喷硼对杨梅植株生长及结瘤固氮的影响

以1年生盆栽东魁杨梅Myricarubra‘Dongkui’嫁接苗为试材,研究硼对杨梅生长和结瘤固氮的影响。试验设5个处理,施硼酸(HBO3)量分别为0.0(ck),6.6,13.2,19.8和26.4mg·株-1·a-1,每个处理重复5次,分7次叶面喷施,每次施用全年总量的1/7。结果表明,1年生杨梅苗喷施硼酸0～26.4mg·株-1·a-1,随着施硼量的升高,杨梅植株生长量、株高、根瘤量、固氮酶活性、土壤全氮和有效氮逐步增加;当施肥量为19.8mg·株-1·a-1时,杨梅植株生长量、株高、根瘤结瘤量和固氮酶活性分别比对照提高30.28%,64.63%,62.02%和31.62%,土壤全氮和有效氮分别比对照增加31.35%和9.16%;随后随着施硼量的增加,这些指标逐步下降。施用适量的硼能提高杨梅结瘤固氮能力,促进植株生长发育。表3参10

Myrica rubra plant growth, nodulation, and nitrogen fixation using a boron spray

Myrica rubra is a boron sensitive plant,and many research were focused on its growth and de-velopment,fruit production,fruit quality by boron fertilization,but no research on the relationship of boron and its nitrogen fixation.One-year-old Myrica rubra 'Dongkui' in a randomized complete-block design with five replications was sprayed with five treatments of boron 0(control),6.6,13.2,19.8,and 26.4 mg total boric acid per tree,each treatment divide into seven times,sprayed on 15th from May to November of 2005] in fruit tree greenhouse of Guangxi University to quantify plant growth,nodulation,and nitrogen fixation.Results showed that trees sprayed with boric acid had higher growth,nodule biomass,and nitroge-nase activities as well as higher total nitrogen(TN) and soluble N in the soil than the control(P<0.05).With boric acid application over a year,as the concentration of boric acid increased,the growth,nodule biomass,nitrogenase activity of the trees along with TN and soluble N in the soil gradually improved(P< 0.05).Compared to the control,over a year the 19.8 mg boric acid spray caused 1) maximum plant biomass(30.3%),tree height(64.6%),nodulation(62.0%),and nitrogenase activity(31.6%) and 2) in-creased TN(31.3%) and soluble N(9.2%).Therefore,a proper supply of boric acid could improve nodula-tion and nitrogenase activity of Myrica rubra 'Dongkui' and promote its growth and development Ch,3 tab.10 ref.]