Root zone temperature,plant growth and yield of broccoli [Brassica oleracea (Plenck) var. italica] as affected by plastic film mulches

Plastic film mulches are often associated with increases in plant growth and yield of vegetable crops. Few studies, however, report on the effect of plastic film mulches on root zone temperature on broccoli. The objectives of this study were to determine the effects of colored plastic mulches on root zone temperature and broccoli plant growth and yield Broccoli (‘Packman’) plants were grown using plastic film mulch and drip irrigation. The treatments consisted of plastic film mulch (black, blue, gray on black, red, silver on black, and white on black mulches) and bare soil. Colored plastic film mulches affected root zone temperature and the accumulation of soil degree-days. Mean daily RZT, maximal daily RZT and degree day accumulation in the soil were highest in dark-colored mulches (blue, black, red, and gray) and lowest in light-colored mulches (silver and white), while minimal daily RZT was highest in silver mulch and lowest in white mulch. Silver mulch showed the smallest diurnal fluctuations in RZT among plastic mulches, with the highest RZT during the night and among the lowest in the afternoon. Colored plastic mulches also affected broccoli plant growth and yield, although the effect of mulches was more dramatic in the spring than in the fall seasons. Broccoli yield was linearly related to both the vegetative top dry weight and root dry weight of mature plants. Broccoli yield was little affected at mean RZT of <21 °C but increased with increasing mean RZTs above 21 °C up to 25 °C. Thus, broccoli plant growth and yield responded more favorably to dark-colored mulches than to light-colored mulches, suggesting that broccoli benefited from increased soil warming. No high RZT stress effects on broccoli plant growth or yield were observed in this study. Thus, this study suggests that plastic film mulches, particularly the dark-colored mulches, may be an option for spring broccoli production in areas with cool conditions early in the spring.     

Methods of Raising Cocoa Seedlings in the Nursery and their Effect on Subsequent Growth in the Field

Trials were conducted near Ibadan, Western Nigeria, to find the best method of raising cocoa seedlings in the nursery, and the plants were subsequently transplanted to the field and observed for two further years. In one trial the experimental treatments were amount of shade, time of sowing, amount of watering and type of pot; in a second trial times of sowing and transplanting were varied and seed was also sown at its permanent site.

Seedlings grew well in the nursery in polythene pots under a shade of from eight to ten palm fronds per 10 ft. length and with light watering. Late sowing and early transplanting were satisfactory, so seedlings need only remain in the nursery for five or six months; in the Ibadan area this was achieved by sowing in December and transplanting in late Mayor early June. Younger plants also grow well in the field, but there are risks in sowing seed in January, when cold, dry harmattan winds may be expected. Provided a plant is big enough to transplant, its original size has no bearing on its subsequent growth in the field, as measured by trunk girth at threemonthly intervals. Sowing seed at permanent sites is risky, as beans may be eaten by rodents.     

陇东旱塬地区不同栽培模式对马铃薯产量和经济效益的影响

为探索陇东旱塬地区马铃薯不同栽培模式的产量和经济效益,采用单因子随机区组试验设计,以马铃薯品种陇薯7号为材料,共设4种栽培模式。处理T1为露地坑栽,处理T2为黑色地膜单行栽培,处理T3为黑色地膜双行栽培,处理T4为黑色地膜双行微沟栽培,通过农艺性状、商品率、产量和经济效益的比较,选择出最佳的栽培模式。结果表明：相较于露地坑栽模式,3种地膜覆盖栽培方式的出苗率略低、生育期晚,而株高、分枝数、地上干质量、穴薯块数、穴薯质量均较高,其中地膜覆盖双行微沟栽培方式（T4）表现最佳, 667 m2产量最高,为3 280.2 kg,较露地坑栽增产19.5%;且667 m2产值最高,达到3 936.28元;667 m2纯收益较露地坑栽增收657.2元,增加率达27.6%;因此,地膜双行微沟栽培不但产量高,而且纯效益也高,可作为陇东旱塬地区马铃薯栽培方式进行推广应用。     

Effects of plastic mulches on root zone temperature and on the manifestation of tomato spotted wilt symptoms and yield of tomato

Tomato spotted wilt (TSW) disease is a serious constraint to tomato production in various regions of the world. The effect of TSW on tomato yield is largely influenced by time of infection. Early infection usually results in severe stunting of the seedling and even death of the plant. Plastic film mulches affect both the incidence of TSW, and plant growth and yield of tomato. The objective of the present study was to determine the effect of root zone temperature (RZT) as affected by plastic film mulch on the manifestation of symptoms of TSW, and growth and yield of tomato plants either artificially inoculated with tomato spotted wilt virus (TSWV) or under natural TSW infection. In artificially inoculated plants as well as in plants under natural TSW infection, vegetative top fresh weight (FW) and fruit FW both increased with the length of time after transplanting that the plants remained free from TSW symptoms. The root zone temperature was highest under black mulch (seasonal mean = 27.5 °C), followed by gray (27.0 °C), silver (25.8 °C), and white (24.8 °C) mulches. The plants grown on black mulch showed the earliest appearance of TSW symptoms, and had significantly reduced vegetative growth and fruit yields compared to plants on the other mulches. In conclusion, utilization of plastic mulches that created conditions of high RZT stress resulted in reduced plant growth and yield and predisposed the plants to earlier expression of TSW symptoms compared to plants grown at RZTs more favorable to tomato plant growth (optimal RZT = 26.1 °C [Díaz-Pérez, J.C., Batal, K.D., Granberry, D., Bertrand, D., Giddings, D., Pappu, H., 2003. Vegetative top growth and yield of tomato grown on plastic film mulches as affected by the appearance of symptoms of Tomato spotted wilt virus. HortScience 38, 395–399]). Since these plant responses to TSW under heat stress occurred in artificially inoculated plants as well as in plants under natural TSW infection, high RZTs probably affected the plants directly, independently of any possible effects on the thrips vectors.     

不同颜色地膜对蒜田韭菜迟眼蕈蚊发生的影响

以山东秋蒜为试材,通过田间调查和室内试验研究了覆盖银灰、银黑、蓝色、黑色和透明5种颜色的地膜对蒜田韭菜迟眼蕈蚊的种群发生数量的影响,并测定分析不同地膜的反射光谱特性,探讨其防虫机制,以期为大蒜害虫的绿色防控提供参考依据。结果表明:蒜田覆盖银灰和银黑地膜较透明地膜显著降低韭蛆发生数量,每10株韭蛆发生数量分别为33.6头和12.8头,较透明地膜分别减少了63.8%和86.2%;田间成虫选择试验结果表明,韭菜迟眼蕈蚊成虫对银灰、银黑地膜的选择率最低,较透明地膜分别降低了26.2%和27.4%。室内成虫选择试验结果与田间成虫选择趋势一致。进一步测定反射光谱结果表明,银灰、银黑地膜的光反射率和反射光照强度显著高于其它颜色地膜,且其反射率在紫外光(380~400 nm)和黄绿光(512~607 nm)波段最高。综上所述,蒜田覆盖银灰、银黑地膜能显著减轻韭蛆的危害,这是由于韭菜迟眼蕈蚊对银灰和银黑地膜的选择率低,这可能与银灰、银黑地膜的特异光谱反射率以及高反射强度有关。     

辣椒低山工厂育苗高山移栽可行性及新增固碳减排能力研究

为探索低山工厂辣椒苗对高山地区环境的适应性、增产能力和新增固碳减排能力，通过不同播期对比试验、17个品种对比试验和大面积移栽生产试验，比较分析辣椒低山工厂育苗高山移栽的适应性、丰产性以及固碳减排效应。结果表明：辣椒低山工厂育苗不仅可以完全适应宜昌市高山地区生态环境，且各项试验均实现大幅增产、增收，其中大面积移栽生产试验中辣椒667 m²产量为3 280 kg,667 m²产值达15 622.6元；较农民自育苗667 m²增产967 kg，增产率达41.8%,667 m²产值增加7 273.6元，增收率达87.1%;667 m²新增固定减排CO₂量为619 kg，固碳减排效果良好。     

大棚不同地膜栽培对蔬菜生长及产量的影响

通过在大棚内进行不同地膜,研究了大棚内麻地膜覆盖对辣椒、黄瓜生长及产量的影响。试验结果表明,大棚内麻地膜覆盖栽培促进蔬菜生长,提高辣椒、黄瓜产量。麻地膜覆盖栽培辣椒、黄瓜比聚乙烯农用黑膜增产5．2％、14．5％,比CK（不覆盖）增产24．7％、23．0％,与对照相比均达到显著差异。     

Effect of different biodegradable and polyethylene mulches on soil properties and production in a tomato crop

The use of plastic materials for mulching is a very common practice for vegetable crops. Black polyethylene is the most widely used due to its excellent properties and low cost. However, the massive use of these materials supposes an environmental risk. In the last few years, the use of starch-based biodegradable films has been introduced as an alternative to conventional mulches. These materials can be incorporated into the soil at the end of the crop season and undergo biodegradation by soil microorganisms. A 2-year study was conducted to determine the response of a tomato crop to seven mulch materials (polyethylene and biodegradable) in open fields in Central Spain. Biodegradable films underwent early decomposition, but in general remained functional during use and did not affect yield and the fruit quality attributes (total soluble solids, firmness, dry weight, juice content and shape). The temperatures reached under polyethylene films were always higher than under biodegradable films, which could be a disadvantage in certain circumstances, especially in hot climates, although may be advantageous in cool conditions. The use of polyethylene films resulted in the lowest values of soil microbial biomass C and soil organic matter mineralization, probably due to the increase of temperature registered under mulches. The analysis of the marketable yield components indicates that the variability in yield mainly depended on the number of fruits, with mean fruit weight being practically constant in the different treatments and seasons, which suggests the strong varietal character of this parameter.     

Influence of sprayable mulch colour on yield of eggplant (Solanum melongena L. cv. Millionaire)

Planting beds were treated with sprayable, synthetic latex film (BASF, Charlotte, NC, USA) and oversprayed with black, white, red, blue, yellow or silver oil-based paint to study the effect of coloured spray mulches on yield of eggplant (Solanum melongena L. cv. Millionaire). Nonpainted mulch base and bare ground plots served as control treatments. Individual experimental units consisted of three rows, 102 cm wide × 7.3 m long, transplanted with 8 plants per row. Treatments were replicated in four blocks each at two separate locations near Fresno, CA. Plants grown on silver-painted beds produced significantly greater numbers (42–221%) of fruit and total fruit weight (42–237%) than all other treatments at both locations after eight harvests. Silver-painted mulch stimulated significantly greater flowering and fruit set numbers prior to the first harvest at one site. Apart from silver, only blue- and white-coloured mulches provided increased numbers and/or fresh weight yields at one site only. Mulched plots painted with other colours did not produce yields different from either the bare ground or nonpainted mulch base controls at either site.     

The effects of irrigation on the establishment and yield of lettuce and leek transplants raised in peat blocks

The establishment and yield of lettuce and leeks were not reduced by transplanting dry (—0.06 to —0.09 MPa) as compared to saturated peat blocks (3.2 cm cube), provided irrigation was applied immediately after transplanting during the summer. When irrigation was withheld until eight days after transplanting the marketable yield of lettuce was reduced by 30% and 38% when transplanted in saturated and in dry blocks respectively. These reductions were due to reduced survival during establishment and to the more extensive trimming required to produce marketable heads rather than to a reduction in total fresh weight per plant at maturity. The marketable yield of leeks was reduced by 16% and 24% when saturated and dry blocks respectively were transplanted without irrigation, the reduction being largely due to a lower mean shoot weight. Measurements of block and soil water after transplanting suggested that even when the soil was irrigated immediately after transplanting, it was urmble to supply water directly to the blocks for more than a few days.     

新鲜玉米秸秆覆盖对马铃薯产量及效益的影响

为探究新鲜玉米秸秆在南方马铃薯生产中的应用价值,通过随机区组田间试验研究了6种覆盖栽培方式对马铃薯产量及效益的影响.结果表明,不同覆盖方式对马铃薯单薯质量、商品薯数量比率、薯长径和长短径比有显著影响,其中单薯质量和薯长径对鲜薯产量的直接效应较大,通径系数分别达到258.5和88.7.黑膜下覆盖3 cm厚粉碎秸秆处理的薯...     

播期对地膜甜菜个体发育及产质量的影响

为探讨播期与地膜甜菜生长发育的关系,指导生产适期播种,开展播期对地膜甜菜个体发育及产质量的影响研究.试验结果表明,随播期延后地膜甜菜出苗时间缩短,4月1日至5月1日,每晚播10d地膜甜菜出苗所需时间平均缩短1.7d.叶片数、叶丛高度、块根最大直径、根体长度和单根重量等指标均随着播期的延后呈现下降趋势.含糖率随播期延后呈先增后减的变化趋势.每早播10d新甜14号决根产量和产糖量平均提高13.4％和14.0％;Beta218块根产量和产糖量平均提高20.6％和21.8％.因此,应通过适期早播提高甜菜产量和产糖量.     

留瓜数量对日光温室越冬薄皮甜瓜产量和 效益的影响

摘要：为延长日光温室薄皮甜瓜采收期,提高产量和效益,以薄皮甜瓜“永甜十一”为试材,设置1茬留 8个瓜和留9个瓜的试验处理,以常规栽培1茬留4个瓜为对照,研究不同留瓜方式对前2批甜瓜综合性状、产量 以及长势、总产量和收入等影响。结果表明：相对于常规栽培,薄皮甜瓜日光温室越冬栽培1茬留9个瓜处理 的全生育期延长55 d,667 m2 总产量增加1 832.18 kg,667 m2 总收入增加23 746元,在辽宁地区日光温室薄皮甜 瓜生产中值得应用推广。     

直播和育苗移栽对豇豆生长和产量的影响

比较了直播和育苗(穴盘育苗和营养基育苗)移栽对豇豆生长和产量的影响.试验结果表明,育苗移栽降低了豇豆的始花节位,对豆荚性状的影响与对照相比差异不显著.穴盘育苗总产量和直播相比差异不显著,但能显著提高豇豆前期产量的比例.穴盘育苗能作为豇豆的一种有效育苗方式进行推广.     

Screening of genotypes of menthol mint Mentha arvensis for high yields of herbage and essential oil under late cropping conditions of the sub-tropical Indo-Gangetic plains

Summary

The essential oil yields and expression of related characters were compared for seven cultivar genotypes of menthol mint Mentha arvensis using two methods of planting in the winter rabi – summer season (October to July) in a sub-tropical agroclimatic environment. The crops of all the cultivars were planted in the field by (1) sowing of suckers on 2 January and (2) transplanting germinated pieces of sucker at different times between 17 March to 14 April. Staggering of transplanting time up to 7 April did not affect oil yields and the related plant growth properties of mint crops. The oil yields of the crops planted on 14 April were lower by about 30%. In the early sucker planted crops, the oil yields were about 30% higher than those obtained from the transplanted crops of 17 March to 7 April and about double that obtained from crops transplanted on 14 April. The oil yields from the crops of the superior genotype Kosi were equal to or higher than the corresponding means of all genotypes under both planting methods. The oil yield from the crops of Kosi genotype obtained by sucker sowing method was estimated as 333 kg ha^–1. The corresponding average yield from the crops of this genotype obtained by transplanting of germinated suckers between 17 March and 7 April was about 293 kg ha^–1 and that from the crop transplanted on 14 April was 218 kg ha^–1. With the Kosi genotype, the latter two types of transplanted mint crops gave oil yields lower only by about 12% and 33% compared with the long-duration sucker-sown crop. It is concluded that a crop of mustard (brassica), Bengalgram (chickpea) or wheat sown between October and November and harvested between early March to middle of April could be taken before cropping of the Kosi genotype of M. arvensis by plantlet transplanting. These results demonstrate the potential of the following rotation of crops in the sub-tropical environments: from June/July/August to October/November (kharif cropping season), rice, maize, sorghum or pigeonpea; from November/December to February/March, mustard and Bengalgram or from November/December to April (rabi cropping season), wheat; from March/April to June/July (zaid cropping season), transplanted menthol mint.     

Interactive effects of planting time and mulching on ‘Chandler’ strawberry (Fragaria × ananassa Duch.)

Studies were conducted in ‘Chandler’ strawberry with the aim to optimize planting time and mulching material under the semi-arid region of north Indian plains. Three planting times viz., mid-September, mid-October and mid-November and three mulch materials viz., black polyethylene (50 μm), clear polyethylene (50 μm) and paddy straw (10 cm thickness) were tried with three replications in a split plot design. Mid-September planting favoured plant growth, enhanced flowering (77.3 days), which resulted in production of significantly larger fruit (13.0 g) and higher yield (174.4 g/plant) with fruit having higher TSS (9.23%), acidity (1.22%) and ascorbic acid content (44.1 mg/100 g of pulp) with lesser incidence of albinism (9.6%) and botrytis rot (8.1%) than other plantings. Plants mulched with black polyethylene have significantly better growth, and they flowered (80.2 days) and fruited early (29.2 days), and produced larger fruit (12.6 g) and higher yield (172.4 g/plant), with slightly higher incidence of albinism (20.1%), but with lower incidence of botrytis rot (7.3%) than those mulched either with clear polyethylene or paddy straw. Planting time × mulching interaction has significantly influenced plant growth; flowering and fruiting; fruit yield and quality, and albinism and botrytis rot. Plants have best growth parameters like, plant height (11.2 cm), crown spread (24.1 cm) and leaf area (87.9 cm²), they took lesser days to flowering (73.7 days) and fruiting (31.3 days), produced larger fruit (13.7 g) and higher yield (191.3 g/plant) with fruit having higher TSS (9.41%), acidity (1.17%) and higher ascorbic acid content (46.4 mg/100 g pulp) with a slightly higher incidence of albinism (10.3%), but comparatively lower incidence of botrytis rot (5.2%) when planted during mid-September and mulched with black polyethylene than other plantings and mulched either with clear polyethylene or paddy straw. These studies indicated that strawberry could be planted in mid-September with black polyethylene mulch under semi-arid regions of India for early fruiting, and higher yield of better quality fruits.     

种植模式和多茬收割对饲用型甜高粱产量的影响

研究了饲用型甜高粱在不同种植模式条件下（全膜双垄沟灌栽培、全膜覆盖平作栽培、露地栽培）对土壤含水量、植株外部形态及产量的影响;单茬收割以及不同株高条件下2茬收割、3茬收割对产量的影响.结果表明：覆膜处理能高效利用降水和灌水,使植株茎秆含糖率增加,显著增加株高和产量,尤其全膜覆盖平作处理较露地栽培水分利用效率高70.52kg/（mm· hm2）,增产41.74％.收获两茬产量要比收获1茬高10.98％,比收割3茬高18.64％;在收割两茬的情况下,头茬株高150cm时刈割总产量比头茬株高200cm时刈割总产增产4.49％.在生育期只有150d左右的区域,饲用型甜高粱可选择两茬或单茬收割,头茬在株高150cm左右收割,二茬收割时间在早霜来临之前.     

不同栽培方式对甜菜产质量的影响

2006～2007年进行了2年4个点的甜菜覆膜直播栽培（CK）、甜菜纸筒育苗平地移栽、甜菜纸筒育苗覆膜移栽、甜菜纸筒育苗起高垄移栽4种种植方式试验。结果表明,后3种种植方式,根产量、含糖率和产糖量,除了纸筒育苗覆膜移栽的含糖率低于覆膜直播外,均比对照增产增糖。农户种植纯收入比覆膜直播增加1095-3315元／hm^2,企业效益除纸筒育苗覆膜移栽低于覆膜直播．其它高于对照。     

The influence of temperature on growth,bolting and yield of chicory cv. Rosso di Chioggia (Cichorium intybus L.)

Summary

This work on spring-grown chicory shows the influence of temperature from the first stages of development on the subsequent performance of the plant. Temperatures of 20-26°C from sowing to emergence proved most suitable for emergence. Faster growth of seedlings in the following 5-10 weeks was also observed. Moreover, temperatures of about 20°C during emergence proved sufficiently high to reduce the incidence of bolting, and increased marketable yield. These effects on bolting and yield were more evident after early transplanting. A strong reduction in bolting was also observed by delaying transplanting, but this was at the expense of early production. Postponing transplanting improved the number of leaves per plant and the average weight of the heads. Exposure of the seeds to 0°C for two weeks prior to sowing allowed faster emergence of seedlings compared with that of seedlings of seeds exposed to 20, 30 and 40°C. Low temperature also influenced the subsequent development of the plants, favouring their growth in the first three months of the cycle.