Reduction In Dry Matter Research Articles

EFFECT OF EXOGENOUSE LOCAL LIGNINOLYTIC CRUDE ENZYMES ON IN VITRO DIGESTABILITY AND LIGNIN CONTENT OF ROUGHAGES

In current study use local ligninolytic crude extract enzyme (HAMU 8%) to improve IVDMD and reducing lignin content. The result suggest that treated wheat straw (WS), Corncobs (Cc), alfalfa hay (AH), by HAMU increased significantly (p <0.05) in vitro dry matter digestibility (IVDMD) and reduction in lignin content, However, extra enzyme improvement is shown with Corncobs treated with HAMU (average improvement, 19.84%) and lower improvement was shown in alfalfa hay treated with HAMU (average improvement, 10.07%). The higher reduction (P<0.01) in lignin content was shown in Cc treated with HAMU from 9.8 to 7.901%, with average reduction 1.899%; when the lower reduction was observed significantly (P<0.05) with AH treated from 8.26 to 7.77%, average reduction was 0.49%.It could be recommended, treated low quality roughages with HAMU improved the nutritional value of roughages through the digestion of Structural carbohydrates.

Nitrate inhibition of N2 fixation and its effect on micronutrient accumulation in shoots of soybean (Glycine max L. Merr.), Bambara groundnut (Vigna subterranea L. Vedc) and Kersting\u2019s groundnut (Macrotyloma geocarpum\xa0Harms.)

Although nitrate is known to inhibit nodulation and N2 fixation in symbiotic legumes, little is known about its effect on the uptake and accumulation of trace elements such as Fe, Zn, Mn and Cu. The aim of this study was to evaluate the effect of 5 mM NO3− supply, either with or without rhizobial inoculation, on nodulation, nodule functioning and micronutrient levels in the shoots of soybean (Glycine max L.Merr.), Bambara groundnut (Vigna subterranea L. Vedc) and Kersting’s groundnut (Macrotyloma geocarpum Harm). The results showed reduction in plant growth, nodule formation and nodule dry matter by the supply of 5 mM NO3− to inoculated seedlings of all three species. Nitrate inhibition respectively caused 1.2, 1.4, and 1.5-fold decrease in nodule number per plant in Bambara groundnut, soybean and Kersting’s bean, which resulted in 2.3, 3.3 and 4.5-fold reduction in nodule dry weight of the test species (in that order). The application of 5 mM NO3− to soybean plants also resulted in 2.5, 4.0 and 5.4-fold decrease in shoot accumulation of Fe, Zn and Mn, respectively, when compared to the purely symbiotic control plants. Furthermore, we observed 1.3, 1.8 and 1.3-fold decreases in the concentration of Zn, Mn and Cu in shoots of inoculated Bambara groundnut with NO3− supply, levels lower than those found in soybean. With Kersting’s groundnut, shoot concentration of Fe, Zn and Cu were higher with the application of 5 mM NO3− to inoculated plants when compared to the purely symbiotic treatment, which was opposite to soybean. But pure NO3−feeding of this species respectively resulted in 2.0, 1.4 and 1.3-fold decreases in Fe, Zn and Cu relative to inoculated NO3−-fed plants. Clearly, NO3− supply to landraces/genotypes of the three legume species did not only inhibit nodule formation and functioning, it also reduced shoot micronutrient levels in soybean and Bambara groundnut, but not Kersting’s bean.

Response of many maize cultivars to weed control treatments

A field experiment was carried out in fields of Field Crops Department- Agriculture College/ University of Anbar (Abu-Gharaib) and spring seasons of 2016 in order to know the effect weed control treatments in some growth, yield and its components and protein percentage of some maize genotypes (Sarah, Maha and Baghdad 3). The experiment was conducted as split plot arrangement in RCBD with three replications of each treatment. The study included four treatments: weed treatments W1, no weed treatment W0, spraying Guradian herbecide with required recommend concentration C2, and a half required recommended concentration of herbicide C1 and these treatments occupied the main plots while the genotypes represent the sub plots (Sarah, Maha and Baghdad 3). Results showed that there is a clear effects of different weed control treatments in most studied traits under the study. The treatment of full concentration of recommended herbicide achieved lowest of weed density at harvest 4.67 and 5.44 plant m-2 in comparison with the control (weed treatment) which achieved highest mean of weed density 32.11 and 28.33 plant m-2 for both seasons respectively; therefore the full concentration recommended herbicide treatment achieved the best weed control at harvest, 87.1 and 82.7% for both seasons respectively. This has led to reduction in weed dry matter and increase in inhibition in it and that has which reflected positively in improvement of growth traits and yield and its components. As for genotypes, Sarah genotype was superior in showing its ability in reduction of weed density and their dry matter and increase in control of weeds and increase in most growth traits and yield and its components in a best degree in comparison with other genotypes under study. Sarah genotype was superior in achieving highest average of plant height 167.3 and 169.7 cm, plant dry matter 1306 and 1458 g, number of grain in ear 605 and 673 grain ear-1, weight of 500 grain 134.21 and 195.7 gm in turn all has been reflected to total yield in this genotype that gave highest average of total yield 4.08 and 4.37 ton ha-1. This is an indicator that this genotype is a very good accompanied weed competitor in comparison with Maha that gave the lowest average of most of studied traits. The treatment of hand weed control (no weed) showed the clear response of maize genotypes more than other weed control treatments and followed by treatment of herbicide at recommended rate. It can be concluded from the current study that the variance between maize genotypes in most growth traits and yield and its components and protein percentage can be an important parameter in the determination of the variance between these genotypes and their ability in the competition with accompanied weed.

Valorisation of organic waste material: growth performance of wild black soldier fly larvae (Hermetia illucens) reared on different organic wastes

Insects such as the black soldier fly (BSF;Hermetia illucens) are currently being promoted as an alternative protein source for animals and organic waste management agents. To play the dual roles sustainably, there is need to reduce reliance on wild BSF and develop an appropriate farming methodology for the insect. This study aimed at improving larvae production in a black soldier fly colony previously established from the wild in Kenya. The study explored the effect of four locally available organic wastes as feedstocks for production the black soldier fly larvae. Separate feeding trials on faecal sludge (FS), banana peelings (BP), brewer’s waste (BW) and restaurant food waste (FR) was done and their effect on BSF larvae growth rate, larvae weight, total prepupal yield in grams, crude protein and lipid (ether extract) content analysed. The efficiency of the BSF larvae to consume and therefore reduce the waste load of the different substrates was also evaluated. Results showed that BSF larvae fed on FR had significantly higher (P<0.05) total mean yield and average individual weight of 196.9±4.0 g and 0.101±0.002 g, respectively, followed by BW (154.8±6.5 g, 0.078±0.02 g), FS (138.7±5.0 g, 0.070±0.001 g) and with BP the lowest (108.9±5.6 g, 0.055±0.002 g). The harvested BSF larvae crude protein was significantly higher for FS and BW at 45.4±0.1% and 43.0±1.0%, respectively. However, ether extract content was variable and dependent on feedstock used with lower values reported for FS and BW (18.1±0.3% and 27.2%, respectively), and highest for food remains prepupa (36%). Dry matter reduction ranged between 50.3-81.8% with corresponding bioconversion and feed conversion rates ranging from 14.9-20.8% and 2.6-4.5, respectively, was achieved for the substrates used. These results indicated the potential of utilising BSF composting in valorisation of the local organic wastes for their bioremediation from the environment. Due to their availability in large quantities and their low cost, these organic wastes can form important feedstock resources for the sustainable production of BSF larvae as a future alternative protein source for both animal feeds at farm level and industrial scale. In conclusion, embracing nutrient recycling through BSF technology by resource-constrained farmers in Kenya will contribute to food security through supply of proteins for production of poultry and fish.

<b>Salinity reduces carbon assimilation and the harvest index of cassava plants (<i>Manihot esculenta</i> Crantz)

This study was developed to evaluate the effects of salinity on the growth and gas exchange of cassava plants, cultivar Verdinha. The four concentrations of NaCl (mM) were as follows: 0, 20, 40, and 60. Under salinity, the lowest concentration of Na + ions was observed in the tuberous roots; however, the dry matter of tuberous roots was reduced with an application of just 20 mM NaCl. The harvest index was reduced 50% with the highest salt concentration. Salinity reduced carbon assimilation ( A ), stomatal conductance ( g s ), transpiration, and the instantaneous water use efficiency. The correlation between g s and A was high and positive, showing that stomatal movement was one of the responsible for the lower A. Under salt stress, there was an increase in intercellular CO 2 concentration, indicating the impairment of carbon metabolism. Based on the reduction of dry matter of the tuberous roots (reduction of 81% under 60 mM NaCl), it was concluded that cassava is sensitive to salinity. The growth of shoots and the absorbing roots were minimally affected by salinity, even in the situation where A was reduced; therefore, the sensitivity of cassava was related to the high sensitivity of the tuberous roots to the ionic and/or osmotic effects of salinity. Thus, tuberous roots can be the target organ in studies that aim to improve the tolerance of cassava to salinity.

Effect of whole flax seed and carbohydrase enzymes on gastrointestinal morphology, muscle fatty acids, and production performance in broiler chickens

Flax seed is a rich source of α-linolenic acid (18:3 n-3). Feeding broiler birds flax seed can increase n-3 fatty acids in meat tissues. However, non-starch polysaccharides in flax seed decrease nutrient digestibility and can have a negative impact on bird performance and muscle fatty acid content. Addition of carbohydrase enzymes to flax-based broiler diets can decrease the anti-nutritive effects of non-starch polysaccharides. An experiment was conducted to investigate on the effect of flax seed and carbohydrase enzyme foregut morphology, muscle tissue, fatty acids, and bird performance. A total of 112 five-day-old broiler chicks were assigned to one of four treatments: Flax10 (corn-soybean meal basal diet adjusted for 10% flax), Flax15 (basal diet adjusted for 15% flax), Flax10E (Flax10 + 0.05% enzyme), and Flax15E (Flax 15 + 0.05% enzyme). Addition of enzyme led to large increases in villi height and villi width in the jejunum of birds fed Flax10 and increases in crypt depth in the jejunum of birds fed Flax15 (P < 0.05). The ratio of villi height to crypt depth was larger in the duodenum and jejunum of birds fed Flax10E when compared to Flax10 (P < 0.05). Feeding the Flax15 diet led to a significant decrease in total lipids in breast muscle compared to Flax10 (P < 0.05). The effect of level of flax or enzyme supplementation was minimal on the fatty acids measured in breast muscle except for total n-6 fatty acids which was higher (P < 0.05) in Flax15 when compared to Flax10. In thigh muscle, stearic acid, arachidonic acid, and total n-6 fatty acids were higher in birds fed Flax15 vs. Flax10. Feeding Flax15 led to a reduction in dry matter of excreta when compared to Flax10 (P < 0.05). There were no differences in BW, average daily gain, or feed consumption during the starter or grower phase due to flax level or enzyme addition (P > 0.05).

Interactive effects of drought stress and chitosan application on physiological characteristics and essential oil yield of Thymus daenensis Celak

Thymus daenensis, a perennial herb, is often grown in areas that experience drought conditions during its growing period. Application of chitosan may compensate for the negative impact of drought stress on the yield of oil and secondary metabolites in Thymus. The interactive effects of foliar application of chitosan and drought stress on dry matter, essential oil yield, and selected physiological characteristics including photosynthetic pigments, osmotic adjustment, and lipid peroxidation of Thymus were investigated in a two-year study from 2014 to 2015. Treatments consisted of 0, 200, and 400μLL−1 chitosan applied to plants grown under field capacity, mild drought stress (50% field capacity), and severe drought stress (25% field capacity). Dry matter yield decreased substantially as drought stress intensified. However, essential oil content increased under stress conditions, with the highest essential oil yield obtained from plants under mild drought stress. Foliar application of chitosan compensated to some extent for dry matter and oil yield reduction of plants grown under drought stress. The highest essential oil yield (1.52g plant−1) was obtained by application of 400μLL−1chitosan under the mild stress condition in 2015 when plants were mature. The compensatory effect of chitosan in reducing the negative impact of stress conditions on dry matter and oil yield was due mainly to stimulation of osmotic adjustment through proline accumulation and reduction of lipid peroxidase level, which increased the integrity of cell membranes of thyme leaves.

PAR Interception and Utilization in Different Maize and Soybean Intercropping Patterns.

The crop intercepted photosynthetically active radiation (PAR) and radiation use efficiency (RUE) vary markedly in different intercropping systems. The HHLA (horizontally homogeneous leaf area) and ERCRT (extended row crop radiation transmission) models have been established to calculate the intercepted PAR for intercrops. However, there is still a lack of study on the intercepted PAR and RUE under different intercropping configurations using different models. To evaluate the intercepted PAR and RUE in maize and soybean under different intercropping systems, we tested different strip intercropping configurations (SI1, SI2, and SI3 based on ERCRT model) and a row intercropping configurations (RI based on HHLA model) in comparison to monoculture. Our results showed that the intercepted PAR and RUE of intercropping systems were all higher than those of monoculture. The soybean intercepted PAR in strip intercropping was 1.35 times greater than that in row intercropping. In row intercropping (RI), the lack of soybean intercepted PAR resulted in a significant reduction of soybean dry matter. Therefore, it is not the recommended configuration for soybean. In strip intercropping patterns, with the distance between maize strip increased by 0.2 m, the intercepted PAR of soybean increased by 20%. The SI2 (maize row spacing at 0.4 m and the distance between maize strip at 1.6 m) was the recommended configuration to achieve the highest value of intercepted PAR and RUE among tested strip intercropping configurations. The method of dry matter estimation using intercepted PAR and RUE is useful in simulated experiments. The simulated value was verified in comparison with experimental data, which confirmed the credibility of the simulation model. Moreover, it also provides help in the development of functional-structural plant model (FSPM).

The Combined Action Strategy of Two Stresses, Salinity and Cu++ on Growth, Metabolites and Protein Pattern of Wheat Plant

The response of wheat plants to different osmotic stress levels varied among the different organs root, shoot and spike and the situation of these organs with application of two Cu++ levels 5 mM and 25 mM as CuSO4. The sensitivity of root organ was related with reduction in fresh, dry matter and length. This resulted from reduction of soluble sugar reflected a reduction in water uptake and K+ content of the cell sap. In the moderate organ spike, the reduction in fresh, dry matter and length were concomitant with the accumulation of soluble sugar and a huge accumulation of soluble protein. In the higher organ shoot, this related with more water uptake which in turn induced an accumulation of soluble protein and cofactor K+ content. It can be recorded that shoot was higher Na+ accumulation than root and spike. Data also showed further stimulatory effect on growth parameters by Cu++ applications with either concentration (7.5 mM and 25 mM). Irrigating the soil with either 7.5 or 25 mM CuSO4 induced a huge accumulation in soluble sugar, soluble protein and nitrate reductase. Cupper treatment with either concentration 7.5 mM or 25 mM induced a marked decrease in Na+ content at all OSL and has no significant change in the accumulation of K+ in both shoot and spike whereas induced a huge accumulation in root organ. The synthesis of protein bands with molecular weight 32.3 KDa at -1.5 MPa NaCl level treated with either 7.5 mM or 25 mM Cu++ concentrations was induced. Also the appearance of protein band with molecular weight 37KDa induced only at Cu++ treatments with 25 mM concentration in both control and under different osmotic levels (0.0, -0.3 MPa, -0.9 MPa, -1.5 MPa NaCl).

Effect of different coloured plastic mulches on growth, yield and quality of drip fertigated bell pepper (Capsicum annum var. grossum)

Among the different coloured mulches applied in bell pepper maximum rise in soil temperature was recorded under black/black plastic mulch in April (3.6oC). It was followed by silver/black mulch with soil temperature rise of 3.3oC as compared to no mulch application in respective month. The maximum increase in fruit yield (54.9%) was observed in bell pepper grown on silver/black polyethylene mulch as compared to no mulch plots. It was closely followed by black/black mulch. The maximum reduction in weed dry matter and maximum ascorbic acid content in fruit was recorded in black/black coloured plastic mulches.

Control of conyza bonariensis with glyphosate associated to adjuvants applied with different spray nozzles

The study aimed to evaluate the control of C. bonariensis in delayed post-emergence stage using different spray nozzles and solutions with and without adjuvants; and to verify the occurrence of resistance to glyphosate, determining the dose-response curve. The experimental design was randomized in factorial (6 spray nozzles x 5 spray solution) in twenty repetitions. The treatments were represented by spray nozzles: XR 110015 XR 11002, TT 11002 AIXR 11002, AIC 11002 and AI 11002. Tested spray solution were: glyphosate; glyphosate + Nimbus ® ; glyphosate + Agral ® ; Glyphosate + LI-700 ® and without herbicide application. The use or not of adjuvants in the spray solution did not differ statistically from the solution containing the herbicide only. The spray nozzles AIXR 11002, TT 11002 and XR 11002 presented best results of control the horseweed from the evaluation of 07 days after application (DAP) and 28 DAP and such spray nozzles maintained the best average of control percentage. The higher dry matter reductions of horseweed were obtained by spray nozzles 110015 XR, TT 11002 and 11002 XR compared with the control. The population evaluated presents biotypes that resist to doses of 2.880 g.ha -1 a.e. of glyphosate. It is concluded that the evaluated biotypes presents tolerance to glyphosate, independent of your association or not with adjuvants.

Bio-efficacy of tank mixed herbicides for control of complex weed flora in soybean (Glycine max L. Merril)

A field experiment was conducted at ZARS, Jhabua (M.P.) during kharif 2014 to find out most suitable and efficient method of weed control in soybean. The experiment consisted of nine treatments laid out in randomized block design with three replications. All the weed management practices led to significant reduction in density and dry matter of weeds as compared to weedy check. Two hand weeding (20 &amp; 40 DAS) recorded lowest weed density (4.9/ m2), weed dry matter (22.35 g/m2) with highest weed control efficiency of 59.67% and found at par with the application of Chlorimuron Ethyl @ 9gm /ha + Quizalofop-p-ethyl @ 50 g /ha (density 5.48/ m2, dry matter 26.62 g/m2 and WCE of 51.97%) and Imazethapyr @ 35 g /ha + Imazamox @ 35 g/ha (density 6.13/ m2, dry matter 26.00 g/m2 and WCE of 53.08%). Maximum yield of 1782 kg/ha was recorded in two hand weeding (20 &amp; 40 DAS) closely followed by Chlorimuron Ethyl @ 9gm /ha + Quizalofop-p-ethyl @ 50 g /ha (1723 kg/ha) and Imazethapyr @ 35 g / ha + Imazamox @ 35 g/ha (1697 kg/ha). Reduction in soybean yield in weedy check to be recorded is 38.78 per cent when compared to weed free and 36.68 per cent in comparison to Chlorimuron Ethyl @ 9gm /ha + Quizalofopp-ethyl @ 50 g /ha. However, highest Benefit to Cost ratio is recorded in Chlorimuron Ethyl +Quizalofop-p-ethyl (3.26) closely followed by Imazethapyr + Imazamox (3.22) and Weed free (3.21).

Beneficial Nutrient Management Practice for Improving Maize (&lt;em&gt;Zea mays&lt;/em&gt;) Yield in a Tropical Entisol

Beneficial nutrient management practices could increase maize yield via improving soil fertility. A study was conducted in the mid country wet zone of Sri Lanka (WM2b) on Typic Troporthents aiming to formulate a site specific fertilizer (SF) recommendation and to identify beneficial organic soil amendments (OA) to improve the fertility and productivity of soils for maize cultivation. The SF recommendation was developed using modified missing element technique. Incubated mixture of cattle manure and sawdust at 2:1 wet weight basis (CS-i) and biochar (BC) derived from sawdust were selected as OAs. Four treatments, (i) un-amended control (S), (ii) soil amended with SF (SSF), (iii) cattle manure-sawdust CS-i (2.2 Mg ha-1) with SF (CSi+SF) and (iv) biochar (1.1 Mg ha - 1) with SF (BC+SF) were tested in the field for two consecutive growing seasons (Yala 2013 and Maha 2013/14) for maize. According to missing element technique, soil was deficient in K, Mg, P and Zn nutrients and resulted in 38%, 35%, 27% and 24% relative dry-matter reductions, respectively. Addition of OA+SF significantly improved soil organic carbon content compared to SSF. Green cob yield ranged from 7.9 to 16.5 Mg ha-1 in Yala and 5.4 to 12.4 Mg ha -1 in Maha increasing yield significantly in CS-i+SF, BC+SF and SSF over the un-amended control in both seasons. Soil fertility and maize yield were sustained or improved under combined application of site specific fertilizer and organic amendments. Moreover, cut down of K fertilizer is possible with application of BC and CS-i OAs. Hence, SF recommendation along with biochar or cattle manure-sawdust mixture OAs is a beneficial nutrient management practice for cultivating maize.

Precision-feeding dairy heifers a high rumen-degradable protein diet with different proportions of dietary fiber and forage-to-concentrate ratios

The objective of this experiment was to determine the effects of feeding a high-rumen-degradable protein (RDP) diet when dietary fiber content is manipulated within differing forage-to-concentrate ratio (F:C) on nutrient utilization of precision-fed dairy heifers. Six cannulated Holstein heifers (486.98±15.07kg of body weight) were randomly assigned to 2 F:C, low- (45% forage; LF) and high-forage (90% forage; HF) diets and to a fiber proportion sequence [33% grass hay and wheat straw (HS), 67% corn silage (CS; low fiber); 50% HS, 50% CS (medium fiber); and 67% HS, 33% CS (high fiber)] within forage proportion administered according to a split-plot, 3×3 Latin square design (16-d periods). Heifers fed LF had greater apparent total-tract organic matter digestibility coefficients (dC), neutral detergent fiber, and cellulose than those fed LC diets. Substituting CS with HS resulted in a linear reduction in dry matter, organic matter, and cellulose dC. Nitrogen dC was not different between F:C or with increasing proportions of HS in diets, but N retention tended to decrease linearly as HS was increased in the diets. Predicted microbial protein flow to the duodenum decreased linearly with HS addition and protozoa numbers HS interacted linearly, exhibiting a decrease as HS increased for LF, whereas no effects were observed for HF. Blood urea N increased linearly as HS was incorporated. The LF-fed heifers had a greater ruminal volatile fatty acids concentration. We noted a tendency for a greater dry matter, and a significantly higher liquid fraction turnover rate for HF diets. There was a linear numerical increase in the liquid and solid fraction turnover rate as fiber was added to the diets. Rumen fermentation parameters and fractional passages (solid and liquid) rates support the reduction in dC, N retention, and microbial protein synthesis observed as more dietary fiber is added to the rations of dairy heifers precision-fed a constant proportion of rumen-degradable protein.

English

The objective of this study is to determine the dose required to control 50% population (C50) and to reduce 50% dry matter production (GR50) of resistant biotypes of ryegrass in comparison to that of a susceptible biotype as well as to evaluate the mechanism of resistance by cyt-P450 inhibitor application. The study was conducted in a greenhouse in Rio Grande do Sul, Brazil on plants that survived clethodim herbicide application, which were suspected of possessing resistance. For plants surviving field application, the biotypes were 50% controlled with herbicide dose of 28.4- and 29.5-times greater compared to that of susceptible biotypes; 50% of dry matter reduction occurred with doses of 540- and 574-times greater than the susceptibility dose of a biotype, since the dose required to reduce 50% of susceptible biotype was 0.2 g a.i. ha-1. The biotypes showed metabolism of clethodim herbicide as regards the inhibition by piperonyl butoxide, indicating that metabolism is the probable cause of control failures in the field. Key words: Lolium multiflorum, acetyl coenzyme A carboxilase, weed, mechanism of resistance; metabolization.

Root and Shoot Responses of Summer Maize to Waterlogging at Different Stages

The specially designed soil columns experiment was conducted to determine effects of waterlogging for 6 d at the third leaf stage (V3), the sixth leaf stage (V6), and the 10th day after the tasseling stage (10VT) on root growth and development of summer maize (Zea mays L.). Results showed that waterlogging significantly decreased root length, root length density, and number of root tips compared to the control (CK). Waterlogging significantly reduced the total absorption area and active absorption area with the most significant reduction in treatment at V3. The active absorption area of roots at V6, tasseling (VT), milking (R3), and physiological maturity (R6) stages decreased by 68, 67, 57, and 67%, respectively, due to waterlogging at V3. In addition, waterlogged plants generally had much lower root bleeding rates, which were significantly decreased by 46, 28, and 13% from the control by the treatment at V3, V6, and 10VT stages, respectively. The negative effects of waterlogging on root growth and development led to abnormal development of the aboveground biomass, resulting in significant reductions in dry matter, leaf area, net photosynthetic rate, and yield. Compared with grain yield of CK, yields under the treatments at V3, V6, and 10VT stages were reduced by 26, 21, and 13%, respectively. Responses of summer maize root growth and grain yield to waterlogging depended on the growth stage. Summer maize was most susceptible to waterlogging damage at V3 stage, followed by V6 and 10VT stages.Core Ideas We investigated summer maize root growth in response to waterlogging at different stages. We realized summer maize root was most susceptible to damage when waterlogging occurred at V3, followed by V6 and 10VT. Waterlogging reduced grain yield of summer maize, for the delay of root growth.

Drought Tolerance and Water‐Use Efficiency of Biogas Crops: A Comparison of Cup Plant, Maize and Lucerne‐Grass

AbstractThe cup plant (Silphium perfoliatum L.) is discussed as an alternative energy crop for biogas production in Germany due to its ecological benefits over continuously grown maize. Moreover, a certain drought tolerance is assumed because of its intensive root growth and the dew water collection by the leaf cups, formed by fused leaf pairs. Therefore, the aim of this study was to estimate evapotranspiration (ET), water‐use efficiency (WUE) and the relevance of the leaf cups for the cup plant's water balance in a 2‐year field experiment. Parallel investigations were conducted for the two reference crops maize (high WUE) and lucerne‐grass (deep and intensive rooting) under rainfed and irrigated conditions. Root system performance was assessed by measuring water depletion at various soil depths. Transpiration‐use efficiency (TUE) was estimated using a model approach. Averaged over the 2 years, drought‐related above‐ground dry matter reduction was higher for the cup plant (33 %) than for the maize (18 %) and lucerne‐grass (14 %). The WUE of the cup plant (33 kg ha−1 mm−1) was significantly lower than for maize (50 kg ha−1 mm−1). The cup plant had a lower water uptake capacity than lucerne‐grass. Cup plant dry matter yields as high as those of maize will only be attainable at sites that are well supplied with water, be it through a large soil water reserve, groundwater connection, high rainfall or supplemental irrigation.

The Physiological Role of Proline and Sodium as Osmotic Stress Signal Components of Some Crop Plants

The increase of Na + and proline content in maize, wheat, broad bean, cotton and parsley plants indicated that the proline content may act as an indicator of Na + uptake and allow the identification of tolerant plants, which effectively exclude Na + from plant either by exclusion or compartmentalization. In maize and cotton plants while Na + increased in shoots and roots, proline content decreased in these organs of these plants. This concomitant with reduction of dry matter of both organs of the maize and cotton plants. Sodium can be considered as osmotic stress marker component in these plants, especially in shoots of cotton. The percent accumulation of proline in both organs of wheat and parsley plants, shoots of broad bean run parallel with the reduction in dry matter of these plants. This strategy of proline and dry matter was concomitant with the increase of Na + content of these plants. Pytohormonal treatment with either GA 3 or Kinetin 200 ppm was mostly decreased the accumulation of both osmotic stress markers (sodium and proline ) at all levels of salinity in shoots and roots of maize, wheat, cotton, broad bean and parsley plants. Phytohormonal application was significant reduced mostly the accumulation both stress markers sodium ion and proline in shoots and roots of maize, wheat, cotton, broad bean and parsley plants. This can be reflected on the accumulation of metabolities which finally affected on the production of dry matter in shoots and roots of the five tested plants.

Behavior of Eucalyptus urophylla and Eucalyptus citriodora Seedlings Grown in Soil Contaminated by Arsenate

Persistent areas of tailings and deposits from coal and gold mining may present high levels of arsenic (As), mainly in the arsenate form, endangering the environment and human health. The establishment of vegetation cover is a key step to reclaiming these environments. Thus, this study aimed to evaluate the potential of Eucalyptus urophylla and E. citriodora seedlings for use in phytoremediation programs of arsenate-contaminated areas. Soil samples were incubated at increasing rates (0, 50, 100, 200 and 400 mg dm-3) of arsenic (arsenate form, using Na2HAsO4) for 15 days. The seedlings were produced in a substrate (vermiculite + sawdust) and were transplanted to the pots with soil three months after seed germination. The values of plant height and diameter were taken during transplanting and 30, 60 and 90 days after transplanting. In the last evaluation, the total leaf area and biomass of shoots and roots were also determined. The values of available As in soil which caused a 50 % dry matter reduction (TS50%), the As translocation index (TI) from the roots to the shoot of the plants, and its bioconcentration factor (BF) were also calculated. Higher levels of arsenate in the soil significantly reduced the dry matter production of roots and shoots and the height of both species, most notably in E. urophylla plants. The highest levels of As were found in the root, with higher values for E. citriodora (ranging from 253.86 to 400 mg dm-3). The TI and BF were also reduced with As doses, but the values found in E. citriodora were significantly higher than in E. urophylla. E. citriodora plants presented a higher capacity to tolerate As and translocate it to the shoot than E. urophylla. Although these species cannot be considered as hyperaccumulators of As, E. citriodora presented the potential to be used in phytoremediation programs in arsenate-contaminated areas due to the long-term growth period of this species.

Effect of herbicides and row spacing on weed dynamics and productivity of bread wheat (Triticum aestivum L.)

Application of herbicides caused significant reduction in weed density and weed dry matter. The maximum reduction in weed density and weed dry matter was recorded in the plots treated with metribuzin followed by isoproturon and sulfosulfuron at 45 DAS and at harvest. Herbicidal treatments significantly increased number of tillers 45 DAS and plant height at 90 DAS and at harvest. The dry matter accumulation by crop at all the growth stages was significantly higher under isoproturon which was closely followed by sulfosulfuron.The maximum value of effective tillers, ear length, number of grains ear -1 and test weight were observed with isoproturon followed by sulfosulfuron. Consequently, isoproturon produced significantly higher grain (5.72 t ha -1 ) and biological yield (12.64 t ha -1 ) and also net return (83753 Rs. ha -1 ) compared to other treatments. The effect of row spacing was significant on density and dry matter of weeds at 45 DAS and at harvest. The minimum density of weeds was observed under row spacing of 17.5 cm which was closely followed by 20.0 cm and both these had significantly lower than 22.5 cm in this respect. Row spacings did not have significant impact on plant height. The maximum number of effective tillers was recorded under 20.0 cm whereas dry matter accumulation was under 22.5 cm row spacing. Sowing at 17.5 cm row spacing produced significantly higher grain (4.94 t ha -1 ) and biological yield (11.94 t ha -1 ) also net return (71314 Rs. ha -1 ) compared to other row spacing.