Performance of Cultivars for Production of Green Corn in Different Planting Dates in Passos Region, MG

The aim of this work was evaluating the performance of several cultivars of green corn for consumption 'in natura' in different planting dates. The first planting date was on May 26th, and the others, every 40 days. The hybrids (treatments) were: AG-1051, Agroeste 1567, BM-3061, Prezoto-32D10, PL-6880, BX-1382 and GNZ-2004. The following characteristics were evaluated: production, commercial ears weight without husk, commercial ears number, commercial ears diameter and length, male flowering, plant height and height of ear corn insertion. The cultivars AG1051, Agroeste 1567 and BM 3061 presented the best results compared to the others and they should be used in green corn production for ` in natura' consumption in Passos County, MG.

An Innovative Crop-Forage Intercrop System: Early Cycle Soybean Cultivars and Palisadegrass

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Selection of alfalfa cultivars adapted for tropical environments with repeated measures using PROC MIXED of SAS (R) System

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

RFLP and cytogenetic evidence on the origin and evolution of allotetraploid domesticated peanut, Arachis hypogaea (Leguminosae)

Nuclear restriction fragment length polymorphism (RFLP) analysis was used to determine the wild diploid Arachis species that hybridized to form tetraploid domesticated peanut. Results using 20 previously mapped cDNA clones strongly indicated A. duranensis as the progenitor of the A genome of domesticated peanut and A. ipaensis as the B genome parent. A large amount of RFLP variability was found among the various accessions of A. duranensis, and accessions most similar to the A genome of cultivated peanut were identified. Chloroplast DNA RFLP analysis determined that A. duranensis was the female parent of the original hybridization event. Domesticated peanut is known to have one genome with a distinctly smaller pair of chromosomes ('A'), and one genome that lacks this pair. Cytogenetic analysis demonstrated that A. duranensis has a pair of 'A' chromosomes, and A. ipaensis does not. The cytogenetic evidence is thus consistent with the RFLP evidence concerning the identify of the progenitors. RFLP and cytogenetic evidence indicate a single origin for domesticated peanut in Northern Argentina or Southern Bolivia, followed by diversification under the influence of cultivation.

Fungus incidence on peanut grains as affected by drying method and Ca nutrition

An experiment was conducted to study the effects of liming and drying method on Ca nutrition, fungus infection and aflatoxin production potential on peanut (Arachis hypogea) grains. Peanut cv. Botutatu was grown in the absence or presence of liming to raise the base saturation of the soil from 20 to 56%. Calcium contents of the soil were increased from 5.5 to 14.6 mmol((c))kg-1 and pH from 4.2 to 4.9. After harvest, plants and pods were dried in (1) shade, (2) field down to 100 g water kg-1 (3) field down to 250 g water kg-1 and transferred to a forced-air oven at 30°C, (4) field down to 360 g water kg-1 and transferred to a forced-air oven at 30°C. Calcium contents were analyzed in the grains, pericarps and seed coats. The incidence of Aspergillus spp., Penicillium spp., Rhizopus spp. and potential aflatoxin production in vitro were evaluated, as well as the seed coat thickness. The seed coat was thicker when peanut was grown in the presence of lime, leading to a decrease in seed infection by Aspergillus spp. and Penicillium spp. When plants were dried in shade, the growth of aflatoxinogenic fungi was independent of liming. However, in plants dried in the field or field + oven, the development of these fungi was decreased and even suppressed when the Ca content of the seed coat was increased from 2.2 to 5.5 g kg-1.

Evaluation of microsatellite markers in cultivars of sweet orange (Citrus sinensis [L.] Osbeck)

Sweet orange is considered a very important species in the citrus world market and presents wide morphological variability. However, its characterization at the molecular level by random amplified polymorphic DNA (RAPD) and isozyme markers is not appropriate. Microsatellite or simple sequence repeats (SSRs) have been suggested as ideal for studies in cultures of vegetative propagation and as value markers for mapping in several species. However, information on microsatellite polymorphism in citrus species is scarce. In this work, microsatellite markers (AG-repeats) were developed from an enrichment library of genomic DNA of sweet orange cv. Pera (Citrus sinensis [L.] Osbeck), and 31 cultivars of sweet orange were evaluated. Evaluation of 18 microsatellite primers did not permit differentiation of the varieties studied. New microsatellite primers are being evaluated with the aim of detecting polymorphisms among the cultivars and closely related species to be used in genetic mapping programs.

Genetic variation and phylogenetic relationships based on RAPD analysis in section Caulorrhizae, genus Arachis (Leguminosae)

Wild Arachis germplasm includes potential forage species, such as the rhizomatous Arachis glabrata and the stoloniferous A. pinto and A. repens. Commercial cultivars of A. pintoi have already been released in Australia and in several Latin American countries, and most of these cultivars were derived from a single accession of A. pintoi (GK 12787). Arachis repens is less productive as a forage plant than is A. pintoi. However, it can be crossed with A. pintoi, and thus has good potential as germplasm for the improvement of A. pintoi. Arachis repens is also used as an ornamental plant and ground cover. Many new accessions of these two stoloniferous species are now available, and they harbor significant genetic variability beyond that available in the few older accessions, previously available. Therefore, these new accessions need to be conserved, documented and considered in terms of their potential for crop improvement and direct commercial use. Sixty-four accessions of this new germplasm were analyzed using RAPD analysis. Most of the accessions of A. repens grouped together into a clearly distinct group. In general, the accessions from the distinct valleys of the Jequitinhonha, Sao Francisco and Parana rivers did not group together, suggesting there is not a tight relation between dispersion by rivers and the geographic distribution of genetic variation in these species.

Nutrients foliar content for high productivity cultivars of guava in Brazil

Commonly grown in tropical and sub-tropical regions, guava (Psidium guajava L.) is an important fruit crop of Brazil. It is cultivated on a large scale in São Paulo state, and covers about 6,500 hectares. As a result of the guava selection program developed at FCAV/UNESP, two new cultivars were created: 'Rica' and 'Paluma' with a high productivity, and also with higher nutritional requirement. Leaves analysis has become a powerful tool in mineral-nutrition research with fruit crops, not only to determine response to different nutrients, but also for diagnostic techniques in making fertilizer recommendations and assessing deficiency symptoms. Nutrient composition of the leaves varies depending on the leaf maturity, tree age, variety and nutrient supply. For the interpretation of analytical values, selection of the index tissue is important. The results of experiments conducted in the field during 1989-2000 were studied. The nutritional status was evaluated by annual leaf sampling, carried out at full bloom. Recent fully developed leaves, corresponding to the third pair (with the petiole) were collected, starting at the end of the branch, all around the tree, at a height of 1.5 m from the soil, with a total of 30 leaf pairs per sample. The yield was evaluated by weighing all the fruits in the useful area of each lot. Foliar chemical analysis showed excellent correlation with the fruit production. Through the results it was verified that the maximum yield was associated to the following levels: N = 22-26; P = 1.5-1.9; K = 17-20; Ca = 11-15; Mg = 2.5-3.5; S = 3.0-3.5 g kg -1; B = 20-25; Cu = 10-40; Fe = 50-150; Mn = 180-250; Zn = 25-35 mg kg-1 DW in the leaves of the 'Rica' guava and to N = 20-23; P = 1.4-1.8; K = 14-17; Ca = 7-11; Mg = 3.4-4.0; S = 2.5-3.5 g kg-1; B = 20-25; Cu = 20-40; Fe = 60-90; Mn = 40-80; Zn = 25-35 mg kg-1 DW in the leaves of the 'Paluma' guava.

Effect of storage of cuttings on the rooting of different cultivars of cut chrysanthemums (Dendranthema grandiflora Tzvelev) for two different seasons

Chrysanthemums are commercially propagated through cuttings. Pre-rooting storage of cuttings in the dark is a common practice among growers and companies that work and trade with chrysanthemum cuttings. Therefore, the maximum storage period for cuttings and differences in tolerance among cultivars has been investigated. Adventitious roots of cuttings can originate in almost any tissue, including the epidermis, stem cortex and pericycle, ray parenchyma, immature xylem and phloem cells, and pith. The aims of this work were to determine the effect of time of cold storage of cuttings (0, 1, 2, 3, 4, 5 and 6 weeks) on the rooting of four cut chrysanthemum cultivars (Super White, Sheena, Dark Orange Reagan and Town Talk) for two seasons of the year (summer and winter), and also to determine the origin of root formation in chrysanthemum cuttings. The study was carried out as a randomized complete block design with 5 replications for each storage treatment. Each plot was comprised of three cuttings that were examined 14 days after the cutting procedure. During the winter, the roots were studied by scanning electron microscopy (SEM) at the Electron Microscope Laboratory. The following conclusions were made: in winter, cold storage affected the rooting of cuttings, mainly after two weeks of storage for all cultivars. The rooting percentage was lower in the winter and the cuttings could be preserved for a shorter period. The source and growth of roots in chrysanthemum cuttings was found to be endogenous. After three days, callus formed in the pericycle and the first emergence of adventitious roots occurred by the fourth day of rooting. During the summer, cold storage could be up to 4 weeks without any problems.

Cultivation systems and planting seasons effects on the vegetative growing of net melon cultivars

Growth effects of cultivation on soil, sand and commercial substrate, on summer and winter time, of 'Bonus #2', 'Don Carlo's and 'Hy Mark' were assessed. The experiments were conducted in a greenhouse of FCAV-UNESP, in Jaboticabal- SP, Brazil, 21° 15' 22 S, 48° 18'58 W, and an altitude of 595 m, comprising the period from November '99 to April 2000 (Summer), and from July to November 2000 (Winter). On soil cultivation, chemical nutrients were used, and the plants received drip irrigation. On sand, fertigation with recirculation of the nutrient solution were used, and slabs and fertigation with non circulating nutrient solution was used with commercial substrate. 'Bonus #2', grown on sand and in the summer season had improved plant height, internodes length, stem diameter, leaf area and dry matter of shoots and roots. 'Hy Mark', when cultivated on commercial substrate had lower growth. During winter season, the growth was slower.

Net melon cultivars productivity under different cultivation systems, during summer and winter

In order to access the effects of cultivation in soil, sand or a commercial substrate on the productivity of Bonus #2 cultivars, 'Don Carlos' and 'Hy Mark', two experiments were conducted in the greenhouse at FCAV-UNESP, Jaboticabal- SP, Brazil, 21° 15' 22 S, 48° 18'58 W, and altitude of 595 m, from November 1999 to April 2000 (summer), and from July to November 2000 (Winter). For cultivation in soil, chemical nutrients were added, and plants were irrigated with drip irrigation. Fertigation with recirculation of the nutrient solution was used on sand; slabs were used on commercial substrate with the fertigation with non circulating nutrient solution. Bonus #2 cultivar yielded the highest production of marketable fruit, but were later in production, while Hy Mark cultivar had early production but a lower number of fruit per plant. The winter planting yielded higher production of marketable fruit while summer plantings yielded lower number of fruit per plant, but with higher average weigh. The combination between cultivation systems and cultivars yielded higher fruit production in winter.

Damages occurrence and determination of dasineura Sp. (Díptera: Cecidomyiidae) in the pepper cultivars (Capsicum annuum L.) in piracicaba Sp.

The purpose of this study was to evaluate the damage potential of Dasineura sp. (Diptera: Cecidomyiidae) in the pepper cultivars and show its occurrence in Piracicaba, SP. This experiment was carried out from July to November 1998. The occurrence and damages pest in the fruits were determined by weekly evaluations of pepper hybrids, 'Magali R.' larvals were collected from floral buttons and adults were collected from the incubation of buttons in humidity chamber. Healthy and infested fruits were evaluated for damages caused by pest insects. The results indicated that the damages can reach 100% in some periods of evaluation and that the production losses are significantly high with no application of insecticides. The taxonomy study was performed at National Museum of Federal University of Rio de Janeiro (UFRJ). The insect species classification will be the object of study since there is a possibility of observing a specie not described yet.

Mango cultivars behavior in relation to fusarium subglutinans

The mango malformation, caused by the fungus Fusarium subglutinans Wollenweb & Reinking, is probably one of the diseases that causes more damages in the mangoes production in Brazil and other producing countries. This fungus was isolated of a Tommy Atkins plant with advanced symptoms of malformation, purified and prepared to be inoculated in 15 cultivars of national and imported mangoes. Initially, 10 cultivars had been inoculated in July/2000: Bourbon IAC - 100, Coração de Boi, Keitt, Parvin, Primor de Amoreira, Sensation, Smith, Surpresa, Tommy Atkins and Van Dyke. Another group was inoculated in December/2000, on the cultivars: Adams, Bhadauran, Palmer, Princesa and Zill, and with others cultivars Primor de Amoreira, Sensation and Tommy Atkins, that were inoculated in the first time, with the purpose to compare the two times of inoculation. Throughout the evaluated data at the two times of inoculation, after 11 months of evaluation, were maden the analysis of the variance in function of the involved sources of variation and the test of Duncan to compare the averages of inoculated cultivars. With the results obtained, the cultivars Bhadauran, Palmer, Parvin, Sensation, Van Dyke and Zill presents less percentage of plants with malformation symptoms or less progression of symptoms in relation to the others inoculated cultivars, under protected environmental conditions, where the assays were carried out.

Yield and fruit size distribution of processing tomato cultivars

The productivity and fruit size distribution of 28 processing tomato cultivars were analyzed to determine the ones with potential for fresh market. The experiment was done in Jaboticabal-SP, Brazil (21o15'22'' South, 48o18'58'' West, altitude 595 m), in a Haplorthox soil, from June to December. The cultivars H 7155, Hypeel 108, Andino, U 573, H 9036, Ipa 6, H 9494, AG 33, Yuba, RPT 1294, AG 72, Peelmech, Curicó, Hypeel 45, RPT 1478, H 9492, H 9498, H 2710, Hitech 45, Halley, Botu 13, H 9553, U 646, NK 1570, AG 45, RPT 1095, RPT 1570 and PSX 37511 were evaluated. The experimental design was randomized blocks, with four repetitions, and five plants per experimental unit. Fruits harvested from each experimental unit were counted, classified by transversal diameter (large, medium, small, very small and cull) and then weighed. Cultivars AG 72, H 9498, Hypeel 45, RPT 1095 and Curicó yielded more than 70 fruits per plant, on average. The total production per plant of cultivars AG 72, H 9498, Hypeel 45, H 7155, Hypeel 108, Halley, Hitech, RPT 1095, H 9494, H 9036 and Curicó was greater than 4 kg. Considering the weight of large and medium fruits, categories which are important for fresh market, the cultivars H 2710, Botu 13, U 573, Hypeel 45, Yuba, RPT 1294 and Ipa 6 presented values above 50% for production.

Total and harvest-date yield of processing tomato cultivars

The productivity of 28 tomato cultivars was evaluated over three stages of harvest. The study was carried out during from June to December of 1999 in an open field at the experimental area of the Section of Olericulture and Aromatic Medicinal Plants, Department of Crop Production at FCAV-UNESP, Jaboticabal, SP, Brazil. The cultivars studied were H 7155, Hypeel, Andino, U 573, H 9036, IPA 6, H 9494, AG 33, Yuba, RPT 1294, AG 72, Pelmeech, Curico, Hypeel 45, RPT 1478, H 9492, H 9498, H 2710, Hitech 45, Halley, Botu 13, H 9553, U 646, NK 1570, AG 45, RPT 1095, RPT 1570, and PSX 37511. The experimental design was a randomized block design with four repetitions, with five plants per plot. Productivity was evaluated at three stages of harvest at 119, 149 and 179 days after seeding. There were no significant differences among the cultivars at the first harvest (119 days). The majority of the cultivars produced their highest yield at the second harvest; the most productive cultivars were Curicó and AG 72, which yielded 4.69 and 4.67 kg/plant, respectively, although they did not differ statistically from the cultivars Hypeel 45 (4.35 kg/plant) and H 9498 (4.16 kg/plant). Yields of the cultivars Andino and H 9494 were evenly distributed between the second and third harvests. At the third harvest, cultivar IPA 6 had the highest yield (2.9 kg/plant) and was statistically different from all other cultivars except H 9036 (2.34 kg). These two cultivars had the most delayed and concentrated maturity, making them suitable for mechanical harvesting, although at a later time. Cultivar AG 72 had the greatest total yield (5.76 kg/plant), but it was not statistically different from cultivars Hypeel 45 (5.43 kg), Curico (4.17 kg), H 9498 (4.83 kg), H 7155 (4.58 kg) and Halley (4.55 kg). All of the cultivars, with the exception of cultivars H 9036, IPA 6, Andino and H 9494 showed in the second harvest concentrated maturity, making it suitable for mechanical harvesting.