苗圃生态小气候基本特征的初探

本文分析研究了苗圃太阳辐射分布、气温分布、土温分布、蒸发与湿度以及苗圃中的风速等基本特征。并对苗圃生态小气候内诸因子关系作了详细地阐述。从而为有效利用和改变苗圃小气候条件,提供了理论依据。     

苗圃应用化学除草剂“氟乐灵”技术研究

为了有效地控制苗圃杂草,为造林提供足够的优质苗。我们选用了新型的林业化学除草剂——氟乐灵（Frifluralin）进行苗圃除草试验研究。于四月下旬,用2550～3000ml/hm~2剂量,在苗圃喷雾土壤处理,效果良好。对以禾本科为主的杂草的除草效果达80～90％以上,除草率比人工拔草提高五倍以上,比除草醚除草提高二倍以上,节约用工50～90％,节约除草成本90％以上。不仅广谱、高效、低毒、无环境污染,而且苗木质量明显提高,是一种值得推广的苗圃化学除草剂。     

肥床旱育秧田杂草发生特点及化除技术研究

肥床旱育秧田可发生杂草４２种,以稗草、马唐、鳢肠、空心莲子草、丁香蓼等为优势种。杂草群落明显受农业措施的影响,其中床址、盖种土来源可起决定作用。杂草群落主要有两大类型,即前茬为稻田的类型和前茬为旱田的类型。田间杂草的发生高峰在播种盖土后的５～７ｄ。多年的研究结果表明,丁草胺－恶草灵混用和二氯喹啉酸－苄嘧黄隆混用是最适宜药剂配方,前者于播种盖土后作土表处理时杂草的防效达８１．５％～９７．０％,后者在揭膜后２～３ｄ（秧苗达２叶时）作茎叶处理,防效则在９５％以上。并对有关应用技术进行了研究,由此建立的肥床旱育秧田化除配套技术对生产具有较强的指导作用。     

红花木扦插苗白绢病的研究

红花木扦插苗白绢病是一种扦插床内扦插苗上普遍而严重的病害。该病寄主范围很广，在扦插的２０多个花木品种中，几乎都要受害，发病率在２１．７％～９６．７％。该病不仅危害寄主茎基部和根部，也危害苗木的其他部位，引起湿腐和干腐。经病原物分离、培养及接种试验证明，该病由齐整小核菌所引起。病害从６月上中旬开始发生，７～８月是病害盛发期，一般１０月后停止发生，有些年份可延迟到１１月中旬。病害流行与扦插床扦插时间长短和扦插床的湿度关系很密切。经过３ａ防治试验证明，在病害发生初期，用４０％异稻瘟净乳油５００倍液或２０％粉锈宁乳油５００倍液喷雾防治，效果可达９７．５％或８９．８％，可以控制病害蔓延。     

西宁地区王族海棠播种育苗试验研究

通过王族海棠种子不同处理方法、不同基质、不同环境对比等试验,结果表明,在西宁地区沙藏处理种子为最佳处理方法,最佳基质为泥炭土加珍珠岩(7:3),在节能温室播种育苗,出苗率高于露天播种出苗率。     

Effects of Different Seedling Raising Trays on Plant Type and Grain Yield of Machine-Transplanted Double Cropping Rice

【Objective】The objective is to elucidate the effects of different seedling raising trays on plant type and yield of machine-transplanted double cropping rice.【Method】Field experiments were conducted in Jiangxi in 2019, involving two early and two late rice cultivars and three types of nursery trays [blanket tray(CK), bowl tray(D1) and bowl-blanket tray(D2)]. The changing characteristics of plant morphology and yield components were systematically measured. 【Result】The results indicated that: 1) The seedling quality of different seedling raising trays followed the trend of CK>D1>D2. The whole transplanting quality of seedlings under D2 was the best, as reflected by lower floating rate, injure rate and missed rate of seedling than CK. 2) Under D2 treatment, the seedlings turned green quickly and tillering was accelerated after jointing stage. The average number of tillers at booting stage was D2 > D1 > CK, which effectively increased the tiller number and panicle number and directly promote the yield. In the booting stage of early and late rice, the SPAD value of seedling leaves under D2 treatment was 3.2% higher than that under D1, and 9.2% higher than that under CK treatment, which effectively promoted photosynthesis and provided nutrition guarantee for increasing yield; 3) The yield data showed that D2 treatment had the highest yield in early rice, 13.04% and 1.65% higher than CK and D1, 30% and 19% higher than CK, respectively, and 20% higher than CK on average; The high yield of D2 treatment was due to its high chlorophyll contents in leaves, high effective panicle number, high seed setting rate and 1000-grain weight. 【Conclusion】Compared with the blanket nursing tray and bowl tray, the bowl-blanket tray can raise seedling quality and grain yield, which has a potential to be widely applied for high yield cultivation in double cropping rice production.     

Effects of adding liquid dl‐methionine hydroxy analogue‐free acid to drinking water on growth performance and small intestinal morphology of nursery pigs

This study was conducted to evaluate the effect of adding liquid dl ‐methionine hydroxy analogue free acid (LMA) to drinking water on growth performance, small intestinal morphology and volatile fatty acids in the caecum of nursery pigs. Twenty‐four crossbred pigs (Large White × Landrace, BW ～18 kg) were divided into three groups with four replications of two piglets each. The piglets received drinking water without (control), with 0.05 or 0.10% LMA. The results indicated that adding LMA at 0.10% to drinking water significantly increased their weight gain, average daily feed intake (p < 0.05) and tended to improve the feed conversion ratio. Adding LMA to drinking water significantly increased their water intake and significantly reduced the pH of drinking water (p < 0.01), thus total plate count (p < 0.01) and Escherichia coli in drinking water was reduced (p < 0.05), while the total number of bacteria in the caecum was not significantly affected. Liquid dl ‐methionine hydroxy analogue free acid supplementation in drinking water tended to decrease pH in the stomach, duodenum, jejunum, colon and rectum. Furthermore, adding LMA at 0.10% significantly increased villous height in the duodenum, jejunum and ileum (p < 0.05), and the villous height:crypt depth ratio in the jejunum and ileum (p < 0.01) was higher, whereas acetic acid concentration in the caecum was significantly lower than in the control group. It could be concluded that adding LMA to drinking water improved growth performance of the nursery pigs because of high water quality and high nutrient utilization caused by an improvement of small intestinal morphology (not from nutritional effect of methionine source).     

Effect of nursery storage and site preparation techniques on field performance of high-elevation Pinus contorta seedlings

After five years of growth at high-elevations (∼3000 m) in Utah, container lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) seedlings survived well (80–95%) and grew to similar heights regardless of nursery storage method and site preparation technique. Seedlings received one of three storage treatments: (1) spring-sown in the nursery, overwintered in cooler storage and outplanted in July; (2) spring-sown, overwintered in freezer storage, and outplanted in July; or (3) winter-sown, no storage, and hot-planted in late August. We outplanted seedlings at two locations that were clearcut and had received two treatments of surface organic matter (coarse wood, logging slash, and forest floor) removal: surface organic matter (OM) piled with a bulldozer and burned or surface OM remaining in situ. Compared to adjacent uncut stands, both site preparation treatments increased total soil bulk density, but retaining surface OM in situ maintained soil OM, carbon, and nitrogen levels. After one growing season, seedlings planted where surface OM had been bulldozed were taller and had more biomass, although survival was similar (≥96%) across site preparation treatments. The height growth advantage disappeared after five growing seasons and although overall survival was good, survival was highest where site preparation involved removal of surface OM and freezer-stored seedlings were planted. Total non-structural carbohydrates tended to be higher in roots than in shoots and were also higher in hot-planted seedlings than in stored seedlings. Our results indicate that nursery and forest managers have several options for successful nursery production and outplanting of container lodgepole pine seedlings in the central Rocky Mountains. Using hot-planted seedlings allows for a faster turnaround time (from seed to plantable seedling) and maintaining surface OM may be a cost-effective alternative to dozer piling and burning.     

猴欢喜等5种优良野生观赏植物观赏特性和苗木培育

文章介绍了猴欢喜、绒果梭罗、香港四照花、山桐子和野鸦椿5种优良野生观赏植物的观赏特性及其资源分布,并对其进行苗木培育试验,总结了各树种的育苗技术,为其在广州地区的开发利用提供依据。     

草珊瑚林冠下播种育苗试验

草珊瑚播种育苗试验在杉木近熟林、阔叶树近熟林、毛竹林的林冠下进行,结果表明：不同树种林冠下的生长环境和土壤条件对草珊瑚种子的发芽率、苗木保存率及生长量均有显著影响;杉木近熟林林冠下较适宜草珊瑚的种子发芽率、苗木保存率、苗高、地径、主根长度、侧根长度、≥3 cm侧根条数7项指标平均达85.1%、83.6%、8.2 cm、0.18cm、5.3 cm、8.4 cm、4.2条。