[Leaf spreading duration and its influencing factors for two Pottiaceae species in hilly Loess Plateau, Northwest China].

Mosses are poikilohydric plants. The duration of leaf spreading time is a key factor affecting their growth and development in the field. The dynamics of field growth and development and influencing factors of mosses in arid and semi-arid areas are largely unknown.

[Effects of foliar selenium fertilizer on fruit yield, quality and selenium content of three varieties of Vitis vinifera].

With three grape varieties, Red Barbara, Summer Black and Hutai No. 8 as test mate-rials, we investigated the effects of foliar spraying of organic selenium fertilizer on greenhouse grape quality and selenium content. The results showed that spraying 12 mg·L amino acid chelated selenium-enriched foliar fertilizer on grape leaves significantly increased selenium content and the quantity and quality of grape yield, including the contents of soluble sugar, organic acid, soluble protein, soluble solids, vitamin C and proanthocyanidins.

[Soil respiration variations in winter wheat field in different previous crops and its influencing factors].

This study was to define the Variations of soil respiration, the response of influence factors to soil respiration and carbon sink in the total growing season, in winter wheat field of different previous crops. The results showed that: (1) as soil depth increases, the response of temperature to soil respiration rate also increased with a lag; (2) the soil respiration rate was quadric to soil moisture, phosphorus, potassium, soil urease activity, soil temperature, soil moisture as the main factors had an effect on soil respiration rate; soil temperature had the stronger effect on soil respiration rate when potassium had the weaker effect on soil respiration rate; (3) the average carbon emission rate in wheat filed of different previous crops showed as follow: Pepper of previous crops > celery of previous crops > corn of previous crops > eggplant of previous crops. The intensity of carbon "sink" displayed as follow: eggplant of previous crops > celery of previous crops > corn of previous crops > pepper of previous crops.

[Effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash].

A pot experiment with artificial shading was conducted to study the effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash variety "Jingyingyihao". Under all test soil moisture conditions, 30% shading promoted the growth of "Jingyingyihao", with the highest yield at 70% - 80% soil relative moisture contents. 70% shading inhibited plant growth severely, only flowering and not bearing fruits, no economic yield produced.

[Effects of soil covering on solar greenhouse pepper water use efficiency and soil nitrate N and available phosphorus contents].

A greenhouse study on the effects of soil covering on pepper (Capsicum anmuum L.) water use efficiency and soil nitrate and available phosphorus contents showed that straw mulch + plastic film mulch could get the highest pepper yield water use efficiency (33.04 kg .

[Effects of root exudates of squash grafted with cucumber shoot on seed germination].

Cucumber (Cucumis statirus L.) is commonly cultivated by grafting on squash (Cucurbita moschata) in commercial production. The effects of root exudates of squash grafted with cucumber on seed germination rate of cucumber and squash were tested.