摘要:

AbstractThe objective was to study the behaviour of 20 dwarf wheats in a field trial under irrigated situation and also to suggest parameters or group of parameters conducive to high yield. Considerable variability existed in respect of tillering and earing, LAI, net photosynthetic rate, total dry matter production rate (TDMPR), harvest index, number of grains per main and subsidiary ears and grain size (1000 grain weight). Number of grains per main and subsidiary ears, total grains per plant, rate of net photosynthesis, leaf area and harvest index as well as total dry matter production rates were found to be positively correlated with grain yield and as such contributed maximum towards grain yield.Thus, in general, it may be concluded that there should be minimum reduction in grain numbers between the main ear and the subsidiary ears, for this seems to be the one of causes of reduction in grain yield. Besides, there ought to be high ratio between net photosynthetic rate and dark respiration because large amount of dry matter is otherwise lost through respiration and many not be available for grains. High harvest index and high biological yield are also desirable characters which may be combined to obtain higher yields in wheats.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00310.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe influence of N‐dimethylamino succinamic acid (B‐nine) on lucerne plants cv.IGFRI‐244was investigated. B‐nine (a growth regulant) was sprayed as a foliar sprays, employing 10, 100, 250, 500, 1000 and 5000 ppm alongwith water spray as control, and the effects were observed on plant growth, flowering, nutritive constituents and seed yield of the crop. Plant height was reduced from 6.19 to 26.85 % in various concentrations of B‐nine being highest retardation in 5000 ppm, whereas 250 ppm produced more branches and leaves with dense foliage in comparison to control and other treatments. Delayed flowering by 2–15 days with significant increase in seed yield and 1000 seed weight B‐nine bein maximum seed yield in 250 ppm. However, total seed yield was increased by 4.16 to 24.76 per cent over unsprayed control plants. Among the treated levels of B‐nine, 250 ppm also gave higher values for Carbohydrate,IVTDMDin shoot of lucerne plants with considerable decreased in 5000 ppm. NDF condent decreased progressively with increased concentration of B‐nine but always lesser than th

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00311.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractEcological Investigation of a Meadow Developed on a Metal‐Rich SoilThe floristic structure of a meadow over a copper‐rich soil was studied, and four different stages of vegetation succession were described. The following species dominate over the different stages:Minuartia verna, Thymus sibthorpii, Rumex acetosellaandChrysopogon gryllus.Soil analysis showed that the most undeveloped soil of theMinuartiastage exhibits the highest concentration of Cu and of twelve other elements, while the mature soil of theChrysopogonstage exhibits the highest concentrations of Al, Ca, Na and Ni.An inverse relationship was found between the concentrations of Cu in the soil and the number of species in the forty sampling quadrats. Plant analysis showed thatMinuartia vernaandRumex acetosellaaccumulate more copper in their tissues than the other two dominant spec

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00312.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractGenotypical Differences in the Nutrient Uptake of Winter WheatIn order to investigate genotypical differences in the nutrient uptake of winter wheat cultivars the nutrient content of young wheat plants grown during 1982–1984 on three Brown Earth sites of Schleswig‐Holstein were analysed.Significant differences between the cultivars could be found in the content of the plants at shooting stage in P, K, Ca, Fe, Mn and Zn. The maximal difference between highest and lowest content (mean of 3 years) was about 20 % for P, K, Ca, Mn and Zn and 40 % for Mn. Since at shooting stage the dry matter production of the cultivars was about the same, the measured differences in nutrient concentrations may also represent differences in nutrient uptake.Due to the low Mn‐supply of the test soils the cultivars with the lowest Mn‐uptake also produced the lowest grain yield.By use of discriminant analysis it could be shown that the cultivars displayed a typical pattern of the nutrient concentrations. In the whole population two general types in nutrient pattern were found which are different in their concentrations of P, K, Ca

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00313.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIn a long‐term field experiment in progress since 1962 on a luvisol derived from loess the influence of increasing amounts of sewage sludge, garbage compost and farmyard manure on the N dynamic and microbiological soil characteristics was investigated.The following results were obtained:The application of the organic materials over a period of 24 years resulted in an increase of the total C and total N content of the soil. The increase was mostly pronounced in the plots treated with garbage compost. The higher total N content was caused by higher contents of hydrolyzable as well as non‐hydrolyzable organic N compounds. The N mineralization potential of the soil was intensified by the application of all the different organic materials, especially by garbage compost and farmyard manure.Dehydrogenase activity and soil respiration were positively influenced by all organic treatments with the highest effect in the soils with the highest C, conte

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00314.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractGnetum africanumandOcimum viridisare both indigenous leafy vegetables of the humid tropical environment of Nigeria. The former is used in both the raw state and cooked in soups. The latter is used fresh or dry as a spice in foods and stews.One of the components of leaf yield, our goal, is the leaf area. This gives an indication of the response of these plants to manurial and intercropping trials. In the breeding and selection of these leafy plants one also needs a rapid method of assessing accessions for further development. The leaves of both these species are cunate to obvate. Gnetum leaves are entire, whileOcimumleaves are serated.Formulae are given for both plant species collected from six different locations of southern Nigeria, while a general equation that holds true for all is given for each species.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00315.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA biochemical approach to maize breeding must be based on an exact knowledge about changes of relevant traits with ontogenetic stage. In 1983 seasonal patterns of net assimilation rate (NAR), chlorophyll and carotenoids contents, and of activities of RuBP carboxylase, PEP carboxylase and NADP malate dehydrogenase were recorded for two early maturing maize cultivars. For all traits the general trends were similar for both cultivars throughout the growing season but short term fluctuations were less synchronized after anthesis. About 75% of the maximum green leaf area was expanded within 20 days around middle of July. Specific seasonal patterns were observed for all traits. Before anthesis values were maximum for NAR in late June and in early July, for enzyme activities at the end of June and for pigment contents at the beginning of July. First decreases occurred for all traits before anthesis, further decreases were observed for PEP carboxylase in August and for chlorophyll content in September. Marked temporary declines coincided for NAR and pigment contents with a cold spell end of June and for these traits and RuBP carboxylase activity with anthesis. Evidence was scarce that any of the photosynthetic traits reflected the photosynthetic efficience of the two cultivars for a long stretch of time.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00316.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIntercropping of sorghum and pearl millet with different growth cycles is used widely in third‐world countries to ensure and increase yields. However, it is questionable whether yield increases because of intercropping can be maintained under more developed systems, since temporal differences are necessary to allow mechanized planting and harvesting.Three sorghum hybrids with expected growth cycles from 90 to 110 days were planted in sole stands and in alternate rows and mixed within the rows with a pearl millet hybrid having a growth cycle similar to that of the early sorghum. Sole stands of millet also were included. The plots were planted at three locations in Kansas, two dryland and one including dryland and irrigated. Results show that yields were consistently highest in sole stands of sorghum, owing to the higher yield level of sorghum. No yield increase could be found on a land equivalent ratio basis, indicating no intercropping advantages. However, under good moisture conditions, a tendency toward yield increase was observed with the later maturing sorghums, which had 1–2 weeks of grain filling after the millet was mature. When moisture supply was insufficient, millet showed higher competitiveness for water than sorghum, and sorghum was adversely affected more than pearl millet was favored. It was concluded that moisture conditions have to be good and that temporal differences between sorghum and millet have to be greater than those used in this experiment to achieve intercropping yield advanta

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00317.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractIn years 1982–1985 flag leaf area, concentration of chlorophyll and macronutrients (N, P, K, Ca, Mg, Na) and also their correlations to grain yield in static field experiment were studied. The main experimental plots comprised crop rotations containing 50, 75, 100% cereals. Treatments with or without irrigation were subplots and nitrogen levels (0, 60, 120, 180 kg N/ha) were sub‐sub‐plots.The cultivation of winter wheat in rotations containing more than 50% cereals affected the drop of winter wheat grain yield, which was especially high on the plots without nitrogen fertilization or with low N level. The dose of 120 kg N/ha gave the highest grain yield in each rotation and, at the same time, decreased to minimum the differences between them, although wheat grown in the full cereal rotation yielded much less. The response of wheat grain yield to previous crop was affected by photosynthetic potential of a plant, which was constituated by flag leaf area and concentration of chlorophyll. The deteriorating nutrient economy in wheat plants grown in rotations containing more than 50% cereals decreased the photosynthetic potential of wheat. In addition, in these rotations the importance of macronutrients concentration in the flag leaf at anthesis as a source of nutrients for the developing grain is vi

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00318.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAn experiment with squash (Cucurbita pepoL.) was conducted at the University of Jordan Research Station, located in the Jordan Valley in Jordan during the 1984 and 1985/86 seasons. Its objectives were to determine the effects of different plastic mulch using drip irrigation on soil temperature, root growth distribution, and production dates, Earliness in picking dates under mulch was obtained during the relatively warm 1985/86 season, where picking started 13 days earlier under mulch. Root weights, secondary root lengths, and horizontal root distribution were not significantly different between treatments, during each season. Tap roots were not significantly different between treatments during the 1984 season, yet those under transparent mulch were significantly higher (5% level) from those under bare soil conditions, during the 1985/86 season. Density of plant canopy influenced mulching effect on soil temperature. High plant canopy under mulch prevented solar radiation from increasing soil temperature. Whereas, higher soil temperature was obtained under non‐mulched conditions when compared to the mulched ones. This was most probably due to relatively low vegetative cove

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1988.tb00319.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY