Journal of Agronomy

Published by Asian Network for Scientific Information
Online ISSN: 1812-5417
Publications
Article
A soil-zinc calibration test study based on 0.1 N HCl extractable zinc and Cation Exchange Capacity (CEC) was carried out with upland soils of Northern Nigeria using maize ( Zea mays L. moench) as a test crop. Treatments consisted of (I) no zinc and (ii) 10 mg kg<sup>-1</sup> Zn (greenhouse) and five levels of Zn as ZnSO<sub>4</sub>. 7 H<sub>2</sub>O (field) replicated 3 and 6 times in a randomized complete block design respectively. Plant zinc concentration increased with levels of applied Zn. Higher zinc concentrations were observed in plants that received Zn application. Extractable Zn concentration increased with an increase in CEC. A positive correlation was also observed between extractable Zn and pH. HCl extractable-Zn correlated positively and significantly with Zn uptake in the first and second crops (r = +0.735** and +0.575**), respectively. The amount of Zn extracted by 0.5 N HCl was also significantly correlated with CEC. The amount of Zn extracted by 0.1 N HCl was significantly correlated with the Zn uptake by the first and second crop. The regression equations obtained from this study indicated that the distribution of ions in the exchange site of soils should be considered in estimating plant Zn requirements in soils of the northern Nigeria. However available information on the soil CEC can be used to estimate or predict the Zn concentration of the plant tissue. Critical limits may not be required in estimating or interpreting plant Zn fertilization, as regression equations are more reliable and not empirical.
 
Article
Two six row barley cultivars ( Hordeum vulgare L.): Acsad 1230 and Arig 8, were grown under three salt treatments: Control, 70 and 140 mM of NaCl. Physiological related traits were assessed using mature kernels including 1000 kernal weight (TKW), soluble and total proteins, soluble and bounded phenols and Na<SUP>+</SUP> and Cl<SUP>-</SUP> content per kernel. Responses to salt tolerance were different for both cultivars. Results suggested that Acsad 1230 was more tolerant to salt treatment than Arig 8. Greater TKW and increased accumulation of soluble and total proteins as well as soluble and bound phenols were noted in kernels of Acsad 1230 along with high ions concentration of Na<SUP>+</SUP> and Cl<SUP>-</SUP>. The amount of total protein and phenol components were found stable in Acsad 1230 whereas these components decreased significantly in Arig 8. Soluble proteins increased significantly in Acsad 1230 and were reduced in Arig 8. The higher level of soluble proteins in Acsad 1230 was associated with increased ions concentration of Na<SUP>+</SUP> and Cl<SUP>-</SUP>. This investigation suggested that total and soluble proteins as well as phenol components along with Na<SUP>+</SUP> and Cl<SUP>-</SUP> concentrations may have a different control on the expression of TKW and indicates a different salt tolerance path expressed in both barley cultivars.
 
Article
Phenolic compounds and peroxidase activity in both leaves and roots were used to assess salt tolerance in Acsad 1230 and Arig 8 barley cultivars originated from Lybia and Morocco, respectively. This assessment was carried out at Z2.1 and Z4.5 of Zadock’s scale using 70 and 140 mM NaCl treatments. Rates of soluble phenolic compounds and its various constituents were carried out using HPLC. Results indicated that Acsad 1230 is less sensitive to salt stress than Arig 8. Increased accumulation of soluble phenolic compounds and higher peroxidase activity were observed in the Acsad 1230 treated with 140 mM of NaCl. Phenolic compounds increased by 30% while peroxidase activity increase ranged from 50 and 239% at Z2.1 and Z4.5, respectively in Acsad 1230. Phenolic compounds were not affected by greater salt treatment, whereas an increase of 159% of peroxidase activity was observed in Arig 8 at Z4.5 growth stage only. Results of HPLC showed significant accumulation and modification of the composition of derived benzoic acid, several ferulic, apigenin and luteolin derivatives in extracts from leaves for both cultivars under salt stress. Extracts from roots of both cultivars showed that the profile of phenolics is characterized by an accumulation of benzoic acid, p-coumaric acid derivatives and other non identified chemical compounds. These results suggest that genetic variability for salt tolerance could be associated with phenolic compounds and peroxidase activity. The magnitude of expression of these compounds may be considered as valuable tool to select for salt stress.
 
Article
Studies conducted under controlled laboratory conditions using <sup>14</sup>C showed a reduction in the rate of decomposition of plant residues with increased chemical complexity of the material; glucose being the most rapidly decomposed and least transformed into humic compounds. Lignin carbon was the most recalcitrant, but up to 50% was transformed into stable humus fractions. Rate and extent of immobilization and remineralization of N decreased with increased complexity of the plant residues/components; maximum being observed for glucose and minimum for lignins. Immobilization and remineralization turnover of N was used to determine dynamics of microbial biomass as well as to test assumptions used for its quantification with chloroform fumigation method. Chloroform fumigation was found to cause a substantial increase in the extractability and mineralization of non-biomass N. Quality of plant residues had a significant bearing on mineralization of N and its interaction with native soil N. Residues with narrow C/N ratio and high content of labile C had a positive effect on release of N from soil organic matter and its availability to crop plants. A substantial and real added nitrogen interaction was observed following application of fertilizer N (more for NH<sub>4</sub> than NO<sub>3</sub>) and leguminous plant residues. In plant experiments, the interaction was exhibited by a substantial increase in root biomass especially under salinity stress. Higher amounts of N were released from leguminous plant residues in the presence of NH<sub>4</sub> than NO<sub>3</sub>. Residues from cereal crops like rice and wheat had a negative effect on the plant availability of N from soil organic matter rather than from applied fertilizer. Studies under field conditions compared leguminous and non-leguminous crops for biomass accumulation and grain yield. When used as a green manuring crop, maize had an effect similar to recommended dose of fertilizer. Green manuring of cereal crop residues like wheat, avena and barley also had a positive effect on yield of wheat.
 
Article
This study was conducted to determine the performance of new improved banana cv. FHIA 17 and FHIA 23 ( Musa AAAA hybrids) in the Eastern zone of Tanzania compared to popular local cooking banana cv. Bukoba, Uganda, Embwailuma, Malindi and Mshale and dessert banana cv. Kisukari, Mtwike and Jamaica. Results showed that cv. FHIA 23 and FHIA 17 were more (p<0.05) resistant to black sigatoka disease with infection index (II) of 16.0 and 18.7% compared to local banana cv. Jamaica, Uganda, Bukoba, Mshale, Mtwike, Embwailuma and Malindi with II of 23.3, 23.5, 24.4, 24.5, 27.1, 30.5 and 39.7%, respectively. Moreover, cv. FHIA 17 and FHIA 23 were earlier (p<0.05) maturing with bunches harvested at 360 and 375 days from the date of planting compared to cv. Jamaica, Malindi and Bukoba harvested at 405, 407 and 411 days, respectively. Conversely, the improved cultivars were later maturing than cv. Embwailuma, Uganda and Mshale harvested at 330, 334 and 345 days, respectively. Cultivars FHIA 17 produced bigger (p<0.05) bunch weighing 36.5 kg than all local cultivars while cv. FHIA 23 produced higher bunch yield of 25.0 kg than cv. Kisukari, Uganda, Embwailuma, Mshale and Jamaica with bunch weights of 13.7, 15.6, 16.1, 16.6 and 16.8 kg, respectively. On the contrary, cv. FHIA 23 produced as big (p<0.05) bunch as cv. Malindi with bunch weighing 22.9 kg, but smaller than that of cv. Mtwike of 31.3 kg. The dissemination of these cultivars to farmers in the Eastern zone of the country is highly recommended though further studies are required to determine their suitability for dessert and matoke consumption as perceived by consumers in this zone and urban markets.
 
Article
A suitable combination of Azolla and urea-N was investigated for cultivation of rice (cv. BRRI Dhan 29). For this purpose an attempt was made to apply 30, 40, 50, 60 and 70% of the recommended doses of urea in 2 or 3 splits along with incorporation of one layer of Azolla grown from 0.2 kg m<SUP>-2</SUP> inoculum. Two separate treatments of applying 100% of the recommended dose of urea in 3-splits (without Azolla) and no application of N at all from either urea or Azolla were included. Azolla covered the surface area in 13 days after inoculation at 7 DAT and reached the maximum growth in 19 days producing 14.0 to 18.3 t ha<SUP>-1</SUP> fresh biomass containing 20.7 to 26.4 kg N ha<SUP>-1</SUP>. Incorporation of one layer of Azolla at 30 DAT plus application of 50, 60 and 70 kg N ha<SUP>-1</SUP> in 3 splits constituted the application of 72.7, 81.6 and 91.1 kg N ha<SUP>-1</SUP> that produced 5.58, 6.00 and 6.02 t ha<SUP>-1</SUP> grain yields which were statistically similar to each other but the latter two were statistically superior to the grain yield of 5.40 t ha<SUP>-1</SUP> produced by conventional recommended practice. Total uptake of N, P and S by the rice plants (grain+straw) were increased significantly due to incorporation of Azolla. Incorporation of one layer of Azolla plus application of 60% of urea-N appeared as the best combination in this study.
 
Article
An experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh from July to December, 2001 to study the performance of BRRI Dhan 32 in SRI and conventional methods and their technology mixes. The experiment was laid out in a split-plot design with three replications. The treatments used in the experiment consisted of (A) two planting methods viz., i) SRI planting method and ii) conventional planting method, (B) two types root placement e.g., i) J shape and ii) L shape and (C) three sources of fertilization viz., i) chemical fertilizer (N-60, P<SUB>2</SUB>O<SUB>5</SUB>-40, K<SUB>2</SUB>O-40, S-10, Zn-5 kg ha <SUP> -1 </SUP> , respectively) ii) organic fertilizer (cowdung, 10 t ha <SUP> -1 </SUP> ) and iii) 50% chemical fertilizer + 50% organic fertilizer. Grain and straw yields were the highest (5.6 and 5.98 t ha <SUP> -1 </SUP> , respectively) in SRI planting method. The highest grain yield of SRI planting method was mostly the outcome of higher total number of tillers hill <SUP> -1 </SUP> , highest panicle length and highest number of grains panicle. Conventional planting method produced the lowest grain and straw yields (3.65 and 4.29 t ha <SUP> -1 </SUP> , respectively). Among root placement methods L shape root placement found to be better and produced higher grain yield (4.97 t ha <SUP> -1 </SUP> ). Fertilization with 50% chemical fertilizer + 50% organic fertilizer performed the best regarding both grain and straw yields. The highest grain yield (5.04 t ha <SUP> -1 </SUP> ) and straw yield (5.67 t ha <SUP> -1 </SUP> ) were produced when 50% chemical + 50% organic were applied while the lowest ones were recorded in chemical fertilizer.
 
Article
The experiment was carried out at the field laboratory of Bangladesh Institute of Nuclear Agriculture, Mymensingh, during amon season (July to October, 2001) to study the effects of different tillage practices on growth, yield and yield contributing characters of BRRI Dhan-33. The crop was grown under supplemented irrigation condition. The soil was calcarious grey belonging to Sonatola series of old Brahmaputra flood plain. The treatment of this study comprised of power tiller with 1, 2, 3 and 4 passes at 7 and 15 cm depth and 4 passes with country plough at normal depth. The 4 passes at 15 cm deep ploughing by power tiller showed the highest yield of grain (4.95 t ha<SUP>-1</SUP>) and straw (5.89 t ha<SUP>-1</SUP>) which was associated with higher leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR), total dry matter (TDM), leaf numbers/hill, plant height, number of total and effective tillers, panicle length, number of filled grains/spikelets/panicle and with lower number of non-bearing tillers/hill and sterile spikelets/panicle. The lowest values of all parameters were found in 1 pass with power tiller at both 7.5 and 15 cm depth. Though 4 passes with country plough at normal depth and 3 passes with power tiller at 15 cm depth showed statistically identical results of 4 passes with power tiller at 15 cm depth in respect of yield performance, this treatment (4 passes with power tiller at 15 cm depth) gave the highest yield practically.
 
Article
In order to study effects of wastewater with two kind of fertilizers (manure and chemical fertilizer) on grain yield and yield components in corn (KoSc 704) a field experimental was conducted at the university of Zabol in Iran during 2007 growing season. The experiment was conducted as split block design with three replications. The treatments were comprised of two levels of irrigation water (W<SUB>1</SUB> = well water and W<SUB>2 </SUB>= wasetewater) in main plot and five levels of fertilizer (F<SUB>1 </SUB>= control, F<SUB>2 </SUB>= manure: 30 ton ha<SUP>–</SUP><SUP>1</SUP>, F<SUB>3 </SUB>= manure: 15 ton ha<SUP>–</SUP><SUP>1</SUP>, F<SUB>4</SUB> = NPK: 350, 200 and 100 kg ha<SUP>–</SUP><SUP>1</SUP> and F<SUB>5</SUB> = NPK: 175, 100 and 50 kg ha<SUP>–</SUP><SUP>1</SUP>) in sub plot. Results showed irrigation with wastewater significantly increased grain yield of corn than usual water. Also, wastewater had positive significantly influence on grain yield and all yield components, but the most effective of wastewater on yield components was on the 1000-seed weight. Among the fertilizer, F<SUB>4</SUB> in all situations had the most effective on the grain yield and yield components and increased them.
 
Article
Field experiments were conducted at the Teaching and Research Farm of the Department of Crop Science, Adamawa State University, Mubi in 2007 and 2008 cropping seasons with the aim of assessing the effect of spacing and NPK fertilizer on the yield and yield components of okra ( Abelmoschus esculentus L.). Treatments consisted of four spacing (60x30 cm, 90x30 cm, 60x60 cm and 75x45 cm) and four NPK rates (0, 100, 150 and 200 kg ha<SUP>-1</SUP>) in a split plot design with plant spacing allocated to main plots and fertilizer in sub plots. The treatments were replicated three times to give a total of forty eight sub plots. Parameter such as number of fruits per plant, length of fruit, fresh weight of fruits per hectare and dry weight of fruits per hectare were measured. Data collected were subjected to Analysis of Variance (ANOVA) as described by Gomez and Gomez and treatment means were separated using Duncans Multiple Range Test (DMRT). Results showed that yield and yield components such as number of fruits per plant and length of fruit were not significantly affected by spacing in 2007. However, significant difference was obtained at 52 DAS in 2008. Number of fruits per plant and length of fruits were significantly affected by fertilizer levels. In 2008, there was significant interaction in respect to fresh weight of fruits per hectare. Also, there was significant interaction between spacing and fertilizer in respect to dry weight of fruits per hectare in 2007 and 2008. The results indicated that spacing of 90x30 cm and application of 150 kg ha<SUP>-1</SUP> (22.5 kgN, 22.5 kg P<SUB>2</SUB>O<SUB>5</SUB> and 22.5 kg K<SUB>2</SUB>O<SUB>5</SUB>) of NPK gave the highest yield of okra in Mubi.
 
Article
The effects of various row spacing on the yield and yield components of okra with groundnut were conducted at the training and research farm of the Federal University of Technology, Owerri. Yield and yield components of the crops in the various row spacing, monetary value of fresh okra fruits and dry groundnut pods were determined. The efficacy of the inter-cropping on weed suppression was evaluated. Okra plant height showed that R<SUB>30</SUB> (30x50 cm) was highly significant than the other treatments in the experiment. Treatment R<SUB>90 </SUB>(90x50 cm) and R<SUB>75 </SUB>(75x50 cm) had significantly higher number of branches (p=>0.05). The results show that productive nodes increased with increasing row spacing, R<SUB>90</SUB> had 77%, while R<SUB>75</SUB> and R<SUB>60</SUB> had 69 and 66%, respectively. This actually affected crop yield. However, R<SUB>75</SUB>, R<SUB>60</SUB> and R<SUB>90 </SUB>had the highest fruit yield and were significantly higher than R<SUB>30</SUB> and R<SUB>45</SUB> at p>0.05. Conversely, R<SUB>30</SUB> and R<SUB>45 </SUB>suppressed weeds better but had low fruit yield compared to R<SUB>75</SUB>, R<SUB>60</SUB> and R<SUB>9d </SUB>. The yield of groundnut showed that R<SUB>60</SUB> and R<SUB>75 </SUB>had the highest yield although it was not significantly different from R<SUB>90</SUB>. Treatment R<SUB>75</SUB> had the highest monetary yield of N 132,200.00 ha<sup>-1</SUP> than the other treatments compared.
 
Article
The present research has studied the effects of NaCl and temperature on germination and emergence of okra. Studies were carried out with seeds of a local okra variety (Marsaouia) subjected to 0 and 100 mM NaCl, performed in the dark at 10, 15, 25, 35 and 40°C at germination stage and by 12 h light at emergence stage. The cumulative germination percentage, the cumulative emergence percentage, starch content, the reducing sugars levels, total amylase activity, sodium and potassium accumulation were quantified in germinated seeds at 15°C, 25 and 35°C. Temperature presented a significant effect on salt sensitivity of this species at germination and emergence stages. Germination of okra seeds was completely inhibited at 10 and 40°C. The best germination and emergence temperature was recorded at 25°C. The adverse effect of salt was more pronounced at low and high temperature. During the salt stress treatment, the level of starch reserves was higher at 25°C and lower at 15 and 35°C, an increase in reducing sugars content in cotyledons was observed. The activity of total amylase was most intensive at lower temperature in control seeds and at higher temperature in salt treated seeds. The sodium concentration on germinated seeds increased significantly at 15 and 35°C, but potassium amount did not change regularly within thermal and salt stress interaction.
 
Article
Correlation, stepwise multiple regression and path coefficient analysis were used to determine the relationships, direct and indirect effects of agronomic and reproductive characters on pod and seed yield. Eighteen F<SUB>2</SUB> generation obtained from hybridization of West African okra were planted for evaluation in a randomized complete block design with two replications in a single locations. Data were collected on agronomic and reproductive characters. Significant differences were observed among the segregating population for pods/branch, seeds/pod, inter node distance, seeds/ridge branch length, height at flower bud initiation and height at flowering. A positive correlation (p<0.05) was recorded for number of pods/plant and seed weight, height at maturity, ridges/pod and seeds/ridge. The seed weight recorded a positive correlation coefficient with edible pod width, seeds/ridge and pods/plant. The stepwise multiple regression analysis identified two characters (height at maturity and number of pods/plant) to have accounted for 31% of variation observed in seed weight. Mature pod length was responsible for 39% of variability in seed weight. The numbers of ridges per pod and plant height at maturity were responsible for 25% of variation due to regression in pod yield. The path analysis identified plant height at maturity, ridges/pod, pods/plant, mature pod length and seed/ridge as selection indicators for pod and seed yield improvement in West African Okra.
 
Article
In the tropical and subtropical regions of the world, okra pods are consumed fresh. The introduction of pure lines and hybrids with improved length and width into the cropping system, necessitate studies on the combining ability and genetic components for the length and width of pods. Seven parents and 21 F<SUB>1</SUB> generations were planted for evaluation in a randomized complete block design with two replications. The results indicated that the means squares due to GCA and SCA for length and width of pods were significant. The estimated variance due to SCA was greater than GCA variance for length and width of pods at edible stage and vice versa for length and width of pod at maturity. The study identified Parents 7, 6, 4 and 5 as best combiners for edible pod length and width, mature pod length and width. Component analysis indicated that the dominant genetic action predominate other genetic effects in the inheritance of length and width of pods. The dominance components (H<SUB>1</SUB> and H<SUB>2</SUB>) were found to be greater than the additive gene effects (D). The ratio VH/D revealed overdominance loci for characters evaluated. The estimate F were positive (edible pod length and mature pod length) and negative (edible pod width and mature pod width). The proportion V4(DH<SUB>1</SUB>+F)/ V4(DH<SUB>1</SUB>-F) was unity. While the ratio 4H<SUB>2</SUB>/4H<SUB>1</SUB> = 0.25 for all characters evaluated. The non-additive genetic effects accounted for a low to moderate heritability estimate in narrow sense recorded in the study. Both Oligogenic and polygenic action were found in the study. The study indicated an empirical superiority of the possibilities of evolving pure lines and hybrid okra with improved length and width into the cropping system.
 
Article
A two-year study was conducted to determine the effects of some Plant Growth Regulators (PGRs) and nutrient complexes on biomass weight, seed yield and yield components of both main and double cropped soybean grown under hot and dry conditions. The experimental design was Randomized Complete Block with four replications. Atonik, Biomaster, GA<sub>3</sub>, Kinetic, Maxicrop, Cytozyme and Megahix were used as plant growth regulators. The soybean cultivar was A3935 (MG III). Application of PGRs had different effects on biomass weight, seed yield and yield components of both main and double cropped soybean. The highest biomass weight (1054.0 g<sup>-2</sup>) was obtained from Maxicrop and the lowest (891.8 g<sup>-2</sup>) was obtained from Megahix applied plots in main cropped soybean. Under double crop conditions, however, the highest biomass weight (857.6 g<sup>-2</sup>) was obtained from Cytozyme and the lowest (780.0 g<sup>-2</sup>) was obtained from control. Application of PGRs increased the seed yield and yield components of soybean under both main and double cropped conditions. The highest seed yield was obtained from Atonik with 3876 kg ha<sup>-1</sup> for main crop soybean and 47 kg ha<sup>-1</sup> for double cropped soybean. The lowest seed yields were obtained from no chemical applied control plots of both main and double cropped soybean with 3386 and 838 kg ha<sup>-1</sup>, respectively. Application of Atonik, Cytozyme and Maxicrop could be suggested to alleviate heat stress and increase seed yield of both main and double cropped soybean grown under hot and dry conditions.
 
Article
The objective of the two-year study was to determine the effect of N fertilizer placement and timing on wheat plant biomass accumulation and distribution in the vegetative and reproductive plant parts of spring wheat ( Triticum aestivum L. Cv. Spectrum). Spring wheat was grown under rainfed conditions with four treatments. Results show that there was a significant bulge of aboveground plant biomass in plots fertilized with N across all phenological stages of spring wheat in both years of the study. Results indicate that the raw and dry plant biomass sampled from 0.25 m<sup>2</sup> area of each plot at tillering stage was 25.5-90.3 and 6.2-11.3 g higher, respectively for the first season compared with the second season of the study. Single basal application of N fertilizer (N<sub>90</sub>P<sub>90</sub>K<sub>60</sub>) before planting (T<sub>2</sub>) had comparatively higher aboveground plant biomass at tillering stage in comparison with other treatments in the first year of study. Combined results for both years of the study clearly show that at early stages of growth and development of wheat plants, single basal applications of N fertilizer (N<sub>90</sub>P<sub>90</sub>K<sub>60</sub>) before planting (T<sub>2</sub>) significantly amplify biomass accumulations (109.7 g raw mass, 19.8 g dry mass) compared with split applications. This is attributed to the relatively rapid root biomass increase by a temporarily elevated availability of N in this treatment, which triggered a bulge in the aboveground biomass (trigger effect). It would appear therefore that N fertilizer applied before planting has a very significant influence on the subsequent plant biomass growth of the wheat crop. In second year of the study treatments effect did not have a distinct pattern at tillering stage. Results show that raw and dry biomass across all treatments increased by about 71-85% (335.1-576.2 g) and 76.9-91.7% (76.1-155.4 g) respectively at heading phenological stage. However, the largest raw and dry substance accumulations were observed in T<sub>3</sub> (677.5 g raw mass, 122.5 g dry mass) and T<sub>4</sub> (681.5 g and 175.3 g) raw and dry mass respectively, in the first season of study. This pattern was maintained in all the subsequent phenological stages. Research results elsewhere reported enhanced translocation of plant biomass materials from both leaves and stems. However, this study observed a clear pattern of translocation of biomass materials from aging leaves and not stems. In fact, the study distinctively reported net plant biomass increase in stems (28.0-78.2 g raw, 2.2-22 g dry) in the post anthesis period. In the first and second years of study, peak plant biomass bulge in the reproductive organs for grain formation and its maximum depletion (by translocation to spikes for grain formation) in leaves were observed at milky ripe stage. �Biomass �accumulations �of �130.2-232.5 �g (raw mass) and 84.8-102.6 g (dry mass) in wheat spikes and biomass depletions of 30.4-83.7 g (raw mass) and 0.3-22.9 g (dry mass) in leaves were recorded in the study at milky ripe stage in �the first season and 228.3-292.4 �g �(raw mass) and 102.4-128.2 g (dry mass) in the second season.
 
Article
Immature embryos of maize ( Zea mays L.) were aseptically excised and cultured on Murashige and Skoog (MS) media containing four different Abscisic Acid (ABA) concentrations (Control 0.0, 0.1, 1.0 and 10.0 mg L<SUP>-1</SUP>). The ABA effects on the germination of cultured embryos, number of leaves per plant, plant height, percentage of dry matter and protein expression for plants regenerated from ABA treated embryos were studied. Effects of ABA on germinating embryos were found to be associated with time; it reduced the germination during the first week. ABA affected the percentage of dry matter significantly.
 
Article
Field experiments were conducted to detect the influence of varying N rates and weed control methods and 2, 4-D ester which was applied at two growth stages on yield, yield components, and phenological traits of barley. Among N rates significantly highest grain yield (2112.5 kg ha‾<sup>1</sup>) was obtained under 120 kg N ha‾<sup>1</sup> owing to the highest numbers of spikes m‾<sup>2</sup> (537.5), spike length (7.5 cm), and number of grains per spike (56.3) though it had the lowest 1000 seed weight. Hand weeding provided the better weed control method and this was reflected in higher barley yield. Application of 2,4-D at stage 22-28 also produced significantly higher grain yield as compared to unsprayed control. The only weed control treatments, that reduced barley yield when 2,4-D was applied at mid boot stage.
 
Article
Laboratory trials were carried out to investigate the effect of Accel on the postharvest vase life of Easter lily cut flowers. Flowering stems of Easter lily cultivar `St. Joseph` were purchased from a commercial farm in Gaborone, Botswana. Accel at 25, 50, or 75 mg L<sup>-1</sup> significantly delayed postharvest catastrophic leaf yellowing of Easter lily, flower senescence and abscission, improved flower water uptake, increased flower vase life and retarded leaf chlorophyll and nitrogen degradation. The results indicated that Accel can be used as a commercial cut flower preservative solution for Easter lily and other cut flowers with postharvest leaf yellowing as a problem.
 
Article
Enset ( Ensete ventricosum ) plants grown in the middle and low altitudes are experiencing different degrees and length of summer drought every year. Information is lacking on plant responses to drought stress, underlying mechanisms of response and effect of drought on the growth and yield of enset. The effect of induced drought/irrigation on growth parameters, gas exchange and biomass accumulation and partitioning of enset clones was studied in the field at Guebre, Southern Ethiopia. One year old plants of two enset clones were either irrigated or droughted by with holding water for 90 days. Prolonged drought markedly and significantly reduced growth parameters of both enset clones. Drought stress significantly reduced specific leaf area and net assimilation rate and these reductions showed significant positive correlations with relative growth rate. Stomatal conductance, net photosynthesis rate and transpiration declined considerably after 60 and 90 days of drought. Despite the reduction in stomatal conductance, leaf water status showed little change. Quantum yield of PSII photochemistry showed a reversible diurnal depression which was accompanied by a marked increase in non-photochemical fluorescence quenching. Proportionally, droughted plants accumulated significantly more dry matter to belowground parts and drought appeared to increase harvest index of the corm. The enset clone Ameratye produced a significantly higher total dry matter than Yesherakinkye both under drought and/or irrigation. Both stomatal and non-stomatal factors might have contributed for the observed decline in carbon dioxide uptake rates of droughted plants. Present findings indicated that seasonal dry periods could considerably alter enset physiology and reduce growth and yield. Moreover, harvest index of the corm can be used as a selection criterion in screening enset clones suitable for drought prone areas.
 
Article
This study was conducted to determine the effect of saline water, potassium and gypsum application on accumulation of some mineral nutrients in plant and grain protein content in wheat ( Triticum aestivium L. cv. Tajan ), during 2002-2003 growing season. For this purpose, five levels of electrical conductivity of irrigation water namely 0.8 (well water), 3, 6, 9 and 12 dS m<SUP>-1</SUP> (mixture of Caspian Seawater and well water), four levels of potassium (0, 0.4, 0.8 and 1.2 g K<SUB>2</SUB>O pot<SUP>-1</SUP>) and three levels of gypsum (0, 1.75 and 3.50 g pot<SUP>-1</SUP>) were applied in a Completely Randomized Factorial Design in pot experiment. The results showed that with increasing salinity of irrigation water, amount of sodium accumulation in leaves, roots and grain protein content increased, potassium content and K<SUP>+</SUP>/Na<SUP>+</SUP> in roots and leaves decreased, significantly (p<0.01). With increasing salinity of irrigation water, the amount of sodium in roots, leaves and grain protein content increased, but K<SUP>+</SUP> and K<SUP>+</SUP>/Na<SUP>+</SUP> decreased in leaves and roots. Potassium application increased the amount of potassium and K<SUP>+</SUP>/Na<SUP>+</SUP> in roots and leaves, and gypsum application increased the calcium accumulation and reduced the Na<SUP>+</SUP>/Ca<SUP>2+</SUP>. Grain protein content, K<SUP>+</SUP> and K<SUP>+</SUP>/Na<SUP>+</SUP> increased with interactive effects of potassium and salinity. Simultaneous application of potassium and gypsum increased the accumulation of K<SUP>+</SUP> and Ca<SUP>2+</SUP> in leaves and reduced Na<SUP>+</SUP> in roots. The amount of grain protein increased in lower potassium treatments, but decreased in higher amounts of K<SUP>+</SUP>.
 
Article
In this research we examined the effect of 0.25, 0.5 and 1 mM Pb(No<sub>3</sub>)<sub>2</sub> with and without 0.5 mM EDTA in pH 4 and 6 on the growth and Pb accumulation in the root and shoot of four day old seedlings of Zea mays at the controlled condition in the period of 72 h. At the end of treatment we determined the length and dry weight of the root and Pb content in the root and shoot of the seedlings. In the second test we considered specially the effect of 0.25, 0.5, 1, 1.5 and 2 mM EDTA with 0.5 mM Pb(No<sub>3</sub>)<sub>2</sub> on the seedlings of Zea mays at the same condition. After 72 h we determined the amount of Pb by Atomic Absorption and EDTA by HPLC and water content of shoot. We concluded (from the results of two tests) that: Pb absorption has grown up parallel to its concentration in growth solution and has inhibited root growth and biomass significantly. Pb taking up in pH 4 was higher than pH 6 and EDTA enhanced Pb accumulation in shoot. But water content of shoot decreased at the concentrations more than 0.5 mM EDTA in growth solution. Maximum level of EDTA accumulated in shoot of plants was at the concentration of 1.5 mM EDTA in the culture, but the highest level of Pb and the least water loss of shoot was at the equimolar Pb and EDTA (0.5 mM Pb with 0.5 mM ETDA). It may concluded that EDTA is taken up by plants, accumulated in shoots in the form of Pb-EDTA or protonated form and enhanced Pb accumulation in shoots of seedlings. So it can be used for phytoextraction of Pb and other metals not only by accumulators but also by tolerant plants such as Zea mays . But if EDTA is used for supplying plant micronutrients, its concentration should be minimized and its damage to plants should be clearly considered.
 
Article
A filed research was carried out in the years of 2000, 001 and 003 in order to determine the effect of different irrigation regimes and water stress imposed at earlier growth stages on vegetative growth and dry matter accumulation of flue-cured tobacco plant ( Nicotiana tabacum L.). The field trials were conducted on the fields of Atatürk Soil and Water Resources Research Institute in Kirklareli. A randomised complete block design with three replications was applied and K-326 Virginia tobacco cultivar was used in the experiment. Three levels of irrigation water amount reduction (0, 0 and 60%) were applied at each development stage. Single irrigation was applied during the second part of vegetative stage, while subsequent water applications were done at 50 and 70% depletion level during the yield formation and ripening stages, respectively. Results of this 3-year study show that all vegetative parameters as well as dry matter accumulation processes were significantly affected by water shortage in the soil profile during the earlier growth stages. Water stress in various severity occurring during the rapid vegetative growth and yield formation periods reduced plant height, as well as influenced leaf number and leaf area development. Short-duration water deficits during the rapid vegetative growth period caused 26, 7 and 0; 10, 8 and 9 and 1.3, 8.5 and 9% loss of final dry matter weight of the plants, respectively for the three stress levels in 2000, 001 and 003. Losses in the ranges of 40-70, 5-17 and 2-25% could be expected as a result of water stress at three different levels during the yield formation period. Much greater 71, 82 and 71% losses were recorded as result of prolonged water stress during the periods of rapid growth and yield formation.
 
Article
In order to assess the role of root CEC on the accumulation of Calcium in roots or shoots, pot-culture experiments with wild grasses was carried out. The seven species of grasses used were Sporobolus diander (L.), Eleusine indica (L.) Gaertn., Heteropogon contortus (L.) P. Beauv. Ex Roem and Schult, Cynodon dactylon (L.) Pers., Panicum repens Jacq, Stenotaphrum dimidiatum (L.) Brongn. and Chloris barbeta Sw. These grasses were significantly different in their root cation exchange capacity (4.6 to 12.3 C mol (P<SUP>+</SUP>) kg<SUP>-1</SUP>; p<0.05) as well as in their average root biomass (10 to 121 g per plant; p<0.05)/shoot biomass (4 to 60 g per plant; p<0.05) while growing in same environments. Four treatments of calcium (0.20, 0.25, 0.30 and 0.37 g kg<SUP>-1</SUP> of soil) were given to all these species against a control; each treatment was given in four split doses with a gap of about 10 days in between. Calcium in the roots and shoots of these grasses was assessed at the end of the experimental cultures. Negative correlations were found between average Ca accumulations in plant tissues and root cation exchange capacity at all treatment levels. The correlation patterns between root cation exchange capacity and Ca in roots and that in shoots were quite distinct. Experiments of these kinds can reveal exact relationships between root characteristics and mineral accumulations in plants, which will have applications in agriculture involving mixed crops.
 
Article
Grevillea robusta seedlings were intercropped with maize ( Zea mays ) on a humid tropical Alfisol. Tree growth and nutrient concentration in tree leaves were monitored to assess the impact of competition between the young tree and maize. Intercropping maize and Grevillea significantly reduced the collar diameter and shoot biomass of Grevillea robusta; collar diameter by 32% and shoot dry weight by 39% four Months After Transplanting (MAT) and by 18.7 and 13.5%, respectively at 16 MAT. The lower values of percentage growth reduction at 16 MAT compared to 4 MAT indicates the capacity of the trees to make up for the lost growth with time. Concentrations of N and P in Grevillea leaves were lower (3.42 and 0.09%, respectively) in intercrop than in sole Grevillea (3.56 and 0.11%, respectively).
 
Article
Field studies were conducted at the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife, Nigeria, to compare the plant population estimates by physical counting and by using existing mathematical formula, on sole crop fields of tomato ( Lycopersicon esculentum (L.) Mil.), amaranth ( Amaranthus cruentus L.), cock`s comb ( Celosia argentea L.) and snake tomato ( Trichosanthes cucumerina L.). Each crop was established on a 5x10 m (50 m<SUP>2</SUP>) plot and sowing was done at one plant per stand. The planting spacing used were 50x50 cm, 20x20 cm, 20x20 cm and 1.0x1.0 m for L. esculentum , A. cruentus , C. argentea and T. cucumerina , respectively. Results showed that there was a significant difference between the estimate by physical counting and estimation by the existing mathematical formula. On the basis of the variation observed in the plant population estimation by physical counting and existing mathematical formula, a new formula was developed. The formula is flexible and can be used for direct estimation of plant population in any given four dimensional fields of sole crop. The optimization analysis of the farm field was also considered.
 
Article
A net greenhouse experiments were carried out to evaluate the effect of promalin on growth and development of kale. Promalin at 25, 50 and 75 mg L<SUP>-1</SUP> significantly increased total leaf chlorophyll content, chlorophyll a and b contents, the percentage of chlorophyll a and b to chlorophyll, total leaf area, plant height, leaf number per plant, leaf size (leaf length, leaf blade diameter, leaf blade length and petiole length), plant dry matter and fresh leaf yield. Promalin at 50 or 75 mg L<SUP>-1</SUP> increased stem and root dry matter accumulation and partitioning to the stem. Promalin at 25, 50 or 75 mg L<SUP>-1</SUP> decreased significantly the leaf water content and significantly increased vegetative, root growth and yield of kale plants. Promalin also induced the growth of a leaf petiole from the mid-rib leading to a leaflet from the leaf mid-rib. Promalin at 50 mg L<SUP>-1</SUP> has the potential to be used to improve the growth, development and yield of kale.
 
Article
A greenhouse study was conducted at the crop pavilion of the Department of Agronomy, Faculty of Agriculture, University of Ilorin, Nigeria to investigate the interactive effects of soil moisture content and fertilizer level on growth and achene (seed) yield of sunflower. Four irrigation amounts (900, 1800, 2700 and 3600 cm<sup>3</sup>, equivalent to 25, 50, 75 and 100% of field capacity) and four fertilizer levels (equivalent to 0, 30, 60 and 90 kg N ha<sup>-1</sup>) were evaluated in a factorial randomized complete block design in split-plot arrangements with four replications. Plant growth parameters of plant height and number of leaves per plant were significantly (p<0.01) reduced by low soil moisture contents, but were not appreciably affected by fertilizer application (p>0.05). However, yield components and seed yield were significantly (p<0.001) better with 75 and 100% soil moisture and 60 kg N ha<sup>-1</sup> fertilizer. Significant interactions of soil moisturexfertilizer level (p<0.01) showed that application of fertilizer has no significant effects at 25 and 50% soil moisture content, while it significantly increased yield components and seed yield at 100% soil moisture content. Results of simple linear regressions show that all yield components significantly (p<0.001) contributed to achene yield variation in sunflower, with the number of achenes per head being the best predictor (R<sup>2</sup> = 86.8%) of achene yield. Conclusively, results of this study showed that factorial combination of 60 kg N ha<sup>-1</sup> fertilizer level at 75% soil moisture content are optimum for profitable achene yield of sunflower in the study area.
 
Article
The mature grains of two Egyptian and six imported Triticum species were analyzed for protein patterns, total protein and amino acids content to characterize the variations between them. The data showed twenty two bands of total proteins with an obvious variation in the number and position of bands from one species to another. The highest numbers of proteins bands were recorded in T. paleocolchicum (18 bands) whereas, the lowest ones in T. durum (12 bands). The eight examined Triticum species share nine bands (6, 13, 16, 19, 20 and 21), while there were also some bands which characterize each species. The band (10) is characteristic for T. paleocolchicum and the band (12) for T. dicoccoides . Cladistic analysis support the delimitation of studied species in the two subgenera Triticum and Boeoticum. A high degree of similarity (94%) was observed between T. aestivum and T. spelta . Total protein of the grains varied from a minimum of 9.3% in T. aestivum to a maximum of 14.8% in T. dicoccoides . Most amino acids showed a significant variation between the examined Triticum species and all essential amino acids compared well with FAO/WHO reference pattern. The nutritional quality of proteins as measured by their essential amino acids chemical scores ranged from 14.29% for tyrosine in T. spelta grain protein to 239.29% for isoleucine in T. durum grain protein. Most essential amino acid of grain protein in T. aestivum and T. dicoccoides record higher values than the FAO/WHO (1990) recommended pattern. All the studied Triticum species had high content from the non-essential amino acids, particularly glutamic acid that had the greatest proportion ranging from 24.86 g/100 g protein in T. dicoccoides to 36.13 g/100 g protein in T. spelta . The six studied Triticum species imported from outside Egypt had pronounced total protein and amino acids content and consistent the most suitable condition for growing under Ismailia conditions.
 
Article
The study was carried out at three locations using six sorghum genotypes in Bomet district, Kenya during the long rains of the years 2001, 2002 and 2003. The objective was to determine the nutrient composition of six sorghum ( Sorghum bicolour (L) Moench) varieties across agro-ecological zones. The sorghum varieties selected at KARI-Lanet included E1291, Ikinyaruka, Lan-1, BJ28, E6518 and a local variety. The samples collected were analyzed for DM, OM, CP, NDF and ADF. There were significant differences (p< 0.001) in OM, CP, NDF and ADF at all locations. There were also significant differences (p< 0.001) in nutrient composition among the six varieties. Ikinyaruka had the highest OM across the locations. Mulot had the highest CP while Kapliyo gave the highest amount of ADF among all the varieties. E6518 and Ikinyaruka showed the highest OM, NDF and ADF and were lowest in CP, respectively. Mulot was the best location for all the varieties while BJ28 was the most stable variety with the highest CP and moderate amounts of fibre across all the three locations.
 
Article
In this study, the effects of different concentrations of Indol Butyric Acid (IBA) and growing media on root growth of kiwifruit cutting were investigated. Organic materials such as hazelnut husk compost, farmyard manure, peat and inorganic materials such as perlite and pumice were used as rooting medium, with 2000, 4000 and 6000 mg kg<sup>-1</sup> IBA concentration. The experiment was arranged in a completely randomized design with five media, four IBA doses with ten replicates under mist propagation in heated greenhouse conditions. After a growing period of 45 days, some root parameters were measured. Inorganic materials were found to be suitable based on the rooting ratio, dry matter weight and root size. While the IBA-2000 mg kg<sup>-1</sup> dose on rooting ratio and root dry weight was found to be sufficient, IBA-6000mg kg<sup>-1</sup> dose on rooting size was effective dose. Organic materials affected root length and root area. The best effect on these parameters was obtained from husk compost medium with IBA-6000 concentration and followed with peat medium with IBA-2000 concentration.
 
Article
Synergistic effect of W. calendulacea plant extract combined with Lamda cyhalothrin were demonstrated against red flour beetle T. castaneum in methanol extract. W. calendulacea plant extract offered synergistic action when used Lamda cyhalothrin . It was noted that plant extract indicates synergistic action from 1:1 to 1:5 ratio and above.
 
Article
Soil equilibrium can easily be disturbed by unsuitable agricultural practices especially in arid and semi-arid regions which are prone to organic matter losses. A comparative study was conducted to investigate the effects of cow manure, sewage sludge (25 and 100 mg ha<SUP>-1</SUP>) and chemical fertilizer (250 kg ha<SUP>-1</SUP> of ammonium phosphate and urea) application on Microbial Biomass C (MBC) and enzyme activities in a calcareous soil cropped to corn. Results illustrated that applications of sewage sludge and cow manure increased soil organic C, total N, MBC, L-Glutaminase, alkaline phosphatase, arylsulfatase, β-glucosidase activities and corn yield compared to control and chemical fertilizer treatments. An increasing trend was observed in all studied parameters, as rates of application increased. Manure-amended soils showed higher alkaline phosphatase, arylsulfatase and β-glucosidase activities than that of sewage sludge treatment. Results obtained by discriminant analysis indicated that rates of application were more effective to create discrimination among treatments. It was also understood that β-glucosidase activity was the most useful variable for discriminating among fertilizer types. This study showed that MBC and enzyme activities were significantly correlated with SOC. Significant correlations were also observed between enzyme activities and MBC.
 
Article
An investigation was made at farmers level of Kishoregonj and Manikganj, the two important jute growing areas of Bangladesh in order to enumerate the water management status in jute production in terms of farmers actual practices and their feeling of need about the same. Results revealed that average 64% farmers at Kishoregonj and 69% at Manikganj felt the necessity of irrigation, whereas 13 and 40% farmers at Kishoregonj and Manikganj actually practiced the same respectively. Similarly, 79 and 70% of farmers at Kishoregonj and Manikganj respectively felt the necessity of draining out the excess water from their jute field but 70 and 52% farmers actually practiced the same respectively. The difference between farmers feeling and actual practice on irrigation was wide while the difference between farmers feeling and actual practice on draining out the excess water was narrow which clearly showed the importance of drainage over irrigation in jute production at farmers level. But the statistical significant difference between feeling need and actual practice for improved water management are yet to prevalent over what farmers got from their forefathers.
 
Article
Tepary bean (TB), a drought tolerant bean variety has become popular among poor small-scale farmers in semi-arid Kenya, where it is predominantly intercropped with maize. Field experiments were conducted on effect of intercropping TB and maize on nitrogen fixation and crop yield in semi-arid Kenya over two cropping seasons. Experimental design was randomised complete block with eight treatments: TB sole crop not inoculated with Rhizobium (R3254) and without N fertilizer (N), TP sole crop not inoculated with R3254 with or without N, TB sole crop inoculated with R3254 without N, TB with maize intercrop not inoculated with R3254 with or without N and maize sole crop with or without N. Each treatment was replicated four times. Significant differences (P # 0.05) were observed in total plant dry weight in treatment R3254 at both 21 and 42 days after emergence (DAE). TB yields were significantly reduced in uninoculated intercrop. Inoculated TB treatments had significantly higher seed dry weights and yields ha G <sup>1</sup>. Intercropping TB and maize suppresses the yield of the former under semi-arid conditions. Inoculating TB with Rhizobium strain R3254 was infective, effective and significantly improved TB yields in sole and intercrop. Soil analysis after the two cropping seasons indicated enhancement of soil N in sole TB plots above pre-planting levels. Maize plots exhibited a decline in soil N. Total N concentration in plant tissues was significantly enhanced in treatment R3254. There was a marked increase in soil P in all treatment plots following amendment.
 
Article
Application of fertilizer N to soil or to the soil-plant system often leads to enhanced mineralization and plant availability of N. By using <sup>15</sup>N isotope methodology, it has been found that the extra N comes from soil organic matter as a result of interaction of the added N. This phenomenon is termed "priming" action or added nitrogen interaction (ANI) and may be apparent or real and positive or negative. Apparent ANI is supposedly caused by pool substitution, while real ANI results from changes in the processes that move N into or out of a given pool. Although ANI is generally positive, negative ANIs may arise from processes like net immobilization, denitrification and NO<sub>3</sub>- leaching. Occurrence of ANI has implications to the determination of fertilizer use efficiency as well as to the fate of fertilizer and soil N. Hence, an understanding of the occurrence of ANI and the mechanisms involved is necessary to devise strategies for improved fertilizer management practices.
 
Article
Studies were conducted in the Dominican Republic during two years on adult ‘Keitt’ mango ( Mangifera indica L.) fields to examine the long-term effect of chemical and organic fertilization programs on marketable fruit yield. The treatments were (a) 1.8 kg 15-15-15 (N-P-K)/tree, once a year (b) 1.1 kg 15-15-15/tree, twice a year (c) 1.4 kg 15-15-15/tree, once a year (d) 1.8 kg 15-15-15/tree, once a year, plus 13.6 kg compost/tree (e) 1.1 kg 15-15-15/tree, twice a year, plus 13.6 kg compost/tree and (f) 1.4 kg 15-15-15/tree, once a year, plus 13.6 kg compost/tree. The results indicate that the application of 1.8 kg 15-15-15/tree, once a year, plus 13.6 kg compost/tree and 1.3 kg 15-15-15/tree, twice a year, plus 13.6 kg compost/tree improved marketable fruit number during both harvest years. The addition of compost for two years increased fruit number by averages of 17 and 24% in comparison with the same treatments without compost.
 
Article
Kids weights recorded from eight indigenous goatherds raised under arid pastoral conditions were used to characterise kid`s growth curve. Among twelve tested non-linear models, Gompertz function permitted the best kids growth curve fitting by its convergence rapidity and estimation accuracy. Models iterative behaviour were tested by the iterations number, the Coefficient of Determination (CD) and the Residuals Means Squares (RMS). Convergence was reached after 9 iterations at a CD equal to 67%. Indigenous kids weighed 2.41 kg at birth and reached 16.18 kg in 8 months of age with a wide individual variation. Kid`s growth showed stagnation at the summer beginning, due to climate stress and forage scarcity. During the first 4 months of age, the daily weight gain reached 102 g/day as a maximum average and then, decreased to less than 25 g/day. About 80% of asymptotic weight was reached since the 4 months of kid`s age. Kid`s early separation from pastoral herds was recommended to reduce land degradation and to allow better reproduction performances. The indigenous kid`s growth process illustrates the adaptation of the population with the arid environment under natural harsh conditions. Small body size and low weights mean fewer requirements and may permit to reach rapidly the physiological maturity needed to start the reproduction process despite of the constraining arid conditions.
 
Article
The objectives of this study are to promote the growing of striga tolerant maize varieties in striga endemic locations of Northern Ghana. Three striga tolerant/resistant maize (STR) varieties, ACR 94 TZE Comp 5-W, ACR 97 TZL Comp 1-W and IWD STR C1, were grown in rotation and in intercropping with soybean, TGX 1442-2E, in 2003, 2004 and 2005 on farmers fields. Striga incidence was recorded as the number of striga plants at ten weeks after planting, visible effects due to striga, height of maize and maize grain yield. The results showed that the STR varieties grown in sole cropping supported few striga plants and produced up to 70% more grain than the farmers` maize. The maize grown under intercropping supported fewer striga plants compared to those grown in sole cropping. STR grown in intercropping with soybean lead to a reduction of 17.6% emerged striga plants while when grown in rotation for three seasons had up to 89.4% less emerged striga plants as compared to maize grown after maize. Therefore, the growing of STR varieties in rotation with soybean may be one of the best and practical methods of control.
 
Article
The pure compound, 6-(-3-methylbut-2-enyl)-6´-7-dihydroxycoumestan (1) isolated from the chloroform extract of the seeds of Psoralea corylifolia Linn. was evaluated for the pesticidal activity against both adults and different instars of Tribolium casteneum Hebrst. under laboratory conditions. The LD<sub>50</sub> values for the compound were 910.34, 620.47, 388.45 and 1159.87, 714.88, 404.26 and 1395.70, 740.75, 493.97 and 1605.34, 835.61, 565.83 and 1652.84, 916.79, 729.50 and 1764.32, 994.16, 784.09 and 1678.52, 992.04, 795.67 and 2350.41, 1395.70, 985.12 ppm for the 1st, 2nd, 3rd, 4th, 5th, 6th, adult male and female, respectively at 24, 48 and 72 h post exposure. These results demonstrated that the earlier instars were more sensitive to the compound than those of late instars those follow to those of individual adults.
 
Article
This study aimed to evaluate Piper aduncum L. seed germination restricted of water, simulated by solutions prepared with polyethylene glycol (PEG 6000) and thermal action influence, using germination chambers with temperatures controlled from 24 to 30?C. The experimental design was carried out in a 3H5 factorial scheme which counted three temperatures (24, 27 and 30?C), combined with five osmotic potential levels (0.0, -0.1, -0.2, -0.3 and -0.4 MPa). The analyzed variables were germination percentage and mean germination time. The results revealed that as the water restriction rose there was a decrease in the germination percentage and an increase in the mean germination time, demonstrating that seeds of this species are extremely sensitive to water shortage. The temperature increase from 24 to 30?C, accelerated germination.
 
Article
Tomato ( Solanum lycopersicom L.) fruit cv. "508" grown in plastic houses were obtained from two farms located in the Uplands and Jordan Valley. Fruits were harvested at the pink to light-red stages of development. Fruit samples were either kept as packed by the farmer (Group 1-traditional handling) or handled by the working team (Group 2-advanced handling). Harvesting was repeated three times with a week interval between harvests. Two main treatments were applied to the fruit samples: either held at 22 °C continuously or at 12 °C for 10 days and then removed to 22 °C to the end of the experiment. Soluble Solid Content (SSC), firmness, water loss, decay and defects and shelf life were evaluated at 0, 10 and 20 days. Crop enterprise budgets are used in economic analysis to estimate the profitability of agricultural products High temperature inflicted serious deteriorative consequence evident by accelerating the rate of loss of firmness (softening), increasing weight loss and decay incidence, aggravating defects and reducing the shelf life of the fruits held at 22 °C. Similarly, improper and rough handling (traditional handling) exerted detrimental effects clearly pronounced in fruits from group 2. Higher economic profits are obtained from tomatoes of the advanced handling comparable to those of the traditional handling.
 
Weight loss percentages'v-' of grapes following testing at 0, IO"C and Room Temperature (RT), for group I(traditional handling) and group II (advance handling) Harvest
Article
The aim of present study was to compare the effect of the traditional postharvest practices vs. modern technology in handling of grapes. Superior seedless grapes were subject to storage treatments at 0, 10 and 22°C in two groups, advance vs. traditional handling for 10 days. Marketability of grapes was evaluated from technical and economical aspects. Technical evaluation was based on some quality parameters such as Total Soluble Solids (TSS), shattering, weight loss, decay incidence and shelf life. Economical evaluation was based on the crop enterprise budgets to estimate the profitability. Results revealed that TSS was not affected by treatments, rather by delayed harvest time, while all other parameters were substantially affected by temperature management and advance handling. Additionally, an increase in the farmer’s net profit and the benefit-cost ratio by 9.3%. and from 5.62 to 6.05, respectively. Thus, the use of proper postharvest handling including sorting and temperature management is highly recommended for the export produce.
 
Article
Agro-economic advantages of different intercropping systems i.e. canola+one row of wheat, canola+two rows of wheat, canola+one row of gram, canola+two rows of gram, canola+one row of lentil, canola+two rows of lentil, canola+one row of linseed and canola+two rows of linseed were compared with sole cropping of canola for two consecutive years under field conditions. Canola seed yield equivalent, land equivalent ratio, area-time equivalent ratio and net income values of canola+one row of wheat intercropping system was higher than the other intercropping systems and sole cropping of canola.
 
Article
In the present study the damaging effects of ambient air on healthy of soybeans ( Glycine ma x L. cv. Crawford) were assessed by comparison of three non-filtered air (NF) exposed plants in an open-top chambers (OTC`s) and three Ambient Air (AA) plots exposed plants with three pure charcoal filtered air (CF) exposed plants in OTC`s system. In parallels, another group of NF-OTC`s, AA-plots and CF-OTC`s were treated with EDU to reduce air pollution impacts on plant growth. This field experiment was conducted at rural site of Abo Kabeer, Sharkia (East of Egypt) for full-season exposures. Monthly concentrations of ambient O<sub>3</sub> have significant increase throughout the duration of soybean cycle till reaching 88 nL L<sup>-1</sup> during August, while the concentrations of SO<sub>2</sub> and NO<sub>2</sub> are below toxicity levels. At the onset of the experiment, no significant difference between AA and NF air treatments was observed before and after of EDU applications. Also, no significant difference between CF/-EDU and CF/+EDU treatments for all soybean measurements. The total leaf area was decreased by 26 and 5% in case of NF/-EDU and AA/-EDU treatments, respectively. The 18% stimulation in Leaf Area Index (LAI) observed in the application of EDU under the AA plots treatments. The obtained results recorded an 8 and 6% more pods per plant in the NF/+EDU OTCs and AA/+EDU plots treatments, respectively. The EDU has improved nitrogen content in leaves by 26.1% in NF/+EDU and by 25.3% in the AA plots treatments. In general, mixed treatments from EDU soil drench and foliar spray proved all soybean growth and yield characters than its treatments singly. For an evaluation of these results, O<sub>3</sub> is only having adverse effects on agricultural crops in rural sites of Egypt. The absolute amounts of EDU protection against negative effects of O<sub>3</sub> could reach to 22.7% when using it as soil drench plus foliar spray.
 
Article
A two-year (2002/03 and 2003/04) experiment was conducted in the research site of the Agricultural University of Athens, Greece, to study the effects of Bermudagrass ( Cynodon dactylon L.) in several agronomic and physiological characteristics of cotton ( Gossypium hirsutum L.). Effects on cotton depended on timing of weed influence. Bermudagrass reduced stomatal aperture, chlorophyll content and chlorophyll fluorescence of cotton plants. Growth of cotton was also significantly reduced. Maximum reduction was 41.7% for stem height, 62.0% for root dry matter, 61.9% for stem dry matter and 34.7% for stem diameter. Stomatal resistance, chlorophyll content and chlorophyll fluorescence are proposed as suitable indicators that in addition to agronomic characteristics can reliably be used to measure adverse effects caused to cotton due to Bermudagrass interference.
 
Article
Some physical and aerodynamic properties of soybean were determined in order to design processing equipment and facilities. In this study, some physical properties of soybean were evaluated as a function of moisture content in the range of 6.7-15.3% (db). At the 6.7% (db) moisture content the average length, width, thickness, unit mass, the geometric mean diameter, arithmetic mean diameter, sphericity, porosity, true and bulk density soybean were 7.41 mm, 5.34 mm, 4.50 mm, 121.76 g, 5.62 mm, 5.75 mm, 75.0, 51.0, 062.6 and 804.8 kg m<sup>-3</SUP>, respectively. Corresponding values at 15.3% (db) moisture content were 9.57 mm, 6.75 mm, 5.17 mm, 23.65 g, 5.62 mm, 5.75 mm, 72.0%, 4.2%, 1086.4 and 689.3 kg m<sup>-3</SUP>, respectively. In soybean, terminal velocity increased from 7.13 to 9.24 m sμ<sup>-1</SUP> and the coefficient of static friction increased linearly against all the tested surfaces as the moisture content increased.
 
Article
The effect of boron and iron was studied on wheat subjected to moisture stress. All possible combinations of 0, 2, and 4kg ha<sup>-1</sup> of B and 0, 10 and 20 kg ha<sup>-1</sup> of Fe were studied in the experiment on Barani-70 variety of wheat which was subjected to early stress by delaying the first irrigation to 20 days after sowing instead of 10 to 15 days after sowing. Logistic function was fitted to shoot mass recorded at 15 days interval and useful biological constants were calculated. Logistic function fitted the data well. B @ 2kg ha<sup>-1</sup> and Fe @ 10kg ha<sup>-1</sup> and their combination increased AGR and the maximum biomass but their combination at the highest levels decreased the maximum biomass. RGR maximum which occur at initial stage of the crop growth was only increased by iron application @ 20kg ha<sup>-1</sup> and by combination of B and Fe at their highest levels.
 
Article
A study was carried out to determine the effect of N fertilizer placement and timing on accumulations of nitrogen, phosphorus and potassium in the aboveground wheat biomass at Krasnodar Agricultural Research Institute in Krasnodar County (45�5`N, 38�50`E, >400 m elev.) in Eastern Europe. The experiment was designed as Randomized Complete Block with four replicates, which were subjected to N fertilizer treatments. Spring wheat was grown under rainfed conditions with six treatments. In both seasons, results shows that T<sub>4</sub> plots recorded the highest N accumulations (177.4 and 156.6 kg ha <sup>1</sup>) in the plant biomass during the early growth stages of wheat (tillering and heading). In the post-heading period, highest N build-ups switched to T<sub>3 </sub>plots where a peak of 271.4 and 258.6 kg ha <sup>1</sup> for the first and second seasons, respectively were attained at mature stage. Single split application of N into N<sub>45</sub>P<sub>90</sub>K<sub>60 </sub>applied as incorporated basal fertilizers before planting and N<sub>45</sub> applied at tillering stage by broadcasting method, supported comparatively higher build-ups of nitrogen, phosphorus and potassium in the plant biomass in almost all the phenological stages of spring wheat in both years of the study. Triple split applications of N fertilizer in the T<sub>4</sub> plots did not significantly improve nutrient accumulations in wheat tops compared with those in T<sub>2</sub> plots (184.2 and 186.0 kg ha <sup>1</sup>) where pre-planting single basal N<sub>90</sub>P<sub>90</sub>K<sub>60</sub> was applied. Split application of N fertilizers in early stages of growth and development of spring wheat, which coincides with the onset of the most rapid phase of biomass accumulations dramatically amplifies the content of nitrogen, phosphorus and potassium in the aboveground plant parts.
 
Article
To evaluate drought tolerance of 20 genotypes of bread wheat under different irrigation regimes, a strip plot experiment based on a complete randomized block design with 3 replications was conducted for 2 growing seasons (1998-2000). Main plots were allocated to 3 levels of irrigation namely 10 days (A<SUB>1</SUB>), 20 days (A<SUB>2</SUB>) and 30 day (A<SUB>3</SUB>) intervals. Sub plots were allocated to 20 genotypes of winter and facultative bread wheat. Grain yield, total biomass, number of spike m<SUP>-2</SUP>, harvest index and 1000 kernel weight significantly affected by irrigation treatments and therefore negative responses were more pronounced by increasing irrigation intervals. Water use efficiency was higher for 2o days irrigation interval compared with other treatments. Grain yield, biological yield and number of spikes m<SUP>-2</SUP> were higher for C-75-6, C-75-10 and C-75-16 genotypes for all treatments. However when a 20 and 30 days irrigation interval were applied, grain yield, number of spike m<SUP>-2</SUP>, harvest index and water use efficiency for C-75-14 and C-75-9 genotypes were higher. These genotypes were more flexible under drought condition. They were relatively early maturing and had relatively higher number of spike m<SUP>-2</SUP> and also higher harvest index and water use efficiency.
 
Top-cited authors
Stephan Weise
  • Bioversity International
A. Aguilera
  • University of Guelph
Clarence J Swanton
  • University of Guelph
Matthijs Tollenaar
  • The Climate Corporation
C.F. Oliveira Neto
  • Amazonian Federal Rural University