Tomas Ayala | USDA Agricultural Research Service (original) (raw)

Papers by Tomas Ayala

Mangifera casturi is one of about 31 species of mango that can be found in Kalimantan, Indonesia.... more Mangifera casturi is one of about 31 species of mango that can be found in Kalimantan, Indonesia. The ‘Casturi’ may have originated in a very small area around Banjarmasin in southern Borneo, Indonesia, where is it called Kalimantan or Kasturi.The species was endemic to the region, but it is believed extinct as a wild population. The tree is about 10–30 m tall, which is endemic to a very small area around Banjarmasin in southern Borneo (Indonesia). The ‘Casturi’ mango is believed to be first introduced to Florida by Garry Zill and Richard Campbell in early 2000 as part of a germplasm conservation effort. The study was conducted at the USDA/ARS Subtropical Horticultural Research Station (SHRS), National Germplasm Repository, Miami, FL. The fruits were harvested in June–July 2012. After harvest, color, several physicochemical and morphological characteristics (weight, length, width and thickness, total soluble solids, Brix, pH, and titratable acidity) of fruit, stone, and seed fresh a...

Horttechnology, Apr 1, 2013

Page 1. Teconia Benth. (Bignoniaceae) is a genus of 14 species of shrubs and small trees, 12 of w... more Page 1. Teconia Benth. (Bignoniaceae) is a genus of 14 species of shrubs and small trees, 12 of which are native to America and two to Africa (Gentry, 1992). Of these, the most widely cultivated are Tecoma capensis (Thunberg ...

The present study was carried out to evaluate the mineral content of five popular mango (Mangifer... more The present study was carried out to evaluate the mineral content of five popular mango (Mangifera indica L.) varieties in South florida. The macro/micro nutrients and heavy metal content of ‘Haden’, ‘Tommy Atkins', 'Kent' and 'Keitt' ‘Irwin’ mango leaves after harvest were determined. The experiment was conducted at the National Germplasm Repository, Subtropical Horticulture Research Station (SHRS) in Miami, FL. Sixty leaves were randomly selected from three different locations (four trees per location) within an 85 ha field at the National Germplasm Repository, Subtropical Horticulture Research Station (SHRS) in Miami, FL. The soil was a Krome (Loamy-skeletal, carbonic, hyperthermic Lithic Udorthents). The precipitation was 1.29 inches from November through February 2008-2009 and 9.52 inches from November to February 2009–2010. The soil pH ranged between 7–7.5. The mango trees were fertilized every six months with an N–P–K rate of 8–4–12 at 1 pound per inch of ...

Mango cultivars are mostly the result of random selections from open pollinated chance seedlings ... more Mango cultivars are mostly the result of random selections from open pollinated chance seedlings of indigenous or introduced germplasm. The National Germplasm Repository (genebank) at the Subtropical Horticulture Research Station (SHRS) in Miami, FL, is an important mango germplasm repository and has contributed in many ways to the development of numerous tropical and subtropical fruit cultivars. This study was carried out to compare the physico-chemical and morphological characteristics of these two promising mango cultivars. In an effort to develop novel mango cultivars at the SHRS, mature fruit was randomly harvested from open pollinated trees. From these fruit and subsequent seedlings two selections have been developed and named, ‘Seedling of S-10’ and ‘Seedling of Keitt’. Data on various physico-chemical and morphological characteristics were collected on ripe fruit. Traits assessed included fresh and dry fruit weight, weight, length and width of seed, and stone, total soluble ...

Banana has been grown both in open-field and protected cultivation in Turkey. Protected cultivati... more Banana has been grown both in open-field and protected cultivation in Turkey. Protected cultivation is very popular due to the high yield and quality. The objective of the study was to evaluate agronomic performance of five new banana cultivars under plastic greenhouse. ‘MA 13’, ‘Williams’, ‘Jobo’, ‘CV 902’, and ‘Dwarf Cavendish’ (control) cultivars were used as experimental material. Stem circumference, stem height, plant height, total number of leaves, active number of leaves /bunch, stalk circumference, and days from shooting to harvest and bunch weight were determined according to cultivar. The lowest stem circumference, stem height and bunch stalk circumference were found in ‘Dwarf Cavendish’ and the highest in ‘Williams’. Total number of leaves varied between 26 and 33. Number of days from shooting to harvest was the shortest (141 days) in ‘Williams’ and the longest (163 days) in ‘MA 13’. ‘MA 13’ had the highest bunch weight (59 kg) and the lowest (43 kg) in ‘Dwarf Cavendish’....

Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed f... more Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22% to 25% protein. The crop is very sensitive to alkaline soil conditions. When grown at soil pH of 7.5 or higher, cowpea develops severe leaf chlorosis caused by deficiencies of Fe, Zn and Mn resulting in stunted plant growth and yield reduction. We evaluated in replicated field experiments at St. Croix, U.S. Virgin Islands, and Miami, Florida, four plant introductions (PIs) and one commercial cultivar some of which have shown some tolerance to alkaline soils in unreplicated, seed regeneration plots of the U.S. cowpea collection. Alkaline soil conditions at St. Croix were severe resulting in average yield of genotypes at this location being significantly lower and 69% less than that in Florida. Nevertheless, some genotypes performed well at both locations. For example, PI’s 582605 and 582674 had signi...

Fruit of five Jaboticaba (Myrciaria caulifloria) cultivars ‘MC-05-06’, ‘MC-05-14’, ‘MC-05-12’, ‘M... more Fruit of five Jaboticaba (Myrciaria caulifloria) cultivars ‘MC-05-06’, ‘MC-05-14’, ‘MC-05-12’, ‘MC-06-15,’ and ‘MC-06-14’ were evaluated and characterized at the National Germplasm Repository, Subtropical horticulture Research Station (SHRS) Miami, Florida. Thirty fruits were harvested from clonal accessions during March and April, 2013 and2014 and allowed to ripe at room temperature (24-29 oC). Physical characteristic of fruit were determined by measuring fruit length, diameter and weight. Jaboticaba physio-chemical characteristics were determined by measuring the BRIX (°Bx), pH, tritatable acid, and fruit color (L*, a*, b*) values. The average mean fruit weight ranged from 4.02 to 7.0 for ‘MC-05-06 ’ ; 3.5 to 9.9 for MC-05-14; 3.34 to 7.0 for ‘MC-05-14’ for ‘MC-05-12’ , 3.25 to 7.5 for ‘MC-06-15’ and 2.76 to 7.5 for ‘MC-06-14’. Mean fruit length ranged from 24.75 to 13.24 mm, diameter was 22.53 mm, and peel weight fluctuated from 0.25 grams to 0.93 grams. The pH ranged from 2.32 t...

Tamarind (Tamarindus indica L) is native to tropical Africa and grows wild throughout the Sudan. ... more Tamarind (Tamarindus indica L) is native to tropical Africa and grows wild throughout the Sudan. It was introduced into India many years ago; it has often been reported as indigenous there also. The fruit was well known to the ancient Egyptians and to the Greeks in the 4th Century B.C. It is extensively cultivated in tropical areas of the world. Sometime during the sixteenth century, it was introduced into America and today is widely grown in Mexico. Tamarind is well adapted to semiarid tropical conditions, although it does well in many humid tropical areas of the world with seasonally high rainfall. Young trees are very susceptible to frost, but mature trees will withstand brief periods of 28° F without serious injury. Tamarind can be propagated vegetatively, but vegetative propagation by cuttings or air layering has not been very successful. Therefore, grafting is generally used commercially. For grafting, first of all we must obtained seedlings. Tamarind seeds are recalcitrant, t...

Pakistan Journal of Biological Sciences, 2006

A fast identification of insufficiency of nutrients using spectral features would be a useful ins... more A fast identification of insufficiency of nutrients using spectral features would be a useful instrument in farming and in other nutrient demanding agricultural systems such as those proposed for long period space missions. A Multilayer Perceptron (MLP) neural network and ...

Genetic Resources and Crop Evolution, 2014

Journal of Agricultural Science, 2013

Journal of Phytopathology, 2011

Avocado sunblotch viroid (ASBVd) causes an important disease of avocado, Persea americana. Sympto... more Avocado sunblotch viroid (ASBVd) causes an important disease of avocado, Persea americana. Symptoms of avocado sunblotch were first observed in the avocado germplasm collection at the National Germplasm Repository in Miami in the early 1980s; however, the ...

Journal of …, 2009

Plant germplasm collections serve as repositories for important genes. However, insufficient and ... more Plant germplasm collections serve as repositories for important genes. However, insufficient and inaccurate characterization of the genetic diversity in a collection can slow or can prevent full utilization of genetic resources. Bananas and plantains (Musa spp., Colla) ...

…, 2009