matter were examined.Significant difference in yield was observed among different types of rice,and followed by IJs<HIs<IJHs.The average lodging index(LI)of hybrid varieties(HIs and IJHs)was higher than that of the inbred varieties(IJs)with higher plant height;moreover,lower apparent export rate of dry matter resulted lower LI in IJHs than in HIs.The HIs had a large difference in the LI,which came from the difference in bending stress(BS)induced by the difference in the apparent export rate of dry matter,varieties with lower leaf angle of upper three leaves possess strong lodging resistance capacity;however,the gap among the IJs was due to the difference in the cross section modulus(Z).The LI in the IJs or IJHs increased slightly with the increased N application,and there was no lodging incidence under the high N level,which was due to the low leaf angle and barely changed under high N;there was a significant interaction between varieties(HIs)and N rates in lodging rate and LI,varieties with lower leaf angle of upper three leaves were resistant to high N.These results suggest that compact plant type rice has higher lodging and N resistance at machine-transplanting method.

Effects of Seedling Cutivation with Mat-fiber Mulch on Quality and Quantity of Early-season Rice

[Objective] The aim was to explore effects of tray mat of fiber mulch on quality and yield of early rice-season rice transplanted by machine. [Method] Seedling quality, the rate of leaked rice, density of mechanical transplanting rice, mature rate and yield covered with fiber mulch were compared with groups not covered with mulch. Furthermore, different indices of cultivated rice with and without fiber mulch were analyzed and compared. [Result] The rice yield in the group with fiber mulch improved by 11.9% and rice quality enhanced as wel . What＇s more, rice plants were much easier to be col ected, and the rate of leaked rice lowered by machine. [Conclusion] The research provides theoretical references for seedling transplanting and cultivation of early-season rice by machine with tray mats.