Two types of double low rapeseed oil cultivars including Huashaung No. 4 and Zhongshuang No.10 were used to study the effects of stem-cutting under different densities, stem-cutting stage and stem-keeping height on yield of rapeseed oil. The effect of popularization and application of Planting Once and Harvesting Twice(POHT) was analyzed. The results showed the effect of stem-cutting on yield of rape was significantly different under different densities. The highest yield of rapessed was at 120 000 plants/hm2. The highest yield of fresh stem was at 150 000 plants/hm2. The highest yield of rapeseed and fresh stem of stem-cutting stage was on December 23 th with and the stem-keeping height of 12 cm. The popularization and application of Planting Once and Harvesting Twice(POHT) can stabilize the yield of rape, increase significantly the planting benefits and improve stem utilization of the rape.

Early hybrid rice Liangyou 302 was used as materials to study effects of nitrogen rate on growth characteristics and yield of early rice under no-tillage throwing and tillage throwing. The results showed that the N application rate has the same effect on early rice under no-tillage throwing and tillage throwing. With the increase of N application rate, the peak seedling and leaf area index increased, but the percentage of earbearing tiller, maturing rate and 1 000 grain weight were decreased. However, when the N application rate was 180 kg / hm2, number of panicles per plant and number of grains per panicle were the highest. Moreover, the relationship between nitrogen rate and yield was consistent with quadratic parabola. The yield was the highest when the N application rate was 180 kg / hm2.

　　畸形果是果菜类蔬菜中常见的一种现象。不同蔬菜的畸形果表现不同。在茄果类蔬菜中，番茄最容易产生畸形果。番茄畸形果是指番茄在低温、光照不足、肥水管理不善、植物生长调节剂使用不当时而出现的各种变形果实。

<正>SH31是由四川省农科院作物所利用棉花核不育技术选育的两系抗虫杂交棉品种,2007年武穴市(属鄂东地区)作为优质棉品种引种试验,当年每hm2子棉、皮棉产量分别为5104kg、2200kg,子棉和皮棉单产均居14个参试品种之首。2008年武穴市农业局在石佛寺镇观湖村张从斌0.17hm2棉田进行了超高产栽培