摘要:

AbstractThe protective effect of a synthetic terpenoid analog of abscisic acid (ABA), coded LAB 173711, on transplant shock in rice was investigated under field conditions. Rice seedlings (Fujisaka 5 and IR 20) were taken from a seed bed and their roots were immersed in aqueous solutions of the growth regulators for 24 h. Afterwards they were drought‐stressed for 3 or 6 h by exposing them to direct sunlight before they were transplanted to the field. A pretreatment with either LAB 173711 alone or in combination with the growth retardant tetcyclacis reduced the loss of water during the exposure to sunlight, increased the percentage of survival of the seedlings in the field, and increased the percentage of grain filling of the plants which had survived. The combined application of growth regulators was most effective and may be useful for minimizing transplant shock in rice and other crop

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01097.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractSorghum hybrid CSH‐6 was grown in fields in Delhi, India between July–November 1986 in order to study the effect of nitrogen nutrition and irrigation on dry matter accumulation, grain yield and water use. The treatments included 40 Kg Nha−1combined with two irrigations (30 DAS, 60 DAS), one irrigation (60 DAS) and no irrigation respectively. Rainfall during the crop season was only 17 cm. The unirrigated plants were considerably water stressed and exhibited very low leaf water potential, less leaf area, delayed anthesis, longer crop duration but shorter grain filling duration. The ears showed sterility and yield was only 0.41 t ha−1without nitrogen fertilization. Addition of nitrogen fertilizer had no significant effect on yield in unirrigated plants. A single irrigation 60 DAS increased yield due to increase in both grain number and grain weight per ear in fertilized and unfertilized crop respectively. Two irrigations in the unfertilized crop increased the yield to 2.2 t ha−1while similar treatment in the fertilized crop did not increase the yield significantly. Irrigation increased the WUE for grain yield. The results indicate that nitrogen stress and water stress reduced grain yield primarily through grain number rather than grain weight. Irrigation relieved both water stress and nutrient stress. Nitrogen nutrition was not beneficial under severe water stress conditions but was considerably helpful under mild stress. Biomass, grain yield and harvest index show significant correlation with preanthesis

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01098.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractFive short‐duration pigeonpea (Cajanus cajan(L.) Millsp.) genotypes were grown at three plant populations in three locations during the 1986 and 1988 rainy seasons, to determine the physiological basis of observed variations in yield. Significant differences were found in seed yield (Y), crop growth rate (C), and the durations of vegetative (Dv) and reproductive (Dr) growth, and partitioning (P). These were attributable to genotypes and their interactions with environments (except for C). Variation in C, Dr, and P together explained 78 % of the observed variation in Y due to different genotypes and environments. Crop growth rate alone contributed about 71 % of the variation in Y, and reached an optimum value of around 6.5 kg ha−1°Cd−1. Crop growth rates increased with the duration of the vegetative period and with plant population. However, a negative relationship between C and P resulted in plant population having little effect on seed yield. The maximum‐yielding genotype, ICPH 8 had the highest C and an interm

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01099.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe number of productive tillers is an important yield component in wheat and is affected by water stress and genetic factors. A greenhouse experiment was conducted during spring 1992 at ICARDA, Tel Hadya, Syria, with eight genotypes representing twoTriticumspecies (Triticum turgidumL. ssp.durumandTriticum aestivumL. ssp.aestivum) under four soil‐moisture regimes (95 %, 75 %, 55 %, and 35 % field capacity) to study the effect of water deficit on tiller development and tiller contribution to grain yield. In the highest watering regime appearance of Tiller 1 was delayed in both species. Also Tiller 2 was suppressed in this treatment indurum, while its appearance was delayed inaestivum.In the driest treatment, a majority of the tillers were suppressed and the ones which emerged were delayed. Indurum, the heat units required to produce successive leaves on the tillers were higher than that for the main stem and increased with increasing water stress, causing high rate of tiller abortion. Inaestivum, each tiller, once produced, developed leaves at the same rate as on the main stem. Phyllochron of tillers as well as main stem was not affected by water stress inaestivum.Inaestivum, contribution by tillers to yield was higher than that ofdurumin all treatments. Results indicate that early appearance of tillers and faster rate of leaf appearance under water stress result in higher tiller survival and greater tiller contribution to final yield. Hence, tiller dynamics under water stress can be used as a selection criterion for breeding for drought toleranc

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01100.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe effects of six seeding rates (50‐300 seeds m−2:) on some morphological traits with hay and seed yield were evaluated in common vetch (Vicia sativaL.) under fall and spring sowing conditions. The mutual correlations among yield and yield components were also determined.The sowing seasons and seeding rates significantly affected hay and seed yield, and most of the yield components. Fall sowings resulted in significantly higher hay and seed yield than spring sowings at all seeding rates, and the highest seed and hay yield was achieved in densities of 250 and 300 seeds m−2. In spring sowings there was a positive response in hay yield up to 250 seeds m−2while no further increase in seed yield at the seeding rates higher than 150 seeds m−2. Average protein content of hay and seed was found to be higher in spring sown crops than fall. The highest protein yields of hay and seed were obtained at 250 seeds m−2in fall sowings, and 150 seeds m−2in spring sowings.Most of the correlations between both hay and seed yields with the yield components were not consistent and differed with the sowing time. Only the correlations between number of the plants per unit area with hay yield, and number of the pods and seeds per unit area with seed yield were statistically significant in both sowing seasons. Close positive associations were obtained between hay a

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01101.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe determination of the leaf area index of sugar beet canopies by using direct measurement techniques is very laborious. Indirect measurement techniques based on the theory of gap fractions offer a non‐destructive and rapid determination of the leaf area index. In this study the performance of the LAI‐2000 instrument from LI‐COR1 which measures the gap fraction at five zenith angle classes with an upward looking sensor was compared to a direct determination.A thinning test and two measurement series in sugar beet with different population densities and varied nitrogen application were conducted in 1992 and 1993 at the site of Göttingen. The direct determination of leaf area index was based on a destructive sampling of leaves and measurements with a Delta‐T2 image analysis system (DIAS).The results of the thinning test and the measurement series in 1992 did not indicate a significant difference between the LAI‐2000 and the direct determination. With correlation coefficients of 0.98 and 0.95 respectively, the relation between the two techniques was very close. The measurement series of 1993 showed a worse correspondence. In general the values of the LAI‐2000 measurements tended to be a bit lower than those of the direct determination. The leaf area index of sugar beet can be determined with sufficient accuracy using the LAI‐2000 instrument if light conditions are favourable and if the measurement procedure is ada

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01102.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe water sensitivity of soybeans was determined on a day‐to‐day basis from the onset of flowering to physiological maturity by correlating daily leaf water potential values of 50 different soil water regimes with corresponding grain, vegetative and biomass yields. Days, and consecutive days forming periods, during which significant negative correlations were obtained were regarded as water sensitive periods during the reproductive growth phase of the soybean crop.Water deficits during flowering significantly inhibited vegetative and biomass production but inhibited grain yields only when occurring during early flowering. During pod elongation and seed development the sensitivity of the soybean plant to water stress was present but diminished in time with regard to vegetative and biomass yields. The effect on grain yields was restricted to pod elongation and to later seed development stages. Water stress affected grain yields to a far greater extent than vegetative growth during seed filling and physiological matur

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01103.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe relations between the extent of injuries in seedlings caused by a few day‐long exposures to chill (5°C) and the leakage of K+, Mg2+and Ca2+ions from the leaves as well as the electric potential in seven maize hybrids, were investigated. The permeability of cells to ions was defined based on their absolute concentration in a water diffusate (Ct) and concentration expressed in relation to the total ion content in the leaves (IL index).At lowered temperature the hybrids of higher resistance to chilling temperature were characterized by a lower value of the IL index for K+and Mg2+ions than the chill‐sensitive hybrids. On the other hand, absolute concentration of the ions (Ct) Mg2+and Ca2+leaking from the leaves before chill exposure of the seedlings was positively and highly correlated with the extent of injuries in hybrids caused by 4 day‐long exposures to chill. This observation is evidence that the chill injuries were predetermined through increased cell permeability to the mentioned ions at room temperature.Changes in the electric potential of leaves in conditions of lowered temperature preceded the injuries of leaves, which became apparent after a longer period of exposure to chill. Thus, as the leakage of Mg2+and Ca2+ions occurs, changes in the electric potential may supply early information about the predisposition of the particular maize hybrids to chilling injuries. Leakage measurements of Mg2+and Ca2+ions from the leaves at room temperature may find application in the selection of chill‐tolerant maize g

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01104.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Books Reviewed in this Article:Kindl, H., Biochemie der Pflanzen.Bajaj, Y. P. S. (ed.), Biotechnology in Agriculture and Forestry. Vol. 26. Medicinal and Aromatic Plants VI.Singh, K. B. and M. C. Saxena (eds.), Breeding for Stress Tolerance in Cool‐Season Food Legumes.Franke, G. (Hrsg.). Nutzpflanzen der Tropen und Subtropen. Band 2: Spezieller Pflanzenbau‐Getreide, Obst, Faserpflanzen.Band 3: Spezieller Pflanzenbau‐Genußmittel liefernde Pflanzen, Kautschuk liefernde Pflan‐zen, Gummi liefernde Pflanzen, Öl und Fett liefernde Pflanzen, Knollenpflanzen, Zucker liefernde

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01105.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1995.tb01106.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY