淳安县2014年晚秋蚕病大面积暴发原因的调查分析

2014年淳安县晚秋蚕病大面积暴发,通过现场调查、随机抽样、病害诊断、成份检测和统计分析的方法,进行了蚕病损失评估,并系统分析了引起蚕病大面积暴发的气象条件、桑树病虫害、桑叶营养等因素。结果显示:晚秋蚕病大面积暴发是受持续低温阴雨少光照的气候条件影响,多种桑树病虫交错暴发叠加危害,使桑叶减产,叶质下降,造成蚕体质虚弱抗病力下降而诱发。并针对性地提出防止蚕病大面积暴发、提高蚕桑生产效益的措施。

四川内地蚕区桑树草本化栽培试验

以桂特优2号为供试桑品种,按60 000、90 000、120 000株/hm^2等3种栽植密度分别建立桑树草本化栽培桑园,以常规栽植密度4 995株/hm^2拳式中干树型养成的桐乡青桑园为对照,进行了杂交桑桑树草本化栽培试验。结果表明,草本化栽培桑树的产叶量与栽植密度密切相关,随栽植密度增加,单株产叶量呈降低趋势,但每667 m^2桑园产叶量呈增加趋势,2015—2016年2年平均栽植密度为120 000株/hm^2的桑园每667 m^2全年产叶量为2 504 kg,是对照的2.14倍;草本化栽培桑树的桑叶含水率比对照高4.74个百分点,粗蛋白、粗脂肪、粗纤维、粗灰分含量分别比对照低1.264、0.014、0.744、0.002个百分点。草本化栽培桑树的片叶育与对照桑片叶育相比,家蚕生长状况无明显差别,川山×蜀水的全茧量、茧层量、万蚕收茧量、茧丝长、解舒丝长分别比对照低12.81%、14.29%、13.85%、5.95%、7.68%,但普茧率比对照高0.16个百分点,清洁和洁净分别比对照高0.2分和1.25分,纤度比对照低0.196 dtex;菁松×皓月的全茧量、茧层量、万蚕收茧量、茧丝长、解舒丝长分别比对照低11.06%、10.20%、11.53%、9.46%、9.03%;但普茧率比对照高1.77个百分点,清洁和洁净分别比对照高0.1分和2.50分,纤度也比对照低0.196 dtex。

有机-无机桑树专用复混肥对中根刈桑树的影响

为了解有机-无机桑树专用复混肥的效果,连续1年对试验桑园施用有机-无机桑树专用复混肥,对照区施用尿素和复合肥,全年采用中根刈收获法,研究两种不同肥料对桑树的影响。结果为:(1)有机-无机桑树专用复混肥在产叶量、枝叶比、千克桑叶叶片数、单株发条数等方面与对照区之间差异不显著。(2)两种不同肥料施用后,土壤p H都有所下降,其中试验区从7.60降到6.11,对照区从7.57降到7.22。关于土壤养分的储备状况,试验区全氮试验后比试验前高了35.7%,全磷、全钾试验后比试验前分别降低了3.0%、12.1%;对照区全氮、全磷施肥后比施肥前分别降低了23.6%、44.6%,全钾施肥后比施肥前高了68.5%。而土壤中的碱解氮、速效磷、速效钾的含量,对照区分别比试验前降低了44.1%、63.5%、49.6%,而试验区分别比试验前增加了243%、24.7%、35.3%。(3)桑叶中营养元素含量,全氮含量试验区与对照区相比,第2造减少了8.4%,第3、4造分别增加了3.1%和3.7%;全磷含量,试验区比对照区分别低8.9%、2.7%、18.9%;全钾含量试验区与对照区相比,第2造增加了2.9%,第3、4造分别减少了2.7%和14.3%。

Scheme of Nitrogen Reasonable Fertilization in Mulberry Gardens of Sichuan Hilly Areas

Abstract In the research, five test groups were set, including urea at O, 120, 240, 360 and 480 kg/hm^2, respectively, and analysis was conducted on mulberry leaf yield and some characters of the quality in order to establish utility functions of ap-plied N in mulberry gardens with different production purposes and to provide schemes of rational N fertilization. The results indicated that yield of mulberry leaf and content and yield of active nutritional substances in the leaves would be reduced either by insufficient or excessive N quantity. In addition, 240 kg/hm^2 of applied N significantly improved active nutritional substances in leaf and 360 kg/hm^2 of applied N significantly improved yields of mulberry leaf and active nutritional sub-stances. Therefore, utility functions of applied N quantity with leaf yield, DNJ content and yield were established accordingly. The optimal N quantity in mulberry gardens for sericulture is recommended 360 kg/hm^2 and the optimal N quantities in mulberry gardens for increase of yield and content of DNJ are 299.56 and 294.72 kg/hm^2, respectively.