Effects Of Cutting On Yield And Forage Quality Of Different Type Of Maize

In this two years'study with three maize cultivars: Keduo8(multi-axillary buds and multi-spikes), common breed Taiyu 2 (multi-axillary buds and single spike), and commen breed Zhengdan 958 (none-axillary bud and single spike), we discussed the effects of cutting caulis and clipping spike on grain yield and quality, total dry matter accumulation and feeding quality of different cultivars.The main findings were obtained as following:1 Effects of cutting caulis on grain yield of different types maizeAfter cutting caulis at jointing stage, grain and total dry matter yield were significantly lower than that of none cutting, grain yield of KD8, TY2 and ZD958 were decreased by 11.15%, 25.77% and 22.19% respectively, and total dry matter yield of KD8 and ZD958 were decreased by 20.0% and 20.7%, while that of TY2 has no significantly difference with that of none cutting. It's showed that cutting caulis at jointing stage goes against the improving of grain and total dry matter yield.Grain yield of fodder maize KD8 increased significantly when cutting at booting stage, in this treatment ,grain yield of commen cultivar TY2 reduced, while ZD958 can't regenerate and fruit, there's no yield after cutting caulis at booting stage. The whole plant biomass production of these three varieties represents the same changes as grain. It's concluded that cutting caulis at booting stage is conducive to improve the grain and straw yield.Because KD8 is a cultivar of multi-axillary buds and multi-spikes, clipping top spike has no adverse effects on grain yield and whole plant yield, conversely, grain yield and straw yield can be increased, and those of TY2 and ZD958 reduced, while there's no significant difference from the control.When clipping the top spike at milk stage,grain yield of KD8 reduced significantly, while the lower spike can't pollinate and fruit, so there's no yield. In this treatment, the whole plant yield of KD8 increased significantly, while that of TY2 and ZD958 reduced.2 Effects of cutting caulis on quality of different types maizeContent of grain amylase ,amylopectin and sugar soluble were significantly higher, so grain quality was improved a little, content of crude protein, ether extract, crude ash and acid detergent in stalks were lower, feeding quality of stalks were decreased. So it's favorablelessness to cutting caulis at jointing stage for improvement of grain and total dry matter yield and breeding quality.When cutting caulis at booting stage, content of grain amylase, amylopectin, ether extract and sugar soluble increased greatly, so grain quality of fodder maize KD8 was improved notably; besides, content of crude protein and ether extract content of all these three cultivars were improved, so the feed quality of the straw improved accordingly. Cutting caulis at booting stage is conducive to improve the grain quality and the straw feed quality.In the treatment of clipping top spike at silking stage,straw forage quality of KD8 improved, grain quality and straw forage quality of TY2 decreased while grain quality and straw forage quality of ZD958 improved a little. We can conclude that when clipping spike at silking stage, we can harvest one batch of baby corn with no significant effects on grain and whole plant yield and grain quality, so the economic output of maize improved.When clipping top spike at milk stage, content of grain crude protein and amylase, straw content of crude protein and acid detergent fiber of KD8 all improved significantly. TY2 and ZD958 have no yield because of the lower spike can't pollinate and fruit;straw content of crude protein, ether extract and acid detergent fiber improved significantly, so the forage quality improved. From this, straw forage quality of this three cultivar can be improved. 3 Effects of cutting caulis on growth of different types of maizeDetermination of feasible cutting stage is one of the important factors which modulating dry straw of high yield and quality, so when we determinate the feasible cutting stage, we should consider the growth of the above ground biomass and nutrient dynamics during the growth period of forage to obtain the most nutrients yield per unit area. When cutting caulis at jointing stage and booting stage, dry matter accumulation of different cultivar tillers improved, and it's more that of dry matter accumulation of tillers when cutting caulis at booting stage, and only the whole plant dry matter accumulation of KD8 improved when cutting caulis at booting stage. So cutting caulis is beneficial to dry matter accumulation of tillers, and dry matter distributed to grain slightly increased, so grain harvest index improved.4 Effects of cutting caulis on endogenous hormones content of different types of maizeDormancy of crop lateral buds is regulated by their own endogenous hormones, especially content of gibberellin,cytokinin and abscisic acid and their interaction balancement. The results showed as follows: from three leaves stage, content of endogenous hormones in tillering nodes of different types of maize decreased at first, then increased and decreased later. After cutting caulis at jointing and booting stage, content of endogenous hormones IAA, GA and ZR in tillering nodes of different types of maize all increased, and it's beneficial to break dormancy of regenerated bud, promote their germination and growth, induce differentiation of tillers, promote the growth of tillers and transportation of photosynthate to growth center, break the apical dominance, promote the stomatal opening and chlorophyll biosynthesis of leaves, so accelerate dry matter accumulation of tillers.