Intelligent Control System to Irrigate Orchids Based on Visual Recognition and 3D Positioning

This work develops a novel automatic irrigation system to implement the customized and accurate watering for an individual seedling. The system integrates the modules of visual recognition of the stem-leaf junction, identification of the stem-root junction as the watering point, and control of the spraying nozzle. The model of YOLOv3 is employed to screen the stem-leave junction of an orchid seedling, whose depth map then acquired by the method of Semi-Global Block Matching (SGBM) extracts the three-dimensional (3D) coordinates of the junction center. Next, the concept of leaf vector is introduced to identify the stem-root junction of the orchid seedling as the accurate watering point, which the spraying nozzle is controlled to reach for supplement of the specific amount of water. A number of experiments were conducted to verify the proposed irrigation system for orchid seedlings at different locations with various heights. The experimental results show that the rates of successful watering are 82% and 83.3% for the uni-pot and multi-pot orchid seedlings, respectively.

EKSPLORASI LAPANGAN JENIS PENGHASIL GAHARU (Gyrinops verstegii) DI PULAU LOMBOK NUSA TENGGARA BARAT

High economic value encourages the hunt for agarwood in nature to increase and not be controlled so that the existence of agarwood becomes threatened and rare. Gyrinops versteegii (Gilg.) Domke is one example of agarwood-producing plants that are native to Indonesia and have different characteristics from other types so that it is preferred by consumers. Exploration and study of Gyrinops is very necessary, because information about Gyrinops is still very limited, especially to find out the population and its presence in nature and which has been cultivated by the community. The study of G. versteegii population was conducted in 7 locations in four districts namely West Lombok, North Lombok, East Lombok and Central Lombok conducted on 16-29 April 2018. There were 210 G. versteegii individuals found with 20 individual seedling growth stages, 54 individual saplings 98 individual poles and 38 individual trees. The location of the meeting is marked by its geographical location with the Global Positioning System (GPS). G. versteegii can be found in various environmental parameters, namely altitude 99 - 925 masl; slope 0 - 36.6 °; soil pH 5.5 - 6.6; soil moisture 50 - 95%; Light intensity 212 -> 20,000 Lux; air temperature 26.4 - 32.5 ° C and relative humidity 66.5 - 90%. G. versteegii that grows naturally can only be found at the Aikmel Resort in the Mount Rinjani National Park (TNGR) and there are only two individuals. Further exploration needs to be carried out in the area to determine the amount and conservation steps of G. versteegii remaining on the Island of Lombok.

Seed germination and vigor of passion fruit hybrids

Most commercial plantations of passion fruit is propagate plants by seed, but germination is irregular, which hinders the growth of seedlings and uniformity, and is connected with the plant genotype. The objective of this study was to evaluate the germination and early growth of passion fruit hybrid seedlings, obtained from different genetic combinations. The hybrids were obtained from the cross between progenies from the breeding program of the Universidade Federal de Viçosa with hybrids of the Empresa Brasileira de Pesquisa Agropecuária and of the Viveiros Flora Brasil. The experimental design was completely randomized with six hybrids, five replicates and fifty seeds per experimental unit. Germination was assessed daily until the 28 days, and at the end of the period it was obtained the mean time germination, emergence speed index, seedling height, the length of shoots and roots, and the individual seedling dry matter (root + shoot)was assessed. Among the passion fruit hybrids evaluated, hybrid HB2 (UFVM0212 × BRS Sol do Cerrado) showed the highest germination and seedling biometric values and might be a genotype with potential for breeding programs for seed quality. The specific combining ability of parents can influence the quality of seeds and the vigor of passion fruit seedlings. A factor must be considered is the correct choice of maternal and paternal parents, since they influence the quality of seeds.

Effects of the number of embryos in a seed and seed mass on seedling survival and growth in polyembryonic Ophiopogon japonicus var. umbrosus (Asparagaceae)

Research on polyembryony suggests that the presence of multiple embryos in a seed confers an advantage for seedling survival. Because observations from embryo to seedling stages are lacking, however, the effect of the exact number of embryos on seedling survival is unclear. In this study, we evaluated the effect of seed embryo number on seedling survival and growth to determine the number of embryos in a seed that are advantageous for seedling survival in Ophiopogon japonicus (Thunb.) Ker Gawl. var. umbrosus Maxim., which is a taxon exhibiting cleavage polyembryony. We also investigated whether seed mass affects seed embryo number and seedling survival and growth. We found that the number of embryos in seeds of O. japonicus var. umbrosus was weakly dependent on seed mass. As the number of embryos increased, the number of seedlings surviving from seeds initially increased and then decreased; the greatest number of seedlings was produced from an intermediate number of embryos, with the number of embryos producing the greatest number of seedlings increasing with seed mass. The sum of individual seedling lengths increased with the number of seedlings. Our results indicate that an intermediate number of embryos may be advantageous in polyembryonic O. japonicus var. umbrosus.

Estimation of Correlation Coefficients between 17 Quantitative Traits in Hazelnut

Thirty-five hazelnut (Corylus avellana L.) progenies and 41 parent genotypes were used to estimate phenotypic and genetic correlation coefficients among 17 nut, kernel, and phenological traits from 1994 to 1996. Correlation coefficients were large and positive for nut size traits (nut length, width, depth, nut weight and kernel weight). Phenological traits (days of opening of female flowers, time of catkin elongation and leafing out) were also highly correlated. But most other traits were uncorrelated with each other. Plots of progeny means and individual seedling values were inspected to verify which data points to have bigger effect on coefficients. These results and their application in the OSU hazelnut breeding program will be discussed.

Leaf-cutting ants and early forest regeneration in central Amazonia: effects of herbivory on tree seedling establishment

ABSTRACTThe effects of herbivory by the leaf-cutting antAtta laevigataFr. Smith on the re-establishment of forest trees in an abandoned farm near Manaus, central Amazonia, were investigated. Experimental seedling transplants and observations on seedlings which emerged naturally in the study area showed that damage by leaf-cutting ants negatively affected tree seedling survival and growth. However, excluding leaf-cutting ants from experimental plots for 20 mo did not significantly increase tree seedling densities. The number of seedlings emerging varied considerably between plots and this obscured any effect the ants may have had on seedling survivorship. Taller seedlings, and seedlings attacked only once, suffered less mortality than smaller seedlings and seedlings attacked twice or more. In general, mortality was greater for those species preferred by the ants, indicating that selective herbivory by leaf-cutting ants affects tree species composition. The number of seedlings attacked byA. laevigataremained approximately constant throughout the period of this study in spite of the fact that the number available for attack increased. Thus, the chance of any individual seedling being attacked declined with time, suggesting that the effect ofAttaherbivory on tree establishment is stronger during the first few years of forest regeneration.

Photosynthetic response of loblolly pine and sweetgum seedling stands to elevated carbon dioxide, water stress, and nitrogen level

Seedling stands of loblolly pine (Pinustaeda L.) and sweetgum (Liquidambarstyraciflua L.) were grown in monoculture or mixed stands for two growing cycles in controlled-environment chambers. Treatments consisted of ambient (408 ppm) and elevated (806 ppm) CO2, concentrations, water-stressed and well-watered conditions, and low (20 kg N/ha) and high (215 kg N/ha) nitrogen application rates. Photosynthesis rates were measured under ambient and elevated cuvette CO2 concentrations for both whole stands and individual seedlings from these stands. Significant interactions between CO2 and water suggested that elevated CO2 concentration compensated for low water availability in individually measured loblolly pine and in whole seedling stands regardless of stand type. Expressing photosynthesis on a soil area versus a leaf-mass basis influenced the photosynthetic rankings of the three stand types relative to one another. Net photosynthetic rates per unit leaf mass were 390 and 880% higher in individually measured seedlings than in whole monoculture stands for loblolly pine and sweetgum, respectively. Lower photosynthetic contributions from lower canopy leaves in whole seedling stands compared with the upper canopy leaves used in individual-seedling measurements were thought to be responsible for lower photosynthetic rates in seedling stands. These results suggest that photosynthetic response is influenced by canopy dynamics that are unaccounted for by individual-seedling measurements of photosynthesis. Differences in photosynthetic response between loblolly pine and sweetgum stands and individuals are thought to be largely due to species-specific differences in canopy light extinction characteristics.

Quantitative genetic analysis in Phalaris tuberosa III. Maternal effects on seedling growth and development

SUMMARYThe genetic basis of variation in rate of seedling growth, and development has been examined in the Australian commercial population of Phalaris tuberosa. A model of additive genetic maternal effects has been used, with seed weight of the female parent as an index of maternal ability. Rate of leaf appearance, rate of tillering and growth per tiller are all genetically variable in the population, with estimated heritabilities of 0·36, 0·23 and 0·34 respectively on an individual seedling basis. Total seedling growth has a lower heritability (0·17), due to a negative genetic correlation between tiller production and growth per tiller ( − 0·46). These two components have also been shown to be subject to qualitatively different seed size maternal effects. Genetic differences in seed size in the female parent have been found to influence growth per tiller, while environmental differences in seed size affect primarily the rates of leaf appearance and tiller production.