拟茎点霉B3与有机肥配施对连作草莓生长的影响

通过盆栽试验探讨了内生拟茎点霉B3与有机肥配施对连作草莓土壤的改善及对草莓生长的影响。试验共设5个处理,分别为对照(CK)、施有机肥与灭菌固体培养基(A)、施有机肥与内生拟茎点霉B3固体菌种(B)、施有机肥与绿色木霉、黑曲霉、枯草芽孢杆菌固体菌种(C)、施加有机肥与绿色木霉、黑曲霉、枯草芽孢杆菌和内生拟茎点霉B3固体菌种(D)。结果表明:A、B、C和D处理平均单果鲜重分别为对照(CK)的1.1、1.4、0.9和1.1倍。B处理比对照增产19.7%,A处理增产8.2%,C和D处理产量均比CK低。B处理草莓生长最好,植株株高及叶面积均值比其它4个处理大。发病率及病情指数结果表明B处理抗病效果最明显,推断内生拟茎点霉B3可以用作生防菌剂。进一步的研究表明土壤真菌和细菌数量在整个生育期先上升后下降,在花期达到最大。成熟期A、B、C、D处理的土壤放线菌数量分别比CK增加7.2%、160.3%、124.5%及82.6%。在花期,B处理及D处理蔗糖酶酶活达到最大,其中A、B、C及D处理的蔗糖酶酶活分别比CK高11.1%、69.4%、50.3%及77.2%。B处理整个生育期都保持较高的土壤蔗糖酶活性。花期是草莓生长的关键期,需氮量较高。A、B、C及D处理脲酶酶活分别比CK处理高250.0%、700.0%、250.0%及175.0%,B处理花期土壤脲酶酶活性显著高于其它4个处理,促进了有机氮向速效氮的转化。花期A、C处理磷酸酶酶活比对照低67.0%、46.7%,B、D处理比对照高122.5%,227.5%。B处理在整个生育期都有较高的土壤磷酸酶酶活, D处理组在花期土壤磷酸酶酶活较高。可见含内生拟茎点霉B3菌的B及D处理组能增加土壤磷酸酶酶活。B处理在苗期和花期土壤纤维素酶活较低,而结果期和成熟期较高。说明内生拟茎点霉B3菌剂与有机肥配施可以改善连作草莓土壤微生物区系,提高土壤酶活性,增强草莓抗病能力,增加草莓产量,是一种有效缓解草莓连作障碍的方法。

The effect of Phomopsis B3 and organic fertilizer used together during continuous cropping of strawberry (Fragaria ananassa Duch)

The effects of Phomopsis B3 and organic fertilizer used together on soil improvement during continuous cropping of strawberry and on the growth of strawberry plants were investigated using pot experiments conducted at Nanjing Normal University. The experiment involved five treatments, including a control (CK); (A) organic fertilizer and sterilized solid medium; (B) organic fertilizer and Phomopsis B3; (C) organic fertilizer, Trichoderma viride, Aspergillus niger, and Bacillus subtilis; (D) organic fertilizer, Phomopsis B3, T. viride, A. niger, and B. subtilis. Results showed that the average fresh fruit weight resulting from treatments A, B, C, and D was 1.1 times, 1.4 times, 0.9 times, and 1.1 times that of CK, respectively. Compared with CK, yields from treatments B and A increased by 19.7% and 8.2%, respectively, with lower yields following treatments C and D. Strawberry plants exposed to treatment B grew best; plant height and leaf area following treatment B were greater than for the other treatments. The infection incidence and disease index showed that disease resistance in strawberry plants following treatment B was most significant, leading to the determination that Phomopsis B3 can be used as a biological control agent. Additional results showed that during the growing period, the number of fungi and bacteria initially increased with a subsequent decrease, and was highest during flowering. The number of actinomycetes following treatments A, B, C, and D increased by 7.2%, 160.3%, 124.5%, and 82.6%, respectively, compared with CK during the maturation stage. During flowering, B and D treatments produced the highest percentage increases in soil invertase activity, with treatments A, B, C, and D resulting in increases by 11.1%, 69.4%, 50.3%, and 77.2%, respectively, compared with CK. Treatment B maintained a higher invertase activity throughout the growing period. The flowering stage was a critical growth period for strawberries because of an increased need for nitrogen. Urease activity resulting from treatments A, B, C, and D increased by 250.0%, 700.0%, 250.0%, and 175.0%, respectively, compared with CK. Urease activity following treatment B was greater than for the other treatments during flowering, which helped to improve the conversion of organic nitrogen to effective nitrogen. Soil phosphatase activity following treatments A and C decreased by 67.0% and 46.7%, respectively, while treatments B and D resulted in increases of 122.5% and 227.5%, respectively. Treatment B led to higher soil phosphatase activity throughout the growing period while treatment D resulted in higher phosphatase activity only during flowering. This indicated that treatments B and D, which included Phomopsis B3, can significantly increase soil phosphatase activity. Treatment B produced lower soil cellulase activity during the seedling stage and flowering, but led to higher soil cellulase activity during the fruiting and maturation stages. Phomopsis B3 and organic fertilizer used together can improve soil microflora, improve soil enzyme activity, enhance disease resistance in strawberry plants, and increase strawberry yields. Using Phomopsis B3 and organic fertilizer together might be an effective method to overcome current strawberry cropping obstacles.