摘要:

AbstractAs the incident radiation penetrates vertically in any plant stand having green closed canopy, the PAR flux density (Rn) gradually decreases with depth in a manner that the radiation flux density (Rn) is inversely proportional to the photosynthetic‐area percentage (Pap), and the radiation interception density (Rid). The radiation interception density (Rid) is a function of net radiation intercepted, total photosynthetic‐area percentage and the thickness of that photosynthetic

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00092.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA field experiment was conducted at Samaru, Nigeria to study the influence of nitrogen fertilization and plant density on the agronomic performance and nutrient concentration of maize (Zea maysL.). The treatments were factorial combinations of five nitrogen fertilization rates (0, 50, 100, 150 and 200 kg N/ha) and three plant density levels (25000, 50000 and 75000 plants/ha).Nitrogen fertilization up to 150 kg N/ha enhanced grain and stover yields and increased kernel number and weight up to 100 kg N/ha. Nitrogen supply also increased maize ear length. Increased N fertilization rates increased concentrations of N, K and Mg but had no effect on P and Ca concentrations. Higher grain yield was closely associated with higher N concentration in ear leaf; with 0.1 % change in N concentration causing 177 kg/ha change in grain yield. Increased plant density increased stover yield up to 50 or 75 thousand plants/ha but depressed kernel number and weight and ear length.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00093.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractInvestigations on the effect of number of plants/area on the yield potential of rapeseed plants (Brassica napusL. var.napus)Based on field experiments with winter rapeseed, the effect of number of plants per area on yield potential and components of yield were investigated. The dependence of yield from number of plants per area before and after winter was analyzed by manipulating the number of plants immediately after sowing and in spring before beginning of growth. The number of plants per area was varied between 10 plants/m2till 185 plants/m2. The results show that the yield potential is partly dependend on the growing conditions before winter as influenced by the number of plants per area; the yield potential declines with increasing number of plants/area before winter; affected are the number of siliquae producing lateral shoots, the number of siliquae per shoot and seeds per siliqua. The growing conditions before winter, in this way control the capacity of the rapeseed plant to utilize environmental factors in the main growing period. 50–100 plants/m2before winter and 45–90 plants/m2after winter are within the compensation capacity of rapeseed pla

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00094.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe lateritic sandy loam soil of Gopali suffers by a high infiltration rate and percolation loss. The investigated soil was treated by four soil conditioners, CMC, PVA. Guargum and Lignosulphonate (LIG.) at 0.05 per cent and 0.10 per cent concentration level. The infiltration of water at −2 m bar pressure in horizontal column of soil was studied. The experimental results indicate that the lignosulphonate has increased the time by 30% and 70% to penetrate the 15 cm depth of soil column at 0.05 and 0.10 per cent concentration level, respectively. In the case of PVA, increase of time was 18 per cent and 33 percent at these the concentration level. Guargum at high concentration level increased the time by 31 per cent to penetrate the same depth of soil. Whereas CMC at high concentration reduced the time by 8 per cent. Similar trends were found in case of volume of water penetration and infiltration rate of treated soi

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00095.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractWhen one of the crops is a legume, intercropping has potential to reduce fertilizer nitrogen (N) needs and increase food quality. Total dry matter (DM) and grain yields of different plant populations of intercropped maize (Zea maysL.) and climbing beans (Phaseolus vulgarisL.), cowpeas (Vigna unguiculata[L.] Walp.), or velvet beans (Mucuna pruriens[L.] DC. varutilis[Wight] Bruck.) were compared in two experiments. Maize populations were 40,400 and 50,500 plants ha−1in combination with climbing bean populations of 0, 20,200, 40,400 and 80,800 plants ha−1in Experiment 1. In the second experiment, climbing beans, cowpeas and velvet beans at 215,200 plants ha−1were intercropped with maize at 64,600 plants ha−1. Climbing beans contributed up to 5% to total DM yields in the first experiment. In the second experiment legume contributions to total DM were 20% for climbing beans, 12% for cowpeas and 8% for velvet beans. Increasing populations of maize and climbing beans increased grain and DM yields. Dry matter yield of maize was lowered by intercropping. However, DM yields of the intercrop were not different to maize sole cropped. Maize/cowpeas produced more total DM than maize/climbing beans. Cowpeas increased the total yield of crude protein by over 15% without lowering total DM yield of the intercrop compared to maize alone and are promising as a legume for intercropping with maize. Climbing beans show little promise as a possible legume for intercropping wit

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00096.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractInfluence of long‐time Nitrogen‐fertilizing on yield response of agricultural crops and mineralized Nitrogen in soilIn the years 1979–1986 a fertilizer trial with increasing Nitrogen amount was performed in order to prove the Nmin‐method according to Scharpfand Wehrmann. The Nmin‐method regards the mineralized N in soil (Nmin) for optimizing the N‐fertilizer amount at the begin of vegetation, could be confirmed. The optimal N‐rate (including Nmin) was for winter wheat and winter barley 120 kg/ha, winter rye 100 kg/ha and sugar beet 200 kg/ha. For cereals additional N‐rates were given at the end of tillering 20 kg/ha N and at ear emergency 60 kg/ha N. For the optimal N‐fertilizing system we found a positive N‐balance (input‐output) in a range of 10–25 kg/ha. The influence of N‐fertilizing on the mineralized N‐amount in soil was very small comparing to influence of weather, soil type or crops. Only at one location a little increase of Nmin(10–15 kg/ha) could be observed after a

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00097.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe direct and indirect contributions of root characters — root length, roots/plant, fresh and dry root weight on grain yield/plant were worked out from a 7 × 7 diallel set of rice hybrids. The materials were grown in pots with four replications. Path analysis was done at genotypic level of correlation.The grain yield/plant showed positive correlation with all the root characters in parent, F1and F2except with roots/plant in F1population. Fresh root weight demonstrated positive direct effect on grain yield/plant in all the three generations. Roots/plant had highly positive direct effect in F2. Direct effects were negative in respect of root length and dry root weight in F2generati

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00098.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn three genotypes of cotton differing in height, reproductive growth increased with the increase in number and size of the leaves and was maximum when leaf area was also maximum. After this stage though the leaf area continued to remain high for 3 weeks and then declined, more buds were shed than produced. Within genotypes the taller typeLRA 5166produced more leaves with greater area thanMCU‐5whereas the dwarf typeKD (CAKD)had more leaves with lesser area thanMCU‐5.The maximum leaf area as well as the yield of seed cotton were one and a half times inLRA 5166than inMCU‐5.Though the maximum leaf area inMCU‐5was also one and a half times than inKD (CAKD), their seed cotton yields were the same. Since even during the period of maximum reproductive growth substantially more number of leaves were produced byLRA 5166andKD (CAKD)thanMCU‐5, maintenance and retention of bolls appeared to depend not only on leaf number and area but on their photosynthetic efficiency and perhaps nutrient

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00099.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe response of seedlings of 51Sorghum bicoloraccessions to 0, 50, 100, 150, 175, and 200 mM NaCl in solution culture was examined. Plant growth was measured as longest root lengths, maximum shoot lengths, and total plant dry weights after 14 days. Increasing NaCl concentration caused significant reductions in all three characters. Accession response to increasing NaCl also varied. The data suggest that increase in NaCl tolerance in this species through recurrent selection may be possible.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00100.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractInH. cannabinusmutagenic efficiency and effectiveness of EMS decreased with increase in concentration after excised mature embryo treatment whereas, a reverse trend was observed following seed treatment. Comparatively, maximum effectiveness vis‐à‐vis mutation induction was obtained at 0.1 % EMS after mature embryo treatment. The chlorophyll and other mutational spectra were also examined and discu

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1987.tb00101.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY