Inhibitors of Non-for Profit Organisations’ activities and survival in a crisis context

Purpose Tunisia has been living a decade of democratic transition since 2011. In this new context, the civil society has been fervently expressing claims for democracy and social justice through creating thousands of NPOs (23456 NPOs in 2020 against 9000 established in 30 years up to 2010). However, this shift seems to be misleading, as only 3000 NPOs are actually active, indicating that NPOs are struggling to sustain their activities and ensure their survival. The purpose of this study is to uncover the factors hindering NPOs activities and survival. Design/methodology/approach Semi-structured interviews were carried out using a purposive sample of 32 NPOs members in two main economic and touristic cities -Tunis and Sousse- selected using snow ball method. A considerable amount of qualitative data was produced (400 pages of text). This seems representative of Tunisian citizens’ inclination to protest in the new prevailing political and social context. The data collection benefited from the freedom of speech gained after the 2011 civilian uprising as interviewees were enthusiastic in voicing their opinions. Findings Two main categories of inhibitors were identified. First, endogenous inhibitors including (i) inhibitors under the control of the NPO (i.e. use of illegal and foreign sources of funding, limited financial resources, unavailability of NPOs’ members, short term planning, conflicts between managers, autocratic leadership, organisational support, activities diversification and organisational justice, leadership and communication skills, “NPO culture”, members’ opportunistic behaviour and, generation gap) (ii) inhibitors related to NPOs inter-relationships: stiff competition, unfair and dishonest competition, lack of collaboration, trust and communication between NPOs. Second, exogenous inhibitors, i.e. perceived unethical practices and image transfer, economic crisis, foreign funding sources and the media. Research limitations/implications This study has some limitations mainly due to the sample size and characteristics of the selected interviewees. In addition, data was collected in only two regions (Tunis and Sousse). Therefore, the results lack generalisability.   Practical implications The findings highlight the critical impact of the inhibitors under the control of NPOs compared to those out of their control. NPOs in crisis context, could overcome these inhibitors by ensuring congruence between the NPOs’ mission, objectives and activities and designing suitable marketing strategies. Originality/value This study contributes to elucidate this complex circular system of exchange and its inhibitors in challenging and understudied context. It offers support to Bagozzi’s (1974; 1975; 1994; 2011) calls for uncovering the factors constraining or facilitating exchanges that have an impact going beyond the relationship between three or more partners and the conditions that govern these exchanges. Moreover, and to the best of our knowledge, this is the first empirical attempt to support Bagozzi’s (1994) conceptualisation. It also brings an update to NPOs' data and marketing strategy in a region near the crossroads of Middle Eastern, North African and Western influences. Keywords: Not For Profit Organisations (NPOs), endogenous and exogenous inhibitors, NPOs’ inter-relationship, circular exchange system

Effect of Thiourea on Yield and Quality of Potato (Solanum tuberosum L.)

A field experiment was carried out to study the effect of five concentrations (0, 250, 500, 750 and 1000 mM) of thiourea application on mother tubers on yield and quality attributes of harvested potato, variety Spunta in the region of Chott-Mariem in Tunisia. Treated tubers (Ш = 50 mm) were planted in field after breaking dormancy at a spacing of 80 cm x 30 cm according to completely randomized design (CRD) in three replications. Quality attributes of potato tubers especially fresh matter and dry matter of plant, total reducing sugars in leaves, tuber yield, number and diameter of tubers per plant and number of sprouts per tuber was measured. Soluble proteins and starch content in potato tubers were also quantified.In general we noted that application of thiourea showed significant influence on yield and on quality of tubers comparing to control. Maximum tuber yield per plant, maximum number of tubers per plant and maximum starch content was recorded with 250 mM of thiourea. Moreover, highest dry matter of potato plant was found also at this concentration. While increasing dose of thiourea thereafter it showed slight significant improvement and do not affect significantly the diameter of tubers comparing to control

PHYSIOLOGICAL MECHANISMS FOR POTATO DORMANCY RELEASE AND SPROUTING: A REVIEW

Potato ( Solanum tuberosum \ua0L.) tubers undergo a period of dormancy, during which visible bud growth is inhibited. The length of the dormancy is determined by environmental, physiological and hormonal control mechanisms. Dormancy is the final stage of tuber life, which serves to preserve tubers as organs of vegetative reproduction under unfavourable growth conditions. Since the duration of potato tuber dormancy and sprouting time bear significant economic importance, this review considers the regulation of dormancy and sprouting of potato by phytohormones and reactive oxygen species. Two phytohormones, ABA and ethylene suppress tuber sprouting; however, the exact role of ethylene remains to be elucidated. Cytokinins and gibberellins are required for bud breaking and sprout growth, respectively. The auxin seems to play a role in vascular development. Thus, tuber dormancy and sprouting can be controlled in potato by manipulation of Reactive Oxygen Species (ROS), especially H2O2\ua0metabolism via the inhibition of catalase (CAT) activity.The possible mechanisms by which CAT inhibitors or H2O2\ua0overcome dormancy and promote sprouting in the potato tuber are discussed.La pomme de terre ( Solanum tuberosum \ua0L.) conna\ueet une p\ue9riode de dormance durant laquelle la germination des bourgeons visibles est inhib\ue9e. La dur\ue9e de dormance est d\ue9termin\ue9e par des m\ue9canismes de contr\uf4le environnemental, physiologique and hormonal. La dormance est le stade final de la vie des tubercules servant \ue0 pr\ue9server les tubercules comme organes de reproduction v\ue9g\ue9tative sous condition de germination d\ue9favorables. Etant donn\ue9 que la dur\ue9e de la dormance des tubercules de la pomme de terre et le temps de rejet rev\ueatent une importance \ue9conomique significative, cette revue consid\ue8re la r\ue9gulation de la dormance et le rejet de la pomme de terre par des hormones et d\u2019esp\ue8ces r\ue9actives d\u2019oxyg\ue8ne (ROS). Deux phytohormones\ua0; ABA et \ue9thyl\ue8ne emp\ueachent le rejet des tubercules\ua0; par ailleurs, le r\uf4le extractif de l\u2019\ue9thyl\ue8ne reste \ue0 \ue9lucider. Les cytokinines and les gibb\ue9rellines sont n\ue9cessaires dans l\u2019\ue9limination des bourgeons et la croissance des rejets, respectivement. L\u2019auxine semble jouer un r\uf4le dans le d\ue9veloppement vasculaire. Ainsi, la dormance et les rejets des tubercules peuvent \ueatre contr\uf4l\ue9s par manipulation d\u2019esp\ue8ces r\ue9actives d\u2019oxyg\ue8ne (ROS), sp\ue9cialement le m\ue9tabolisme du H2O2\ua0\ue0 travers l\u2019inhibition de l\u2019activit\ue9 de la catalase (CAT). Les m\ue9canismes possibles par lesquels les inhibiteurs du CAT ou H2O2\ua0 surmontent la dormance et facilitent le rejet de la pomme de terre sont discut\ue9s

EFFECT OF HYDROGEN PEROXIDE AND THIOUREA ON DORMANCY BREAKING OF MICROTUBERS AND FIELD-GROWN TUBERS OF POTATO

Potato ( Solanum tuberosum L.) microtubers or field-grown tubers have a dormant apical bud (also called tuber dormancy). They do not readily sprout even if environmental conditions are favorable, including optimum temperature and humidity. The objective of this study was to evaluate the involvement of hydrogen peroxide (by direct or indirect application of thiourea, a catalase inhibitor) in dormancy release and sprouting of potato microtubers and tubers was evaluated using two complementary experiments. First, the kinetics of the sprouting (percentage of sprouted microtubers with time) was examined on microtubers planted in peat and cultivated in a glasshouse after exogenous application of different concentrations of hydrogen peroxide (20, 40 and 60 mM) and thiourea (250, 50 0 and 750 mM). Second, the sprouting kinetics was examined on field-grown tubers during storage, after application of hydrogen peroxide (20, 40, 60 and 80 mM) and thiourea (250, 500, 750 and 1000 mM). Their sprouting capacity was also evaluated. Then, kinetics of field emergence of treated and sprouted tubers was examined after planting them in a field. Direct application of hydrogen peroxide or application of catalase inhibition through thiourea application on the release of dormancy promote sprouting on potato microtubers and field-grown tubers. Results showed that hydrogen peroxide (20 mM) caused rapid and synchronous sprouting of microtubers; while higher concentrations (40 and 60 mM), caused asynchronous sprouting. Thiourea at a concentration of 250 mM was the most effective in reducing the dormancy period and increasing the number of sprouted microtubers. In field experiment, sprouting was optimal when tubers were treated with 60 mM of hydrogen peroxide; whereas at a lower concentration, sprouting was less stimulated. In addition, tubers treated with 250 mM thiourea had maximum sprouting and better sprouting capacity. It is clear that both substances affect hormonal regulation and antioxidant enzymes, leading to dormancy release in both: microtubers and tubers.Les microtubercules de la pomme de terre ( Solanum tuberosum L.) ou bien les tubercules cultivées en champs sont dotées d’une dormance des tubercules. Elle ne poussent pas facilement, même si les conditions environnementales sont favorable, incluant température optimal et l’ humidité. L’objectif de cette thiourea, une catalase inhibitrice) dans la libération de la dormance et la germination des microtubercules de pomme de terre était évalué utilisant deux essais complémentaires. D’abord, la cinétique de germination (pourcentage de microtubercules germées avec le temps) était examinee sur des microtubercules plantées sur susbtract tourbeux et cultivées dans une serre après application exogène de différentes concentrations du peroxide d’hydrogène (20, 40 et 60 mM) et thiourea (250, 50 0 et 750 mM). Deuxièmement, la cinétique de germination était examinée pendant le stockage sur des tubercules cultivées en champ après application du peroxide d’hydrogène (20, 40, 60 et 80 mM) et thiourea (250, 500, 750 et 1000 mM). Leur capacité de germination était évaluée. En suite, la cinétique d’émergence au champs des tubercules traitées et germées était examinée après les avoir plantées au champs. L’application directe du peroxide d’hydrogène ou application de la catalase inhibitrice à travers l’ application du thiourea sur la liberation de la dormance promeut la germination des microtbercules ainsi que les tubercules produites en champs. Les résultats ont montré que le peroxide d’hydrogène (20 mM) ont cause un rapide et une germination synchronisée des microtubercules; alors que les concentration plus élevées (40 et 60 mM), ont cause une germination non synchronisées. Thiourea avec une concentration de 250 mM était le plus efficace en terme de réduction de la période de dormance et l’augmentation du nombre des microtubercules germées. Dans l’essai en champs, la germination était optimal lorsque les tubercules étaient traitées avec 60 mM du peroxide d’ hydrogen; pendant qu’ à une basse concentration, la germination était moins stimulées. En plus, les tubercules treatées avec 250 mM de thiourea avaient un maximum de germination et une meilleur capacité de germination. Il est claire que toutes les deux substances affectent la regulation hormonale et les enzymes antioxidants, conduisant ainsi à la libétation de la dormance dans les microtbercules et les tubercules

Effect of hydrogen peroxide and thiourea on fluorescence and tuberization of potato (Solanum tuberosum L.)

The aim of this study is to determine the effect of hydrogen peroxide and thiourea on potato crop (quantum yield (Fv/ Fm), chlorophyll content, tuber diameter, tuber number and total tuber yield). The concentrations of these two chemicals are hydrogen peroxide: 0, 20, 40, 60 and 80 mM, and thiourea : 0, 250, 500, 750 and 1000 mM. The experiment was conducted in the farm of Chott-Mariem Institute during three months using variety 'Spunta' and arranged in a completely randomized block with three replications. Results show that there is no significant difference in tuber diameter between treatments and among the same treatment. However, tuber yield is significantly increased by 20 % by thiourea (250 mM). Maximum total yield was obtained at this concentration (810 g/plant). In addition, application of thiourea (500 and 750 mM) results in a significantly higher number of tubers number (5.7 and 5.2 respectively). In contrast, treatment with hydrogen peroxide brings about similar tuber yields. Although, application of hydrogen peroxide at low concentration (20 mM), decreases chlorophyll content and stresses plants, application of thiourea increases chlorophyll content, and improve quantum yield especially when it is applied at 250 mM