Effect of Liquid Pig Manure and Chemical Fertilizers on Shoot Growth and Nitrogen Status of Young “Fuyu” Persimmon Trees

Liquid pig manure (LPM), digested from pig slurry, has been used as a nutrient source substituting chemical fertilizer (CF) for some crops. This experiment was conducted to evaluate the effect of different levels of CF and LPM in early July on nitrogen (N) uptake of pot-grown young “Fuyu” persimmon (Diospyros kaki). The total N and potassium (K) from CF and LPM applied to a 3 L pot were 1.2 g N and 1.15 g K for the low and 2.4 g N and 2.3 g K for the high level. From 2 weeks after the applications, secondary shoots started to grow for the CF but none for the LPM. Two nutrient sources did not significantly affect the amount of N increase in different tree parts from July 1 to August 6. At the high level, tree total N increased by 80% from 551 mg for the CF and by 31% from 583 mg for the LPM. The nutrient sources did not affect soil pH. The soil that received LPM contained more organic matter (P = 0.048), available phosphorus (P) (P = 0.002), and exchangeable K+ (P = 0.001) and Mg2+ (P = 0.009) than the soil that received CF on August 6. These results indicated that N in LPM becomes available later but its effect is more durable than CF.

The Equilibrium and Growth Stability of Winter Wheat Root and Shoot Under Different Soil Water Conditions

The equilibrium between root, shoot and growth stability under different soil water conditions were investigated in a tube experiment of winter wheat. The water supplying treatments included： sufficient irrigation at whole growth phase, moderate deficiency irrigation at whole growth phase, serious deficiency irrigation at whole growth phase, sufficient irrigation at jointing stage, tillering stage, flowering stage, and fillering respectively, after moderate and serious water deficit during their previous growth stage. Root and shoot biomass were measured. On the basis of the cooperative root-shoot interactions model, the equilibrium and growth stability were studied on the strength of the kinetics system theory. There was only one varying equilibrium point between the root and shoot over the life time of the winter wheat plant. Water stress prolonged the duration of stable growth, the more serious the water deficit, the longer the period of stable growth. The duration of stable growth was shortened and that of unstable growth was prolonged after water recovery. The growth behavior of the plants exposed to moderate water deficit shifted from stable to unstable until the end of the growth, after rewatering at flowering. In the life-time of the crop, the root and shoot had been adjusting themselves in structure and function so as to maintain an equilibrium, but could not achieve the equilibrium state for long. They were always in an unbalanced state from the beginning to the end of growth. This was the essence of root-shoot equilibrium. Water stress inhibited the function of root and shoot, reduced root shoot interactions, and as a result, the plant growth gradually tended to stabilize. Rewatering enhanced root shoot interactions, prolonged duration of instable growth. Rewatering at flowering could upset the inherent relativity during the long time of stable growth from flowering to filling stage, thus leading to unstable growth and enhanced dry matter accumulating rate in the whole plant.

Variations in shoot and root growth of three provenances of Faidherbia albida in clay and sand soil

The variation in shoot and root seedling growth traits was compared among three Faidherbia albida （Del）. A. Chev. provenances originating from Kenya （Taveta）, Malawi （Bolero） and Ghana （Bolgatanga）; representing east, south and west Africa, respectively. Bulked seeds from three provenances were grown in two soil types （clay and sand） at the World Agroforestry Centre nursery, Nairobi. Seedlings grown in clay soil had high shoot growth and shoot to root ratios but shorter root length, lower number of nodules and specific root length compared to seedlings in sand soil. Shoot to root ratios reduced with time and this was more pronounced in sand soil. Overall, the Bolero and Taveta provenances had higher growth than the Bolgatanga provenance. This was probably because plants grown in nutrient-rich clay soil invest more in shoot growth as compared to root growth. Longer root growth in sand soil shows a better adaptive mechanism that increases competitive ability and survival in nutrient-poor systems. Variations observed among the seedling variables such us shoot and root growth could be used for early selection for reforestation and agroforestry in predominantly clay and sand soil areas.

Optimization of rhizosphere cooling airflow for microclimate regulation and its effects on lettuce growth in plant factory

In plant factories,the plant microclimate is affected by the control system,plant physiological activities and aerodynamic characteristics of leaves,which often leads to poor ventilation uniformity,suboptimal environmental conditions and inefficient air conditioning.In this study,interlayer cool airflow(ILCA)was used to introduce room air into plants’internal canopy through vent holes in cultivation boards and air layer between cultivation boards and nutrient solution surface(interlayer).By using optimal operating parameters at a room temperature of 28℃,the ILCA system achieved similar cooling effects in the absence of a conventional air conditioning system and achieved an energy saving of 50.8% while bringing about positive microclimate change in the interlayer and nutrient solution.This resulted in significantly reduced root growth by 41.7% without a negative influence on lettuce crop yield.Future development in this precise microclimate control method is predicted to replace the conventional cooling(air conditioning)systems for crop production in plant factories.

Assessment of factors affecting in vitro shoot regeneration from axillary bud explant of Camptotheca acuminata

Axillary buds from 3-yr.-old seedlings of Camptotheca acuminata in the greenhouse were cultured on the different basal media with different concentrations of growth regulators for shoot regeneration for studying the effects of different basal media, different concen- trations of growth regulators (BA or TDZ), sucrose, agar and pH value on shoot regeneration from axillary bud. The results showed that B5 and WPM media were the optimal basal media and the optimal phyotohormone was BA of 1.0 mg/L or TDZ of 0.1mg/L; The concentrations of sucrose of 30g/L and agar of 6g/L were most suitable for the shoot regeneration; pH value from 5.8 to 6.6 were broadly effective, but the best at pH 5.8.

Influence of Additives on Enhanced in Vitro Shoot Multiplication of <i>Stevia rebaudiana</i>(Bert.)—An Important Anti Diabetic Medicinal Plant

The present study was designed to develop an efficient protocol for micro propagation of S. rebaudiana from nodal explants and study the influence of additives on enhancement of shoot proliferation. A two-step protocol has been standardized in which, first step comprising growth hormones concentration is optimized and it was found that MS medium supplemented with 2.0 mg/l BAP + 0.5 mg/l Kin + 0.1 mg/l NAA turned out to be the best treatment for shoot induction. In the second step, the best treatment for shoot induction was fortified with different growth additives for further shoot proliferation. Among the different types of additives used, casein hydrolysate at 0.05% (w/v) was found to be most effective, resulted with maximum of 15.0 shoots. 90% regeneration frequency and shoot length of 6.0 cm were recorded per explant. Thus, the procedure described is a quick and reliable method which could be applied for efficient large scale propagation, genetic transformation assays and secondary metabolite production of Stevia.

Potential of Plant Growth Regulators on Modulating Rooting of <i>Rosa centifolia</i>

Rosa centifolia is grown for its flowers which are used for essential oil extraction. It is vegetatively propagated through its cuttings which are difficult to root. This study was designed to increase the rooting percentage of cuttings by applying plant growth regulators (PGRs) with different levels. In total 31 treatments with different concentrations (450 ppm, 700 ppm and 950 ppm) of indole butyric acid (IBA), indole acetic acid (IAA), naphthalene acetic acid (NAA) alone, in combination and with same concentrations of 6-benzylamino purine (BAP) were used. Healthy similar sized cutting of R. centifolia was treated in solution of PGRs by quick dip method and planted in polythene bags. The data for shoot length, shoot dry weight, number of roots, root length and root dry weight were recorded. All three levels (450 ppm, 700 ppm and 950 ppm) of IBA alone produced maximum results in case of all parameters as compared to all other treatments. Among three levels of IBA, 450 ppm concentration produced maximum shoot length (10.67 cm), shoot dry weight (3.02 g), number of roots (14.00), root length (11.90 cm) and root dry weight (0.50 g). Lower concentrations of plant growth regulators produced better results as compared to higher concentrations.

Influencing in vitro clonal propagation of Chonemorpha fragrans(moon) Alston by culture media strength,plant growth regulators,carbon source and photo periodic incubation

Chonemorpha fragrans is an endangered medicinal woody climber,regarded among alternative plant sources of camptothecin.Camptothecin is a monoterpene indole anti-cancer alkaloid with annual trade value of over three billion U.S.dollars in the recent,and is used in the production of its analog drugs approved for the chemotherapy of cancer of varied types.Effects of plant growth regulators,culture media strength and photoperi-odic duration on the micropropagation ef ciency of C.fragrans from nodal segment explants were studied on Murashige and Skoog(MS)medium amended with Thidiazuron(TDZ),Benzylaminopurine(BAP)or Kinetin(Kin).Thidiazuron was more ef cient over BAP and Kin when half basal MS medium was used over full or quarter strength.Results of carbon source experiment showed sucrose as the most effective over glucose,fructose,and maltose in the clonal production.Studies on the photope-riodic incubation duration showed 12 h as the best light period and sub or supra-optimal resulted in the production of abnormal and albino micro shoots.Experimental results on the evaluation of physiological,biochemical parameters showed the role of pigment molecules and antioxidant systems in the production of albino micro shoots.

铁苋菜提取物和笋乳复合物对哺乳仔猪生长性能、炎症因子水平、免疫能力和肠道形态的影响

本试验旨在研究铁苋菜提取物和笋乳复合物对哺乳仔猪生长性能和肠道形态的影响。试验选取12头胎次相近、母性和乳水较好的母猪,随机分为4个组,每组3头母猪,每头母猪哺育10头初生仔猪。在仔猪出生1~5日龄内,连续3 d往哺乳仔猪口腔内灌服试验样品。Ⅰ组灌服5 mL生理盐水,Ⅱ组灌服4 mL生理盐水+1 m L铁苋菜提取物和笋乳复合物,Ⅲ组饲喂灌服1 mL生理盐水+4 mL铁苋菜提取物和笋乳复合物,Ⅳ组饲喂灌服5 mL铁苋菜提取物和笋乳复合物,试验期21 d。结果表明:1)与对照组相比,在7日龄和14日龄试验Ⅱ、Ⅲ和Ⅳ组哺乳仔猪平均重量差异均不显著(P>0.05);但在21日龄断乳时,试验Ⅳ组仔猪平均重量与其他各组相比显著提高(P<0.05)。2)铁苋菜提取物和笋乳复合物降低了哺乳仔猪的发病率和死亡率。3)哺乳仔猪灌服铁苋菜提取物和笋乳复合物可以降低哺乳仔猪血清中促炎因子TNF-α和IL-6含量,可改善哺乳仔猪血清中抗炎因子IL-10和IL-1β含量。4)与对照Ⅰ组和试验Ⅱ组相比,试验Ⅲ和Ⅳ组哺乳仔猪血清中IgA含量显著提高(P<0.05);与对照Ⅰ组和试验Ⅱ、Ⅲ组相比,试验Ⅳ组补体C4含量显著提高(P<0.05)。5)各试验组哺乳仔猪十二指肠绒毛高度、隐窝深度和绒毛高度/隐窝深度比值差异均不显著(P>0.05);空肠绒毛高度和绒毛高度/隐窝深度比值,试验Ⅲ和Ⅳ组与试验Ⅰ组和试验Ⅱ组相比均差异显著(P<0.05);回肠绒毛高度和绒毛高度/隐窝深度比值,试验Ⅲ和Ⅳ组与试验Ⅰ组相比均差异显著(P<0.05),试验Ⅳ组与试验Ⅱ组相比差异显著(P<0.05),试验Ⅱ组与试验Ⅲ组间差异不显著(P>0.05)。综上所述,铁苋菜提取物和笋乳复合物可提高哺乳仔猪的生长性能,促进炎症因子水平和免疫能力,改善肠道形态结构。

不同竹笋加工废弃物配方对大球盖菇菌丝生长及产量的影响

【目的】分析不同竹笋加工废弃物栽培配方对大球盖菇菌丝生长及产量的影响,为竹笋加工废弃物栽培大球盖菇提供参考依据。【方法】以全木屑配方为对照配制培养基,设置竹笋加工废弃物不同添加比率15%(T1)、30%(T2)、45%(T3)、60%(T4)、75%(T5)共5个配方处理,测定大球盖菇菌丝生长速率、采收时间和产量。【结果】大球盖菇菌丝在不同培养基上均能生长,T1、T2处理菌丝生长速率均快于对照,T2处理的菌丝生长速率最快,达到2.36 mm/d,显著快于对照,随着竹笋加工废弃物添加比率的提高,菌丝生长速率逐渐减慢。在不同培养基上均能出菇,T1、T2的采收时间比对照短,竹笋加工废弃物添加比率大于45%时,采收时间变长,产量降低。各处理之间的产量差异均显著,T1、T2产量显著高于对照,T2产量最高为6.47 kg/m^(2),比对照提高10.79%,竹笋加工废弃物添加到45%以上时,产量逐渐降低。【结论】竹笋加工废弃物添加比率30%(T2)的培养基大球盖菇产量最高,采收时间短,适合大球盖菇栽培与推广。

不同品种玉米根-冠生长对土壤紧实胁迫的差异性响应特征

黄淮海地区农业集约化和机械化发展导致土壤紧实问题日益加重,限制玉米产量的进一步提升。明确不同品种玉米根系和地上部生长对土壤紧实胁迫的差异性响应特征,可为该区玉米高产栽培提供理论依据。本研究选用3个玉米品种,采用机械碾压的方法在同一田块模拟无紧实胁迫(NC:no compaction stress,容重1.0~1.3 g cm^(-3))、中度紧实胁迫(MC:moderate compaction stress,容重1.4~1.5 g cm^(-3))和重度紧实胁迫(HC:heavy compaction stress,容重>1.6 g cm^(-3))3个紧实程度处理,定量解析不同程度土壤紧实胁迫下不同品种玉米根冠生长各指标及产量的变化规律。结果表明,与NC相比,MC和HC处理导致玉米减产3.8%~10.3%和12.5%~33.3%。玉米根冠生长及产量形成对土壤紧实胁迫的响应存在基因型差异。MC处理下,DK517的根长、根干重及根冠比较ZD958和DH605分别提高6.0%和14.0%、15.7%和29.6%、18.8%和24.8%,但最大叶面积指数、植株总干物重和产量无显著差异;HC处理下,DK517的根长和根干重较ZD958和DH605分别提高8.4%和22.5%、29.6%和57.8%,且最大叶面积指数、植株总干物重和根冠比分别提高4.6%和15.5%、3.7%和20.9%、28.0%和32.1%,因此产量分别增加7.5%和27.2%。相关分析表明,土壤容重和贯穿阻力与玉米根冠生长各指标和产量呈显著负相关关系(P<0.01)。综上所述,土壤紧实胁迫会显著抑制玉米根系和地上部生长而造成减产,但不同品种玉米根冠生长对不同程度土壤紧实胁迫的响应存在着差异,重度土壤紧实胁迫下根冠生长均具有优势的品种能够维持较高的产量,研究结果可为玉米品种改良和土壤紧实下耕作措施优化提供理论依据。

不同砧木对多主干树形‘瑞香红’苹果幼树树体生长及果实品质的影响

【目的】探究在多主干树形整形条件下,不同砧木对‘瑞香红’苹果树体生长及果实品质的影响,为‘瑞香红’苹果生产筛选适宜砧木和多主干树形推广应用提供理论依据。【方法】以3年生‘瑞香红’/青砧1号、‘瑞香红’/圆叶海棠、‘瑞香红’/M9T337为试材,结合多主干树形整形。于2023年4月至2024年3月对不同砧穗组合的树体结构、枝类组成、一年生枝生长、光合特性、矿质元素含量及果实品质进行测定分析。【结果】结果表明,‘瑞香红’/圆叶海棠苹果接穗的树高、亲和性、枝量、一年生枝生长量和光合特性都显著高于‘瑞香红’/青砧1号和‘瑞香红’/M9T337,营养生长旺盛。‘瑞香红’/青砧1号树体长势略低于‘瑞香红’/圆叶海棠,但高于‘瑞香红’/M9T337,能较好保持‘瑞香红’果形,硬度高、耐贮存,但单株结果量少、果实偏酸。‘瑞香红’/M9T337树体短枝占比高、树冠各部位营养生长均衡,且果实单株产量高、果实品质好。在春梢和秋梢生长期,3种砧穗组合新梢叶片的矿质元素含量存在差异。圆叶海棠和青砧1号接穗叶片的N、Mg、Fe、B及春梢生长期Mn、Zn含量均显著高于M9T337,而P、K、Mo、Cu及秋梢生长期Mn、Zn含量为M9T337高于圆叶海棠和青砧1号。【结论】M9T337砧木结合多主干树形整形的树体矮化效果最好,单株结果多、果实品质好,但树势弱、抗逆性差。圆叶海棠砧木亲和性高、长势旺盛,结合多主干树形整形密植效果好、抗逆性强、果实品质较好。

氮添加对实心竹竹笋品质的影响

氮素是竹林经营输入的主要养分元素,目前关于氮素对实心竹竹笋品质的影响尚不清楚。以尿素(N-46%)为肥种,设置3个氮添加水平处理[N_(1)(20 g·株^(-1))、N_(2)(40 g·株^(-1))和N_(3)(60 g·株^(-1))],以不施肥为对照(CK),测定实心竹竹笋的生长、营养和食味品质相关指标,并采用主成分分析方法对实心竹竹笋在不同氮添加处理下的品质变化进行综合评价。结果表明:随着氮添加量的增大,实心竹竹笋外观品质变化不明显,营养品质和食味品质显著提高。竹笋营养品质中的蛋白质、脂肪和淀粉含量先稳定后上升,N_(3)处理较CK分别提高25.54%、13.97%和57.47%;维生素C、纤维素和木质素含量持续升高,N_(3)处理分别较CK显著提高20.77%、24.44%和15.39%(P<0.05)。食味品质中糖酸比不断增大,氮添加处理均显著大于CK,其中,N_(3)处理较CK显著提高21.41%(P<0.05),而单宁和草酸占比则相反,N_(3)处理较CK显著减小11.84%。氨基酸总含量、鲜味氨基酸含量及占比均先降低后升高,芳香类氨基酸含量持续升高,甜味氨基酸含量和占比均呈倒“N”形变化,苦味氨基酸占比和芳香类氨基酸占比均呈“N”形变化,且各处理间差异显著(P<0.05)。研究表明,氮添加处理有利于实心竹竹笋营养和食味品质的显著提升,其中N_(3)处理效果最好。

外源调环酸钙对苹果幼树生长发育和叶片矿质营养的影响

以1年生华红/B160苹果树为试材,喷施不同浓度调环酸钙,测定秋梢生长初期新梢长势和叶部矿质元素含量的动态变化,以及第2年的成花情况,以探求外源施用调环酸钙对苹果幼树新梢生长的调控效应,筛选出适宜的调环酸钙喷施方案。结果表明:喷施调环酸钙的华红幼树秋梢生长量受到显著抑制,而新梢粗度、成花率和单株花序数提高;叶片N、Ca、Mg、Fe、Mn、B含量增加。通过主成分分析综合调控效益,发现外源喷施400 mg/L调环酸钙在秋梢控旺及促进树体营养吸收方面有较好的调控效果。

多中心干树形对苹果新梢叶片生长发育和生理特性的影响

为探究苹果树采用多中心干(Guyot)树形整形对树体营养生长的影响,本试验以3年生‘维纳斯黄金/M9’为试材,对当年苹果树冠近远端各部位春梢叶片生长发育、叶绿体色素含量、光合特性及春秋梢停长期叶片激素含量的变化进行测定分析。结果表明,在春梢生长期多中心干树形苹果树冠近端叶片的叶面积、叶厚、叶重、叶绿体色素含量、光合能力等都优于远端叶片;这些指标虽在春梢生长初期近远端叶片间存在差异,且以上部与下部近远端叶片间的差异更为显著,但随着生长发育期延长,后期远端叶片生长迅速,近远端叶片各指标的差异逐渐缩小直至最后无显著差异。同时,6月下旬春梢停长期近端上部叶片促进生长类激素(赤霉素GA_(3)、吲哚乙酸IAA和玉米素核苷ZR)含量均高于远端上部叶片,利于营养生长;9月下旬秋梢停长期,近端上、中、下三部位叶片的脱落酸(ABA)含量均高于远端,近端秋梢生长受抑制,利于促进花芽形成。综上,‘维纳斯黄金/M9’采用多中心干树形整形后其在新梢生长初期明显促进树体近端新梢叶片生长,而远端新梢叶片生长发育较慢,但随着生长发育期延长,新梢生长后期近远端叶片的生长和生理指标无显著差异。

番茄苗期根际加温对其生长及水分吸收的影响

[目的]本文旨在明确适宜的番茄根际加温温度,为北方早春玻璃温室中番茄苗期根际温度调控提供理论和方法依据,缓解低温环境对番茄生长的危害。[方法]在玻璃温室高架岩棉栽培条件下,采用控温加热带对番茄根际进行加温,并设置3个处理即根际不加温(CK)、根际加温至20℃(T20)、根际加温至25℃(T25),研究不同根际加温条件对早春苗期番茄生长、光合、干物质积累和水分吸收等的影响。[结果]根际加温可显著促进番茄株高、茎粗、叶片数的增加,不同时期处理T20比CK株高提高13.6%~17.0%,茎粗提高10.3%~14.3%,叶片数增加3.4%~12.5%;处理T25比CK株高提高7.2%~9.7%,茎粗提高7.7%~15.6%,叶片数增加0%~15.6%;定植后10 d,番茄净光合速率随根际温度呈先升高后降低的趋势,定植后20 d和定植后30 d,番茄净光合速率随根际温度升高而升高;根际加温促进了番茄对水分的吸收,促进了番茄茎、叶干物质积累,提早开花时间,其中处理T20比CK地上部总干重增加79.3%~85.4%,开花提早5 d,处理T25比CK地上部总干重增加29.2%~72.4%,提早开花时间3 d。[结论]T20处理番茄株高和茎粗最大、积累干物质总量最多、开花时间最早,即20℃是早春苗期番茄较为适宜的根际加温温度。

光竞争对杉木幼苗生长、生物量分配及叶片化学计量特征的影响

通过研究杉木幼苗在不同光竞争条件下的生长特性及叶片C、N、P化学计量响应策略,以探究光竞争环境下杉木叶片营养利用及生长适应性规律。选择生长均一杉木无性系幼苗,采用室内盆栽试验,通过调整相邻盆栽容器高度差以模拟相邻杉木获得不同光资源优势,形成具有明显光资源竞争优势植株(优势木)及竞争劣势的相邻植株(竞争木),根据调整后的高度差共设置3个光竞争强度:强度光竞争(高度差0 cm)、中度光竞争(高度差8 cm)、轻度光竞争(高度差16 cm),通过测定分析光竞争模拟处理1 a后参试幼苗苗高和地径、各器官生物量以及叶片C、N、P含量的差异性,分析各元素间化学计量比特征。结果表明,随着光竞争强度的减小,竞争木苗高比优势木高6.04%,地径比优势木小17.51%,根冠比增大,根系生物量分配比例增大至40.0%。随着光竞争强度的减小,竞争木植株叶片N含量增多达21.63 g/kg;优势木叶片C、P含量变化趋势相同,均随光竞争强度的减小先减小后增大,且显著大于竞争木(P<0.05);优势木C/N、C/P均随着光竞争强度的减小先增大后减小,竞争木C/P随光竞争强度的减小而增大。优势木叶生物量与P含量呈显著正相关,竞争木茎生物量与叶生物量呈显著正相关,与P含量呈显著正相关。不同光资源竞争位置杉木幼苗生长特性及叶片化学计量特征对不同光竞争强度适应策略有差异,表现为随光竞争强度的减小,处于光竞争劣势的竞争木生物量主要分配于地下根系,幼苗株形呈现“细高”的生长趋势;与之相反,光资源竞争的优势木则将生物量分配倾向于叶片,同时C、P含量明显减小,株形呈现“矮粗”的生长趋势。

6种阔叶树种幼苗生物量分配特征及模型构建

以福建省上杭白砂国有林场闽楠、南岭栲、米老排、青冈、云山青冈和木荷2年生幼苗为研究对象,采用全株收获法获取6种树种幼苗根、茎、叶及整株的生物量,比较其分配特征和地上、地下生物量的异速生长关系,建立不同树种幼苗各器官及整株生物量的回归估测模型。结果表明:(1)不同树种幼苗整株生物量差异显著,依次为青冈>米老排>南岭栲>云山青冈>木荷>闽楠。(2)不同树种幼苗各器官生物量分配差异显著,其中青冈根生物量占比最大(39.9%),米老排茎生物量占比最大(45.0%),闽楠叶生物量占比最大(49.2%)。(3)不同树种幼苗地下生物量与地上生物量比值均小于1,表明幼苗生物量更多地分配到茎和叶。除木荷外,其余树种地上、地下生物量均遵循显著的等速生长关系。(4)不同树种幼苗生物量回归估测模型多为幂函数模型,其次为三次多项式模型。6种树种幼苗整株生物量在不同器官分配上存在差异,同时幼苗地上、地下生物量间呈现出等速生长规律。各树种幼苗生物量回归估测模型拟合效果较好,可在相同或相似立地条件下估算不同树种幼苗生物量。

三种生长调节剂对设施冬枣新梢生长及果实品质的影响

以塑料连栋设施冷棚三年生冬枣为试材,探讨调环酸钙、多效唑、烯效唑3种生长调节剂对设施冬枣新梢生长及果实品质的影响。以清水作为对照,喷施调环酸钙、烯效唑、多效唑3种调节剂,分别设置100、300、500 mg/L 3种浓度共9个处理,在新梢生长期进行2次喷施,定株定枝观测新梢生长情况,果实成熟后对品质进行测定。结果表明,喷施调环酸钙、烯效唑、多效唑100~300 mg/L对新梢长抑制效果较好,调环酸钙促进新梢粗度增长效果最好,100 mg/L调环酸钙、烯效唑能有效抑制新梢节间生长;各处理叶片叶绿素SPAD值提高。3种调节剂处理的树体控旺效果优于对照,其中300 mg/L调环酸钙处理的综合指标最好,能促进新梢增粗,抑制新梢旺长,提高叶绿素含量和单果重,改善果实品质。

夏季疏花疏果对油茶生长与主要经济性状的影响

【目的】油茶是我国南方重要的木本食用油料树种,发展油茶产业对山区乡村振兴和绿色增长具有重要意义。探讨疏花疏果对油茶生长与产量的影响,为油茶丰产稳产栽培提供科学依据。【方法】以油茶主栽品种‘湘林210’的6年生植株为试验材料,运用裂区试验设计,在7—8月分别进行不同程度的疏花芽疏果处理,对油茶的叶片、春梢、成花数量、产量等性状进行对比分析,明确疏花疏果对油茶生长和产量的影响。【结果】不同时间疏花疏果(A)对油茶侧梢的数量、生长和开花影响显著;不同程度疏花疏果处理(B)对叶片叶绿素SPAD值、坐果率影响显著,其中在A1B1处理下,油茶叶片叶绿素SPAD值最大(36.21);在A2B2处理下,油茶叶片氮含量最高(15.87 mg/g);在A2B4处理下,油茶侧梢数量最多(280条/m2),一级侧梢生长最长(33.76 cm)且开花数量最多;在A2B1处理下,一级和三级侧梢叶片数量最多,二级侧梢粗度和叶片数量值均最大;在A3B4处理下,油茶的坐果率最高(33.84%)。疏1/2花芽处理的油茶结果数量最多为155个/株;疏1/2果处理的油茶产量最高为8.23 kg/株。【结论】疏花疏果明显改变了当年油茶树的生长状况,提高了当年油茶果实的经济性状,同时也影响了翌年侧梢生长与花芽分化,在一定程度上改变了不同年份油茶产量大小年的格局。