Constraints and Suggestions of the Cotton Growers in Vidharba for Adoption of Improved Integrated Management Practices of Pink Bollworm

The pink bollworm (PBW) is an insect known for being a pest in cotton farming. In Maharashtra cotton growers are set to lose nearly 13 % of their output due to pink bollworm attacks on the standing crop in major production regions of the state. The impact of PBW attack has been felt the most in regions of vidarbha where cotton is cultivated as the main cash crop. Present study was conducted in six districts of Vidarbha region in Maharashtra considering the maximum area under cotton cultivation namely Buldana, Akola, Amravati, Yavatmal Wardha and Nagpur. A sample of 300 cotton growers were randomly selected from twelve taluka (two taluka from each district).The major constraints faced by cotton growers were non availability of labourers and high wage rate for undertaking the manual work of handpicking of larvae destruction of affected fruiting bodies and removal of rosette flower (95.00 %), non availability of biofungicides Beauveria bassiana at nearby market (90.33%), non availability of good quality pheromone trap & good quality pheromone lure (89.00%). In case of suggestions expressed by cotton growers overcome constraints were availability of biofungicides Beauveria bassiana should made available at subsidized rate nearby market, followed by availability of recommended insecticides should made available at subsidized rate in nearby market (94.33%), the government should made available good quality pheromone trap and lure used for pink bollworm at village level (93.00%), credit facilities should be increased and process should also easy and quick (87.33%).

Estimation of Productivity and the Construction of Energy Budgets

Methods to assess the size of a population and the interactions between populations in terms of biomass (weight of living material) or energy content are described. Biomass can be expressed as wet weight, dry weight (DW), shell-free dry weight (SFDW), ash-free dry weight, or as the amount of organic carbon present. The energy content of a material may be determined directly by oxidation, either by potassium dichromate in sulphuric acid, or by burning in oxygen and determining the amount of heat liberated. The latter method—bomb calorimetry—is most convenient and is widely used in ecology, but it involves drying the material, and volatile substances can be lost. Methods to estimate standing-crop, energy density, feeding and assimilation, and production are reviewed. Energy budgets can usefully be summarized and compared if the efficiencies of various processes are calculated. Dynamic energy budget models are introduced.

Long-term overgrazing restricted the proliferation of shrubs in a desert steppe

Maintenance of a desirable mixture of shrubs and grasses is a key issue in sustainable grazing management. The aim of this study was to explore the effect of long-term sheep grazing on desert steppe shrubs. Based on a long-term controlled sheep stocking rate experiment in a desert steppe of north China, combined with long-term random sampling monitoring of above-ground vegetation standing crop (14 years) and short-term systematic sampling monitoring of vegetation cover and individual characteristics of shrubs (3 years), we analyzed plant community changes, the current situation of shrubs and the response of individual shrub characteristics to stocking rate. We found that low stocking rates have increased the cumulative above-ground standing crop of shrubs and herbaceous plants, but the cumulative above-ground standing crop of shrubs under high grazing rates tends to be flat. The cover and height of four shrub species generally showed a decrease with increasing stocking rate, while the response of the four shrubs to the stocking rate gradient varied. Among four shrub species, Artemisia frigida was the most sensitive to stocking rate, followed by Ceratoides latens and Caragana microphylla, while Kochia prostrata was relatively insensitive to stocking rate. These results suggest that grassland managers can use an appropriate stocking rate to maintain desirable plant community composition and configuration in the temperate grassland.

Comparative mycorrhizal fungal production and respiration of a neotropical rainforest versus a California mixed forest

<p>Mycorrhizae are a symbiosis between fungi and plants. We have learned about the complexity of mechanisms of interaction and interactions between the mycorrhizae and the local environment from over a century of laboratory observations experiments. Point observations and laboratory studies identify processes, but cannot delineate activity. Our goal is to use an in situ system to study mycorrhizal roots and fungi during hot moments, daily shifts, and seasonal change.</p><p>We integrated continuous in situ observation-sensor measurements using our Soil Ecosystem Observatories. As turnover rate estimates are related to sample frequency, individual scans using manual minirhizotrons (Bartz and Rhizosystems) and Rhizosystems Automated Minirhizotrons (32,000-3.01mm x 2.26mm 307,200 pixel images). Automated scans were collected up to 4x daily. Manual scans across multiple tubes in campaigns provided spatial variation. Images were organized into mosaics using RootView software, and roots and hyphae identified and length, width and biovolume determined using RootDetector <http://www.rhizosystems.com/>. Individual roots and hyphae were tracked using RootFly <https://cecas.clemson.edu/~stb/rootfly/>. Lifespans were determined using Mark-Recapture modeling and turnover calculated. With each minirhizotron tube, sensors were placed at 3 or 4 depths for temperature, moisture, CO<sub>2</sub> and O<sub>2</sub> at 5minute intervals.</p><p>Mycorrhizal fungi (MF) explore soil for nutrients and requiring C. Most C to the hyphae is respired (with a <sup>14</sup>C signal of autotrophic respiration), with the remaining divided into decomposing (heterotrophic respiration) and sequestered C pools.</p><p>Our first site is a mature neotropical rainforest, the La Selva Biological Station, Costa Rica. Trees predominantly form arbuscular mycorrhizae (AM). AMF fungi comprise 50% of total fungal mass (PLFA). Aboveground NPP-C was 750g/m<sup>2</sup>. Root standing crop C was 120g/m<sup>2</sup>, average lifespan 60days, =6 generations/y, = root NPP of 720g/m<sup>2</sup>/y. The AMF hyphal standing crop C was 12.5g/m<sup>2</sup>, average lifespan of 25 days, =14.7 generations/y, = AMF NPP of 183g/m<sup>2</sup>/y. With an NPP of 1,650g/m<sup>2</sup>/y, then AMF comprises 11% of NPP.</p><p>Soil respiration provides CO<sub>2</sub>, converting in water to HCO<sub>3</sub><sup>-</sup>, altering soil pH (Henry's Law). AMF respiration thereby increases P availability. If 10% of the AM fungal hyphae are live, then the hyphal respiration is 438g/m<sup>2</sup>/y of C, =38% of total soil respiration and 16% of site respiration.</p><p>Our second site is a mature California mixed forest, USA. Ectomycorrhizal (EM) trees predominate. Annual NPP-C was 200g/m<sup>2</sup>, and root NPP was 200g/m<sup>2</sup>. EMF NPP was 162.6g/m<sup>2</sup>, or 27% of the NPP. N, water, and temperature limit NPP. The seasonal signal was very high in this ecosystem. Peak standing crop of extramatrical EM hyphae was 19gC/m<sup>2</sup> in April. Total soil respiration in April was 0.26g/h, and extramatrical hyphae 0.029g/h, or 11% of the total soil respiration. Since P is less limiting, but N and water are, hyphae likely play a greater role in enzymatic activity and exploratory surface area.</p><p>In summary, different mycorrhizal fungi play different roles depending on ecosystem limiting factors. With global change, our challenge is to determine how an ecosystem will change and the extent and rapidity of mycorrhizal fungal change.</p>

Impact of Delayed Harvest on Corn Yield and Harvest Losses

Highlights Changes in yield, losses, and quality due to delayed harvest were evaluated. No significant changes in potential yield were observed over three years. Observed yield decreased late season with lodging present. Losses at the combine head represented largest fraction of measured loss. Abstract . Potential changes in yield and harvest losses that can occur while field drying corn are key considerations when evaluating harvest timing and energy costs associated with artificial drying. This study presents a three-year evaluation of corn harvest in Kentucky. Potential yield, observed yield, measured losses, and quality changes were monitored in a single field at multiple points over the harvest season to assess changes with respect to time and moisture. Measured losses were typically less than 1% of the potential yield in a good standing crop, consistent with results from cooperator combines (0.8% to 2.4%). When lodging was present, variability increased, and measured losses increased to between 5.3% and 9.1% of the potential yield, primarily as a result of ears missed by the combine head. No significant changes in potential yield were found, indicating potential yield was stable over the period examined. In two of the three seasons evaluated, extended delays resulted in an increase in lodging, and the observed yield was significantly reduced by up to 42.5%. Allowing the grain to field dry generally improved test weight; however, there was a trend of increased mold and other damage with prolonged field drying in one season. Keywords: Combines, Grain quality, Harvest loss, Maize, Preharvest loss.

Extreme Drought Affects Visitation and Seed Set in a Plant Species in the Central Chilean Andes Heavily Dependent on Hummingbird Pollination

Rising temperatures and increasing drought in Mediterranean-type climate areas are expected to affect plant–pollinator interactions, especially in plant species with specialised pollination. Central Chile experienced a mega drought between 2010 and 2020 which reached an extreme in the austral summer of 2019–2020. Based on intensive pollinator sampling and floral studies we show that the subalpine form of Mutisia subulata (Asteraceae) is a specialised hummingbird-pollinated species. In a two-year study which included the severest drought year, we quantified visitation frequency, flower-head density, flower-head visitation rates, two measures of floral longevity, nectar characteristics and seed set and monitored climatic variables to detect direct and indirect climate-related effects on pollinator visitation. Flower-head density, nectar standing crop and seed set were significantly reduced in the severest drought year while nectar concentration increased. The best model to explain visitation frequency included flower-head density, relative humidity, temperature, and nectar standing crop with highly significant effects of the first three variables. Results for flower-head density suggest hummingbirds were able to associate visual signals with reduced resource availability and/or were less abundant. The negative effect of lower relative humidity suggests the birds were able to perceive differences in nectar concentration. Reduced seed set per flower-head together with the availability of far fewer ovules in the 2019–2020 austral summer would have resulted in a major reduction in seed set. Longer and more intense droughts in this century could threaten local population persistence in M. subulata.

Studies on Standing Crop Biomass and Primary Productivity of Horse Gram in Jharkhand

The standing crop biomass in different plant compartments was found to be variable with the age of the crop. The total plant biomass of ageing plant indicated a sigmoidal curve in three varieties of Birsa Kulthi–1, Birsa Kulthi–2 and Birsa Kulthi–3. The total plant biomass was recorded to be 115.53 g/m2 (Birsa Kulthi–1), 92.85 g/m2 (Birsa Kulthi–2) and 72.42 g/m2 (Birsa Kulthi–3) at final harvest i.e. 105 days. Contribution of stem and leaves to the total plant biomass has increased between 15 and 90 days. Infl./pod biomass per cent as found to be increasing throughout. Standing dead biomass was maximum 9.40 per cent (Birsa Kulthi–1), 8.97 per cent (Birsa Kulthi–2) and 6.53 per cent (Birsa Kulthi–3) at final harvest i.e. 105 days. Peak values for current increments in biomass were observed at 90 days in Birsa Kulthi–1 and 105 days in Birsa Kulthi–2 and Birsa Kulthi–3. The peak values for net primary productivity were found to be highest at 90 days for Birsa Kulthi–1 and 105 days harvest for Birsa Kulthi–2 and Birsa Kulthi–3.