RELATIVE TOXICITY OF SOME CHEMICAL PESTICIDES AGAINST JUTE HAIRY CATERPILLAR (SPILOSOMA OBLIQUA W.) IN TOSSA JUTE (CORCHORUS OLITORIUS L.)

Pesticides have been a major contributor to the growth of agricultural productivity and food supply. Pesticides were a key factor in significant agricultural productivity growth during the last century and continue to be a critical factor in reducing crop damage. Fifteen insecticides were investigated to select their effective and economic doses against Hairy caterpillar in a Tossa Jute variety during April-October’ 2020 at the Department of Entomology, Manikganj and Narayanganj, Bangladesh Jute Research Institute (BJRI), Bangladesh following Randomized Completely Block Design with three replications. All new insecticides with a standard were found effective for controlling jute hairy caterpillar giving 95.38, 94.55, 95.19, 92.85, 93.59, 94.22, 93.49, 93.62, 89.84, 95.72, 93.56, 93.38, 94.42, 95.39, 91.34 and 95.41 % at Manikganj; 95.78, 93.32, 93.97, 93.18, 92.09, 92.49, 93.74, 92.93, 92.29, 93.69, 93.95, 93.17, 95.31, 94.99, 92.11 and 94.53 % reduction of infestation at Narayanganj at 5th day after spray over control plot respectively. In Manikganj, the highest fibre yield (3.66 t/ha) was found in the plot treated with Rock 20 EC and the lowest (2.96t/ha) was found in Reset 20WDG treated plot. In case of Narayanganj, the highest fibre yield (3.85 t/ha) was found in the plot treated with Proxy 20 EC and the lowest (2.79t/ha) was found in Daman treated plot. These insecticides can be recommended for the farmer’s use to control jute hairy caterpillar.

Germination and Seedling Growth Response of Sprouts and Leafy Vegetables after Applying Oxygen Nanobubble Water

Background and objective: The nanobubbles remain stable in water, and it increased dissolved oxygen (DO) in the water that promotes the seed germination and the plant growth. We evaluated the seed germination and growth of sprouts (radish, wheat, and barley) and leafy vegetables (red mustard and pak choi) when irrigated with various DO of nanobubble water (NB).Methods: The oxygen NB was generated by surface friction and treated in 4 levels: NB 0% (control, DO 9.21 mg·L-1), NB 20% (DO 15.40 mg·L-1), NB 33% (DO 20.93 mg·L-1), and NB 100% (DO 39.29 mg·L-1).Results: The root length of radish and wheat increased more in NB 33% than the control plot. The fresh weight increased in NB 33% compared to the control plot in radish and wheat, and both fresh and dry weight increased more in NB 20%, NB 33%, and NB 100% than the control plot of barley. The leaf length and width of red mustard decreased more in NB 33% and NB 100% than the control plot and NB 20%, which indicated the leaf compactness. The fresh and dry weight of shoot and root increased more in NB 100% than the control plot in red mustard. In pak choi, the shoot fresh weight increased more in NB 100% than the control plot. In leafy vegetables, the germination rate of red mustard in NB 100% was higher than the control plot, however, it was not significantly different between oxygen NB plots in sprout vegetables.Conclusion: The results showed that the root growth and biomass increased after applying NB 33% in sprout vegetables. The leaf growth properties as the number of leaves and leaf size were not significantly different or decreased in NB treatments compared to control plots, but NB 100% (DO 39.29 mg·L-1) effectively increased the root growth and plant biomass in leafy vegetables.

Effects of Selected Soil and Water Conservation Structures on Soil Physiochemical Properties, Lemo Woreda, Southern Ethiopia

Soil erosion is now almost universally recognized as a serious threat to man's well-being, if not his very existence. As a result, we assessed the soil physicochemical properties of two possible levels of soil bund and fanya juu. RCBD with three replications was used to collect soil samples from each soil conservation structure. Five composite soil samples were collected from each soil structure based on slop (0-30cm). Soil physicochemical properties such as erosion index, dispersion ratio, and erodibility proportionality ratio were investigated. The effect of different soil structure levels revealed that soil properties differed significantly (P≤0.05) for all parameters studied. The control plots had significantly higher (P≤0.05) dispersion ratio, erosion indexes, and erodibility proportionality than the soils treated by the level bund and level Fanya juu structures. On the control plot, this result showed lower clay content and higher sand content. The level of soil bund and fanya juu had a significant (P≤0.05) effect on soil OC, CEC, OM, and TN, as well as available phosphorous and potassium. As a result, all related soil properties show a positive relative change when the level of soil bund and fanya juu is compared to the control plot. Aside from this result, the dynamic natures of the sciences compel us to conduct additional research based on the agro-ecological zones of the study area.

The damage caused by wind in middle-aged Scots pine stands on permanent thinning experimental plots

In July 2002, the very strong hurricane appeared in northern Poland, which caused destruction of forest cover of area more than 10,000 ha. The permanent thinning research plot in a 53-year-old pine stand located in Myszyniec forest district (150 km north of Warsaw) was lying on the edge of damaged area. The following treatments were tested on this plot: 1) control plot (without thinning); 2) schematic cut in 20-year-old stand, selective thinning to 40 years, then thinning from below; 3) schematic cut in 20-year-old stand, then selective thinning; 4) selective thinning in young stand (20–40 years), then thinning from below and 5) selective thinning all the time. A significant part of this plot was completely destroyed and in the other part of the plot, some trees survived. A small part of the plot resisted the wind attack. An analysis of the amount of destroyed trees (measured by basal area) showed no differences between particular silvicultural treatments. The level of damage differed between particular parts of the plot. Another plot located in Ostrów Mazowiecka forest district (100 km NE of Warsaw) with the same thinning treatments was touched by heavy wind in July 2011 when the stand was 62 years old. Unlike the hurricane of 2002, this storm did not destroy the experimental plot which was located outside the zone of heaviest calamity. Therefore, damage on this plot had point and group character. Although on particular measurement units, share of broken or fallen trees did not exceed 10% of total basal area, it can be observed that the lowest level of damage was noticed on plots with selective thinning in young age and thinning from below in older stand.

The effect of application of control techniques to the population, damage intensity of onion caterpillar (Spodoptera exigua hubner) and yield of shallots

Shallot is an important cash crop in Indonesia. However, its productivity is relatively low, due to the attack of the onion caterpillar (Spodoptera exigua Hubner). This study aimed to identify the effect of the application of control techniques on the population, damage intensity, and shallots yield. This research was conducted by field experiment. Control treatment consisted of covering shallots by using gauze/net and insecticide treatment with active ingredients of profenofos, metomil, and carbosulfan. The research variables consisted of the population and the damage intensity of S. exigua, as well as the yield of shallots. The results showed that the caterpillars population of S. exigua was found at 16 DAP and increased up to before harvest at 44 DAP. Covering shallots with gauze effectively suppressed the population of S. exigua (0.0 per hills), followed by treatment with profenofos (0.14 per hills), carbosulfan (0.15 per hills), and methomyl 0.32 per hills). The damage intensity of S. exigua in the plot gauze covered was 0%, lower than 32%, 25%, 12%, 10%, respectively, in the control plot, treatment of metomil, carbosulfan, and profenofos. Covering shallots with gauze also increased the weight of wet-harvested tubers (50.83 g per hills).

Effects of dose of pyrophyllite on yield and quality of the cabbage

In this study was researched the influence of the pyrophyllite as a nutrient, bio-stabilizer, soil conditioner, as the adsorbent in different combinations and correlated standard quantitative relations with mineral fertilizers (NPK 15 : 15 : 15), on the yield and nutritional value of Bravo cabbage (Brassica oleraceae var. capitata). Within the examined factor of fertilization treatment, the following variances were represented: a1 – 800 kg ha–1 NPK 15 : 15 : 15 (control plot), a2 – 800 kg ha–1 NPK 15 : 15 : 15 + 2200 kg ha–1 pyrophyllite, a3 – 800 kg ha–1 NPK 15 : 15 : 15 + 1700 kg ha–1 of pyrophyllite, a4 – 800 kg ha–1 NPK 15 : 15 : 15 + 1200 kg ha–1 of pyrophyllite, a5 – 800 kg ha–1 NPK 15 : 15 : 15 + 700 kg ha–1 of pyrophyllite. The purpose of this research was to determine the extent to which the components of the yield and nutritional quality of cabbage depend on the different applied doses of pyrophyllite. The results indicate the fact that the treatments with the application of higher participation of pyrophyllite had a positive effect on the weight and quality of the cabbage head in relation to the control variance.

Efficiency Improvement of Ground-Mounted Solar Power Generation in Agrivoltaic System by Cultivation of Bok Choy (Brassica rapa subsp. chinensis L.) Under the Panels

An agrivoltaic system is a combination of solar power generation and crop production that has the potential to increase the value of land. The system was carried out at a 25-kW photovoltaic (PV) power plant located at the Asian Development College for Community Economy and Technology (adiCET), Chiang Mai Rajabhat University, Thailand. The growth and yield of bok choy (Brassica rapa subsp. chinensis L.) and the solar power output were investigated and compared with the control. Moreover, the efficiency of the agrivoltaic system was evaluated. The results indicated that the average intensity of solar radiation of 569 W/m2 was obtained. The highest power generation was recorded in the PV with crop production of 2.28 kW. Furthermore, the control plot of crop production at 35 days provided higher growth than bok choy plots under solar panels of 2.1 cm in plant height, 6 in leaf number, 2.2 cm in leaf length and 0.2 cm in leaf wide. High-yield of bok choy was also obtained in the control plot of 17.31 kg. Although the yield of bok choy is extremely low, possibly because of light intensity, crop cultivation under solar panels could reduce the module temperature to less than the PV control of 0.18 °C, resulting in increased voltage and power generation by around 0.09 %. Therefore, an agrivoltaic system is another option for increasing revenue and land equivalent ratio in solar power plants focusing only on electricity generation. However, suitable crops for the space under PV panels should be investigated further.

Global Landscape of Organic Carbon and Total Nitrogen in the Soils of Oasis Ecosystems in Southern Tunisia

The oasis soils of Tunisia face several climatic and soil constraints. Trying to have cultures that are profitable and beneficial in terms of soil C and N sequestration in such environments is already a challenge. To conduct this, we tested under identical conditions four types of occupation in sub-plots adjacent to the crops; barley alone, alfalfa alone, intercropping barley/alfalfa, and a control fallow in a saline gypseous desert soil poor in organic matter. Field experimentation was carried out in the oasis of Degache, which is very representative of other Tunisian oases. The stocks of C and N of the plot were calculated from the start in September 2019 before the installation of the different crops. After 21 months, the control plot shows a decrease of −41% in its stock of C and −25% in its stock N. However, the best result is that of the barley/alfalfa intercropping with an increase of +126.46% in the C stock and +178.67% in the N stock. After almost two years of experience, the beneficial effect of the intercropping system in the oasis is clear. These results are very motivating and seem to be a solution to the rapid decline in soil organic stocks.

Efektivitas Pengendalian Penyakit Tungro secara Terpadu dengan Pendekatan Pengendalian Biointensif

<p>Tungro disease is one of the obstacles to increase the national rice production program. In some areas, this important disease is endemic. On the one hand, some farmers in controlling plant pests and diseases still use pesticides, which negatively impact health and the environment. On the other hand, environmentally friendly tungro disease control technology is available. This study aims to determine an environmentally friendly integrated control technique for tungro disease consisting of resistant varieties, biopesticides, and conservation of natural enemies with flowering plants in suppressing green leafhopper populations and the incidence of tungro transmission in infection-sensitive plant stage. The test area is located in Lanrang,Sidrap at the Experimental field of Tungro Disease Research Station, Lanrang Sidrap, South Sulawesi, Indonesia from April to September 2017, using a split-plot design. Main plots are: 1) Biointensive control plots, using flowering plants (refugia) and pest control with andrometa which is a mixture of the entomopathogenic fungus Metharizium anisopliae and sambiloto extract; 2) Conventional plots, without flowering plants and pest control using pesticides. As sub-plots are rice varieties: 1) TN1, 2) IR64, and 3) Inpari-9 Elo which differ in resistance to tungro. Observations were made at 2, 4, 6, and 8 weeks after planting (MST). The results showed that the population of green leafhoppers in the TN1, both in the bio-intensive control plot and in the conventional control plot, was higher than the other two varieties. The population of natural enemies in bio-intensive control consists of 10 predator families and the conventional control consists of 9 predator families. The effectiveness of bio-intensive control has an effect on decreasing the population of green leafhoppers and the diversity of natural enemies, and has no significant effect on the incidence of tungro transmission, and has no effect on grain yield. Therefore, biointensive control needs to be developed to create a pesticide-free agricultural environment.</p>

Do Woody Tree Thinning and Season Have Effect on Grass Species’ Composition and Biomass in a Semi-Arid Savanna? The Case of a Semi-Arid Savanna, Southern Ethiopia

Encroachment of woody plants has negative effects on grass species and seriously challenging livestock production and pastoral livelihood in semi-arid savanna. The effect of thinning and season on grass species composition and biomass was investigated in lowland grazing area for three seasons. The study consisted of 15 plots (each 50 m × 50 m), thinned to differing intensities. The plots were located next to each other on a homogeneous area of 3.8 ha. Five thinning intensities (0, 25, 50, 75, and 100%) were allocated randomly to the plots and replicated three times. The 0% plot was left unthinned referred to as the control plot. The remaining plots were thinned to the equivalents of 25, 50, 75, and 100% of the tree density of that of the control plot. A two-way analysis of variance and Tukey Honest Significant Differences tests were used to compare responses of grass species. Ordination of variables was carried out by multivariate technique using correspondence analysis to explore the similarity relationship of plots, seasons and species. The differences in species composition and biomass in the control and the thinned plots were significant (p &lt; 0.05). Higher grass species composition and biomass were documented in thinned plots than in the control plot. Species abundance in thinned plots ranged from 11 to 12, while that of the 0% plot was six species. Grass biomass (Kg ha-1) varied from 2,688.4 ± 736.8 to 5,035.8 ± 743.9 across thinned plots, whereas in the control plot the yield was 885.8 ± 369.1. The result showed that grass species composition and biomass increased with the increasing intensity of thinning. Grass values appeared to be optimum at the heavy intensity of thinning woody plants. Seasons were also significant with the highest values recorded in the rainy season. Rainfall played an important role by interacting with thinning and influenced total grass values. Overall, thinning that combined improved soil moisture negatively influenced woody cover and enhanced grass species composition and biomass production. Thinning of bushes to the 75% of tree density would sustain the original savanna and maximize forage production for grazers.