| In a trial with special oil-bearing crops—castor (Ricinus communis. L) as objective to be studied. It based on climate environment of Ningxia to study 18 varieties castor suitable planting in Ningxia irrigation area by experiment, measurement, investigation and analysis. The results are as follows:1. There is enough resource of sunlight and hot to plant castor in Ningxia irrigation area. Accumulated temperature which equal or over 10*C is at range of the suitable planting in all counties and cities of irrigation area from May to September.2. The varieties of the correlation degree more than 0.7 are selected to be planted in Ningxia irrigation area. They are Jing castor No.2, Zibo castor No.2, Zibo castor No.5, CSR190, Zibo castor No.4 and En te No.3.3. The yield of castor is relative to the shape of ear, tower shape is higher than column and spindle.4. The yield is obviously increased in sowing earlier than later; film mulch than open land. The suitable date to cultivate is 20 April in open land, mid-April in film mulch. Castor grows faster after blooming than seedling stage.5. Pure N fertilizer 12kg per 667m2 to medium fertility soil has obvious respondence, the same as pure P 8kg per 667m27. High density is not suitable for castor growth, it will affect economic characteristic of castor and yields, the most suitable density is 780 plants per 667m2.8. Pruning can change the shape of ear, and restrained the apical dominance. It is necessary that timely pruning to reduce nutrition, improve castor normal maturation and increase yields. |
