遮阳网与防虫网在蔬菜生产中的应用技术

遮阳网和防虫网覆盖栽培是近年来发展起来的一种新的蔬菜保护栽培技术，对于蔬菜的越夏及季节栽培和防虫越夏栽培起到了十分积极有效的作用。本文仅对两种保护型式的主要技术要点作一介绍。１ 遮阳网保护蔬菜栽培 遮阳网是以聚烯烃为主要原料，经拉丝编织而成的塑料网，是继农膜之后又一重要新型覆盖材料。遮阳网覆盖栽培在南方发展较快。近几年北方地区将遮阳网与大棚结合起来，对大棚蔬菜夏季早秋的育苗及栽培起到了很好的作用。１．１ 遮阳网的作用及效益 遮阳网的作用主要有五个方面：一是遮强光，降高温，一般遮光率可达３５％～７５％…     

蔬菜防虫网覆盖栽培技术

防虫网是继农膜、遮阳网之后出现的一种新型农用覆盖材料。采用添加防老化、抗紫外线等化学助剂的优质聚乙烯（ＰＥ）原料，经拉丝织造而成，形似窗纱。具有抗拉强度大、抗热、耐火、耐腐蚀、无毒无味的特点。蔬菜防虫网覆盖技术目前在发达国家和地区的夏秋蔬菜生产中早已广泛使用，是生产绿色无公害蔬菜的关键技术。现将这项技术简介如下：１　蔬菜防虫网的防虫原理蔬菜防虫网的防虫原理，是采用物理防治技术，即以人工构建的隔离屏障，将害虫拒之网外，达到防虫保菜的目的，此外防虫网反射、折射的光对害虫还有一定的驱避作用，不同于化学…     

越夏蔬菜“两网一膜”生产技术

夏季强光、高温、暴风雨以及病虫害对蔬菜生产不利,常常导致蔬菜多病虫、产量低、品质差，而采用“两网一膜”（即覆盖塑料薄膜、防虫网、遮阳网）技术，可起到遮光、降温、避雨、防虫的作用，能提高夏季蔬菜的品质和产量。     

蔬菜遮阳网覆盖栽培技术

蔬菜塑料遮阳网覆盖栽培是继农膜,地膜之后又一新型农用覆盖材料在蔬菜生产上应用的新技术。1蔬菜遮阳网覆盖栽培应用的范围生产实践证明,遮阳网具有遮强光,降高温,防暴雨,保湿度的功能,并具有重量轻,耐使用,易收藏,操作方便的特点,另外,遮阳网在冬季还有防霜冻,四季还有防虫害     

"两网一膜"越夏蔬菜生产配套技术探讨

越夏蔬菜＂两网一膜＂安全生产技术,是针对夏季强光、高温、暴风雨以及病虫害对蔬菜生产的为害,而提出的一项夏季安全生产技术。即采用遮阳网、防虫网、塑料膜,搭起一个全封闭的棚室,为蔬菜起到遮光、降温、避雨、防虫的效果,为蔬菜生产创造一个良好的环境条件,从而提高夏季蔬菜的产量和质量。     

蔬菜防虫网覆盖栽培技术

防虫网是继农膜、遮阳网之后出现的一种新型农用覆盖材料,系采用添加防老化、抗紫外线等化学助剂的聚乙烯（ＰＥ）原料,经拉丝织造而成,形似窗纱。具有抗拉强度大、抗热、耐火、耐腐蚀、无毒无味的特点。蔬菜防虫网覆盖技术目前已广泛应用于发达国家和地区的夏秋蔬菜生产。镇江市从１９９５年起在全国率先引进和示范推广这项新技术,课题组先后就防虫机理、防虫效果、小气候效应、产投比等进行了深入研究。１９９７年通过成果鉴定,专家认为该成果居国内领先水平,１９９８年获镇江市科技进步一等奖。这项技术一经问世,就得到了国内蔬菜…     

越夏蔬菜两网一膜优质安全无公害栽培技术

夏季强光、高温、暴风雨以及病虫害严重等多种不利因素,造成很多蔬菜生长不良甚至无法生产。芹菜在强光、高温条件下纤维增多;菠菜、香菜夏季易抽薹、产量低;番茄夏季病虫严重、裂果多、商品率低;茄子夏季坐果少。而生产中采用两网一膜（防虫网、遮阳网、塑料薄膜）技术,可为蔬菜生长起到遮光、降温、避雨、防虫的作用,从而提高夏季蔬菜的产量和品质,     

富川推广节水灌溉发展特色农业的探讨

推广节水灌溉技术是适应现代农业发展的要求，是实现水资源可持续利用的关键所在。通过分析富川在推广节水灌溉发展特色农业、实施水肥一体化节水灌溉项目等方面的情况、做法和取得的成效，指出仍存在的农业基础薄弱、灌溉技术落后、节水意识淡薄、节水项目示范时间短、水资源日益短缺等问题，并有针对性地提出解决问题的对策措施。     

我国将建立现代节水农业体系

作为“十五”重大科技专项之一的“节水农业”项目，将改变我国农业用水的严峻形势和节水农业技术相对落后的局面，建成现代节水农业体系。这个科技专项以建立具有中国特色现代节水农业技术体系为目标，以提高农业水资源利用率、作物水分利用效率和农业生产效益为核心，按照节水农业前沿与关键技术、节水农业关键设备与重大产品研发及产业化、节水农业技术集成与示范3个层次设计，重点突出生物节水、农艺节水、工程节水与管理节水的有机结合，加强节水农业新产品与节水农业技术的创新集成与产业化示范。据了解，项目完成后，我国节水农业技…     

国外农业节水政策对比分析

目前,水资源短缺已成为限制世界多国经济社会发展的重要因素之一,而大部分水资源主要用于农业生产。该文主要对国外农业节水在政策方面的成功经验进行了对比研究与分析,以期指导我国农业节水的高效开展。     

不同覆盖材料对热带夏季白子菜（富贵菜）生长及小气候环境的影响

以小叶白子菜（富贵菜）为试验材料,采用白色防虫网、黑色防虫网、遮阳网覆盖材料,对白子菜的产量、品质及环境因子进行比较研究。结果表明：遮阳网与白色防虫网、黑色防虫网和露地处理相比,显著提高了产量,增加了叶片叶绿素含量,降低了设施内温度和光照强度,从而减少了硝酸盐含量,改善了白子菜品质,促进了白子菜植株生长。综合分析得出,遮阳网可在热带夏季白子菜设施栽培中推广应用。     

秸秆生物分解技术在西葫芦温室栽培上的应用研究

引进作物秸秆生物分解技术在西葫芦温室栽培上进行试验研究,结果表明,应用该技术的温室,室内温度升高,相对湿度降低,CO2浓度增高;西葫芦长势明显好于对照温室,生长旺盛,叶片浓绿,落花、落果、早衰、午休现象减少或消失,果型整齐好看;病害减轻;化肥、农药用量减少50/以上;西葫芦收获期长10~12d,产量增加32/以上,扣除成本,净增效益高者达31.5/。     

Sucrolytic activities in cherry tomato fruits in relation to temperature and solar radiation

A study has been made concerning the influence of two environmental factors (temperature and solar radiation) on sugar content and sucrolytic activity in cherry tomato fruits during the crop cycle. For this, Solanum lycopersicum cv. Naomi plants were grown in an experimental greenhouse. Three fruit samples were taken over the entire production period: the first sampling at the beginning of harvest [85 days after transplanting (dat)], the second at mid-harvest (160 dat), and the third at the end of harvest (229 dat). The values for temperature and solar radiation peaked in the third sampling, coinciding with an increase in lipid peroxidation, without lowering yield with respect to previous samplings. Regarding the sugar content in the cherry tomatoes, our results showed that the increase in temperature and solar radiation diminished the sucrose content at 229 dat and raised the hexoses (glucose and fructose) as well as starch content, produced primarily by the enzyme sucrose synthase. On the contrary, the rest of the enzymes responsible for sucrose degradation, acid and neutral invertases, showed no notable changes in their activity at the end of the crop cycle. In short, our results suggest that the increase in sucrolytic activity, induced mainly by sucrose synthase under these conditions, contributes to the mechanisms of antioxidant defense by supplying precursors (glucose and fructose) of antioxidant compounds in order to restrict the massive accumulation of ROS and thereby avoid the appearance of cell necrosis and reduce yield losses.     

文昌市东路镇水芹生产基地调查报告

通过2a调查,确定文昌市东路镇水芹生产基地为海南省水芹生产典型,但调查该基地硬件基础、产量、产值以及目前的技术水平等现状后．发现存在如种苗性状退化、降温技术欠妥、病害严重、周年茬口低、商品率低以及水肥管理水平低等主要问题,并有针对性地提出了相关建议。     

Greenhouse tomato limited cluster production systems: crop management practices affect yield

Limited-cluster production systems may be a useful strategy to increase crop production and profitability for the greenhouse tomato (Lycopersicon esculentum Mill). In this study, using an ebb-and-flood hydroponics system, we modified plant architecture and spacing and determined the effects on fruit yield and harvest index at two light levels. Single-cluster plants pruned to allow two leaves above the cluster had 25% higher fruit yields than did plants pruned directly above the cluster; this was due to an increase in fruit weight, not fruit number. Both fruit yield and harvest index were greater for all single-cluster plants at the higher light level because of increases in both fruit weight and fruit number. Fruit yield for two-cluster plants was 30% to 40% higher than for single-cluster plants, and there was little difference in the dates or length of the harvest period. Fruit yield for three-cluster plants was not significantly different from that of two-cluster plants; moreover, the harvest period was delayed by 5 days. Plant density (5.5, 7.4, 9.2 plants/m2) affected fruit yield/plant, but not fruit yield/unit area. Given the higher costs for materials and labor associated with higher plant densities, a two-cluster crop at 5.5 plants/m2 with two leaves above the cluster was the best of the production system strategies tested.     

Fruit thinning in ‘Conference’ pear grown under deficit irrigation: Implications for fruit quality at harvest and after cold storage

Fruit thinning in pear is feasible for mitigation of water stress effects. However, it is not well known how fruit quality at harvest and after cold storage is affected by pre-harvest water stress. Even less is known about the effects of fruit thinning on quality under these circumstances. To elucidate these, we applied deficit irrigation (DI) and fruit thinning treatments to ‘Conference’ pear over the growing seasons of 2008 and 2009. At the onset of Stage II (80 and 67 days before harvest in 2008 and 2009, respectively), two irrigation treatments were applied: full irrigation (FI) and DI. FI trees received 100% of crop evapotranspiration (ETc). DI trees received no irrigation during the first three weeks of Stage II to induce water stress, but then received 20% of ETc to ensure tree survival. From bud-break until the onset of Stage II and during post-harvest, FI and DI trees received 100% of ETc. Each irrigation treatment received two thinning levels: no thinning leaving commercial crop load (∼180 fruits tree⁻¹), and hand-thinning at the onset of Stage II leaving a light crop load (∼85 fruits tree⁻¹). Under commercial crop loads, DI trees were moderately water-stressed and this had some positive effects on fruit quality. DI increased fruit firmness (FF), soluble solids concentrations (SSC) and acidity at harvest while no changes were observed in fruit maturity (based on ethylene production). Differences in FF and acidity at harvest between FI and DI fruit were maintained during cold storage. DI also reduced fruit weight loss during storage. But fruit size was reduced under DI. Fruit thinning under DI resulted in better fruit composition with no detrimental effect on fresh-market yield compared to un-thinned fruit. Fruit size at harvest and SSC values after five months of cold storage were higher in fruit from thinned trees than fruit from un-thinned trees. Fruit thinning increased fruit ethylene production, indicating advanced maturity. This may lead to earlier harvest which is desirable in years with impending drought. Fruit thinning is therefore a useful technique to enhance pear marketability under water shortage.     

Historical Milestones,Current Methods,and Strategies Resulting in Year-Round Strawberry Production in Belgium

ABSTRACT

Strawberry production in Belgium has evolved from being a June-harvested crop grown in soil to a year-round crop grown in multiple production systems, as a result of the development of new cultivars and production techniques. Strawberry cultivation used to be one aspect of diverse family enterprises, but now strawberry farms are specialized. In the beginning, strawberries were only harvested in June. Covering the crop with plastic tunnels allowed the harvest to advance to May. Subsequently, an important innovation was the use of cold-stored plants in year-round plantings, which also allowed later production. This evolution in combination with the development of various cultivation systems using peat substrates (including table-tops, plastic greenhouses, and glasshouses) resulted in a strawberry production period from March until December–January. Recently, interest in assimilation lighting in glasshouses has increased. At first, this allowed advanced production in February, but now even winter production is possible, resulting in fresh Belgian strawberries 365 days a year.     

Responses of pepper to deficit irrigation for paprika production

Pepper (Capsicum annuum L.) production is normally carried out under irrigation as the crop is very susceptible to water shortage. Deficit irrigation strategies in pepper for paprika could increase production and facilitate mechanical harvest and, at the same time, save water. We conducted a field experiment that imposed water deficits, either during ripening (T1) or throughout the season (T2), and compared them to a fully irrigated control (T3). Stem water potential varied from −0.6 MPa in T3, early in the season to −1.5 MPa in T2 prior to harvest. Applied irrigation water for T1, T2, and T3 was 456, 346 and 480 mm, respectively. Water deficits depress leaf area and biomass production but did not affect the proportion of flowers that set fruit. Dry fruit weight in T2 at harvest was 66% of T3, but did not differ significantly between T1 and T3. However, commercial yield (based on colour production) was significantly higher in T3 than in the other two treatments, as the late water deficits imposed in T1 delayed harvest. We concluded that water deficits, either sustained or applied at fruit ripening, required for mechanical harvest do not hasten ripening and are detrimental to commercial yields and that pepper plants should be well supplied with water until harvest for maximum paprika production.     

A critical path analysis of fruit production in strawberry

The method of Critical Path Analysis has been applied to strawberry fruit production from runner propagation to first harvest in an experimental situation. The quantitative components of yield and the stages of their creation have been identified and arranged in sequential order.Analysis of crop data showed that large variations in yield potential arose early in development, from causes not identified in the experiment. In the fruiting season there was a substantial shortfall in realisation of existing potential due to inefficient fertilisation of ovules and poor berry development.The analysis indicates three phases of development where factors not yet examined can have a large effect on yield.     

Postharvest sprouting of onion bulbs grown in different temperature and C02 environments in the UK

Summary

The effects of different mean growing season temperatures and C0₂ concentrations during bulb production on postharvest bulb sprouting in a common storage environment at Reading, UK, was examined in two cultivars of the Rijnsburger type of onion (Allium cepa L.). Crops were grown in the field in temperature gradient tunnels maintained at either 374 or 532 ppm C0₂. At crop maturity, cohorts of bulbs were harvested, transferred to a constant temperature room (at an average of 11.6°C) and the subsequent duration to sprouting recorded. The duration to the onset of sprouting (expressed as days in storage until the first bulb sprouted) was not affected by cultivar, mean growing season temperature or CO₂ concentration, and was 165 d. The subsequent rate of sprouting (expressed as bulbs per day) was a positive linear function of mean growing season temperature, but no effects of CO₂ or cultivar were detected. Mean rate of sprouting increased from an average of 0.036 bulbs per day at 12.3°C to 0.093 bulbs per day at 18.6°C. Rapid sprouting in storage was associated with lower levels of total non-structural carbohydrate in the bulbs at the time of harvest. Thus, postharvest susceptibility of onion bulbs to sprouting in storage is expected to increase in warmer crop production temperatures.