The Ecophysiology of Abiotic and Biotic Stress on the Pollination and Fertilization of Cacao (<em>Theobroma cacao</em> L.; formerly Sterculiaceae family)

The cocoa crop growth is highly influenced by environmental conditions, viz. temperature, which influence the phenological stages of flowering, fruiting, and pod growth. The plant produces caulescent flowers that are hermaphrodite and pollinated by insects, mainly Forcipomyia sp. (Diptera: Ceratopogonidae), but flowers setting to pods are very low. The efficiency of pollination depends on the degree of pollen compatibility and the number of pollen grains deposited on the stigma. It is assumed that midge population can be a limiting factor in the pollination of cocoa in addition to the environmental conditions. However, populations of insect pollinators are often severely disturbed by hurricanes through flooding of essential habitat and the widespread loss of existing flowers. This chapter will explore the role of midges [biotic] and the effect of climate [abiotic] variables. Understanding these ecological dynamics can lead to ways of conserving midge populations, mitigating the effects of global climate change and extreme climatic events

Postharvest Handling of Indigenous and Underutilized Fruits in Trinidad and Tobago

This chapter briefly outlines the origin of some indigenous and underutilized fruit crops found throughout Trinidad and Tobago. It also examines the current situation, current practices, and maturity standards for postharvest handling of these commodities and examines the principle causes of postharvest losses and poor quality. Finally, the chapter includes some recommendations on the best postharvest practices for these indigenous and underutilized fruits, including field harvesting practices, storage and transportation, and cool storage

Herbicide Use and Increased Scourge of Parthenium hysterophorus in Vegetable Production in Trinidad and Tobago

This chapter highlights a survey of vegetable-producing areas to determine the occurrence, distribution and importance of Parthenium hysterophorus in Trinidad. The weed can significantly reduce crop yields and quality due to its aggressive growth habit, competitiveness and allelopathic interference. Due to its invasive capacity and allelopathic properties, Parthenium hysterophorus has the potential to disrupt the natural ecosystem and threaten the biodiversity. It is a difficult weed to manage, and a wide variety of methods, starting with prevention and containment, is necessary to reduce the incidence and spread of this weed. An integrated approach using cultural, physical, chemical and biological techniques is necessary to be successful. Focus is made on specific herbicides currently being used to manage this weed in vegetables. Despite the negative impact of this weed on the biodiversity, this chapter also explores the potential of the beneficial properties of Parthenium hysterophorous as a mechanism of management

Floral odors and the interaction between pollinating Ceratopogonid midges and Cacao

Most plant species depend upon insect pollination services, including many cash and subsistence crops. Plants compete to attract those insects using visual cues and floral odor which pollinators associate with a reward. The cacao tree, Theobroma cacao, has a highly specialized floral morphology permitting pollination primarily by Ceratopogonid midges. However, these insects do not depend upon cacao flowers for their life cycle, and can use other sugar sources. To understand how floral cues mediate pollination in cacao we developed a method for rearing Ceratopogonidae through several complete lifecycles to provide material for bioassays. We carried out collection and analysis of cacao floral volatiles, and identified a bouquet made up exclusively of saturated and unsaturated, straight-chain hydrocarbons, which is unusual among floral odors. The most abundant components were tridecane, pentadecane, (Z)-7-pentadecene and (Z)-8-heptadecene with a heptadecadiene and heptadecatriene as minor components. We presented adult midges, Forcipomyia sp. (subgen. Forcipomyia), Culicoides paraensis and Dasyhelea borgmeieri, with natural and synthetic cacao flower odors in choice assays. Midges showed weak attraction to the complete natural floral odor in the assay, with no significant evidence of interspecific differences. This suggests that cacao floral volatiles play a role in pollinator behavior. Midges were not attracted to a synthetic blend of the above four major components of cacao flower odor, indicating that a more complete blend is required for attraction. Our findings indicate that cacao pollination is likely facilitated by the volatile blend released by flowers, and that the system involves a generalized odor response common to different species of Ceratopogonidae

évaluation à effet de serre des sargasses algues comme milieu de mise en pot pour les légumes

The Sargassum seaweed &lsqb;Sargassum natans and S. fluitans&rsqb; can be classed as a perennial invasive weed problem in all the Caribbean islands. It has been shown to affect fisher-folks, sea bathers, and tourists. It is proving to be costly to remove; in addition to its offensive odour which hampers the clean-up operations. The University of Trinidad and Tobago at the BAFT campus is engaged in series of activities to find suitable uses of the seaweed as animal feed, and as soil medium and ameliorant. This study aimed at evaluating the suitability of the seaweed as a growing media for the production of sweet peppers &lsqb;Capsicum annuum var. annuum&rsqb; using different percentage of the weed (0, 25, 50 and 100%) with soil under greenhouse conditions. The crop growth and development and yield were monitored. The results indicated that the plant height &lsqb;Y pl ht = 16.6 + 0.3 DAT - 0.11 TRT&rsqb; and leaf number &lsqb;Y no.lvs = 0.90 + 1.04 DAT - 0.206 TRT&rsqb; increased as age of the crop increased, but decreased with the increase in percentage of seaweed/ soil mixture. A similar response was observed for the flower buds and fruits numbers and percentage soil mixture. The medium had no effect on the crop transpiration and net photosynthesis rate &lsqb;PN&rsqb; , photosynthesis active radiation&lsqb;PAR&rsqb; , and stomatal conductance. A nutrient analysis of the medium was also conducted

The performance of selected high yielding passion fruit lines in Dominica

Self-incompatibility in yellow passion fruit (Passijlora edulisf flavicarpa) hinders the selection of a single high yielding variety (HYV). Selection and evaluation efforts, initiated in 1989; for 3 years in Dominica by MOA-IICA-CARDI (M-1-C) on 28 farms have identified 9 lines which show consistent desirable characteristics in terms of fruit size, yield, juice content and quality, number of seeds, and freedom from pest and disease. This paper presents a model used in the selection and evaluation of the HYV fruits, and the maintenance of a germplasm bank using selections propagated vegetatively and by F 1 seedlings. Physiological and phenological characteristics, yield and yield components of selected lines are highlighted. A program to produce, distribute and monitor a composite (M-1-C selection) with high yield seed and juice quality to farmers is also discussed

MORINGA OLEIFERA – AN UNDER EXPLOITED SOURCE OF CROP PROTEIN IN THE CARIBBEAN

Drumstick vegetable (Moringa oleifera) is considered to have the highest protein ratio of any plant so far identified, and better than soy protein. This under-exploited perennial tree crop, which is used as a vegetable in the Southern Caribbean for over 150 years, has lost it dietary significance. However, it can still be an ideal replacement for soybean meal in animal and fish feed as an energy and protein source. Agronomic trials and chemical analysis have been conducted to evaluate its growth, development and protein yield performance, as well as nutritive value as a stable animal feed. The results indicated that the yield (i.e. 13.12t.ha-1) is double that of soybean, and the protein content is better (i.e. 5.03t.ha-1(38.4%CP)) than most tropical forage legumes. It can be easily cultivated at low input cost, and the plant vegetative parts can also be utilized fresh, or the seeds processed/unprocessed as animal protein feed

Incubator Farms as a Sustainable Approach for 'Neo Farmers'

Trinidad and Tobago is facing a challenge of urban migration and a reduction in an already ageing farming population. There is an urgent need to attract new and emerging farmers to this vocation and guide them to be economically viable and educated farmers of the future. Incubator Farm is a unique and successfully proven approach which will be appropriate for Small Island States Economies, and will assist to educate aspiring farmers and establish their business as incubators. This paper discusses the creation of a more closed-loop food system through the establishment of several farms for the production of dwarf pommecythere, cassava, and hot peppers linked to a post-harvest facilities and multi-purpose pilot processing plant

Economic importance of White Top (Parthenium hysterophorous L. [f]) under intense vegetable production in Trinidad

A weed survey conducted to determine the incidence of Parthenium hysterophorous l. (f) in vegetable crops during the wet and dry seasons in Trinidad indicated that the plant is a predominant noxious weed. It has shown the ability to survive bipyridylium herbicide treatments, and biological and cultural control was insignificant in reducing the population of the weed. The weed reduced crop yield in tomato (lycopersicon esculentum Mill.) cv, Calypso by 10~ and crop quality in Cauliflower (Brassica aleracea var. botrytis l.j by 75-100% due to its competitive ability and allelopathic potential. The plant served as a suitable 'resting site' for the adult insect pest Plutella xylostella (l.) (Lepidoptera: Yponomenitidae) which attacks cruciferous crops