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Project Title: HOT PEPPER IMPROVEMENT FOR THE CARIBBEAN (Code C2 B13) 1.0.0.0 OBJECTIVES The objectives of the project are as follows:
2.0.0.0 BACKGROUND This reporting period spans the transition from the old to the new financial year from September 1998 to December 1998 as well as the calendar year of 1999. The main activities, which were undertaken, were as follows:
This project has now moved into the second 3-year phase. The phases are as follows:
An effort will therefore be made to describe all the achievements to date, and to indicate the directions in which the main genetic improvement work should proceed. 3.0.0.0 MATERIALS AND METHODS 3.1.0.0 The Germplasm Collection 3.1.1.0 The seed room At the beginning of the reporting period, there were 65 accessions in the collection and they were stored as seed in a cool room where the temperature was 18-20°C and the relative air humidity 40-60%. The seeds were packed into metal tins with silica gel as a drying agent. The most recent additions and those accessions with very little seed were planted out into the field for observations and seed increase. Plants were widely spaced, 150cm x 84cm. Individuals were isolated in cages to keep out pollen grains from other plants whether wind blown or carried by pollinators. 3.1.2.0 Collecting missions Collection Missions were mounted in Guyana, Dominica and Trinidad and Tobago. The methods employed in the Collecting Mission could be described under the following topics:
3.1.2.1 Literature review A search for publications on the Caribbean hot pepper landraces was initiated. Oral reports of previous collections were invited. The folk memory in the farming communities of all three countries was tapped through interviews with the experienced farmers in particular. 3.1.2.2 Financial resources Estimates of costs and a budget were drafted and applications for funding were positively evaluated by the OAS. The funds were administered via the Department for Biological and Chemical Sciences of UWI, Cave Hill and through UWI, Mona Campus. 3.1.2.3 Applications for permits Guyana had a clearly defined authority mandated to manage its biodiversity and germplasm. The application for the permit to collect and export germplasm, was therefore addressed to the Environmental Protection Agency. With the kind assistance of the National Agricultural Research Institute (NARI), verbal permission was granted to allow the Mission to proceed without the written permit which takes several months. In the case of Dominica the request was made to the Director of Agriculture and verbal permission was granted on one condition. The landrace called Bonda Ma Jacque was not to be distributed for commercial exploitation for a period of at least two years. In Trinidad and Tobago the request was also addressed to the Director of Research in the Ministry of Agriculture. Permission was only granted for the collecting of the landraces but not for the export of the germplasm. The collection was to be lodged with the MoA. 3.1.2.4 Acquisition of scientific equipment, materials and references The updated Collecting Forms were obtained from IPGRI and adequate numbers were copied. Lead pencils of the appropriate softness were to be used on the forms to guard against smearing when caught in rains in the fields. Waterproof materials were acquired to hold all the forms and equipment to be used in the fields. Field photography was a very important means of recording field work. Therefore, a camera with tripod, films and a piece of black velvet cloth for backdrop were packed. It was very important to have markers and strips of cardboard paper to make labels in the field and for the labels to be incorporated into the coloured photographic 35 mm slides. Metric rulers and calipers were to be used for measurements and magnifiers and a small field microscope were needed to examine plant parts. Strong canvas bags with draw strings served to transport and protect the samples under the most difficult conditions. The berries were processed in laboratories and the seed treated and packed for transportation to Barbados. The Collecting Manual (Hawkes, 1980) and the Descriptors for Capsicum (IPGRI, 1995) were applied in the field. 3.1.2.5 Sensitizing farmers, local authorities and extension agents Ahead of the field visits, the farmers and local authorities were requested through the extension agents, to provide information on the locations of the hot pepper landraces. Heirloom germplasm was traced this way. Time was spent to speak to the elders in farming communities in order to tap the folk memory. Local guides, found with the aid of the extension agents, were the source of useful information. 3.1.2.6 Travel arrangements Travel arrangements were left as flexible as possible to allow for field conditions in remote locations. Time had to be spent to hold discussions with as many people as possible. The field survey did not permit scheduling with great accuracy and allowances had to be made for this. 3.1.2.7 Collecting in the field The map of the given country was divided into grids, which roughly coincided with the topography. The more diverse the ecosystems the more diverse the landraces and hence the smaller the grids. As far as possible a local guide was found for a grid or neighboring grids. The extension officers acted as guides for their districts. The collecting team comprised the Team Leader (the Plant Breeder), the Agricultural Extension Officer, the local guide, the driver or boatman and a graduate assistant. It was an asset to have a member of the team also proficient in photography and drawing. One of the most important tasks in the field was to fill out the Collecting Form for each accession. The questionnaire with its 43 questions was upgraded by IPGRI for use internationally. Sampling followed the methods described in the IBPGR Manual (Hawkes, 1980). The frequency of sampling depended on the actual diversity on the ground. The greater the diversity the closer the sampling locations. Samples were collected in duplicates and the Collecting Form was also duplicated to safeguard against loss and to provide a complete set for the host country. The collection sites were, viz.:
The sampling protocol, which guided collection, was as follows:
The taxonomic indicators mainly used to distinguish between the Capsicum spp. which were most likely to occur in the fields, are shown below:
Source: Greenleaf, 1985. 3.1.3.0 Characterization and preliminary screening Work was continued on the morphological characterization of those accessions in the germplasm collection transplanted this season. The Descriptors for Capsicum (IPGRI, 1995) were applied. Thirty-two accessions were planted in rows of varying lengths. The least number of plants per accession was 10. Wide spacings, 150cm x 84cm, were used to permit single plant observations. Preliminary screening of the 20 Cayenne introductions from AVRDC was done in order to determine those with the highest number of berries per plant and the highest level of general adaptability. Samples of berries were processed by the food technology laboratory of the BADMC into powdered pepper. Seven accessions were selected through the application of the above criteria and upon the high quality of powdered pepper produced from their dried berries. The first round of selection was based on visual observations for robustness of plants and the presence of pests and diseases. Samples of seed and berries were supplied to our collaborators in the Department of Biological and Chemical Sciences of UWI at Cave Hill. They have been doing chemical analyses on pungency levels and molecular analyses to determine genetic relatedness of the accessions. 3.2.0.0 Resistance Breeding The Backcross procedure (Allard, 1960) was followed. The F1 (Scotch Bonnet x Bird Pepper) was transplanted into the permanent field on 6 April 1999. The crop was managed to produce F2 seed. Upon the appearance of developed berries, ten (10) plants were confirmed as genuine F1s and ripe berries were harvested to yield F2 seeds. These were treated with trisodium phosphate, insecticide and fungicide, dried and put into storage. 3.3.0.0 Improvement of Caribbean Landraces Seedlings of ten Caribbean landraces were transplanted into the permanent on the 1 April 1999. These plants were observed and managed to produce pure seed. Fruiting branches were isolated to keep out pollinators. Characterization was planned but was not done owing to the competition between task. 3.4.0.0 Breeding new improved cultivars Ten Parental genotypes were transplanted into large pots on 15 April 1999. Ten plants of each of the following were transplanted viz.: West Indies Red, Tiger Teeth, Serrano Gigante Ebano, Scotch Bonnet, Salmon, Thailand, Soudan, Touvin, Trinidad Red, Cayene, Red Scotch Bonnet. All these plants went down with mites and were no longer fit for crossing. Time and resources did not permit a replanting. This activity has to be repeated in the 2000 season. 3.5.0.0 Improvement of West Indies Red The cultivar West Indies Red was subjected to mass selection the previous year and three (3) breeding lines were extracted from the original population. These three breeding lines were planted out in 3 separate blocks, spaced widely at 168cm x 100cm,on 31 March, 1999:
Single plant selections were made and single bearing branches were isolated to produce pure seed. Characterization was done according to the IPGRI Capsicum Descriptors (IPGRI, 1995). A varietal test of the 3 breeding lines and their parental population was planted on 27 March 1999. Varietal Test The three (3) breeding lines extracted from the cultivar, West Indies Red, were planted in a replicated trial to compare them with their parent population. The latin square comprising four treatments was replicated twice thus providing 8 replications for treatments. The two 4x4 latin squares were fully randomized. This design was chosen to counteract a northward slope and strong prevailing Easterly winds. The soil was fairly uniform and the results of the chemical analyses are presented (Table 1). Accordingly, 1100 kg NPK (0-3-23+3MgO) per hectare was incorporated by harrowing into the soil before transplanting. Another application of a compound granulated fertilizer (NPK 12:12:17-2) was applied after transplanting as a side dressing at a rate of 125 kg/ha. Soluble fertilizers were applied fortnightly through the drip irrigation system, at the following rates:
Insect pests were managed by the application of imidacloprid after transplanting. Weeding was done manually and also by inter-row herbicide applications until the canopy closed over. Data were collected at each of seven pickings on the following variables:
The first picking was completed on 15 June 1999 and the last and seventh on 15 September 1999. 3.6.0.0 Agronomic Improvement 3.6.1.0 The Population Density Trial This was the second round of the population density trial. The first round was done in 1998 and it was concluded that higher plant population densities should be tested. Hence, this trial was planted. The objective of the population density trial was to compare the farmer practice (10,000 plants per hectare) with two higher densities, three and four times that used by the farmer. The 3 treatments were laid out in a Latin square design (Lauckner et al., 1988) replicated 4 times. This design was chosen to counteract two variables running at almost right angles: a north facing mild slope and steady NE winds. The size of the experimental plots in the treatment was
adjusted to measure 4.2 m x 4.76 m in order to accommodate a minimum of
20 plants in the treatment with the widest spacing. The data management
and analyses were the same as described above for the varietal test above.
The crop management practices were also similar. The crop was transplanted
on 6 May 1999. The first picking was on 27 July 1999 and the last and
seventh picking on 11 November 1999. 4.0.0.0 RESULTS AND DISCUSSION This section is addressed under the same sub-titles as Materials and Methods. 4.1.0.0 Germplasm Collection 4.1.1.0 The Seed Room At the beginning of the reporting period, September 1998, the Hot Pepper Germplasm Collection contained 65 accessions stored as seed in the cool storage room at CARDI'S biotechnology laboratory, Diamond Valley, St Phillip, Barbados. The seed room was maintained at 18-20°C by an air conditioning unit and the humidity was kept down to about 40-60% relative air humidity. Some power failures were experienced during the year and these lasted for the greater part of the day sending the room temperature as well as humidity, up. The standby generator helped during power outages but this machine also experienced problems sometimes. All this meant that the conditions in the seed room were not stable and uniform at all times. This condition was also disrupted daily to permit the emptying of the water container of the dehumidifier located inside the room. Thus, the room had to be opened whilst this task was performed. Hot air would then enter the room since there was no double door. A better dehumidifier/air-conditioning system is needed to maintain a stable and uniform environment within the seed room. Also the thermometer and hygrometer need to be replaced by better functioning instruments. The 65 accessions in the germplasm collection were increased by introductions as follows:
4.1.2.0 The Collecting Missions The three countries covered by the collecting missions were Guyana, Dominica and Trinidad and Tobago. 4.1.2.1 Guyana The two regions surveyed were the North West District and the Corentyne Coast. A total of 45 accessions were collected (Table 2). Eight of them belonged to the Capsicum frutescens L. and 37 to C. chinense Jacquin. A greater degree of variability was found in C. chinense than in C. frutescens. A wide range of plant ideotypes, berry shapes, berry colours, berry sizes and plant responses to pests and diseases, were described and recorded in the Collecting Forms. One set of the seed collected and a duplicate of the Collecting Forms, were presented to the National Agricultural Research Institute (NARI) of Guyana. The most important issues raised were the need to extend the Collecting Missions to encompass the entire country and all the species of economic importance. Guyana already had a system in place for the protection of its biodiversity and Plant Genetic Resources. The Environmental Protection Agency was mandated to oversee the management of biodiversity in general. There was also a PGR Working Group organized within the framework of NARI and it was of immense assistance to the Collecting Mission. Very valuable support was also obtained from the Extension Service of the Ministry of Agriculture. 4.1.2.2 The Commonwealth of Dominica A total of 19 accessions were collected (Table 3): 12 belonged to C. chinense and 7 to C. frutescens. The variability in both species was sizable. It was evident that many landraces, which existed in the folk memory, were not found on the ground. These were most probably lost through land clearing for banana plantations, roads and settlements. They could have also disappeared through out-crossing with introduced cultivars. This pointed to the need to mount germplasm conservation programmes at a parallel with crop development projects. Duplicates of the seed and documentation were presented to the Ministry of Agriculture, along with 3lb of seed of Bonda Ma Jacque, a popular landrace. Some very important issues were raised. Since there was no national policy, nor legal framework, for the specific protection of PGR, the Ministry of Agriculture requested that the hot pepper landrace, Bonda Ma Jacque, be reserved exclusively for commercialization by Dominica for the next 2-3 years before the distribution of its germplasm to any other commercial users. A special Memorandum of Agreement was drafted to define this ownership over germplasm which was contributed to the regional germplasm collection. An urgent need was expressed for technical assistance to put policies and the legal framework in place for the protection of the PGR of Dominica. 4.1.2.3 Trinidad and Tobago There was a great diversity of terrain and a correspondingly wide range of diversity in the hot pepper landraces. Twenty-two accessions (Table 4) were collected. The 11 accessions of C. frutescens represented the greatest variability for this species encountered in the region so far. The sizes of the berries ranged from very tiny ones of the Tobago Small Bird Pepper to the very large ones of the Tobago Big Bird Pepper. The pungency levels spanned the entire range from very mild as in the Paramin Seasoning to the super-hot types like the Seven Pod. The latter was reported to be so hot that only a few berries were needed in a big jar of pepper sauce filled with the milder cultivars. The entire range of shapes was collected in C .chinense. This was also true for the colour of the berries. Plants of C. frutescens as old as 10 years were found to be still prolific and free of pests and diseases. This was an indication of resistance in the species especially since they were surrounded by fields of hot pepper which went down with viral diseases and mites in less than a year. Only one set of seed samples was collected and deposited with the Chaguaramas Agricultural Development Project (CADP) of the Ministry of Agriculture in accordance with their instructions. They would probably release it for use by CARDI when "they would have put in place the requisite policies and laws to safeguard PGR". An important discovery was made. A tiny larvae was found in the base of the petioles of the berries of the popular landrace, Seven Pod, in Princes Town. The larvae looked like the Contarinia spp. found in Jamaica where exports to the USA were badly affected. This early discovery allowed for the timely control of this potentially dangerous pest before it spread to other fields. It was also evident in this country that the hot pepper landraces were fast disappearing mainly from out-crossing and the absence of any conservation programme. A vivid example illustrating this problem was the case of the Paramin Seasoning Pepper of very low pungency but very aromatic. The farmers complained that their seed stock was producing hot instead of mild pepper. This was to be expected since they recouped seed from previous crops grown without any isolation. The seasoning pepper was out-crossing with the super hot types in adjacent fields and since the genes governing capsaicin production were dominant, the progenies of the crosses were bearing hot berries. The solution of this problem lies in the purification and isolated seed production of this valuable landrace. This would have been promptly addressed by this project if we were allowed to bring the germplasm to Barbados. The authorities in Trinidad and Tobago should be alerted to this problem. Another widespread problem in Trinidad and Tobago was mites. The most important problem was that of policies and laws to protect PGR. This would also facilitate the movement of germplasm within the region. 4.1.3.0 Morphological characterization and preliminary screening Morphological characterization was a time consuming operation which needed at least 600 person days of trained personnel. As a result the task was partly done. The 7 best Cayenne selections were described (Table 5) along withal the 20 cayenne entries (Table 6). Samples of berries were supplied to the food technology laboratory of BADMC (Table 7). The end product, powdered pepper, was of a very high quality. The deep red pigmentation and the aroma were very acceptable. 4.2.0.0 Resistance breeding The backcross breeding procedure was followed (Allard, 1960). The (Scotch Bonnet x Bird Pepper) F1 plants were grown and ten plants were confirmed as true F1s. Their berries were twice as large as the parental Bird Pepper whilst the conical shape and red colour of the Bird pepper were dominant. Also the two other dominant traits from this same parent were the soft smearable endocarp and the dehiscence of the berries. The plants were extremely prolific and robust. F2 seed was produced (Table 8). Individual seeds would be planted out under natural field conditions to expose them to infestation by geminiviruses and whitefly. Selections will be made for resistance or high levels of tolerance. It would have been ideal to have a method to confirm infestation and to perform artificial inoculations with the right organisms. Reliable and low cost methods to measure resistances in large numbers of seedlings, are also urgently needed. These methods would have to be developed. 4.3.0.0 Improvement of Caribbean landraces Ten selected Caribbean landraces were planted out as follows: Wirri Wirri, Cayenne, Tiger Teeth, Bonda Ma Jacque, Touvin, Barbados Seasoning, St. Lucia Seasoning, St. Johns Market and Red Flat. These plots were used for pure seed production but isolation cages were in short supply. As a result the seed obtained would not be as pure as planned. Work, however, must continue with these seeds while efforts must be made to provide full isolation the coming crop. 4.4.0.0 Breeding new improved cultivars The plan was to make a set of non-reciprocal crosses with 10 parental genotypes and test these combinations for the highest General Combining Ability and Specific Combining Ability. The Diallel Analyses (Griffing, 1956) were to be applied. The entire planting went down with mites. Scarce labour prevented a replanting. This approach needs to be reviewed and a new planting made. The availability of skilled labour must also be addressed. 4.5.0.0 Improvement of West Indies Red 4.5.1.0 Breeding line extraction The three breeding lines extracted from the cultivar West Indies Red, were further observed and described (Table 9). They were named Caribbean Red, Caribbean Green and Caribbean Purple. Their main distinguishing characters are described below: Caribbean Green: The fully developed berry is of a deep dark green colour before it finally turns into a dark red. The average length of the berry is 3.76cm and the width is 3.32cm giving it a blocky shape. The fruit wall thickness is 2.6mm and the number of locules in a fruit is 4. It takes an average of 85 berries to weigh a kg (38 in a lb). Caribbean Red: The fully developed berry is of a pale light green to cream colour. The average fruit length is 4.2cm and the width 2.8cm giving the fruit an elongate shape. It takes an average of 89 berries to weigh a kg (40 in a lb). The fruit wall thickness is 1.2 mm. There are 4 locules in a berry. Caribbean purple: The fully developed berry is light green in colour with the sides and shoulders painted a purple blush. The berry is 4.6cm long and 3.9cm wide giving it a lantern shape. It takes about 100 berries to weigh a kg (45 in a lb). The fruit wall thickness is 2mm and there are 4 locules in a berry. A fourth breeding line was selected this season and single fruits were isolated to produce pure seed. The berries of this line carried a well-developed equatorial fold just like the Scotch Bonnet but with the difference that the mature berries were deep red in colour. This breeding line could be described as a Red Scotch Bonnet. Single fruit selections were made from the most typical plants of all 4 breeding lines. Seeds from single fruits would be planted out in progeny rows. Selection for fruit type, fruit quality, prolificacy and high general adaptability, would be made both between and within rows. 4.5.2.0 Varietal test A varietal test was done to compare the 3 breeding lines with their parent population the West Indies Red. The data presented in Figure 1 showed that the average yield per plot over 7 pickings for all the 3 breeding lines and the parent population, were the same. The highest yields were obtained at the third and fifth pickings. The important indication was that the breeding lines did not suffer any reduction in yield due to the selection process. They retained the genes for yield from the parent population, the West Indies Red. Table 10 and Figures 2-4 also showed that the breeding lines did not differ significantly from West Indies Red in the following characters:
The treatments, however, differed in the mean average length of fruit. The Caribbean Purple bore significantly longer fruits than the other 2 breeding lines and the parent population (P = 0.02). The varietal test confirmed the assumption that selection for fruit colour and shape would change neither the yielding ability nor the plant ideotype. 4.6.0.0 Agronomic Improvement The component research activity accomplished this season was a second round of spacing trial. The first round was completed in the 1998 planting season when 5 plant population densities were compared with that of the farmer. Those densities were as follows:
It was concluded then that the yield continued to increase in a linear manner from the lower to the higher plant population densities. A plateau effect was not reached even at the highest density. It was therefore decided to test even higher densities in the planting season of 1999. 4.6.1.0 Spacing trial 1999 The following plant population densities were tested in the 1999 planting season:
The cultivar West Indies Red (Capsicum chinense Jacquin) was used. The experiment was transplanted on 6 May, 1999 and the last picking was done on 10 November, 1999. Crop growth was normal and no extreme environmental conditions were experienced. The total yield per plot (Table 11 and Fig. 5) over seven (7) pickings has shown that the farmer practice yielded 15.88kg (equivalent to 15,125 kg/ha) whilst the other two higher plant population densities yielded 34.27kg (equivalent to 32,641 kg/ha) and 35.46kg (equivalent to 33,775 kg/ha), respectively. This difference between the yields of the lowest density and those of the two higher densities, was very significant (P<0.001). Treatment C, the highest plant population density, yielded 123% more than the farmer practice whilst the next higher density out-yielded the farmer practice by 115%. The same data presented graphically in Figure 2 showed clearly that there were no differences between the two higher densities. It was interesting to note that the yields peaked at the 3rd and 4th pickings and decreased over time until the crop was discontinued at the 7th picking. The data clearly showed (Table 11 and Fig. 6) the trend for plants at the wider spacings to yield a larger number of mature fruits. The differences between the treatments were statistically significant (P<0.001). However, the yields per plot from the closer spacings were higher as was described above. This meant that although the number of fruits per plant was less at the higher population densities, the larger number of plants per unit area more than compensated for the shortfall. The mean average plant height and plant width were significantly (P<0.001) affected by the treatments (Table 11 and Figures 7 and 8). There was a clear tendency for the plants to grow taller and narrower as the plant population density increased. Yield components, the mean average fruit weight, the mean average fruit length and the mean average fruit width (Table 11) were not affected by the treatments. The following conclusions could be drawn:
However, the economic costs of high population densities need to be measured. Its effect on weed management, fertilizer rates and water consumption, inter alia, must be determined through subsequent work. References
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