Effects Of Chemistry Regulation On Straw Quality Of High-yield Maize

Nowadays, the demand for maize is growing. The primary way of increase production is increase plant density. However, the soil and climate conditions of Northeast determines the density and yield of spring maize. The high density decreased the stem quality and mechanical strength, and will greatly increase the probability of lodging. This study focuses on the quality of maize stem and yield in different densities and the effect of chemical control techniques in maize stem quality and yield. We took the pre-experiment in Qiqihar City in 2008, Heilongjiang. The experiment launched in Jilin City, Jilin Province in May 2009, we selected the local varieties Xianyu335 and CK Jingdan28 as materials, setting 45 000 plants ? hm-2 (the following are representative of using D1), 56 250 plants ? hm-2 (the following are representative of using D2), 67500 plants ? hm-2 (the following are representative of using D3), 78 750 plants ? hm-2 (the following are used D4 representative), 90 000 plants ? hm-2 (the following are representative of using D5) densities gradient, used ECK as Chemical regulator. The main conclusions of this experiment as follows:1. Chemical regulation can improve the yield of spring maize.With the density increases, Xianyu335 and Jingdan28 showed the output of the two species: first increased and then decreased. Xianyu 335 and Jingdan28 reached the highest value under D2 (56250 plants ? hm-2), and then the yield decreased when the density increase. The yield of Xianyu335 and Jingdan 28 increased with the density increased after ECK treatment. The highest yield of Xianyu 335 was 15389.23 kg ? hm-2 ,and Jingdan 28 14485.15 kg ? hm-2; The experiment showed that the length of the tip-barrenness was decrease by the treatment of ECK in the high density, the length of the ear and the kernels of spike were increased, the 100-kernels weight and the yield were also remarkably increased.2. Chemical regulation can improve the morphological characters of spring maize stalkThe effects of ECK also can lower the height and the ear height of the spring maize in the high density, increase the dry weight pre-length and the transverse section area of the stalk,enhance the thrust of the stalk. The above results indicated that ECK promoted the yield combination and the characters of the stalk effective.3. Chemical regulation can enhance the mechanical properties of maize stalkThe stalk sheathed thickness of maize and the puncture bending strength of stalk (PSS) were increased when density and the probability of lodging were increased either. ECK treatment can increase the stalk sheathed thickness, increased PSS, and then ensure the lodging resistance of maize. When density increased, the moisture content of stalk and bending strength of stalk (BSS) were decreased. ECK treatment can increase water content of stalk, increased the BSS especially in high-density conditions.4. Chemical regulation changes hormone levels of the maize stalk.The experimental results showed that when the density increased, the content of IAA, ZR and DHZR decreased in Xianyu 335 and Jingdan 28 .The content of GA was increased in the high-density conditions. In ripening stage (147 days after seeding), the content of IAA, GA, ZR and DHZR were all reduced than early filling stage (106 days after seeding); ECK can improve the level of hormone effectively, after ECK treatment, the content of hormones(IAA, GA, ZR and DHZR) were all increase in both early filling stage (106 days after seeding) and the ripening stage (147 days after seeding,),This indicating that ECK treatment can improve the vitality of stalk effectively, increase the stem mechanical strength.5. Chemical regulation can improve the composition and physiological function of maize stalkWith the density increases, the sugar content of the stalk of spring maize was decreased. The experimental results has showd that, ECK treatment can effectively increase the content of soluble sugar in stalk, enhance the content of the components of stalk, then increased energy and mechanical strength of stem.