盆栽竹芋的养护要点及老苗快速复壮技术

针对竹芋对环境因子敏感、栽培技术要求高,易出现叶片生理病害及叶斑病、根茎腐病等病害的情况,介绍了竹芋小苗、大苗期盆栽不同生长时期栽培管理的要点.针对盆花养护与栽培中出现的秋季、冬春季普遍存在大量失去美感的盆栽竹芋老苗,通过大量养护复壮工作,总结了秋季盆栽竹芋适当重剪、夏季高温后盆栽加强遮荫与叶面喷水、长期室内摆放后的老苗适当增光控水迅速复壮技术;春季分盆换土、保湿、保温促新芽萌发的低温冬季后的竹芋盆花彻底复壮技术.     

武汉市江夏区苗木产业现状及发展探讨

花卉苗木是颇具前途的朝阳产业,武汉市江夏区发展花卉苗木产业具有得天独厚的自然资源优势和气候资源优势。通过分析这一地区花卉产业发展现状、问题和潜力,对武汉地区发展花卉苗木产业的对策与措施进行探讨。     

Tomato yield, biomass accumulation, root distribution and irrigation water use efficiency on a sandy soil, as affected by nitrogen rate and irrigation scheduling

Florida is the largest producer of fresh-market tomatoes in the United States. Production areas are typically intensively managed with high inputs of fertilizer and irrigation. The objectives of this 3-year field study were to evaluate the interaction between N-fertilizer rates and irrigation scheduling on yield, irrigation water use efficiency (iWUE) and root distribution of tomato cultivated in a plastic mulched/drip irrigated production systems. Experimental treatments included three irrigation scheduling regimes and three N-rates (176, 220 and 230 kg ha⁻¹). Irrigation treatments included were: (1) SUR (surface drip irrigation) both irrigation and fertigation line placed right underneath the plastic mulch; (2) SDI (subsurface drip irrigation) where the irrigation line was placed 0.15 m below the fertigation line which was located on top of the bed; and (3) TIME (conventional control) with irrigation and fertigation lines placed as in SUR and irrigation being applied once a day. Except for the “TIME” treatment all irrigation treatments were controlled by soil moisture sensor (SMS)-based irrigation set at 10% volumetric water content which was allotted five irrigation windows daily and bypassed events if the soil water content exceeded the established threshold. Average marketable fruit yields were 28, 56 and 79 Mg ha⁻¹ for years 1-3, respectively. The SUR treatment required 15-51% less irrigation water when compared to TIME treatments, while the reductions in irrigation water use for SDI were 7-29%. Tomato yield was 11-80% higher for the SUR and SDI treatments than TIME where as N-rate did not affect yield. Root concentration was greatest in the vicinity of the irrigation and fertigation drip lines for all irrigation treatments. At the beginning of reproductive phase about 70-75% of the total root length density (RLD) was concentrated in the 0-15 cm soil layer while 15-20% of the roots were found in the 15-30 cm layer. Corresponding RLD distribution values during the reproductive phase were 68% and 22%, respectively. Root distribution in the soil profile thus appears to be mainly driven by development stage, soil moisture and nutrient availability. It is concluded that use of SDI and SMS-based systems consistently increased tomato yields while greatly improving irrigation water use efficiency and thereby reduced both irrigation water use and potential N leaching.     

Integrated effect of transplanting date, cultivar and irrigation on yield, water saving and water productivity of rice (Oryza sativa L.) in Indian Punjab: Field and simulation study

Individual effect of different field scale management interventions for water saving in rice viz. changing date of transplanting, cultivar and irrigation schedule on yield, water saving and water productivity is well documented in the literature. However, little is known about their integrated effect. To study that, field experimentation and modeling approach was used. Field experiments were conducted for 2 years (2006 and 2007) at Punjab Agricultural University Farm, Ludhiana on a deep alluvial loamy sand Typic Ustipsamment soils developed under hyper-thermic regime. Treatments included three dates of transplanting (25 May, 10 June and 25 June), two cultivars (PR 118 inbred and RH 257 hybrid) and two irrigation schedules (2-days drainage period and at soil water suction of 16 kPa). The model used was CropSyst, which has already been calibrated for growth (periodic biomass and LAI) of rice and soil water content in two independent experiments. The main findings of the field and simulation studies conducted are compared to any individual, integrated management of transplanting date, cultivar and irrigation, sustained yield (6.3-7.5 t ha⁻¹) and saved substantial amount of water in rice. For example, with two management interventions, i.e. shifting of transplanting date to lower evaporative demand (from 5 May to 25 June) concomitant with growing of short duration hybrid variety (90 days from transplanting to harvest), the total real water saving (wet saving) through reduction in evapotranspiration (ET) was 140 mm, which was almost double than managing the single, i.e. 66 mm by shifting transplanting or 71 mm by growing short duration hybrid variety. Shifting the transplanting date saved water through reduction in soil water evaporation component while growing of short duration variety through reduction in both evaporation and transpiration components of water balance. Managing irrigation water schedule based on soil water suction of 16 kPa at 15-20 cm soil depth, compared to 2-day drainage, did not save water in real (wet saving), however, it resulted into apparent water saving (dry saving). The real crop water productivity (marketable yield/ET) was more by 17% in 25th June transplanted rice than 25th May, 23% in short duration variety than long and 2% in irrigation treatment of 16 kPa soil water suction than 2-days drainage. The corresponding values for the apparent crop water productivity (marketable yield/irrigation water applied) were 16, 20 and 50%, respectively. Pooled experimental data of 2 years showed that with managing irrigation scheduling based on soil water suction of 16 kPa at 15-20 cm soil depth, though 700 mm irrigation water was saved but the associated yield was reduced by 277 kg ha⁻¹.     

Simulation of transpiration, drainage, N uptake, nitrate leaching, and N uptake concentration in tomato grown in open substrate

Free-drainage or “open” substrate system used for vegetable production in greenhouses is associated with appreciable NO₃⁻ leaching losses and drainage volumes. Simulation models of crop N uptake, N leaching, water use and drainage of crops in these systems will be useful for crop and water resource management, and environmental assessment. This work (i) modified the TOMGRO model to simulate N uptake for tomato grown in greenhouses in SE Spain, (ii) modified the PrHo model to simulate transpiration of tomato grown in substrate and (iii) developed an aggregated model combining TOMGRO and PrHo to calculate N uptake concentrations and drainage NO₃⁻ concentration. The component models simulate NO₃⁻-N leached by subtracting simulated N uptake from measured applied N, and drainage by subtracting simulated transpiration from measured irrigation. Three tomato crops grown sequentially in free-draining rock wool in a plastic greenhouse were used for calibration and validation. Measured daily transpiration was determined by the water balance method from daily measurements of irrigation and drainage. Measured N uptake was determined by N balance, using data of volumes and of concentrations of NO₃⁻ and NH₄⁺ in applied nutrient solution and drainage. Accuracy of the two modified component models and aggregated model was assessed by comparing simulated to measured values using linear regression analysis, comparison of slope and intercept values of regression equations, and root mean squared error (RMSE) values. For the three crops, the modified TOMGRO provided accurate simulations of cumulative crop N uptake, (RMSE = 6.4, 1.9 and 2.6% of total N uptake) and NO₃⁻-N leached (RMSE = 11.0, 10.3, and 6.1% of total NO₃⁻-N leached). The modified PrHo provided accurate simulation of cumulative transpiration (RMSE = 4.3, 1.7 and 2.4% of total transpiration) and cumulative drainage (RMSE = 13.8, 6.9, 7.4% of total drainage). For the four cumulative parameters, slopes and intercepts of the linear regressions were mostly not statistically significant (P < 0.05) from one and zero, respectively, and coefficient of determination (r²) values were 0.96-0.98. Simulated values of total drainage volumes for the three crops were +21, +1 and −13% of measured total drainage volumes. The aggregated TOMGRO-PrHo model generally provided accurate simulation of crop N uptake concentration after 30-40 days of transplanting, with an average RMSE of approximately 2 mmol L⁻¹. Simulated values of average NO₃⁻ concentration in drainage, obtained with the aggregated model, were −7, +18 and +31% of measured values.     

海带配子体克隆育苗的关键技术

海带配子体克隆育苗生产技术工艺包括克隆的扩增培养、采苗及幼苗培育3部分。从生产应用的角度总结并探讨了海带克隆育苗工艺中各环节的关键技术。     

8种木兰科树种苗期在呈贡的适应性研究

从2004年至2009年在昆明市呈贡县进行了绒叶含笑、马关木莲、状丽含笑、香木莲、小果含笑、大果木莲、金花含笑、单性木兰8种木兰科树种的苗期适应性研究。5年多的育苗试验结果表明:单性木兰、金花含笑、大果木莲为该地区不适宜育苗用的木兰科树种。现存的5个木兰科树种苗木的保存率顺序是:绒叶含笑香木莲状丽含笑马关木莲小果含笑。适应性差或抗寒力弱的单性木兰等3个树种的苗木已在逐年的霜冻中被冻死。现存树种是苗期抗寒力较强的树种,其苗木的抗寒力的排序是:绒叶含笑马关木莲小果含笑状丽含笑香木莲。由于树种间苗木的抗寒力差异和生长差异,现存5个木兰科树种苗木的主要生长指标排序是:绒叶含笑马关木莲状丽含笑香木莲小果含笑。绒叶含笑与各树种间其苗木的苗高生长均具有极显著差异或显著差异,地径生长差异也较大;故绒叶含笑是昆明市园林、庭园绿化的一个首选树种,其次是马关木莲、状丽含笑。     

超级稻扬粳4227机插秧壮秧培育技术

应用高吸水种衣剂种子包衣,研究其在扬粳4227机插秧上的应用效果,分析不同药种比种子包衣处理对水稻秧苗出苗率、成苗率、秧苗素质及秧苗根系形态特性的影响,结果表明,适宜药种比包衣(1∶30)处理出苗率、成苗率分别比不包衣处理高出3.93个百分点和7.35个百分点;且壮秧率大幅度提高,秧苗素质明显增强;同时还起到了适当增强秧龄弹性,延长适栽期的效果。     

油菜毯状育苗基质改良Ⅳ硫酸铵施用量

为优化培育高质量油菜毯状苗的方法,完善育苗体系,以甘蓝型双低油菜品种宁杂1838为材料,采用传统标准的水稻育秧盘进行油菜毯状苗育苗,设置了在试验基质中拌入不同量硫酸铵的处理,通过测定油菜苗在不同时期的农艺性状、器官干重,研究了硫酸铵在不同用量对油菜毯状苗的调控效应;结果显示,试验基质中硫酸铵最佳用量范围为每盘4.37~4.62 g,这一用量条件下可显著增加存苗数、出叶数、绿叶数和单株叶面积,且干物质积累最多,最有利于毯苗移栽后返青活棵。     

论园林绿化工程中的大树移栽

论述园林绿化工程大树移栽的定义、意义、特点和原则,并对大树移栽前的准备和处理、移栽中的操作规程、移栽后养护管理等方面进行了较为详细的阐述,方法简明、技术适用、科学有效,对各地园林绿化大树移栽成活有一定指导意义。