Effects of mechanical sowing on yield formation of different sweet corn varieties in southern area

In order to form the technology of agricultural machinery and agronomy，the sweet corn varieties suitable for machinery sowing were selected in the southern fresh corn area. This study used 6～7 sweet corn varieties and spoonful double row planter. The mechanical seeding experiments were carried out in ridge cultivation in Pearl River Delta（ spring of 2016） and various cultivation in the west of Guangdong Province（ spring of 2017）， respectively. The effects of machinery sowing on the yield formation of different sweet corn varieties were studied. The results showed that the fresh ear yield of Yuetian 28，Yuetian 27 and Yuetian 26 was the top three，and the yield stability was well in the two seasons，the average fresh ear yield of two seasons were 16 919.6，17 910.0，15 320.4 kg/hm2，respectively. Among 7 varieties，there were 4 varieties with seed germination rates in more than 85%， germination potential in more than 50% of all varieties. From the perspective of germination，we can preliminary screening suitable mechanical sowing of sweet corn varieties. In ridge cultivation and various cultivation，seedlings emergence per hole were 0.81～1.22 and 0.67～1.73 respectively. After thinning without filling the gaps with seedlings，the average rates of surviving seedings were 87.6% and 82.8% respectively. The highest surviving rates of the top three，in turn，were Yuetian 28，Yuetian 27，Yuetian 26 in ridge cultivation，and were Yuetian 27， Zhengtian 68 and Yuetian 28 in various cultivation. The result shows that from the perspective of seeding survival rate can preliminary screening suitable for mechanical sowing of sweet corn varieties. Two seasons of field trials showed that the highest uniformity of the top three varieties in seedling stage were Yuetian 28，Yuetian 27，and Zhengtian 68. Conclusion，from the seed germination rate，germination potential，rates of surviving seeding，and yield stability can preliminary screening suitable for mechanical planting varieties. From two sites and seasons of the test shows that Yuetian 27 and Yuetian 28 with higher germination rate，germination potential and seedling uniformity，and stability of fresh ear yield，are suitable for mechanical sowing.