Progress 05/01/16 to 04/30/21
Outputs
Target Audience:Throughout the duration of the project, the main target audience was comprised of growers, extension agents, farm workers and students of agricultural sciences in various graduate and undergraduate courses. The target audience was presented with information on the objectives of the project, the procedures, and the project results and impact. Prior to the COVID19 pandemic, those audiences were reached through field visits, Summer Practicums, and in classroom activities, and also in the form of practical activities of crop management, variety evaluations, and short research projects. The experimental orchards were used by personnel of the Agriculture Extension Service of the UPR for workshops and trainings to extension agents and growers. Travel and physical interaction during the COVID19 pandemic limited presential activities during 2020 and 2021, but during the last part of the project audiences were reached through Online lectures and scientific presentations and publications. Changes/Problems:The main problem during the project was the damage caused by Hurricane Maria in 2017. The hurricane directly destroyed many trees in the project orchards by wind force and water running over the soil. Afterwards other trees died from soil-borne diseases favored by the excess of water in the soil. The progress of some parts of the project was delayed because of the time needed to replant the lost plants of specific genotypes. What opportunities for training and professional development has the project provided?Students, growers, and extension agents were able to receive training in morphological identification and evaluation of varieties, general practices for management of avocado production, pest and disease identification, application of growth regulators, evaluation of avocado responses to growth regulators, conservation of avocado germplasm, and avocado fruit quality assessment. How have the results been disseminated to communities of interest?Prior to the COVID19 pandemic, the results were disseminated in situ in the project orchards with visits and workshops of students, extension agents and growers, in classroom lectures, and in scientific presentations and publications. The COVID19 pandemic limited presential training of growers, extension agents, and students in most of 2020 and in 2021. However, Online training was provided through the undergraduate course HORT4015 (2020), and in January-May 2021 with the graduate courses Advanced Fruit Crops Topics (HORT 6616) and Recent Advances in Horticulture (HORT 6675). Through those courses in fall 2020- April 2021, 38 students were informed of the importance of the project and its progress. What do you plan to do during the next reporting period to accomplish the goals?Much information has been gathered during the project, and several manuscripts are in preparation on the aspects of variety evaluation, progeny results, and effects of growth regulators on flowering and fruit yield. Manuscripts have also been submitted to Acta Horticulturae from the presentations in the I International Symposium of Reproductive Biology of Fruit Tree Species and in the XIV International Symposium of Plant Bioregulators in Fruit Production.
Impacts
What was accomplished under these goals?
Project objectives: 1. Evaluation of varieties harvested early in the avocado season (June-August). 2. Evaluation of progeny of late-harvest and early-harvest varieties. 3. Evaluation of physiological regulators to extend or to hasten harvesting in late- and early-harvest varieties, respectively, and treatment effects on fruit yield. Results: 1. Several early-season varieties were evaluated in the university experimental farm in Lajas. 'Don Ramon', a variety from Puerto Rico, resulted with significantly higher fruit yield as compared to 'Wilson', 'Wilson Jr', 'Simmons' and 'Russell'. Trees of 'Don Ramon' and 'Wilson Jr' were the largest and may require frequent pruning to control their height. All the varieties were affected mainly by thrips and the Pseudacysta lacewing bug. 'Russell' generally had more damage from those pests, while their damage to the other varieties varied between low and intermediate during the project. 2. The progeny of late-harvest and early-harvest varieties was evaluated for pest damage, harvesting season, and fruit yield. There was ample difference in the months of harvest, shape, size and amount of fruits produced by trees that grew from seeds of early varieties (such as 'Wilson'. 'Russell', and 'Don Ramon'), intermediate-season varieties (such as 'Butler') and late-season varieties (such as 'Pico Godreau' and 'Fuchsia'). Some of the progeny trees produced small fruits with low-quality pulp, whereas others produced attractive fruits with pulp of good quality that may become new varieties or be used for breeding. As for pest damage, in general plants descended from 'Pico Godreau'. 'Russell' and 'Don Ramon' were more severely affected by thrips, plants from seeds of 'Russell' and 'Wilson' were more affected by scales, and plants from seeds of 'Avila' and 'Russell' were more afflicted by the lacewing bug. 3. Foliar sprays of gibberellic acid were applied at different times of the year to the late-season variety 'Semil 34', to determine their effect of flowering, fruit yield and time of harvest. Gibberellin application did not change the length of the harvesting season (October-February), but application in the fall resulted in increased yiedl, heavier fruits, and more fruits being harvested in January and February. In another orchard, paclobutrazol was soil-applied either shortly after the end of the harvesting season, and/or during flower induction to determine their effect on flowering, fruit yield and time of harvest of the early-season variety 'Wilson'. Paclobutrazol treatments did not significantly affect the date of appearance of the first flowers, but treatment increased the number of flowers as compared to check trees. Fruit retention was also greater in paclobutrazol-treated trees, which resulted in significantly higher fruit yield. The highest yield was obtained when paclobutrazol was applied in October, shortly after the end of the previous harvesting season.
Publications
- Type:
Other
Status:
Published
Year Published:
2021
Citation:
Morales-Payan, J. P. 2021. Flower and fruit production of 'Wilson' avocado in response to paclobutrazol. I International Symposium of Reproductive Biology of Fruit Tree Species. (France, online) Book of Abstracts, page 32.
- Type:
Other
Status:
Published
Year Published:
2021
Citation:
Morales-Payan, J. P. 2021. Paclobutrazol Effects on Plant Health and Yield of 'Wilson' Avocado. The Northeastern Plant, Pest, and Soil Conference. Online. January 4-7, 2021. Abstract 35.
- Type:
Other
Status:
Published
Year Published:
2021
Citation:
Morales-Payan, J. P. 2021. Influence of Exogenous Gibberellic Acid on 'Semil-34' Late-Season Avocado. The Northeastern Plant, Pest, and Soil Conference. Online. January 4-7, 2021. Abstract 34.
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Progress 10/01/19 to 09/30/20
Outputs
Target Audience:Target audience, October 2019-September 2020. In October 2019-September 2020, students from the University of Puerto Rico were the main audience of the project. Students enrolled in the courses HORT 4015, HORT 4046, HORT 4009 and CFIT 3005 visited the experimental orchards, mainly between October 2019 and early March 2020. Travel and gathering restrictions after March 2020 precluded study tours to the experimental orchards. However, during the Spring and Fall semesters of 2020, in the courses HORT 4046 and HORT 6669 the PI explained the projects, their procedures and results to the students. It is estimated that in the fall of 2019 about 110 students visited and/or were told about the experiments of the project, while in the spring semester of 2020 about 60 students were made aware of the project in study tours and/or in virtual meetings in formal courses. Efforts: The PI made efforts to involve students in the experiments of the project, by receiving study tours to the orchards, accepting students doing the Summer Practicum to participate in the project activities, bringing students of HORT 4015 and HORT 4046 to practice fruit crop management and organic agriculture management in the orchards, admitting volunteer students to participate in the orchard management, and hiring students to work in the project with assistantship. The students were presented with information on the objectives of the project, its results and impact, and the scientific procedures used in the project. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Human resources was bettered through this project by expanding the knowledge and skills of 170 students of agricultural sciences and 6 field research assistant/associate personnel of the Agricultural Exp Station in Lajas and Isabela. The areas of improvement were those of genetic diversity and breeding of avocado, variety and germplasm evaluation and description, pest identification and quantification, avocado production techniques, fruit harvesting and evaluation of its quality. How have the results been disseminated to communities of interest?Dissemination of results in this reporting period was mainly to students of agricultural sciences at the UPR-Mayaguez Campus, throughout the courses HORT 6669, HORT 4015, HORT 4046, CFIT 3005 and HORT 4009. The COVID19 pandemic made it impossible to hold a field day we wanted to hold in August 2020. What do you plan to do during the next reporting period to accomplish the goals?The evaluations of the varieties and the progenies will continue until April 30. 2021, the termination date of the project. The PI will endeavor in obtaining more funding to continue the evaluation of the progenies and their use to select or breed new varieties with superior traits, including harvesting in the spring season. Because of the COVID19 pandemic, field tours and field days will probably not happen in 2021, and therefore immediate dissemination of results will be through virtual means in formal courses at UPR-Mayaguez, or scientific presentations and publications. Presentations of results of the effects of gibberellin in 'Semil 34' avocado and of paclobutrazol in 'Wilson' avocado are on the program of the Northeastern Plant, Pests, and Soils Summit (Online meeting), January 2021. Later in 2021, the PI expects to present results of the project in the Annual Meeting of the American Society for Horticultural Science (ASHS) in August 2021. Several publications in refereed journal are possible with the results of this project.
Impacts
What was accomplished under these goals?
Main outcomes in October 2019- September 2020: Germplasm availability: The project has augmented the availability of avocado varieties for growers in Puerto Rico. It has also created a living collection of germplasm in its progeny tree orchards, allowing for the opportunity to select individual trees with superior traits and multiply them to become new varieties, and also to use them for breeding to create new varieties as well. Human resources: Another outcome was the training of students and personnel of the Agriculture Experiment Station in areas of avocado production, genetic diversity, variety description, and physiological regulation. Scientific outcomes: 1. Evaluation of early-harvest avocado varieties. All the varieties tended to be tall, showing strong apical dominance. Trees of 'Wilson Jr' and 'Don Ramon' were the largest trees, with values for crown diameter and crown height exceeding those of 'Wilson', 'Russell' and 'Simmonds'. All the varieties were affected mainly by thrips and by the lacewing bug. Damage by thrips was more severe in 'Russell', intermediate in 'Wilson Jr', and less severe in 'Simmonds, 'Wilson', and 'Don Ramon'. The thrips damage was greater in 'Russsell', intermediate in 'Simmonds', 'Don Ramon' and 'Wilson', and lesser in 'Wilson Jr'. 2. Evaluation of progeny of late-harvest and early-harvest varieties. Within the progeny of each variety, there was variation in terms of tree size and damage caused by thrips, scales, and lacewing bug. In the progeny of late-season varieties, in general, the lacewing bug caused more damage in seedlings of 'Fuchsia' and 'Piferrer'. Thrips were more damaging to seedlings of 'Pico Godreau'. Among the progeny of early-harvest varieties, in general, the lacewing bug was more damaging to seedlings of 'Avila' and 'Russell', thrips caused more damage in the foliage of seedlings of 'Don Ramon' and 'Russell', and seedlings of 'Russell' and 'Wilson' being more colonized by scales. 3. Evaluation of physiological regulators to manage the harvesting season in late- and early-harvest varieties and their fruit yield. In the late-harvest variety 'Semil 34', none of the gibberellin treatments caused the harvesting season to start earlier or to extend beyond February. However, tree sprayed with GA in the fall had a significantly greater number of fruits and said fruits were on average larger and heavier than those produced in other treatments. Also, trees treated in the fall had more fruits ready to be harvested in January and February, as compared to the other treatments which had more fruit for harvest in October-December. The results of this research indicate that in 'Semil 34' avocado GA may be used to regulate fruit size/weight and their distribution in the harvesting months. Because in PR the avocado price tends to increase after December, having more and heavier fruits for harvesting in January and February may be financially advantageous for growers. In the early-harvest variety 'Wilson', control trees had the largest crowns, while the treatment with the full rate of paclobutrazol in October resulted in the most compact tree crowns, followed by those treated in December with full rate and those with the lower rates in October and December. The treatments did not significantly change the initial date of fruit harvest, although more fruits were harvested in August from trees treated with the full rate of paclobutrazol in October of the previous year than trees receiving any other treatment. Moreover, the total fruit yield per tree was significantly greater when the full rate of. paclobutrazol was applied in October than when paclobutrazol was applied later in the year or in split rates. These results show that paclobutrazol may be used to constrain crown size in the vigorous variety 'Wilson', and also that fruit yield may be significantly greater and more concentrated in the earlier part of the harvesting season, when fruit price may be higher.
Publications
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Progress 10/01/18 to 09/30/19
Outputs
Target Audience:In October 2018-September 2019, the main audience for the project were students from Puerto Rico and from Oregon, who visited the orchards throughout the FY to learn about the research conducted and to be instructed in general management practices of the crops involved A group of 26 students and faculty from Oregon State University in a study trip to learn about agriculture in the tropics visited the orchards in August 2019. From Academia Serrant, 20 student visited the orchards on December 18, 2018. From UPR Mayaguez we had several groups visiting the orchards, including 15 students of the course CFIT 3005 on November 9 of 2018, and another 15 students of the course CFIT 3005 (a different section) on November 27, 2018. Also 15 students of HORT 4009 on February 15, 2019. Additionally, several undergraduate and graduate students worked either as volunteers or under assistantship helping with general maintenance of the orchards, application and evaluation of treatments. Efforts: Students in the courses HORT 4015, HORT 4009, HORT 4046, HORT 6616, and HORT 6998 were exposed to research methods and or to management practices in avocado through either formal course activities or research (part of student thesis, Special Research Problems). Also, volunteer students (not enrolled in courses) were involved and were trained in different aspects on the research and the general orchard management. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Students, technical assistants and farm labor were trained in various skills such as application and effects of growth regulators, avocado crop management, identification of pests and their damage in avocado, in situ conservation of germplasm, and variety phenotype awareness and description. How have the results been disseminated to communities of interest?We have disseminated results to visitors to the orchards, as well as undergraduate and graduate students in formal courses and or participating in the research. We are preparing publications based on the results gathered so far. What do you plan to do during the next reporting period to accomplish the goals?In FY 2019-2020 the evaluations of the varieties and the progenies will continue, as will the applications of growth regulators and their effects on fruit production and distribution across the harvesting season.
Impacts
What was accomplished under these goals?
Outcomes in October 1, 2018- September 30, 2019: Through this project , we have increased the number of avocado varieties available to Puerto Rican growers. Also, through this project human resources have been involved in activities to increase their knowledge and skills on avocado management, genetic diversity and phenotype description, and physiological management. The results so far show that physiological regulators may have positive impacts on avocado production in Puerto Rico, that existing varieties have important differences, and that progenies of existing varieties express attributes that may be valuable to develop new varieties. 1. Evaluation of early-harvest varieties. Throughout the year, 'Don Ramon' and 'Wilson Jr' had greater values for tree height, crown diameter, leaf area and SPAD as compared to 'Simmonds', 'Russell' and 'Wilson'. The lacewing bug Pseudacysta persea affected the leaves of all the varieties, 'Russell' showing more damage than the other varieties, while 'Don Ramon' was the least affected by this pest. 'Russell' leaves were also more affected by thrips, while 'Wilson'. was affected the least and the other varieties were intermediate in damage. 2. Evaluation of progeny of late-harvest and early-harvest varieties. Trees descending from each variety showed variation in height, canopy width, and leaf SPAD values, as well as in infestation and damage by lacewing bug and thrips. In general, the trees more damaged by lacewing bug were those descendants of 'Fuchsia', 'Russell', 'Piferrer', and 'Avila'. Scales were more abundant in the progeny of 'Wilson' and 'Russell'. Thrips affected more the trees from 'Pico Godreau', 'Russell' and 'Don Ramon', whereas descendants of 'Wilson' showed less damage by thrips. 3. Evaluation of physiological regulators to manage the harvesting season in late- and early-harvest varieties and their fruit yield. For the August-September harvesting in 2019, 'Wilson' (harvested early in the season, July-September) had recovered from the effects of hurricanes Irma and Maria in 2017. Application of paclobutrazol in 2018 affected the performance of 'Wilson' avocados in 2019, resulting in tree size smaller than the control trees by 25% when that regulator was applied in October or in December 2018. There was no effect in overall harvesting earliness, but trees treated in October 2018 had more fruits ready for harvest in the first pick (July 2019) than the other treatments. Also, cumulative fruit yield in 2019 was greater when paclobutrazol was applied in October 2018. Control trees had greater fruit yield than trees treated with paclobutrazol in December 2018 or with half rate in October and December 2018. As compared to the 'Wilson' avocado, the 'Semil 34' avocado has a later harvesting period, usually starting in October. For the FY 2018-2019, the corresponding harvesting season is that of October 2018 through January 2019, as affected by the applications of gibberellic acid conducted in 2018. The orchard was managed organically. As compared to control trees, those treated with gibberellic acid had more commercial fruits. The harvest season was about one month earlier than usual, and it was concentrated between early October 2018 and late January 2019. More and heavier fruits were harvested in late January (end of the season) from trees sprayed with gibberellin in the previous Fall, while almost none were harvested in January from trees treated in the previous Summer or from control trees. Hence, although gibberellin did not extend the harvesting season, it allowed for more and heavier fruit to be harvested late in the season, if applied in the Fall. The growth regulators gibberellic acid and paclobutrazol were applied as programmed during 2019 and the results should be available in July-September for paclobutrazol treatments in 'Wilson' avocado, and in October 2019-February 2020 for gibberellic acid in 'Semil 34' avocado, corresponding to the 2019-2020 FY.
Publications
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Progress 10/01/17 to 09/30/18
Outputs
Target Audience:The orchards were visited by agricultural science students (UPR-Mayaguez) as part of their courses, mainly Tropical Fruit Crops (HORT 4015), Fundamentals of Crop Production (CFIT 3005), Growth Regulation in Horticulture (HORT 6669). In addition, farmers and extension agents also benefited from the information provided by theresults. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project activities provided opportunities to train students and labor personnel in skills including morphological identification and evaluation of varieties, general management of avocado, application of growth regulators, evaluation of avocado responses to growth regulators, and collection/conservation of avocado germplasm. How have the results been disseminated to communities of interest?The results have been disseminated through theoretical and practical training and observation in formal undergraduate and graduate courses offered at UPR-Mayaguez, as well as during visits to the orchards. What do you plan to do during the next reporting period to accomplish the goals?We will continue applying the plant regulator treatments and measuring the results. We will continue to evaluate the varieties as well as the avocado progenies.
Impacts
What was accomplished under these goals?
Project objectives: 1. Evaluation of varieties harvested early in the avocado season (June-August). 2. Evaluation of progeny of late-harvest and early-harvest varieties. 3. Evaluation of physiological regulators to extend or to hasten harvesting in late- and early-harvest varieties, respectively, and treatment effects on fruit yield. Outcomes from October 1, 2017 to- September 30, 2018: The project has increased the number of avocado varieties available to growers in Puerto Rico. The project has enhanced the knowledge and skills of human resources involved in or exposed to its activities, including agricultural sciences students, farm laborers, growers and agriculture professionals and practitioners. Results have shown that physiological regulators may have positive impacts on avocado production. Major activities completed from October 1, 2017 to September 30, 2018: 1. The trees remained juvenile stage during the time period of this report. Growth variables (tree height and diameter, leaf area, leaf chlorophyll concentration) had greater values for the varieties 'Don Ramon' and 'Wilson Jr', followed closely by 'Simmonds'; values for 'Russell' and 'Wilson' were approximately 30% lower than those of the three leading varieties. The two main pests detected were leaf thrips and the lacewing bug. Leaf damage by thrips was more extensive in 'Russell' and lowest in 'Wilson'. Leaf damage by the lacewing fluctuated throughout the year, with the lowest values in 'Don Ramon' and the greatest in 'Russell'. 2. Seedlings coming from fruits of the early-harvest varieties 'Wilson', 'Russell', and 'Don Ramon', the main-harvest season varieties 'Butler' and 'Avila', and the late-harvest varieties 'Fuchsia', 'Pico Godreau', and 'Piferrer' were planted in field orchards. Overall, the progeny of 'Wilson' were infested by fewer thrips, but more prone to infestation by scales. Thrips were more abundant in descendants of 'Russell' and 'Pico Godreau'. Lacewing bug damage was greater in plants descending from 'Piferrer', 'Russell', and 'Fuchsia'. 3. 'Wilson' avocado trees had sparse flowering and in general, fruit production was lower than expected in this variety. It is speculated that the trees were stressed by Hurricane Maria in September 2017, when heavy winds defoliated the trees completely. In addition, excessive rainfall stressed the root system. The trees were tended to immediately after the hurricane, but it is possible that the recovery period from the hurricane coinciding with flowering induction may have contributed to reduced growth and flower production in spring 2018. Nevertheless, Wilson' trees responded to paclobutrazol application in 2017 with reduced vertical and lateral growth of branches, concentrating the foliage in a smaller crown volume in 2018. Overall fruit production was low, but the fruits produced by paclobutrazol-treated trees were larger and heavier than those in the control trees. For this reporting period, fruit harvest in the gibberellin experiment on 'Semil 34' organic avocado was scheduled for October 2017-January or February 2018. Before even the earliest fruits were mature enough to be harvested, Hurricane Maria pummeled Puerto Rico's northwestern coastal plain (where the experimental orchard is located) on September 20, 2017. All of the fruit on the trees was lost to the devastating wind and rain, and exact data on fruit yield is not available for that season. The growth regulators gibberellic acid and paclobutrazol were applied as programmed in the fiscal year October 2017-September 2018; fruit harvest is expected during the second semester of 2019 and early 2020.
Publications
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:Growers and other stakeholders visited the avocado fields at the Lajas Experiment Station during the HortExpo field day on April 4, 2017, organized by the College of Agricultural Sciences of the UPR-Mayaguez. An estimated 120 people attended the field day. On May 1, 2017, a group of 22 agricultural sciences students and professors from the University of Florida received a guided tour in the experimental orchards in Lajas, with details on the research objectives, importance and methods. On May 10, 2017, Dr. Karelyn Cruz and Dr. Denis Ebodaghe from NIFA visited the project's experiments in the Experiment Station at Isabela and were given short presentations on various NIFA-funded projects being conducted by UPR- Mayaguez, with about 50 growers, extension agents, students and UPR faculty also in attendance. Undergraduate students visited the experimental fields and nurseries, and became aware of the avocado varieties, avocado nursery management and avocado production practices. Those activities included formal lectures (fall semester 2016, spring semester 2017, fall semester 2017), and practical training in course lab sessions and summer practicum sessions with students from UPR-Mayaguez and the Inter-American University at San German, Puerto Rico (summer 2017). Changes/Problems:In September 2017 hurricane MARIA struck Puerto Rico. Although all of the island was affected by this event, the eye of the hurricane went over the part of Puerto Rico where the Experiment Station at Isabela is located, causing more damage there than in most other units of the UPR-Mayaguez experimental farm system. As a result, we lost part of the trees in the 'Wilson' orchard as well as all the fruits remaining in all the 'Wilson' trees, and 'all the fruits still developing in the 'Semil 34' trees. The loss of the fruits resulted in limited information being gathered in 'Wilson' avocados in regards to fruit yield and harvest distribution in 2017, and negated the opportunity to evaluate fruit yield, distribution in time and quality for 'Semil 34' in the 2017-2018 season. In Lajas, a number of young avocado trees of the varieties and progenies were destroyed by the hurricane winds and the water running through the fields, as well as from the damp conditions prevailing in the fields afterwards. Thus, we have been working on the recovery of the experimental orchards and replanting trees of some of the varieties when available. What opportunities for training and professional development has the project provided? Students and labor personnel involved in the project were trained in variety evaluation, avocado crop management, fruit crop nursery management, pest ID and monitoring, PGR application, and germplasm collection and conservation. Students and visitors were exposed to the research and the varieties in it. How have the results been disseminated to communities of interest?By means of formal undergraduate courses, summer practicum of undergraduate students, one-on-one training of graduate students, field days and visits to the orchards. What do you plan to do during the next reporting period to accomplish the goals?The main components of the population receiving training and knowledge from this project have been students of the agricultural sciences and related fields, extension agents, faculty members, and growers visiting the orchards. That population has been exposed to the nature of the project, its objectives, the genetic diversity of avocado, the opportunities to develop new varieties of avocado to suit the needs of Puerto Rico, identification of commercial varieties of avocado present in Puerto Rico, avocado orchard management in general and with use of PGRs in particular, as well as the use of the scientific method to solve problems in agriculture.
Impacts
What was accomplished under these goals?
Outcomes so far (October 1, 2016- September 30, 2017): Increased the number of avocado varieties available for growers in the state. Increased skills and knowledge in human resources (labor in research farms, students involved directly in the project or exposed to information of the project through classes or other training). Major activities completed (October 1, 2016- September 30, 2017): Juvenile trees of 'Wilson Jr' were approximately two times as vigorous as those of 'Wilson' and 'Russell'. Trees of 'Simmonds' and 'Don Ramon' were intermediate in vigor. All the varieties had comparable extent of leaf lesions caused by lacewing bugs. Seedlings coming from fruits of the early varieties 'Wilson', 'Russell', and 'Don Ramon' , the intermediate varieties 'Butler' and 'Avila', and the late varieties 'Fuchsia', 'Pico Godreau', and 'Piferrer' were grown in the greenhouse to be planted later in field orchards to evaluate them for desirable traits such as pest and disease presence, earliness, yield, and quality. While in the greenhouse, differences in pest abundance and damage to the seedlings were detected among and within variety progenies. Descendants of 'Wilson' were in general more infested by scales than descendants of other varieties. Thrips were more abundant in descendants of 'Pico Godreau'. In the greenhouse, lacewing bug damage was present in varying degree in the leaves of the progeny of all the varieties, and there were differences among seedlings coming from the same variety. In general, lacewing bug damage was greater in seedlings from 'Piferrer' and 'Fuchsia' than in those from ''Pico Godreau', 'Wilson Jr' and 'Butler'; in general, there was less damage by lacewing bugs in seedlings grown from fruits of 'Avila', and 'Don Ramon'. The young trees will be grown in the field to follow up on their attributes as potential new varieties. Growth regulators were applied to 'Wilson' and 'Semil 34' adult avocado trees. Application of gibberellic acid to 'Semil 34' while in bloom increased the number of fruits harvested per tree, increased average fruit weight and increased the % of fruits collected in the latest part of the 2016-2017 harvesting season. Paclotutrazol application to 'Wilson' after harvest and prior to flowering reduced vegetative growth by up to 40%, increasing fruit set and average fruit weight but did not significantly affect the fruit harvesting season up to mid-September 2017 (when Hurricane Maria occurred, and the trees still held about 35% of the fruits produced that year).
Publications
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Progress 05/01/16 to 09/30/16
Outputs
Target Audience:Students were exposed to new varieties and management practices through formal classroom instruction and field practice (HORT 4015), summer practicum (2016) for agricultural sciences students of the UPR, participation of students in the research process including training in avocado propagation and orchard management. Changes/Problems:For the experiment with existing varieties, some varieties of avocado we expected to bring to Puerto Rico from the USDA germplasm collection in Florida became unavailable. Instead, we have used other varieties for the project and have continued the project with the varieties available to us. Aside from that, we will continue trying to obtain other avocado varieties that may suit the purposes of the project. What opportunities for training and professional development has the project provided?Increased skills and knowledge in human resources (labor in research farms, students involved directly in the project or exposed to information of the project through classes or other training). How have the results been disseminated to communities of interest?By means of formal undergraduate courses, summer practicum of undergraduate students, and one-on-one training of graduate students. What do you plan to do during the next reporting period to accomplish the goals?So far, the main community receiving training and knowledge from this project have been students of the agricultural sciences at the UPR-Mayaguez Campus, who have been exposed to the nature of the project, its objectives, the genetic diversity of avocado, the opportunities to develop new varieties to suit the needs of Puerto Rico, identification of existing varieties, orchard management and the scientific method.
Impacts
What was accomplished under these goals?
Outcomes so far (up to September 30, 2016): Increased the number of avocado varieties available for growers in the state. Increased skills and knowledge in human resources (labor in research farms, students involved directly in the project or exposed to information of the project through classes or other training). Major activities completed (May 1-September 30, 2016): For the development of new early varieties, seeds of existing early varieties such as 'Wilson', 'Don Ramon' and 'Russell' were collected in late summer/fall 2016, to produce seedlings that will be transplanted to the orchard in spring 2017. In December 2016-January 2017 the same will be done for existing late varieties such as 'Semil 34'. For the evaluation of the effects of exogenous substances on time of flowering, time of fruit harvesting, fruit yield and quality, plant growth regulators were applied to 'Semil 34' and 'Wilson' orchards. Results should be available in 2017. For the evaluation of existing early varieties, grafted trees of 'Wilson', 'Wilson Junior', 'Wilson Fino','Russell', 'Simmonds', and 'Don Ramon' were obtained. Other varieties procured were 'Donnie', 'Arue', 'Dupuis', 'Nadir', 'Jose Antonio', 'Hardee', 'Dora', ;and 'Wurtz', but those have not become available to us. An orchard with replicated entries of the varieties available was established at the Lajas Ag Exp Stan of the UPR-Mayaguez Campus.
Publications
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