Showing papers in "The Journal of Agricultural Science in 2019"

Developmental Parameters of Spodoptera frugiperda (Lepidoptera: Noctuidae) Immature Stages Under Controlled and Standardized Conditions

Abstract: The fall armyworm, Spodoptera frugiperda (J. E. Smith, 1797), is the most important noctuid pest in the Americas and has recently become an invasive pest in Africa and in India. Having a detailed and standardized record of the biology and the larval development of S. frugiperda will be critical to further studies on integrated pest management, toxicology, and applied ecology. This study reports the temporal and morphological parameters of the immature stages of S. frugiperda for larvae fed on artificial diet under controlled conditions (25±1 °C, 70±10% RH and 14 hour photophase). The survival of the egg, larval, prepupal and pupal stages was 97.40, 98.33, 99.32 and 97.95%, respectively. The average duration of the egg, larval, prepupal and pupal stages were 2.69, 13.73, 1.43, and 9.24 days, respectively. All larvae passed through six instars, with significantly slower larval development for females. However, females had faster pupal development and heavier pupae, thus total time from egg to adult was not significantly different between sexes. With the growing importance of this highly polyphagous species, centralizing the fragmented information in the literature and standardizing its rearing methods will improve and facilitate future studies on this pest.

Drought stresses on seed germination and early growth of maize and sorghum.

Abstract: Seeds of maize (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench.] were submitted to different osmotic potential levels induced by polyethylene glycol (PEG) with the objective of evaluating the effects of drought stress on seed germination and early seedling growth. Seeds were arranged in paper rolls and soaked in PEG solutions prepared with osmotic potentials 0.0 (control), -0.2, -0.4, and -0.8 MPa and kept into a seed germinator, at 25 °C for 18 days. A completely randomized design in a 2 × 4 factorial scheme with four replications of 50 seeds each was used. The results showed that by increasing of the osmotic potential level, germinated seed number, germination rate index, root and shoot length, shoot and root dry matter, and seedling vigor index (SVI) decreased, while mean germination time (MGT) and root: shoot ratio (RSR) increased in both crops. Additionally, the maize was more susceptible than sorghum to drought stress, with germination response declining more rapidly with decreasing osmotic potential. Sorghum crop tolerates water stress of up to -0.2 MPa, without reducing germination of the seeds; however, the growth of shoots and roots are inhibited. Drought stress limits the process of seed germination and early growth of maize seedlings.

Nutritive value and morphological characteristics of Mombaça grass managed with different rotational grazing strategies

Abstract: Light competition increases and plants’ growth pattern change to optimize light utilization when the leaf area index increases. It has been previously shown that using 95% canopy light interception (LI) as a grazing frequency criterion resulted in a greater proportion of leaves and a lower proportion of stem. The objective of the study was to characterize the forage production, morphological composition and nutritive value of Panicum maximum cv Mombaca. The experiment was carried out during summer, autumn–winter and spring. Treatments corresponded to combinations of two pre-grazing conditions (95% and maximum LI at pre-grazing; LI95% and LIMax, respectively) and two post-grazing heights (PGHs; 30 and 50 cm). The statistical design was a randomized complete block, with a 2 × 2 factorial arrangement. Swards managed with LI95% had greater proportions of leaves and lower proportions of stems compared to LIMax. Leaf proportion was lower during autumn–winter compared to summer and spring. The LI95% had greater crude protein (CP) and digestibility (IVOMD), and lower acid detergent fibre (ADF) concentrations than LIMax. The 50 cm PGH pastures had greater CP content and IVOMD, and lower ADF content than 30 cm PGH pastures. Lower IVOMD was observed during autumn–winter than summer and spring. The variability observed on morphological characteristics was primarily associated with seasonality, whilst the nutritive value was primarily affected by grazing management. The pre-grazing target of LI95% combined with 50 cm PGH was the combination that resulted in an increased proportion of leaves, decreased stems in basal stratum and the greatest nutritive value of the produced forage.

Study on Drying of Black Rice (Oryza sativa L.) Grains: Physical-Chemical and Bioactive Quality

Abstract: The present study aimed to assess the drying kinetics of black rice and fit different mathematical models (empirical and diffusive) to the experimental data, and evaluate the effect of drying air temperature on the physical-chemical and bioactive compounds quality of black rice. Drying air temperatures ranged from 40 to 80 oC and the drying air speed was 1.5 m/s. Physical-chemical characterization of the product was based on the following parameters: moisture, water activity, ashes, total protein content, pH, total acidity, lipids, total carbohydrates, total anthocyanins, flavonoids, total phenolic compounds and antioxidant activity. Among the empirical models, Page showed the lowest mean squared deviations (MSD) and highest coefficients of determination (R2). For the diffusion model, the values of effective mass diffusivity and convective heat transfer coefficient increased with increasing drying air temperature, and the Biot number indicated that the first-type boundary condition would also describe well the drying process. Physical-chemical parameters and bioactive compounds differed between the temperatures used, and the temperature of 60 oC led to the best relationship between drying time and preservation of product characteristics.

Humic Substances and Efficient Microorganisms: Elicitation of Medicinal Plants—A Review

Abstract: In function of the green revolution the indiscriminate use of agrochemicals and pesticides in agriculture has been also shown in the production of medicinal plants, resulting in the increase of productivity but with high residual contamination and low rates in the production of secondary metabolites responsible for the biological and pharmacological activity in vegetable drugs. In another hand, new techniques of elicitation has been applied to stimulate the medicinal plants production through the organic and agroecological management, contributing for the increase of performance, quality and production. In this context, it is aimed with this review to present such as the humic substances: fulvic acid, humic acid and efficient microorganisms which influence and help the ontogeny and the secondary metabolites production of medicinal plants. The reviewed articles show that the use of fulvic acid, humic acid and efficient microorganisms in the production of medicinal plants contributes on the increase of biosynthesis, secondary metabolites production such as coumarins, alkaloids, phenylpropanoids and essential oils, as well as the increase of nutrients absorption, growth and development of species.

Genetic analysis of grain yield and agronomic traits of early provitamin A quality protein maize inbred lines in contrasting environments

Abstract: Early-maturing provitamin A (PVA) quality protein maize (QPM) hybrids with combined drought and low soil nitrogen (low-N) tolerance are needed to address malnutrition and food security problems in sub-Saharan Africa (SSA). The current study's objectives were to (i) examine combining ability of selected early maturing PVA-QPM inbreds for grain yield and other agronomic traits under drought, low-N, optimal environments and across environments, (ii) determine gene action conditioning PVA accumulation under optimal environments, (iii) classify inbreds into heterotic groups and identify testers and (iv) assess yield and stability of hybrids across environments. Ninety-six hybrids generated from 24 inbred lines using the North Carolina Design II together with four commercial hybrid controls were evaluated under drought, low-N and optimal environments in Nigeria in 2016 and 2017. Fifty-four selected hybrids were assayed for PVA carotenoid and tryptophan content. Additive genetic effects were greater than non-additive effects for grain yield and most agronomic traits under each and across environments. The gene action conditioning accumulation of PVA carotenoids under optimal growing conditions followed a pattern similar to that of grain yield and other yield-related traits. The inbred lines were categorized into four heterotic groups consistent with the pedigree records and with TZEIORQ 29 identified as the best male and female tester for heterotic group IV. No tester was found for the other groups. Hybrid TZEIORQ 24 × TZEIORQ 41 was the highest yielding and most stable across environments and should be further tested for consistent performance for commercialization in SSA.

Piperine as a new natural supplement with beneficial effects on the life-span and defence system of honeybees

Abstract: Many factors, including pathogens, environmental change and breeding techniques, affect honeybee immunity/resistance, so substances and natural supplements that enhance it are desired. To eliminate the impact of unknown external factors, in 2016 a cage experiment was conducted under constant laboratory conditions (35 °C, 65% relative humidity). Bees in the control group were fed with sugar dissolved in water at ratio 1:1 ad libitum with no additives, while the other group was fed with sugar syrup (1:1) supplemented with piperine (3 µg/ml) ad libitum. The piperine-treated workers lived 9 days longer compared to the control group. In the piperine-consuming group, protein concentration and the activities of antioxidative enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione S-transferase (GST), were higher than in the control group. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were also higher in the piperine-treated group. Neutral and acidic proteases inhibitors, as well as neutral protease activities, were higher in the haemolymph of the piperine-treated workers than in untreated bees. Acidic protease activities in the haemolymph were higher in untreated workers only on days 18 and 32. Alkaline protease activities in the control bees were higher from day 10. From 10 days old, the total antioxidant capacity level was significantly higher in the haemolymph of piperine-treated workers. Piperine decreased DNA methylation levels significantly in the older bees. The compound could have the potential to be a natural diet supplement increasing apian resistance to stress factors.

Analysis of the Production Chain of Bean Culture in Brazil

Abstract: This bibliographical review brings information about the productive chain of beans, an essential product in the Brazilian diet, but present in several countries of the world. Beans are a source of protein, fiber, minerals and vitamins, allowing for healthy eating for easy access. Being, Brazil is the third largest producer of beans in the world, losing only to Myanmar and India, also the main consumer of beans in the world, having to import part of the beans consumed in Argentina. Due to iss, the bean culture is a promising crop, since the supply does not meet the domestic demand, being necessary the application of technologies that improve the yield and facilitate the cultivation. One of the obstacles of the crop is the susceptibility of the deterioration of the grains to store them, because, these grains stored, the commercial value tends to fall due to loss of quality. The objective of the work was to raise information on the productive chain of the beans. Periodicals, books, and information literatures were explored. Therefore, in view of the above, it was observed that in Brazil, the crop still needs to stimulate cultivation to supply domestic demand, improve storage conditions, invest in genetic improvement to maintain grain quality, and the study is necessary of new alternatives of destination for the residues generated by the processing and beneficiation of grains.

Postharvest Management Practices of Grains in the Eastern Region of Kenya.

Abstract: Cereals and legumes play a major role in the production systems and diets of farmers in the semi-arid eastern region of Kenya. Efficient postharvest management can tremendously contribute to food security in these regions. A study was carried out in three counties in eastern Kenya to assess pre and postharvest management practices among farmers. Data was collected using semi-structured questionnaires designed and administered using Kobo Toolbox via android tablets. Results showed that farmers cultivated three main crops: maize (98%), beans 66%), and pigeon peas (28%). The most saved seed crops were beans (80%) and pigeon peas (50%). Majority of the farmers (80%) experienced pre-drying losses due to insects (48%), rodents (40%) and birds (39%). Farmers stored grain for consumption (80%) and for sale (19%). About 48% of farmers stored the grain for more than 9 months. Challenges during grain storage were insects (57%) and rodents (43%). Primary methods of grain preservation included hermetic methods (61%) followed by insecticides (33%). While progress is being made in addressing storage challenges, there still a need to continue building awareness about improved storage technologies and find solutions for pest infestations in the field and drying after harvest.

Biological Pest Control in Maize Crop in Brazil: A Review

Abstract: The areas of maize production harbor a high number of insect species, some of which are considered pests that cause damage to the crop. The methods of pest control have been a cause of concern for the society since the use of chemicals and the environmental problems arising from this practice indicate the need to search for alternatives to control. In this sense, it is necessary to seek an agricultural production system that contemplates environmental sustainability and promotes biodiversity in the Agrosystem, among which the use of biological agents is highlighted. The objective of this research was to update through a bibliographic review the advances in the literature on biological control of maize crop pests. For the development of this article, we used the method of approach the analytical and as procedural method the monographic, through bibliographic research, using specialized doctrines, appropriate to the object of the study and legislations. Because of the observed aspects, it is possible to conclude that the group of natural enemies that act as biological control agents is formed by parasitoids, predators and entomopathogenic microorganisms. The rationalization of the use of chemicals should be associated with the use of biodefensives in integrated pest management. Advances in the legislation of biological products in Brazil are fundamental to give speed to the registration of new alternatives of biological control, aimed at the safety of the environment, human health and that are generated without the exploratory use of biodiversity.

Production and Decomposition of Cover Crop Residues and Associations With Soil Organic Fractions

Abstract: The decomposition of plant residues, the changes in the total organic carbon (TOC) and the fractions of soil organic matter (SOM) occur differently in irrigated areas. The objective of this study was to quantify the biomass production, the decomposition of cover crops residues and relate them with the changes n the content and fractions of SOM in an irrigated area of vegetable crops. Six types of cover crop treatments were evaluated: brachiaria (B); sunn hemp (S); millet (M); B + S; B + M; S + M, plus an additional treatment (native area), with 4 repetitions. The production of fresh (FB) and dry biomass (DB), the rate of plant residue decomposition, TOC, SOM fractions and the coefficient of SOM (QSOM) were quantified. It was observed that the greatest and the lowest volume of crop residues were from the B and S cover crop, respectively. The cover crops in monoculture presented great decomposition rates and short half-life when compared to mixtures of cover crop. The TOC and QSOM were great in the 0 to 0.05 m soil layer, and in the M + S cover crop mixture, when compared to the 0.05 to 0.1 m soil layer and to other cover crops. Among the SOM fractions, the humin predominated in the most superficial soil layer (0 to 0.05 m).

Row arrangements of maize and soybean intercrop on silage quality and grain yield.

Abstract: The success of maize + soybean intercrop depends on the plant arrangement. An experiment was carried out to evaluate different row arrangements on intercrop forage yield, silage quality and maize grain yield in relation to maize as a sole crop. The experiment was set up with a randomized complete block design with eight row arrangements between maize and Soybean. Maize biomass yield among crop arrangements were similar, although, lower than the maize sole crop. On the other hand, these treatments showed higher soybean biomass yield, which in turn increased silage crude protein and crude protein yield per unit area. Maize thousand grain weight, grain yield per plant and per area was affected by the intercrop arrangements. The use of two corn rows + two soybean rows (2M+2S-30 cm) and four corn rows + four soybean rows (4M+4S-30 cm) showed higher crude protein yield per area associated with similar maize grain yield in relation to the sole maize crop. In conclusion, alternating four maize rows with four soybean rows was the optimum row ratio in maize + soybean intercrop, though this needs to be further confirmed by more trials.

Drying of Albedo and Whole Peel of Yellow Passion Fruit

Abstract: The use of waste has been the focus of attention of the agri-food sector, and a fruit with large amount of waste is the passion fruit. Its peel consists of albedo and flavedo, which can be used to manufacture flour, and some studies propose the need to remove the flavedo as well as to perform maceration. The objective of the present work was to study the drying process to produce flour from passion fruit albedo and whole peel, checking the influences of the flavedo removal and maceration steps, as well as the drying temperatures (70 and 80 oC). Yield after drying was calculated and it was shown to be low. Page, Silva et alii, Henderson and Pabis and Logarithmic mathematical models were fitted to the experimental data using LAB Fit software. The statistical indicators used to identify the best fit were coefficient of determination (R2) and chi-square (χ2). The Page model was the one that fitted best to the data, showing the best statistical indicators. Also, it can also be highlighted that the sample composed of peel without maceration and dried at 70 oC had the best results regarding the statistical indicators.

Influence of Nutrient Solution Temperature on Its Oxygen Level and Growth, Yield and Quality of Hydroponic Cucumber

Abstract: High nutrient solution temperature stress around root-zone (rhizosphere) is a major factor limiting hydroponic crop growth due to change in dissolved oxygen (DO) levels in nutrient solution during the high-temperature seasons. This suggests that easier and economical control of root-zone temperature (RZT) could be an effective solution to the temperature stress for the crop plants in hydroponics. In this respect, the present investigation was undertaken to comprehend the influence of nutrient solution temperature on its oxygen level (ambient dissolved oxygen in feeding tank), growth, yield and quality of cucumber (Cucumis sativus L.) plants. The plants were cultivated in recirculating hydroponic system in a greenhouse with dimensions of 9 m wide × 30 m long and total area of 270 m2 during three cropping periods in Oman viz. summer (June-August), fall (September-November) and spring (February-May) in two consecutive years 2016/2017 and 2017/2018. Three cooling treatments were applied viz. T1 (22 ᵒC), T2 (25 ᵒC) and T3 (28 ᵒC) through cooling nutrient solution besides non-cooled treatment T4 (33 ᵒC) as control. The plants were grown in pots filled with perlite medium in randomized complete design (RCD) with four replications. All the treatments received the same nutrient concentrations. The results showed that cooling of nutrient solution temperature influenced positively the levels of DO in the fresh nutrient solution feeding tank and drain nutrient solution for all cropping periods in both the years. Significant (p < 0.05) differences between the treatments were observed in oxygen consumption by the roots of cucumber in the cropping periods in both the years. High levels of oxygen consumptions were recorded with cooled RZTs as compared to that of control-non-cooled RZT for all cropping periods in both the years. All growth, production and quality attributes were positively influenced and greatly expressed by cooled root-zone temperature in the root-zone of cucumber with increased DO levels in nutrient solution. This study revealed that availability of optimum aeration (oxygen levels) in nutrient solution through cooling of nutrient solution temperature could be of significance for boosting cucumber yield as observed during all the growing periods especially in summer in Oman.

Volatile Organic Compounds Role in Selective Pollinator Visits to Commercial Melon Types

Abstract: Pollination is essential for food production in the world, but in pollinator-dependent crops it relies on the attraction of pollinators to flowers. However, crop varieties vary in their attractiveness to flower visitors and volatile compounds emitted by flowers may play a significant role in attracting or repelling pollinators. Here, we investigated the volatile organic compounds (VOCs) present in both male and hermaphrodite flowers of five commercial types of melon Cucumis melo (Cantaloupe, Charentais, Galia, Piel de sapo and Yellow), and their role in attracting or repelling Apis mellifera foragers. We found significant variation in the identity and proportion of these chemical compounds produced by both melon types and flower genders and observed significant positive and negative correlations between the amount of D-Limonene and Benzaldehyde (bee attractants) and α-Pinene (bee repellent), respectively, to the number of bee visits to flowers particularly in the Cantaloupe type and hermaphrodite flowers, the most visited ones. Our results suggest that differences in the composition of melon floral VOCs and the proportion of the different compounds play significant role in the number of visits by A. mellifera with possible implications to pollination and fruit yield. It also implies to the perspective of breeding varieties more attractive to pollinators through the selection of flower lines richer in bee-attractant and/or poorer in bee-repellent volatiles.

Allelopathy of Dahlstedtia araripensis on Calotropis procera and Zea mays

Abstract: Studies related to the allelopathic properties of plants have aroused great interest, since species that have compounds with allelopathic activity can be used as bioherbicides in the control of weeds. In this way, the aim of this study was to evaluate the allelopathic action of Dahlstedtia araripensis on the germination and growth of Calotropis procera and Zea mays. The bioassays were prepared using two 50 g portions of leaves, stem bark and D. araripensis roots, and each part of the plant received a hot treatment (1 L of distilled water at 100 °C) and one part cold (1 L of distilled water at 25 °C). The experimental design consisted of six treatments and the control group. The variables analyzed were: Index of Emergency Speed (IES), germinability, length and occurrence of necrotic radicles. The results indicated that the extracts interfered negatively on the germinability of the seeds, mainly on those of C. procera, since all extracts significantly inhibited its germination. In the seeds of C. procera and Z. mays there was delay in IES. The results indicated that the cold and hot extracts of the distinct parts of D. araripensis affected the development of the seedlings, besides promoting root necrosis. The observed effects may be due to the presence of secondary metabolites detected in the different extracts of D. araripensis. However, further research is required to prove the performance of such compounds, as well as their isolation, for future use asnatural herbicides.

Botanical Extracts of the Brazilian Savannah Affect Feeding and Oviposition of Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae)

Abstract: The indiscriminate use of synthetic insecticides caused an increase in the resistance of Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae) to almost all classes of insecticides, as well as affected the environment and non-target organisms. Thus, the search for less harmful alternatives with the purpose of reducing the application of these insecticides has become a priority. A possible alternative to reduce the use of synthetic insecticides is by using botanical insecticides, given the thousands of existing compounds derived from secondary metabolism in plants. In this study, we tested the following hypotheses: (i) the aqueous and ethanolic extracts of native plants reduce the food consumption of larvae and oviposition of adults of P. xylostella; (ii) these botanical species can act as potential plant insecticides. The objective of this work was to evaluate the effect of plant extracts on the feeding preference of larvae and oviposition of adults of P. xylostella. For this, cabbage discs treated with aqueous and ethanolic extracts of Schinus terebinthifolius, Annona coriacea, Annona crassiflora and Serjania marginata were given to larvae. The concentrations used for the aqueous extracts were of 5 and 10 mg mL-1, and for the ethanolic extracts were of 1 and 5 mg mL-1. Both extracts of the four tested plant species showed oviposition suppressed. The extract of S. marginata showed the lowest rates of suppression. All treatments with ethanolic extracts showed a phagodeterrant effect being that the aqueous and ethanolic extracts of A. crassiflora and S. terebinthifolius were the most effective as antifeedants on third instar larvae by P. xylostella.

Kinetics of drying and physical-chemical quality of peach cv. Hubimel.

Abstract: The objective of this study was to perform the kinetics of peach drying and to adjust the experimental data obtained to empirical and diffusive mathematical models to evaluate the effect of temperature on the physical-chemical quality of the final product. The drying experiments were performed in an air circulation dryer with a velocity of 1.5 m s-1, the drying kinetics were performed at temperatures of 60, 70 and 80 °C. Among the mathematical models applied, the Page model was the one that best fit the experimental data, because it presents greater efficiency in the description of the drying process. The decrease in the drying rate from the initial time to the end of the process was observed, increasing the temperature of the air caused a reduction in the drying time. It was verified through the analytical solution of the diffusion equation with infinite wall geometry that the increase of the drying temperature caused the increase of the diffusivity and convective coefficient of heat transfer. Through the Biot number, it can be stated that the first-type boundary condition would also describe the process satisfactorily. The fresh peach slices present high water content and water activity and the drying effect caused significant differences in all physical-chemical parameters analyzed.

Influence of indigenous arbuscular mycorrhizal fungus and bacterial bioinoculants on growth and yield of Capsicum chinense cultivated in non-sterilized soil

Abstract: Despite the global importance of Capsicum species, there is limited information on the indigenous endomycorrhizal fungal association in this crop. Therefore, the diversity and colonization patterns of arbuscular mycorrhizal fungi (AMF) in roots of Naga King chilli (Capsicum chinense) were assessed during pre-flowering, flowering and fruit ripening growth stages under a sub-tropical shifting cultivation system of North Eastern India. All the roots examined had AMF colonization and the presence of Paris-type arbuscular mycorrhizal morphology is reported for the first time in C. chinense. A total of 11 AMF spore morphotypes were isolated from both field and trap culture soils. Maximum AMF spore density and root colonization were recorded during the pre-flowering and flowering stages, respectively. The influence of Funneliformis geosporum, individually or in combination with Pseudomonas fluorescens and Azotobacter chroococcum, on growth and yield of C. chinense, was evaluated in a pot experiment using sterilized and non-sterilized soils. The application of AMF and P. fluorescens to sterilized soil significantly increased the growth, flower and fruit production, and nutrient content of C. chinense. The highest growth rates and yields of C. chinense in non-sterilized soils were achieved when AMF was combined with both P. fluorescens and A. chroococcum. The results of the current study indicate the value of applying microorganisms to improve plant growth and performance in chillies. One of the mechanisms for this could be the facilitated assimilation of nutrients promoted by AMF and bacterial bioinoculants.

Assessing climate adaptation options for cereal-based systems in the eastern Indo-Gangetic Plains, South Asia

Abstract: New farming systems and management options are needed in South Asia as the intensive rice–wheat production system is set to become increasingly unsustainable under climate change. In the current study, six cropping systems options/treatments varying in tillage, crop establishment method, residue management, crop sequence and fertilizer and water management were evaluated using a cropping systems model under current (1980–2009) and future (2030 and 2050) climate scenarios in the state of Bihar, India. The treatments were current farmers' practice (CP), best fertilizer and water management practices, zero tillage (ZT) with no crop residue retention, ZT with partial crop residue retention (ZTPR), future conservation agriculture-based rice–wheat intensive cropping system (FCS-1) and future conservation agriculture-based maize–wheat intensive cropping system (FCS-2). The results indicate that climate change is likely to reduce rice–wheat system productivity under CP by 4% across Bihar. All the crop management options studied increased yield, water productivity and net returns over that of the CP under the current and future climate scenarios. However, the ZTPR treatment gave significantly higher relative yield, lower annual yield variability and a higher benefit-cost-ratio than the other treatments across cropping system components and climate periods. Although all the new cropping system treatments had a positive yield implication under the current climate (compared to CP), they did not contribute to adaptation under the future climate except FCS-2 in wheat. It is concluded that adaptation to future climate must integrate both cropping system innovations, and genetic improvements in stress tolerance.

Effect of organic (Jatropha cake) and NPK fertilizers on improving biochemical components and antioxidant properties of five cowpea (Vigna unguiculata L. Walp.) genotypes.

Abstract: Organic and inorganic fertilizers improve the nutritional quality of crop. An experiment in pots of four treatments was conducted in a randomized complete block design in order to evaluate the effect of the application of organic and NPK fertilizers on the biochemical components and antioxidant activities of five cowpea genotypes. Results showed that organic fertilizer and the mixture of organic and NPK fertilizer have significantly (p < 0.05) increased the growth parameters and leaves quality traits of cowpea. The response of cowpea under the different treatment is also function of genotype type. The PCA and the dendrogram performed basis on the different fertilizers effect on growth parameters and leaves quality trait divided the treatments into three main classes. Class I comprising NPK + Jatropha treatment strongly contributed to lycopene, β-carotene and total chlorophyll contents, height and number of branches. Class II comprising NPK treatment solely and Jatropha treatment solely are highly linked to the variables FRAP, DPPH and protein content. Class III comprising control treatment strongly contributed to salicylic, soluble sugar, phenolics and flavonoids contents, and trypsin inhibition activity. The Jatropha cake could be used solely or in mixture with NPK to improve growth and the quality traits of cowpea leaves.

Pregnant cow nutrition and its effects on foetal weight – a meta-analysis

Abstract: The prenatal development of cattle has influence on productive performance throughout postnatal life. The number of muscle and fat cells that the animal will have throughout its life is determined in the foetal stage and is influenced by nutrition of the pregnant cow. A systematic review and meta-analysis was performed to evaluate the effect of different energy levels (total digestible nutrient, TDN) and crude protein (CP) supplied to pregnant cows on foetal weight at 4 (FW4) and 8 months (FW8) and calf birth weight (CBW). Four studies and six trials involving 170 animals were assessed for FW4; four studies, four trials and 156 animals for FW8 and 48 studies, 125 trials and 9053 animals for CBW. High heterogeneity across studies was presented in FW4 (I2 = 94.4%), FW8 (I2 = 91.08%) and CBW (I2 = 96.9%). Dietary TDN and CP levels did not influence FW4. The FW8 was reduced by 2.24 kg when cows were fed 100% of their CP and TDN requirements (I2 = 0%), relative to those fed 70% of their requirements during the first and second trimesters. The CBW was reduced by 0.45 kg (I2 = 96.9%) when cows were fed 130% of their CP requirements relative to other dietary CP levels. When cows were fed 140% of their TDN requirements, CBW decreased by 2.71 kg (I2 = 98.3%) relative to other TDN levels. Dietary energy or CP levels fed above the requirements to pregnant cows restrict foetal development and CBW.

Dry Mass Accumulation, Nutrients and Decomposition of Cover Plants

Abstract: The use of cover crops is an important strategy for soil management in the Brazilian Cerrado to improve no-tillage (NT) systems. For this, it is necessary know the potential of cover crop species for biomass production, nutrient cycling, and persistence of residues on the soil surface in soils and climatic conditions of this biome. Thus, the experiment was developed to evaluate the agronomic potential of cover crops cultivated on an Oxisol (Latossolo Amarelo) in the Cerrado of Piaui, Brazil. The experiment was conducted from January 2015 to July 2016. The experimental design was in randomized blocks with 11 treatments and four replicates. The treatments consisted of single and intercropped cover species. The evaluations were: dry mass production, nutritional composition of the plants, nutrient accumulation by dry mass produced and decomposition rate of the dry mass produced for each treatment. The higher dry matter production was obtained with Crotalaria juncea, Cajanus cajan (cv. IAC-Fava larga), Pennisetum glaucum and Brachiaria ruziziensis. The lower dry matter production was obtained with Mucuna aterrima, and mix of Crotalaria spectabilis + Pennisetum glaucum. The higher nutrients accumulation in the plants occurred for Cajanus cajan (cv. IAC-Fava larga), Crotalaria juncea and Crotalaria spectabilis. The cover plants studied presented good potential for soil conservation, due to the permanence of residues on the surface, except for Mucuna aterrima and Crotalaria spectabilis.

First assessment of Goidanich Index and aerobiological data for Plasmopara viticola infection risk management in north-west Spain

Abstract: The climate of north-western Spain, with high temperatures and relative humidity during the grapevine vegetative cycle, can especially favour the development of fungal diseases in vineyards. One of the most important diseases is downy mildew, caused by the fungus Plasmopara viticola. The aim of the current study is to propose a system containing phenological data, biological sensors of pathogen indicator and the agrometeorological Goidanich Index in order to optimize the application of downy mildew fungicide treatments. The study was conducted in a vineyard of the ‘Ribeiro’ Designation of Origin region from 2005 to 2016 during the Vitis vegetative period. Aerobiological sampling was performed using a LANZONI VPPS-2000 volumetric trap. The highest number of infection cycles was recorded during the 2009 harvest, with a total of 16 cycles. Years with fewer infection cycles were 2008, 2011 and 2012 (13 cycles). Primary infections were produced during the third fortnight of April and a high amount of secondary infection cycles were detected by the Goidanich algorithm during the fruit development and berry ripening stages. The best estimators of the P. viticola spore concentrations were the fungus spore levels during the previous day, the average temperature 5 days before and rainfall 2 days before. The regression equation obtained accounted for the 95.9% of the spore concentration variation. The combination of the Goidanich index and biological sensors provides a valuable tool to establish an accurate, modern, integrated downy mildew pest-management strategy.

Population Fluctuation and Faunistic Analysis of Fruit Flies in a Commercial Guava Orchard (Psidium guajava L.)

Abstract: Knowledge of the population fluctuation of a pest in an orchard allows the producer preventing and making use of techniques that control the insect pest before it causes economic damages. The objective of the present work was to verify fruit fly species population dynamics in a commercial of Psidium guajava L. (Myrtaceae) orchard in the Curimatau microregion of Paraiba, also to characterize the community of fruit flies through faunistic analysis as well. Fruits were collected biweekly, the total was 24 collections between August 2014 and July 2015 in the municipality of Nova Floresta-PB. Fruits were preferentially collected mature or at the beginning of maturation, differentiating fruits harvested on the soil, plants, and through PET traps containing different food attractants. After collection, fruits were kept in plastic trays filled with a layer of two centimeters of sterilized sand and covered with fabric ‘voil’. The trays were labeled with the field data and placed in a greenhouse. Past the period of 15-25 days the fruits, already in the stage of decomposition were examined in order to collect pupae and larvae of 3rd instar. A total of 462 specimens of fruit flies were collected in 12 months sampling period, they were collected from fruits gathered from the ground and from the tree, and through trapping, being 209 males and 253 females, all collected in P. guajava. From the results obtained during the sampling period, a total of four species were recorded by fruit collection and six species by a trap. A new specimen of Anastrepha was found that there was no register in Paraiba yet, Anastrepha hadropickeli Canal, Uramoto and Zucchi (2013), as well as a Rhagoletis sp. (Loew).

Sanitary and Physiological Quality of Soybean Seeds Treated With Ozone

Abstract: Widely used, the seeds chemical treatment can cause physiological quality loss due to phytotoxicity that the active principles may cause. In this context, the ozone gas stands out (O3) as efficient agent biocide, however its use in the pathogens control and their effects on the seeds physiological quality are still little studied. In this context, the objective was to evaluate the ozone gas efficiency as a controller agent of plant pathogens and its effect on the physiological quality of soybean seeds. For this, seeds of two soybean cultivars were treated with ozone gas in two concentrations (15 and 25 g/m³) and in five exposure times (0, 20, 40, 60 and 120 minutes). After the treatments, the seeds quality was evaluated by tests of sanity, tetrazolium, first germination count, germination percentage, initial stand, emergence percentage, emergence speed index, electrical conductivity, accelerated aging and enzymatic activity. Six pathogens were found in seeds of soybeans evaluated, namely: Phomopsis sp., Penicillium sp., Aspergillus sp., Fusarium sp., Cercospora kikuchi and Alternaria sp. It was concluded that the sanitary treatment with ozone gas reduces the incidence of these fungi and does not compromise the physiological quality of soybean seeds.

Biotic Potential and Reproductive Parameters of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae)

Abstract: The fall armyworm, Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), a native to the Americas and recently reported in Africa, Germany, the Netherlands and India, is a significant pest of many crop species. Although a widespread and important pest, information on its biology and development are incomplete and require detailed study. In this study, the biotic potential and reproductive parameters of S. frugiperda were evaluated under controlled conditions (25±1 °C, 70±10% RH and 14 hour photophase). The longevity, pre-, post- and oviposition periods, fecundity, and fertility of 30 pairs were evaluated. The longevity of females (10.87 days) was not significantly different from that of males (10.90 days). The mean durations of the pre-, post- and oviposition periods were 2.63, 0.53 and 7.70 days, respectively. The mean fecundity was 2,370.66 eggs per female and mean fertility was 2,309.03 larvae per female. On average, a female copulated 1.6 times. The biotic potential of S. frugiperda was estimated at 2.086 × 1029 individuals/female/year. The net reproductive rate (Ro) was 1,079.73 times per generation and the mean generation time (T) was 32.00 days. The intrinsic rate of increase (rm) was 0.22, with a finite rate of increase (λ) of 1.24 per day. This study evaluates and describes the biological parameters of S. frugiperda with special emphasis on its biotic potential and reproductive parameters. This information will improve the development of integrated pest management (IPM) and insect resistance management (IRM) for this species.

Chemical composition and in vitro digestibility of alternative feed resources for ruminants in Mediterranean climates: olive cake and cactus cladodes

Abstract: Olive cake (OC) and cactus cladodes (CCs) are two alternative feed resources widely available in Mediterranean areas. Their use in ruminant diets was assessed according to their chemical composition, secondary compound levels and digestibility. The effects of the olive oil extraction period and process, and CCs age and sampling period were evaluated. OC was collected monthly, from November to January, from mills using either a mechanical press or 2-phase or 3-phase centrifugation processes. CCs were collected fortnightly according to age (young and mature) from April to June. Two-phase OC had the lowest content of dry matter (DM), the highest nitrogen-free extract (NFE) and total and hydrolysable tannins and was more rapidly fermentable. Mechanical press OC was the least digestible. OC DM, protein and NFE were affected linearly by the extraction period. Gas production (GP), in vitro digestibility parameters and dry and organic enzymatic digestibility changed with the extraction period. Therefore, OC chemical composition and in vitro digestibility depended mainly on the extraction process and period. Compared to mature CCs , young CCs contained more water, protein, ether-extract and phenolic compounds, but less ash and fibre. GP and digestibility parameters were not affected by age, but in vitro organic matter digestibility and microbial biomass production were higher in young cladodes. CCs chemical composition, GP and digestibility parameters were influenced by the collection period. Due to its limited nutritional quality, OC should be enriched in nitrogen, while CCs could be considered as highly valuable forage in ruminant diet.

Effect of long-term nutrient management practices on soil micronutrient concentrations and uptake under a rice–wheat cropping system

Abstract: A field experiment was conducted to study the long-term effects of nutrient management practices on micronutrient concentrations in soil and their uptake by crops under a long-term rice–wheat cropping system. The treatments comprised different combinations of N, P, K, Zn and farm yard manure (FYM), used as nutrient management practices. After 25 years of continuous cropping, the higher grain yields and uptake of iron (Fe), manganese (Mn), copper (Cu) and zinc (Zn) were obtained when FYM was applied along with mineral sources of nitrogen, phosphorus and potassium (NPK) when compared to mineral sources of NPK alone. The residual effect of FYM, applied to rice, on the yield of subsequent wheat was significant. The application of mineral NPK with FYM recorded higher diethylene triamine penta acetic acid extracted (DTPA)-Fe, Mn and Cu concentrations in the soil compared to any other treatment. The plots with Zn application showed higher DTPA-Zn concentration in the soil compared to any other treatments. The available Fe, Mn and Cu in the soil were higher than their critical limits and the soil was low in Zn where inorganic fertilizers were applied alone (without Zn). Integrated application of mineral NPK and FYM to the rice crop and mineral NPK to wheat was found to be the best nutrient management practice in producing higher yields of rice and wheat and improve long-term soil micronutrient concentrations.

Mathematical Modeling of Thin-Layer Drying Kinetics of Piper aduncum L. Leaves

Abstract: As well as most agricultural products, some medicinal plants need to go through a drying process to ensure quality maintenance, however each product behaves differently. Therefore, the present study aimed to evaluate the drying kinetics of spiked pepper (Piper aduncum L.) leaves and determine their thermodynamic properties at different drying temperatures in laboratory scale. Leaves with initial moisture content of 78% w.b. (wet basis) were subjected to drying at temperatures of 40, 50, 60 and 70 oC and air speed of 0.85 m s-1 in an experimental fixed bed dryer. The drying kinetics of the leaves was described by statistical fitting of mathematical models and determination of effective diffusion coefficient and activation energy. Enthalpy, entropy and Gibbs free energy were also evaluated for all drying conditions. It was concluded that, among the models evaluated, only Midilli and Valcam can be used to represent the drying of Piper aduncum leaves; the first for the two highest temperatures (60 and 70 oC) and the second for 40 and 50 oC. The activation energy was approximately 55.64 kJ mol-1, and the effective diffusion coefficient increase with the elevation of temperature. The same occurs with the values of Gibbs free energy, whereas the specific enthalpy and entropy decrease.