播种期和花期避雨栽培对观赏菜花种子产量和品质的影响

观察播种期和花期避雨栽培对观赏菜花种子产量和品质的影响。结果表明:9月30日播种,单株种子产量最高,花期打顶避雨栽培能提高种子的千粒重,避雨栽培能显著降低种子的破损比例和已发芽种子的比例,适当提早播种可降低种子小籽的比例。观赏菜花采种栽培的最佳播种期为9月30日左右,最佳栽培方式为花期避雨栽培,适当打顶。

Nitrogen/Ammonium Concentration Response of Vegetable and Flower Crops

Nitrogen （N） is the element with the greatest influence on the growth of vegetables and ornamentals, however, form of delivery, either as nitrate （NO3） or ammonium （NH4＋） has different effects on plant development. The NO3 is the main form of N that plants absorb, but when it is the only source of N that has slight effects on root growth, no effects over enzymatic activities, and stimulates the absorption and translocation of cations within the plant. The NH4＋ is the easiest way of assimilation but is highly toxic when the only source or with respect to the concentration of NO3 is too high. To avoid toxicity, the NH4＋ must not exceed 20% of the total N amount in the formulation, however, it is important to consider the species, variety and environmental conditions. The N as supplied also affects the resistance or susceptibility of plants to diseases, but depends on the species and the type of pathogen.