International peer-reviewed journal ISSN 2321-3655 Oct

Abstract: This study was designed to examine the effects of promoting substances on bud retention, rooting and plantlets survival of rooted cuttings on selected tree species using growth promoting substances. Stem cuttings were treated with rooting-promoting substances, planted in plastic pots filled with top soil and arranged using a completely randomized design (CRD) in a screen house. Stem cuttings of pepper fruit, guava, bush mango and cashew were obtained from the Teaching and Research Farm, Federal University of Technology, Akure, Nigeria. The experiments were conducted in 2010. The effects of growth promoting substances namely indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) and 1-naphthalene acetic acid (NAA) applied 50 µM concentration and coconut water (50% dilution ) were evaluated on adventitious root formation, shoot growth (bud retention) and survival of plantlets of hard-to semi-hardwood cuttings of tested tree species. The effects of growth promoting substances were significant on emergence of plantlets (rooting), growth and survival of plantlets. Number of sprouts (plantlets) produced were highest in guava and pepper fruit followed by bush mango and cashew. The cuttings from guava and pepper fruit treated with coconut water and NAA promoted the survival of plantlets. Coconut water and NAA were found better than IBA and IAA in terms of bud retention and rooting, leaf development and survival of plantlets. In most of the tested species, wilting of leaves commenced 6 weeks after planting (WAP) and attained 100% mortality thereafter except for pepper fruit cuttings dipped in coconut water. The treatments modified the rooting response among species by promoting percentages of rooting, reduction in bud abscission and plantlet survival. The results affirmed the possibility of propagating plantlets from stem cuttings of the tested species using growth promoting substances

Within Plant Resistance to Water Flow in Tomato and Sweet Melons

Efficient water resource management in relation to water use and crop yields is premised on the knowledge of plant resistance to water flow. However, such studies are limited and for most crops, the within plant resistance to water flow remains largely unknown. In this study, within plant resistance to water transport (hydraulic conductance) was monitored in tomato ( Lycopersicum esculuntum ) and sweet melon ( Citrullus lanatus ) using the high pressure flow meter (HPFM) and evaporative flux (EF) methods. In the evaporative flux method, measurements of transpiration flux and leaf water potential were used to calculate the total resistance to water flow using Ohm's law analogy. Measurements of tranpiration flux (Q) relationship, plant resistance calculated from the slope of their relationship, ranged from 6.57x10-01 to 2.27x10-03 Mpa m-2s-1 for tomato and sweet melon, respectively. The magnitude of whole plant hydraulic conductance calculated by the evaporative flux method and measured on the HPFM were not significantly different. This is probably due to that fact that Kp includes the hydraulic conductance of the root system, which offers the highest resistance to water flow in a plant, and the frictional resistance of the proximal part of the crown. Day time course of water relation parameters were monitored in melon and tomato (predawn, 1100 to 1400 h). The effect of time of day was pronounced on the dynamics of water relations, particularly around mid-day when sharp differences in the magnitudes of the measured water relation parameters were obtained. Minimum (predawn) leaf water potential (ψl) ranged from 0.135 to 0.207 MPa for both crops. The greatest conductance was found in the leaf and the lowest in the root in both crops. While the highest within plant resistance to the flow is contained in the root system, the stem component constitutes the least resistance (greatest conductance) to within plant flow of water in tomato. Repeated measurement analysis showed the existence of significant species effects on plant water relations (leaf water potential, evaporative/transpiration flux, xylem hydraulic conductance). Superiority within plant xylem transport and evaporative losses were obtained in tomato, from the relations of EF and Kh; this crop showed a higher hydraulic sufficiency than melon. The expression of hydraulic conductance of the root and shoot system relative to plant attributes did not eliminate differences in the magnitudes of conductance elements in tomato and melon. Differences obtained between melon and tomato in whole plant leaf and stem area specific hydraulic conductance (KI) indicate the carbon efficiency and, hence, the cost of resource allocation to areas of root surface and leaves for enhanced scavenging for water and mineral nutrients. Thus, application of mineral nutrients to enhance crop productivity should take into consideration the hydraulic conductance for specific plants.La gestion efficace de ressource d'eau en relation avec son utilisation et son rendement est une prémisse de la connaissance de la résistance des plantes au flux d'eau. Cependant, de telles études sont limitées et pour la plupart des récoltes, la résistance interne de la plante sur le flux d'eau reste principalement inconnue. Dans cette étude, la résistance de plantes sur le flux (la conductance hydraulique) a été contrôlée dans la tomate ( Lycopersicum esculuntum ) et le melon doux ( Citrullus lanatus ) utilisant la méthode de forte pression (HPFM) et le flux d'évaporation (EF). Dans la méthode de flux d'évaporation, les mesures de flux de transpiration et de potentiel d'eau de feuille ont été utilisées pour calculer la résistance totale en utilisant l'analogie de loi d'Ohm. La relation entre les mesures de flux de transpiration (Q) et la résistance des plantes a été calculé, la pente de cette relation, était entre 6.57x10-1 à 2.27x10-3 MPa m-2s-1 pour la tomate et le melon doux, respectivement. La grandeur de la conductance hydraulique de la plante entière prédite par la méthode de flux d'évaporation et mesuré sur le HPFM n'était pas significativement différente. Ceci est probablement en raison du fait que Kp inclut la conductance hydraulique du système fondamental, qui offre la plus haute résistance au le flux dans une plante, et la résistance de friction de la partie proche de la couronne. L'effet du temps de la journée sur les paramètres d'eau a été contrôlé dans le melon et la tomate (de 11.00 à 14.00 h). L'effet du temps a été prononcé sur la dynamique de relations d'eau, particulièrement autour du midi quand les différences tranchantes en grandeur des paramètres de relation d'eau mesurés ont été obtenues. Le potentiel d'eau minimal de feuille était compris entre 0,135 et 0,207 MPa pour les deux récoltes. La plus grande conductance a été trouvée dans la feuille et le plus bas dans la racine dans les deux récoltes. Pendant que la plus grande la résistance interne de la plante au flux est contenue dans le système fondamental, le composant de tige présentait la moindre résistance (la plus grande conductance) au flux d'eau dans la tomate. L'analyse répétée de mesure a montré l'existence d'effets d'espèce significatifs sur les relations d'eau des plantes (le potentiel d'eau de feuille, le flux de d'évaporation transpiration, la conductance hydraulique du xylem). La supériorité dans le transport de xylem de plante et dans les pertes d'évaporation a été obtenue dans la tomate, concernant EF et de Kh; cette récolte a montré une efficacité hydraulique supérieure au melon. L'expression de la conductance hydraulique de la racine et le système relatif aux attributs de la plante n'a pas éliminé les différences dans les grandeurs de la conductance dans la tomate et le melon. Les différences ont été obtenu entre le melon et la tomate dans la feuille de la plante entière et le secteur de tige pour la conductance hydraulique spécifique (KI) indiquant l'efficacité du carbone et, donc, le coût d'allocation de ressource aux secteurs de surface et de feuilles fondamentales pour améliorer la récupération de l'eau et de nutriments minéraux. Ainsi, l'application de nutriments minéraux pour améliorer la productivité de récolte doit prendre en considération la conductance hydraulique des plantes

Effects of synthetic hormone substitutes and genotypes on rooting and mini tuber production of vines cuttings obtained from white yam (Dioscorea rotundata, Poir)

Open Access JournalThis study was designed to evaluate the effects of some root - promoting substances on rooting andmini tuber formation using vine cuttings obtained from two genotypes (TDr 335 and TDr 93 - 49) of whiteyam (D. rotundata). The ashes were obtained from rice straw, bamboo, Gliricidia sepium, dry leaves ofAzardiracta indica (neem), and 1% indolebutyric acid (IBA). These were powdered on the nodal woundsof vine cuttings before they were planted in planting media (carbonized rice husk). The plant asheswere mixed at 1, 3 and 5 g each in 100 ml of water. Coconut water was also diluted at 1, 5 and 10 ml in100 ml of water while pyroligneous acid (PA) was diluted (1 ml each in 500, 1000, 2000 and 3000 ml in5000 ml of water). Both dilutions were used to treat vine cuttings before planting in cups filled withcarbonized rice husk. The vine cuttings were sampled for rooting percentage, number of roots, rootlength and mini tuber initiation 21 days after treatment (DAT). The number and weight of tubersobtained from IBA and wood ash treated vines were not significantly different. The rice straw ash, IBAand neem leaves powder treated vines produced greater rooting percentage (above 70%) than percentrooting obtained from vines treated with other plant ashes. Rice straw ash (5% concentration) had thehighest rooting percentage (80%) relative to other plants ash concentrations. Higher rooting percentagewas obtained in coconut water diluted at 1 and 5% than 10 and 100% dilutions. Rooting percentagesfrom vine cuttings treated with pyroligneous acid (PA) dilutions were not better than control(unteeated). The rooting percentages obtained from vines treated with different concentrations of plantsashes, root - promoting substances and control in this study were not significantly different (P = 0.05),except in vine cuttings treated with 5 g rice straw ash in 100 ml of water. Higher values of rootingpercentage, number of roots, root length and mini tubers were obtained from genotype TDr 93 - 49compared with values recorded from vine cuttings obtained from the genotype TDr 335

Resistência de genótipos de feijão-de-corda ao pulgão-preto Resistance of cowpea genotypes to the cowpea black aphid

O objetivo deste trabalho foi avaliar a resistência de genótipos de feijão-de-corda (Vigna unguiculata) ao pulgão-preto (Aphis craccivora). Foram realizados experimentos com e sem chance de escolha em casa de vegetação, na Universidade Federal do Ceará. O delineamento utilizado foi o de blocos ao acaso com vinte tratamentos, representados pelos genótipos 421-07-44, Chumbinho, Zebu, EPACE 10, Frade Preto, Inhumã, João Paulo II, Manteiguinha, Maranhão, Pitiúba, Quarenta Dias, Seridó, Sete Semanas, TVu 1037, TVu 1888, TVu 310, TVu 36, TVu 408P2, TVu 410 e VITA 7. Verificou-se que TVu 408P2, TVu 1037 e TVu 410 foram preteridos por adultos e ninfas do pulgão-preto, em ambos experimentos. Os genótipos TVu 408P2, TVu 410, TVu 36 e TVu 1037 apresentam resistência provavelmente do tipo antibiose ou antixenose. O genótipo 421-07-44 mostrou-se suscetível ao pulgão-preto.<br>The objective of this work was to evaluate cowpea (Vigna unguiculata) genotypes for resistance to the black aphid (Aphis craccivora). Experiments, with and without choice, were performed in the greenhouse, at the Universidade Federal do Ceará, Fortaleza, Brazil. The experimental design was a randomized complete block with twenty treatments represented by the genotypes 421-07-44, Chumbinho, Zebu, EPACE 10, Frade Preto, Inhumã, João Paulo II, Manteiguinha Maranhão, Pitiúba, Quarenta Dias, Seridó, Sete Semanas, TVu 1037, TVu 1888, TVu 310, TVu 36, TVu 408P2, TVu 410 and VITA 7. The genotypes TVu 408P2, TVu 1037 and TVu 410 were less preferred by adults and nymphs of the black aphid in both assays. The genotypes TVu 408P2, TVu 410, TVu 36 and TVu 1037 probably presented antibiosis or antixenosis resistance. The genotype 421-07-44 was susceptible the black aphid