Fundamental Understanding of Tea Growth and Modeling of Precise Tea Shoot Picking Based on 3-D Coordinate Instrument

Tea is a popular beverage worldwide and also has great medical value. A fundamental understanding of tea shoot growth and a precision picking model should be established to realize mechanized picking of tea shoots with a small product loss. Accordingly, the terminal bud length (Lbud), tea stem length (Lstem), terminal bud angle (αbud), tea stem angle (αstem), and growth time (t) were considered as the key growth parameters; the sum of the vertical lengths of the terminal bud and stem (ξ), the picking radius (r), and the vertical length of the stem (Zstem) were considered as the picking indexes of the tea shoots. The variations in growth parameters with time were investigated using a 3-D coordinate instrument, and the relationships between the growth parameters and the picking indexes were established using an artificial neural network (ANN). The results indicated that the tea growth cycles for periods P1, P2, P3, P4, P5, and P6 were 14, 7, 6, 4, 4, and 6 d, respectively. A growth cycle diagram of the tea growth was established. Moreover, a 5-2-12-3 ANN model was developed. The best prediction of ξ, r, and Zstem was found with 16 training epochs. The MSE value was 0.0923 × 10−4, and the R values for the training, test, and validation data were 0.99976, 0.99871, and 0.99857, respectively, indicating that the established ANN model demonstrates excellent performance in predicting the picking indexes of tea shoots.

Effect of salinity and drought stress on morphological and biochemical properties of two Iranian fenugreek (Trigonella foenum-graecum) populations

In this study, micro propagation of two Iranian fenugreek populations and their morphological and biochemical responses to salinity and drought stresses in in vitro culture condition were conducted using factorial experiment in a completely randomized design in three replications. Different explant type (terminal bud, cotyledon and epicotyledon explant) were cultured in MS medium contain different concentration of plant growth regulators such as kin (0, 0.5 and 1 mg / l) and 2,4-D (0.5, 1 and 2 mg / l). Murashige and Skoog (MS) medium supplemented with 1 mg/l kinetin and 2 mg/l 2,4-D showed the highest callus proliferation rate per explants in both populations. The highest amount of callus volume was obtained from the explants of the terminal bud. Proliferated calli from terminal bud explant were green and yellowish, from cotyledon were yellowish to white with soft texture, and the cotyledons were greenish and compact. The results of salinity stresses with different concentrations of sodium chloride (0, 70 and 120 mM) and drought stress with polyethylene glycol (0, 5 and 10%) showed that both stresses decreased callus growth and increased total protein, proline, catalase, peroxidase and trigonelin content in both populations. Trigonelin measurement showed that ‘Borazjan’ papulation had higher trigonelin content, in vitro, than ‘Ardestan’ papulation.

Cocos nucifera (coconut).

C. nucifera is believed to have originated in the Indo-Malayan to Western Pacific region (Parrotta, 1993) and is now of pan-tropical distribution, mainly the result of cultivation for its nuts and by natural dispersal by the oceans. It can be cultivated up to an elevation of 1200 m near the equator or 900 m at higher latitudes (Moistero, 1978), with annual rainfall of 700-5000 mm but growth and fruit production are reduced at the extremes (Parrotta, 1993). Commercial production of coconuts is mainly concentrated in low coastal lands. It prefers deep, fertile and adequately drained soils at pH 5.5-6.5, with either a high water-table or continually replenished surface soil moisture (Francis and Liogier, 1991; PCARRD, 1993). Generally, C. nucifera is propagated from seeds (the nuts), which take 8-10 weeks to germinate and 30 weeks to reach planting-out size. It is intolerant of shade, self-pruning, highly resistant to wind damage and may tolerate some salinity (Parrotta, 1993). Besides its nuts, C. nucifera trees are of enormous general utility. The timber is used for poles, construction, furniture, boxes, fixtures, particle board, paper pulp, charcoal, and occasionally veneers. The wood is difficult to saw, requiring tungsten carbide teeth. Coconut milk may be drunk or used as a medium for tissue culture; the copra (dried endosperm) is used for extraction of oils for use in foods, cosmetics, and medicines; the cori (mesocarp fibres) is used to construct mats, ropes, carpets, brushes, brooms, and bags, packaging, and potting media; the shell is used to make bowels, cups, spoons, ladles, smoking pipes, ashtrays, vases, boxes, and toys. The leaves are used in thatching, and the terminal bud may be eaten as a vegetable. The roots have medicinal properties, and provide a sweet sucrose-rich liquid known as toddy (Westphal and Jansen, 1989).

Dynamic Changes in Endogenous Hormones in Terminal Buds from Different Crown Positions in Sequoia sempervirens (Lamb.) Endl

Endogenous hormones can improve plant resistance and regulate growth and development. To obtain the basis of chemical control technology for improving Sequoia sempervirens resistance in Xuzhou, China, the current study probed the dynamic changes of endogenous hormones in terminal buds from different crown positions in S. sempervirens. Enzyme-linked immunosorbent assay (ELISA) was used to measure changes in the contents of endogenous hormones in terminal buds from the upper, middle, and lower lateral branches. The results were as follows: Indole acetic acid (IAA) in all terminal positions had a similar change trend of “rise–drop–rise.” Gibberellic acid (GA) in the upper and middle terminal buds showed similar trends of “drop–rise,” but GA in the lower lateral branches presented a “rise–drop” trend. Zeatin–riboside (ZR) in all terminal positions had similar change trends of “drop–rise.” Abscisic acid (ABA) in all terminal positions had similar change trends of “drop–rise–drop.” the trend of (IAA + GA + ZR)/ABA in all terminal positions was the same as that of IAA. Our results confirmed that, in autumn, the high content and ratio of stimulatory endogenous hormones in the terminal bud of S. sempervirens induced the terminal bud cells to continue to divide and grow, and the new branches could not be fully lignified and deeply dormant before the onset of low temperatures in winter, which led to a decrease in cold resistance and even the death of the terminal buds.

Cranberry Response to Sulfentrazone Rate, Timing, and Application Volume

The recent registration of sulfentrazone, a selective, soil-applied, PRE herbicide labeled for control of various weeds in cranberry, expanded the number of modes of action that could be used in the crop. A 2018 preliminary study in Massachusetts showed that high rates of sulfentrazone applied at the cabbage head stage reduced the number of flowering uprights (vertical stems) without impacting the final yield. To clarify the use patterns needed to promote crop safety when using sulfentrazone, six studies were conducted in New Jersey and Massachusetts in 2019 and 2020. Studies compared sulfentrazone applications made at two timings (spring dormant, SD, or cabbage head, CH, stage), two rates (280 and 420 g ai ha-1), and three application volumes simulating either chemigation (3,740 L ha-1) or boom application (190 L ha-1 alone or followed by 0.25 cm water wash off). New Jersey boom application studies in 2018 and 2019 did not show significant long-lasting injury (necrosis or stunting). However, comprehensive observation of cranberry uprights 8 WAT showed a high rate of terminal bud necrosis, a reduction in the number of reproductive structures, and the development of axillary shoots associated with a high rate of sulfentrazone applied at CH. A mitigation study conducted in 2019 and 2020 confirmed the safety of chemigated sulfentrazone at the high rate with no yield reduction, regardless of crop stage at application. Washing off the herbicide from the cranberry canopy immediately after boom application did prevent the necrosis of terminal bud and the related development of non-productive secondary shoots. Considering the results of this study, application of sulfentrazone over the top of cranberry vine before scales of the terminal bud start loosening would be prudent practice at this time.

Reapplication of bud break promoters in ‘Fuji Suprema’ apple trees

The aim of this work was to verify the effectiveness of the reapplication of bud break producers on flowering, sprouting and production of ‘Fuji Suprema’ apple trees. The experiment was carried out in an experimental orchard located in the municipality of Caçador, SC, during 2016/2017 to 2019/2020 seasons. Treatments were applied at stages B and C, and those with reapplication, from 7 to 14 days after the first application. Phenology, axillary and terminal bud break, frui set, production per plant and average fruit mass were evaluated. Phenology was advanced in relation to control with the application of bud break promoters. However, treatments applied at stage B provided greater advance in relation to applications at stage C. In axillary and terminal bud break, all treatments were superior to control. In some seasons, the sequential application of bud break promoters increased bud sprouting compared to single application treatment. There is no reduction fruit set in treatments with sequential application in relation to single application. In plant production, sequential applications did not differ from single application. The average fruit mass was not altered by the sequential application of bud break promoters.

Assessing and minimizing the development and spread of fire blight following mechanical thinning and pruning in apple orchards

The adoption of mechanical thinning and pruning in commercial apple orchards has largely been limited by the risk of development and spread of fire blight. This devastating disease, caused by the bacterial pathogen Erwinia amylovora, may be transmitted by mechanical injury such as pruning, especially under warm, moist conditions conducive to bacterial growth, infection, and disease development. However, risk may be mitigated by avoiding highest risk times and applying a bactericide, such as streptomycin, following mechanical thinning or pruning. In ‘Gala’ and ‘Idared’ orchards, we evaluated the risk of fire blight development and spread following mechanical thinning early in bloom (20% bloom), when seasonal temperatures are cooler and there are few open flowers available for infection. In both orchards, we also evaluated the spread and development of fire blight by mechanical pruning in July and in August, before and after terminal bud set when shoot growth is slowed and less susceptible to infection. We also assessed the potential efficacy of a streptomycin or Bacillus subtilis biopesticide application following mechanical thinning and pruning to mitigate the spread of fire blight. In the ‘Gala’ orchard, disease never developed beyond the inoculated tree following thinning or pruning, which was unexpected for this highly susceptible cultivar. In the ‘Idared’ orchard, incidence of blossom or shoot blight from the point source, represented as relative area under the disease progress curve (rAUDPC) was rarely different for trees that received mechanical thinning or mechanical pruning compared to untreated trees, and was frequently eliminated or reduced when the antibiotic streptomycin or the B. subtilis biopesticide was applied within 24 h of mechanical thinning or pruning. For both thinning and pruning, incidence of fire blight dropped off quickly beyond the inoculated tree in the ‘Idared’ orchard and generally was not observed in trees beyond 10-15 m from the inoculated point source or predicted beyond 10 m by exponential and power law models fit to the disease progress curves. The results of this work demonstrate the low risk for fire blight development and spread by mechanical thinning and pruning when practiced under low-risk conditions—early in bloom for mechanical thinning, and after terminal bud set (in August) for mechanical pruning—especially when paired with a subsequent bactericide application. This study demonstrates the safe use of mechanical thinning and pruning in commercial apple production, corroborated by anecdotal evidence from apple growers in Western New York State.

PENGARUH PEMOTONGAN BUNGA, PUCUK DAN PENGHENTIAN PENAMBAHAN CAHAYA PADA TANAMAN MENTHA (Mentha piperita L.)

<p>ABSTRAK<br />Penelitian bertujuan mengkaji pengaruh pemotongan bunga, pucuk<br />dan penghentian pencahayaan pada tanaman M. piperita L. Penelitian<br />dilakukan di Instalasi Penelitian Lembang, Balai Penelitian Tanaman<br />Rempah dan Obat, Jawa Barat, dari bulan Januari sampai Juli 2000, dalam<br />dua tahap : tahap pertama membuat variasi lingkungan cahaya dan habitus<br />tanaman, dan tahap kedua penyulingan dan analisis komponen minyak<br />dengan kromatografi gas spektrometer massa. Penelitian menggunakan<br />tanaman yang tidak berbunga akibat panjang hari normal dan tanaman<br />berbunga akibat penambahan cahaya empat jam, pukul 18.00-22.00 mulai<br />umur 30 hari. Penelitian menggunakan rancangan acak kelompok 5<br />perlakuan, yaitu B 0 (tanaman berbunga dibiarkan), B 1 (tanaman berbunga<br />dipotong bunganya), B 2 (tanaman berbunga diletakkan pada kondisi<br />normal), B 3 (tanaman tidak berbunga dibiarkan), dan B 4 (tanaman tidak<br />berbunga dipotong pucuk). Hasil penelitian menunjukkan bahwa<br />pemotongan bunga meningkatkan mentol dan menekan menthofuran.<br />Penghentian penambahan cahaya 4 jam pada tanaman berbunga<br />menjadikan tanaman merunduk, kadar mentol menurun dan menthofuran<br />meningkat. Pemotongan pucuk dapat menurunkan kandungan mentol dan<br />meningkatkan kandungan menthofuran.<br />Kata kunci : Mentha, Mentha piperita L., pemotongan bunga, pucuk,<br />pencahayaan, kandungan mentol, kandungan menthofuran</p><p><br />ABSTRACT<br />The effect of inflorescent pinching , bud pinching, and<br />normal light period on peppermint (Mentha piperita L)<br />Experiment on the effect of pinching the inflorescent, pinching the<br />bud, and normal light period on peppermint (Mentha piperita L) was<br />carried out at the experimental garden Lembang of Research Institute for<br />Spice and Medicinal Crops, West Java, from January to July, 2000. The<br />study was conducted with two steps i.e. The first step was manipulation of<br />photo period using TL lamps and the second step was distillation and<br />analisis of peppermint oil from their products with gas chromatography<br />and mass spectrometry. The experiment, 5 treatments were given i.e.<br />using long day treated plants, 3 treatments are given i.e. control, pinching<br />the inflorescent and with holding light supplement (four hours light<br />supplement at the age of 30 days), and using control plants, 2 treaments<br />are given i.e. no pinching and pinching of terminal bud (control or normal<br />light period). The result showed that pinching the inflorescent elevate the<br />menthol and reduce the menthofuran content. Pinching the bud of non<br />flowering plants can reduce the menthol and increase the menthofuran<br />content.<br />Key words : Peppermint, Mentha piperita L, inflorescent pinching, bud,<br />pinching, light period, menthol content, menthofuran content</p>