Effects Of Sandy Field And Water-heat Impact Of Different Coverage Modes On Growth And Development Of Cucumis Melo Var "Inodorus"

Sandy field in Landzhou is a specific and traditional drought-relief culture system in arid and semi-arid area in northwest China. Differences of crop growth and development were resulted at sandy land and different mode of coverage. Studies, of Cucumis melo Var "Inodorus", on moisture, temperature and their transformation of soil, temperature and its transformation of land surface, growth and development of melon, inside sandy field and under different coverage, were performed at Lanzhou during 2003-2004. Effects of water-heat impact on melon growth and development were reported. A practical mode of sandy field with an appropriate covering was seized.Results of 5 different treatment (D1: sandy field with thin plastic cover, D2: sandy field +small shed, D3: sandy field + thin plastic cover+ small shed, D4: sandy field, control 1, and D5: soil field, control 2) experiment were as follows.(1) Treatment D3 was the superior as its water preserved in average was greater than controls. Water in soil descended at fluctuation type, little change at early time (before mid-May), greater later (mid-May through early July) and declined greatly at last (after early July), during whole growing period.(2) Temperature at soil surface, of soil, and moisture of soil, of sandy field or shed were greater than soil or plastic film cover during nursery stage. Seeds germinated earlier of D3 as the superior water and temperature provided.(3) Soil temperature changed daily as "S", with a high and a low period, during fruit development. The top and the lowest temperature of sandy field came 1 h later compared to soil field at upper layer (5 cm) and deeper layer (10 cm).(4) Soil temperature of sandy field was stable, compared to the sandy with plastic cover, which changed greater at surface than deeper soil.(5) During melon development, temperature daily fluctuation at 20 cm above land: D3 > D4 > D5; diurnal temperature range: D4 > D3 > D5.(6) Sandy field, shed or double coverage were superior to soil, plastic film cover or one sort of cover respectively for melon growth and development. Treatment D3 was superior to D2, Dl, D4, D5 orderly, based on seed germination, melon maturation, single melon weight and yield (significant different). One exception was that the sugar content of D2 melon was the greatest.(7) To sum up, the optimum treatment was D3 as the advantage (superior of water, temperature, germination, maturation and yield), which assembled of the advantages of sandy field, plastic film cover, and shed. The mode D3 was the recommended as its lower investment and significant benefit.