紫竹4种栽培类型出笋成竹规律研究

观察了大径紫竹、一年紫、二年紫和三年紫等4种紫竹(Phyllostachys nigra)栽培类型的出笋和成竹过程,比较了它们的出笋和高生长规律。结果表明:紫竹4种栽培类型笋期为20～30天,其中大径紫竹出笋最早;高生长曲线基本为S形,高生长量与温度呈极显著相关。     

Tolerance of four spring barley (Hordeum vulgare) varieties to weed harrowing

We investigated the tolerance to weed harrowing of four spring barley varieties and examined the possible interactions between varietal weed suppressive ability and two nutrient levels. Tolerance was defined as the combined effect of crop resistance (ability to resist soil covering) and crop recovery (the ability to recover in terms of yield). The weed harrowing strategy was a combination of one pre‐ and one post‐emergence weed harrowing. In terms of yield, the four varieties responded significantly differently to weed harrowing and the response depended on nutrient level. At the lower nutrient level, weed harrowing caused an increase in yield of 4.4 hkg ha⁻¹ for a strong competitor (cv. Otira), while there was no effect on yield at the higher nutrient level. For a weaker competitor (cv. Brazil), weed harrowing caused no change in yield at the lower nutrient level, whereas yield decreased by 6.0 hkg ha⁻¹ at the higher nutrient level. There were marked differences between the weed suppressive ability of the four varieties when not harrowed, with less pronounced but significant differences when harrowed. Weed harrowing did not change the weed suppressive ability of a variety. Varieties that are tall at post‐emergence harrowing and have increased density after pre‐emergence harrowing, are the ones that benefit most from weed harrowing.     

Evaluation of salt tolerance in cowpea and tobacco: Effects of NaCl on growth,relative turgidity and photosynthesis

The physiology of NaCl induced stress was studied in two prop species, cowpea and 4 cultivars of tobacco one of which (Jayashree) is salt sensitive. It was found that the growth of all the cvs of tobacco was reduced by the presence of NaCl (100 mH) in the nutrient medium. While the fresh wt per unit area of the leaves of salt‐tolerant tobacco cv. I and PV‐7 (Nicotiana tabacum L.) and MPS‐219 (N. rustica L.) was increased’ significantly, it was decreased in the salt‐sensitive Jayashree. The dry wt per unit leaf area was decreased much more in I, PV‐7 and J than in NPS‐219. The total chlorophyll was reduced in all and more so in Jayashree.

The relative turgidity % was found to decrease in the primary leaves of cowpea (Vigna unguiculata L.) in the first 6 days of treatment with 100 mM NaCl in the nutrient medium while the decrease was less significant in the first and and second trifoliate leaves, showing that there was readjustment with growth of the plant to salinity. The ¹⁴C fixation in the leaf disks of cowpea grown in NaCl was much less than in the control plants. The studies reveal that there is a general reduction in the growth of both tobacco and cowpea following NaCl treatment and this effect is due to a decrease in the total chlorophyll and a reduced rate of photosynthesis.     

Effect of soil pH and N fertilization oh uptake and fractions of Ca and Mg in two barley cultivars

Abstract

A study has been made of the amounts of Ca and Mg removed from dry matter of young barley plants by sequential extraction with water, M NaCl, 0.4 M acetic acid and 0.6 M HCl. Two contrasting cultivars were examined and other factors included the effects of the soil pH in which the plants were grown and the form of N‐fertilizer used. The distribution of total Ca and Mg and the different fractions between young and old tissues was also examined.

Water and NaCl between them removed the bulk of the Ca and Mg (between 80 and 90%) and broadly, where uptake of total Ca or Mg increased with increase in soil pH, there was little change in the percentage of either cation appearing in the fractions, indicating a constant removal by the extractants, irrespective of content.

Only about a third of the total Ca was found in the upper half of the plants, against over 60% in the case of Mg and the same distribution was found for the percentages of the water‐soluble and the exchangeable fractions.

Small differences between cultivars and between N forms in respect of fractions and their distribution in the plant were found, but these did not affect the overall general pattern.     

Effects of Dibutyl phthalate and phthalic acid on chlorosis recovery in iron‐deficiency stressed sorghum cultivars

The effects of DBP (Dibutyl phthalate) and PA (Phthalic acid) supplied to the nutrient medium of Fe‐deficiency stressed sorghum cultivars, CSH‐5, 2077‐A, and CS‐3541 were examined. It was found that both the chemicals (50 mg/1) caused recovery of the cultivars CSH‐5 and 2077‐A in 4 days of treatment. Furthermore, the growth of roots, especially the adventitious roots, was increased by the chemicals.     

亚热带和温带生态条件下籼稻品种产量潜力评价

2001—2002年,对在中国宾川(亚热带)和韩国水原(温带)两生态区8个籼稻品种的产量潜力进行评价.结果表明,亚热带生态条件下实际产量和产量潜力比温带条件下高1.25和4.43t/hm2,差异极显著.亚热带生态条件下具有较高产量潜力,是因为具有较多的生物产量和颖花量,分别比温带条件下多2万/m2和422.25g/m2.对产量构成因子进行通径分析,结果表明,亚热带生态条件下,对产量的影响大小依次是有效穗、穗粒数、结实率、千粒重;温带生态条件下则是千粒重、穗粒数、有效穗、结实率.在亚热带生态条件下,增产途径应是在保证足够有效穗的基础上,适当降低穗粒数而增加结实率;温带生态条件下应在提高千粒重的基础上,保证适当穗粒数.     

甜瓜小拱棚栽培品种比较试验

对6个厚皮甜瓜品种在拱棚栽培条件下的适应性和产量、品质表现进行了比较研究。结果表明，古拉巴和玉金香2个品种兼具优质、丰产、抗病、抗逆性强等优良性状，具有拱棚种植的开发潜力，可作主栽品种推广。伊丽莎白是仅次于古拉巴和玉金香的早熟优良品种，可作为拱棚栽培的搭配品种使用。     

信息熵综合评价方法在小麦品种区域试验中的应用

运用信息熵原理,建立了作物品种综合评价模型,提出了品种多目标综合评价方法,结合小麦品种区域试验,具体介绍了这种方法的应用.研究表明,信息熵综合评价方法对于客观综合评价品种,具有重要的参考价值.     

The Influence of Genotype–Environment Interaction on the Grain Yields of 10 Pigeonpea Cultivars Grown in Kenya

To study the importance of the effects of genotype–environment interactions on the yield of pigeonpea ( Cajanus cajan L. Millsp.), 10 early-maturing genotypes were grown in a randomized complete block design with three replications in a total of seven environments spread over five regions of Kenya between 1987 and 1988. Results indicated the presence of a substantial genotype–environment interaction effect on grain yield. The observed significant genotype–environment interaction effect is discussed in relation to its importance in pigeonpea grain yield evaluation studies. It is noted that the best genotype in one environment is not always so in other environments. Results from regression analysis indicated that this method of analysis is appropriate for describing the response of pigeonpea genotypes grown in a number of locations. Analysis of variance showed significant additive and multiplicative genotype–environment interaction effects. Only the first interaction principal component axis (IPCA) was found to be important in describing the multiplicative interaction effects. The additive main effects and multiplicative effects (AMMI) model allowed the partitioning of interaction variance into agronomically important sources (genotype groups), and the specific genotype × environment patterns that are the basis of these sources of variance were examined.     

大棚草莓优质鲜食新品种引进比较初报

为解决长江中下游地区大棚草莓鲜食的主栽品种“丰香”易感白粉病，“明宝”果实软、不耐贮运的问题，镇江农科所近几年先后从日本引进了6个优质鲜食草莓新品种和从日本实生种子中自选了“益香”新品系，并对其繁育苗能力、生育特性、产量和品质性状、抗病虫能力进行了调查，结果表明：“枥木少女”、“金三姬”、“章姬”早熟性最好，适于大棚促早熟栽培，且均抗白粉病，为11月上市的优选品种；“枥木少女”适于远销，“金三姬”、“章姬”适于近距离销售，但必须避雨和防高温遮荫育苗，在高水平栽培下发展潜力大；“鬼恕甘”长势强而旺，产量高，果形优美，适于大棚促成，但果实也偏软；“益香”、“静岗11号”、“幸香”，采收期均比“丰香”、“明宝迟”，“益香”、“静岗11号”较抗白粉病，且比“明宝”耐贮，有一定应用前景，“幸香”在8个品种(系)中果皮最硬、摘叶省工，最适于远途销售，但仍较感白粉病，需注意防治。