Effects of organic wastes,Glomus intraradices andPseudomonas putida on the growth of tomato and on the reproduction of the Root-knot nematodeMeloidogyne incognita

Effects of organic wastes (biosolids, horse manure, sawdust and neem leaf litter [NLL]), an arbuscular mycorrhizal (AM) fungusGlomus intraradices, and a plant growth-promoting rhizobacteriumPseudomonas putida, were studied on the growth of tomato and on the reproduction ofMeloidogvne incognita. Pseudomonas putida andG. intraradices promoted tomato growth in nematode-infected and nematode-free plants but growth promotion was higher in the infected ones. WhenP. putida andG. intraradices were applied together, the increase in tomato growth was greater than when either agent was applied alone. Of the organic wastes, NLL was better in improving tomato growth of nematode-infected plants followed by biosolids, horse manure and sawdust. Combined use of NLL withP. putida plusG. intraradices was best in improving growth of the infected plants. Root colonization byP. putida was increased more when inoculated withG. intraradices than when inoculated singly. Of the organic wastes, use of sawdust withP. putida caused a greater increase in root colonization by fluorescent pseudomonads followed by NLL, horse manure and biosolids. Nematode parasitism had an adverse effect on root colonization byP. putida. Inoculation ofP. putida and organic wastes increased the root colonization caused by the AM fungus.P. putida was better in reducing galling and nematode multiplication thanG. intraradices, whereas use of the two together was better than that of either of them alone. Among organic wastes, NLL was better in reducing galling and nematode multiplication followed by biosolids, horse manure and sawdust. Combined use of NLL withP. putida plusG. intraradices was better in reducing galling and nematode multiplication than any other treatment.     

Exploring influential plant traits for enhancing upland cotton yield under salt stress

This research was conducted to explore genetic material that can yield better under salt stress conditions. The experiment was laid out using 27 upland cotton genotypes in a RCBD 2 factorial arrangement with two replications. Saline water (NaCl at 20 dS/m) was applied after satisfactory emergence was achieved. The crop was raised to maturity and data relating to yield, fiber quality and ionic traits were recorded. Analysis of variance showed significant variations in the germplasm. Plant height, bolls per plant, boll weight, GOT%, staple length, staple strength, K⁺ and K⁺/Na⁺ ratio under salinity stress showed a highly significant correlation with seed-cotton yield. The highest direct effect on seedcotton yield per plant was exhibited by bolls per plant and boll weight. The results from the correlation and path coefficient analyses revealed that although the K⁺/Na⁺ ratio had a strong positively significant association with seedcotton yield, its direct effect on the seed-cotton yield was negative and thus selection on the basis of K⁺/Na⁺ may not be fruitful. Hence, only indirect selection through bolls per plant and boll weight may be effective in increasing the seedcotton yield per plant under salinity stress.     

Remobilization and utilization of phosphorus in wheat cultivars under induced phosphorus deficiency

A solution culture study was conducted to compare the phosphorus (P) remobilization efficiency of four wheat cultivars under induced P deficiency. Wheat cultivars, i.e. Sarsabz, NIA-Sunder, NIA-Amber and NIA-Saarang were initially grown on adequate P nutrition for 30 days and then exposed to P-free nutrient solution for next 15 days to study P remobilization. Completely randomized design (CRD) with ten replicates per cultivar was employed. Cultivars varied for biomass production, P concentration, P uptake, and P utilization efficiency at both harvests. Overall, more than 75% of absorbed P was mobilized from older leaves to younger leaves as well as roots of all cultivars during P-omission period. However, cultivars could not produce significant variations (P < 0.05) in P remobilization, which implied that P remobilization was only a stress response to P deficiency in wheat cultivars and it could not be related to P utilization efficiency of these cultivars.     

Effects of crude seed extracts of Annona atemoya and Annona squamosa L. against the cabbage looper, Trichoplusia ni in the laboratory and greenhouse

Antifeedant, growth inhibitory and toxic effects of crude seed extracts of Annona squamosa and Annona atemoya from Fazenda Viveiro Bona, Parasisópolis – Minas Gerais, Brazil, were evaluated against the cabbage looper, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) using different bioassays. Crude methanolic seed extracts deterred feeding of third instar T. ni larvae in a leaf disc choice bioassay. A. squamosa was ∼10 times more active as a feeding deterrent than A. atemoya (DC₅₀ = 2.3 mg/ml vs. 20.1 mg/ml). A. squamosa was ∼three times more active as a growth inhibitor than A. atemoya (EC₅₀ = 38.0 ppm vs. 117.0 ppm). Methanolic seed extracts of A. squamosa and A. atemoya were toxic to third instar T. ni larvae both through topical and oral application. A. squamosa was more toxic through feeding (LC₅₀ = 167.5 ppm vs. 382.4 ppm) whereas, A. atemoya exerted greater toxicity via topical application (LC₅₀ = 301.3 μg/larva vs. 197.7 μg/larva). Both A. squamosa and A. atemoya extracts reduced leaf area consumption and larval growth in a greenhouse experiment. Our results indicate that both A. squamosa and A. atemoya have potential for development as botanical insecticides, especially for local use in Brazil.     

Nutrient digestibility and feedlot performance of lambs fed diets varying protein and energy contents

Thirty-six Thalli male growing lambs were used in a completely randomized design with 2 × 2 factorial arrangement of treatments to evaluate the effect of varying levels of energy and protein on nutrient intake, digestibility, weight gain, and gain to feed ratio. Four experimental diets, i.e., low energy–low protein (LE-LP), low energy–high protein (LE-HP), high energy–low protein (HE-LP), and high energy–high protein (HE-HP) were formulated. The low- and high-energy diets contained 2.3 and 2.7 MJ/kg dry matter (DM) with 12% and 14% of crude protein. The lambs were fed ad libitum. Dietary energy and protein levels and their interactions influenced the nutrient intake. Maximum dry matter intake was noted in animals fed LE-HP diet followed by LE-LP, HE-HP, and HE-LP diets. Digestibility of DM and N increased (P < 0.01) and that of neutral detergent fiber decreased (P < 0.01) linearly with increasing levels of dietary energy and protein. Digestibility of N was only affected by protein level and interaction between energy and protein levels. Average daily gain was higher (P < 0.01) in lambs fed HE-HP diet followed by LE-HP, LE-LP, and HE-LP diets. Dietary energy and protein levels and their interaction had significant effect (P < 0.01) on gain to feed ratio.     

Impact Assessments of Transgenic cry1Ab Rice on the Population Dynamics of Five Non-Target Thrips Species and Their General Predatory Flower Bug in Bt and Non-Bt Rice Fields Using Color Sticky Card Traps

A 2-yr field study was conducted to assess the effects of transgenic japonica rice(KMD1 and KMD2) with a synthetic cry1 Ab gene from Bacillus thuingiensis Berliner on population dynamics and seasonal average densities of five thrips species including Stenchaetothrips biformis(Bagnall),Frankliniella intonsa(Trybom),F.tenuicornis(Uzel),Haplothrips aculeatus(Fabricius),Haplothrips tritici(Kurd) and their general predatory flower bug,Orius similis Zheng as compared to the parental control rice line using the white,blue and yellow sticky card traps.Population dynamics and seasonal average densities of these five thrips species and their general predatory flower bug were not significantly affected by rice type.Additionally,the white sticky card trap was suggested to be the most suitable for monitoring the population of these five thrips species and their general predator.These results show that our tested Bt rice lines do not interrupt the population of non-target thrips species and their general predatory flower bug in the field,and also cannot result in more occurrence of these thrips species in the rice ecosystem.     

Structured analysis of seepage losses in irrigation supply channels for cost-effective investments: case studies from the southern Murray-Darling Basin of Australia

Much of inland Australia has been in perpetual drought since 1997 except during 2010 when above average rainfall occurred. It has been the worst drought since 1788 when European settlement began. Water scarcity poses a serious threat to the sustainability of the irrigated agriculture in major irrigation systems across the Murray-Darling Basin (MDB). There is a need for water-saving measures and a structured approach to assess water loss in earthen supply channels. This paper presents such an approach to assess and reduce seepage losses for improving irrigation efficiencies. Main elements of this approach are the following: field measurements, hydrologic modelling, potential options for seepage reduction, economic analysis and financing water-saving investments. Using data from two irrigation systems in the southern MDB, a case is made for reducing seepage water losses in irrigation supply channels in a cost-effective manner using low-cost technologies. Increasing the level of security for investments in water-saving programs provides incentives to key stakeholders to achieve water-saving targets. Considering the value of water recovered from reducing seepage loss at irrigation system level, this study demonstrates how reducing just one component (seepage) from the total water losses in irrigation systems can help improve water supplies as well as the environmental flows. Potential options for financing infrastructure improvement for saving irrigation water are proposed and discussed.     

Evaluating the effectiveness of biofertilizer on salt tolerance of cotton (Gossypium hirsutum L.)

In the present study, the effectiveness of biofertilizer containing plant growth promoting rhizobacteria was evaluated on growth and physiology of cotton under saline conditions. Cotton plants were exposed to different levels of NPK (50%, 75%, and 100% of recommended levels) along with coating with biofertilizer under saline (15 dS m^?1) and non-saline conditions. It was observed that the biofertilizer seed coating improved growth, physiological (relative water content and chlorophyll content index), and ionic (K⁺/Na⁺) characteristics under saline and non-saline conditions. However, shoot growth (shoot fresh and dry weight) and leaf gas exchange characteristics (CO₂ assimilation rate, A; intercellular CO₂ concentration, C_i; transpiration rate, E; stomatal conductance, g_s) were decreased by biofertilizer coating under saline condition. Increasing levels of NPK fertilizer increased shoot growth, whereas root growth was maximum at 75% NPK level under saline conditions. The results of the study indicate that the biofertilizer application was very effective for cotton plant in non-saline conditions but not very effective in saline conditions.     

Sodicity Intensifies the Effect of Salinity on Grain Yield and Yield Components of Wheat

ABSTRACT

This study reports the relationship of the leaf ionic composition with the grain yield and yield components of wheat in response to salinity x sodicity and salinity alone. The study was conducted in soil culture in pots with three treatments including control (ECe 2.6 dS m^{? 1} and SAR 4.53), salinity (ECe 15 dS m^{? 1} and SAR 9.56), and salinity x sodicity (ECe 15 dS m^{? 1} and SAR 35). The soil was treated before being put in the pots and the pots were arranged in a completely randomized factorial arrangement with five replications. The seeds of three wheat genotypes were sown directly in the pots and the study was continued till the crop maturity. At booting stage, the leaf second to the flag leaf of each plant was collected and analyzed for sodium (Na⁺), potassium (K⁺), and chloride (Cl^?). At maturity, plants were harvested and data regarding grain yield and yield components were recorded. This study shows that salinity and sodicity in combination decreases the grain yield of wheat more than the salinity alone with a greater difference in the sensitive genotype. This study also shows that as for salinity, the maintenance of lower Na⁺ and higher K⁺ concentrations and higher K⁺: Na⁺ ratio in the leaves relates positively with the better development of different yield components and higher grain yield in saline sodic soil conditions. Although, the leaf Cl^? concentration was increased significantly by salinity as well as salinity x sodicity and would have affected the growth and yield, yet it does not seem to determine the genotypic tolerance or sensitivity to either salinity or salinity x sodicity.