Dry Weight Yield Research Articles

Yield components and nutrients content in summer cover plants used in crop rotation in no-tillage system

ABSTRACTThis study aimed at identifying the proper developmental stage for the cutting of cover crops with high nutrients content in the shoots of plants to be used as green manure on crop rotation in the no-tillage (NT) system. Crotalaria juncea, Cajanus cajan, Mucuna aterrima, and Sorghum bicolor were collected at five different vegetative stages for assessing of fresh weight yield (DWY) and dry weight yield (DWY), as well as determining the carbon (C)/nitrogen (N) ratio and the contents of nutrients in the shoots of plants. The experiment was performed on a completely randomized design, with five replicates. Except for the nutrients contents in S. bicolor, for the assessed legumes the DWY, FWY, C/N ratio, nutrient concentration and nutrient accumulation in the shoots have increased with the development of plants. Therefore, it can be inferred that grasses studied will provide greater soil cover, while the legumes will provide a greater nutrient cycling.

Ketersediaan Fosfat, Serapan Fosfat, Dan Hasil Tanaman Jagung (Zea mays L.) Akibat Pemberian Kompos Granul Ela Sagu Dengan Pupuk Fosfat Pada Inceptisols

Inceptisol is a young and newly developed soil so it needs to be optimized for crop cultivation. The aim of this research is to know the availability of soil P, P uptake and corn yield after application of granular composting of sago waste (KGES) together with phosphate fertilizer to Inceptisols soil. The experimental treatment was KGES which consisted of three levels: without KGES, 40 tons KGES ha-1, and 80 tons KGES ha-1, and the use of SP-36 (P) fertilizer consisting of three levels: without P fertilizer, 120 kg P ha-1, and 240 kg P ha-1. The experiment used a complete randomized design with 3 replications. The result of the experiment was analyzed variance and relationship test using interlaced analysis. The results showed that KGES together with phosphate fertilizers could increase soil pH causing phosphate to be available and plant roots could absorb nutrient phosphate well, so that the yield of corn kiln dry weight also increased. The highest yield of dry weight of grains (7.85 tons per ha) was obtained from a combination of 80 tons of KGES ha-1 and 240 kg P ha-1.Keyword: Keywords: Ella Sago, Inseptisols, maize, phosphate

Iron and manganese effect on soil chemical properties, yield components, and nutritional status of soybean

ABSTRACTIn plants, iron (Fe) and manganese (Mn) have many functions, as the transport and electron transference during photosynthesis, and their deficiencies affect the chlorophyll formation, plant growth and grain yield (GY). We carried out two experiments under greenhouse conditions with the aim of determining the influence of Fe and Mn on nutritional status, physiological components, soil chemical properties and yield components of soybean plants. In both experiments, five Fe and Mn rates were used. The GY, shoot dry weight yield (SDWY), the number of grain per pot (NGP), photosynthesis rate (A) and chlorophyll content were influenced by Fe rates, while GY, SDWY, root length and A were influenced by Mn rates. Iron and Mn concentrations in leaves and grains increased with rates of Fe and nutrients. The Mehlich 1 and DTPA-TEA extractants were efficient to determine the Fe and Mn available in the soil.

Concentraciones e intervalos de aplicación del aceite esencial de Tagetes lucida Cav. contra Nacobbus aberrans


 
 
 La escaza información sobre los efectos del aceite esencial de Tagetes lucida contra nematodos y la riqueza de poblaciones nativas de esta especie vegetal en algunas áreas en el Estado de México resultan condiciones favorables para derivar insumos naturales inocuos de esta especie que posibiliten enfrentar problemas de agallamiento por N. aberrans en la producción de jitomate. El objetivo de este estudio fue evaluar en condiciones de invernadero la aplicación de aceite de T. lucida de una población natural de Ixtapan de la Sal, Estado de México en la formación de agallas por N. aberrans en plántulas de jitomate. El aceite esencial se extrajo por hidrodestilación a nivel piloto con rendimiento en peso seco de 0.4% (mL 100 g-1) y se analizó por CG/EM identificando los compuestos mayoritarios siguientes: acetato de geranilo (40.8%), β-ocimeno (15.1%), nerolidol (8.1%), β-cubebeno (5.1%) y cariofileno (5.2%). Plántulas de jitomate en maceta se inocularon con N. aberrans (10 mL kg-1 de sustrato) y se les dosificaron concentraciones de aceite desde 0.01 hasta 10 mg mL-1, como tratamientos preventivos y de control, en intervalos de aplicación de aceite de 1, 2 y 3 semanas. La inhibición del agallamiento de la raíz fue consistente en el tratamiento de control (TC) que en el preventivo. En TC, concentraciones de aceite de 0.35 y 1 mg mL-1 produjeron 63 a 80% de inhibición del agallamiento y se obtuvieron valores de CL50 de 0.06 mg mL-1 para los intervalos 1 y 2, y de 0.13 mg mL-1 para el intervalo 3.
 
 

Photosynthetic Characteristics and Chloroplast Ultrastructure of Summer Maize Response to Different Nitrogen Supplies.

Maize (Zea mays L.) is the important crop over the world. Nitrogen (N) as necessary element affects photosynthetic characteristics and grain yield of summer maize. In this study, N0 (0 kg N ha-1), N1 (129 kg N ha-1), N2 (185 kg N ha-1), and N3 (300 kg N ha-1) was conducted using hybrid ‘ZhengDan958’ at Dawenkou research field (36°11′N, 117°06′E, 178 m altitude) in the North China Plain to explore the effects of N rate on photosynthetic characteristics and chloroplast ultrastructure. Gas exchange parameters, chlorophyll fluorescence parameters, leaf area index (LAI), chlorophyll SPAD value, chloroplast ultrastructure, dry matter weight and grain yield were measured. At physiological maturity stage, dry matter weight and grain yield of N2 increased by 33–52% (P ≤ 0.05) and 6–32% (P ≤ 0.05), respectively, compared with other treatments. During the growing from silking (R1) to milk (R3) stage, LAI of N0 and N1 were 35–38% (P ≤ 0.05) and 9–23% (P ≤ 0.05) less than that of N2, respectively. Chlorophyll SPAD value of N0 and N1 were 13–22% (P ≤ 0.05) and 5–11% (P ≤ 0.05) lower than that of N2. There was no significant difference in LAI and chlorophyll SPAD value between N2 and N3 during the period from R1 to R3 (P > 0.05). The net photosynthetic rate (Pn), maximal quantum efficiency of PSII (Fv/Fm) and quantum efficiency of PSII (ΦPSII) were higher with the increase of N rate up to N2 (P ≤ 0.05), and those of N3 were significantly less than N2 (P ≤ 0.05). In compared with N2, the chloroplast configuration of N0 and N1 became elliptical, almost circular or irregular. The membrane of chloroplast and thylakoid resolved with growing stage, and the number of chloroplast per cell and lamellae per grana decreased under N0 and N1 treatment (P ≤ 0.05). Under N0 and N1 treatments, summer maize had more negative photosynthetic characteristics. The more number of osmium granule and vesicle and the larger gap between lamellae were shown in N3. Therefore, N2 treatment, 185 kg N ha-1, is the appropriate application rate for grain yield, photosynthesis and chloroplast ultrastructure.

Exogenous Spermidine Affected Leaf Characteristics and Growth of Common Bean Under Water Deficit Conditions

ABSTRACTIn order to investigate the effects of exogenous spermidine on water limitation-induced damage on common bean (Phaseolus vulgaris L.) genotypes, a field experiment was conducted over two growth seasons. The experiment was arranged as a split-split plot design and three replications. Treatments were three water stress levels (non-stress, moderate and severe stress), three bean genotypes (Akhtar, Pak and COS12) and two spermidine levels (control and foliar application). The results showed that water stress reduced markedly leaf relative water content, SPAD values, specific leaf area, leaf area index, plant height, relative growth rate, shoot dry weight and grain yield; however, increased leaf density, leaf relative electrolyte leakage, stomatal density, leaf angle and leaf temperature of bean genotypes. Spermidine application increased relative water content, SPAD values, leaf area, leaf area index, shoot dry weight and grain yield. Overall, exogenous spermidine usage as a free radical scavenger counteracted deleterious water deficit effects.

Does the application of silicon and Moringa seed extract reduce heavy metals toxicity in potato tubers treated with phosphate fertilizers?

Two field trials were carried out in two successive agricultural seasons to study the possibility of using silicon (Si) and Moringa seed extract (MSE) for reducing heavy metal contamination resulting from phosphate fertilizers addition to potato tubers. A randomized complete block design experiment was performed using three replicates. Various sources of phosphate fertilizers as ordinary super phosphate and rock phosphate were added at rate of 100kgPha-1 prior sowing. Silicon was added as potassium silicate (20% SiO2) at rate of 6Lha-1, and MSE was also added at rate of 150Lha-1 in three equal doses with the 2nd, 4th, and 6th irrigations during the last 10min of drip irrigation. Results indicated that the addition of phosphate fertilizers increased fresh tuber yield, dry weight yield, NPK uptake, catalase, peroxidase, superoxide dismutase, and glutathione reductase of potato either alone or combined with silicon and MSE. The accumulation rate of Cu, Cd, and Ni in potato was higher with the single addition of rock phosphate fertilizer compared with single addition of super phosphate fertilizer. The highest reduction (P < 0.05) in heavy metal accumulation in potato leaves and tubers as well as soil was found with MSE treatment plus super phosphate fertilizer. It is recommended to add MSE at a rate of 150Lha-1 along with fertilizing the potato crop with ordinary super phosphate fertilizer.

The compensation effects of physiology and yield in cotton after drought stress

The objective of this study was to investigate the root growth compensatory effects and cotton yield under drought stress. The results indicate that the root dry weight, boll weight, and cotton yield increased in both the drought-resistant cultivar (CCRI-45) and the drought-sensitive cultivar (CCRI-60). Compensation effects were exhibited under the three-day drought stress treatment at a soil relative water content (SRWC) of 60% and 45% during the seedling stage, and flowering and boll-forming stage over two years. The yield of the drought-resistant cultivar (CCRI-45) was higher than the control, however, following the six-day 45% SRWC drought treatments, the yield of the drought-sensitive cultivar (CCRI-60) was lower than the control. The soluble sugar content, proline content, superoxide dismutase (SOD) activity, and peroxidase (POD) activity of the roots increased under drought stress and then decreased after re-watering, although the values remained higher than those of the controls for a short period. These physiological measures may represent stress reactions and thus may not indicate factors that result in compensation effects. However, catalase (CAT) activity and gibberellic acid (GA) content of the roots decreased under drought stress. After re-watering, the CAT activity and the GA content increased and were significantly higher than those of the controls under the six-day 60% SRWC and 45% SRWC drought treatments. The abscisic acid (ABA) content of the roots increased under drought stress. After re-watering, the ABA content decreased to a lower level under the three and six-day 60% SRWC and 45% SRWC drought treatments than in the controls. According to an analysis of various indicators, the interaction between ABA and GA signals may play an important role in root growth compensatory effects. In summary, the results demonstrate that moderate drought stress is beneficial to root growth and yield. This conclusion is of great significance to improving our understanding of the maximum utilization of limited water resources.

Effects of seed mixture sowing with resistant and susceptible rice on population dynamics of target planthoppers and non-target stemborers and leaffolders.

The widespread planting of insect-resistant crops has caused a dramatic shift in agricultural landscapes, thus raising concerns about the potential impact on both target and non-target pests worldwide. In this study, we examined the potential effects of six seed mixture ratios of insect-resistance dominance [100% (R100), 95% (S05R95), 90% (S10R90), 80% (S20R80), 60% (S40R60), and 0% (S100)] on target and non-target pests in a 2-year field trial in southern China. The occurrence of the target pests Nilaparvata lugens and Sogatella furcifera decreased with an increase in the ratio of resistant rice, and mixture ratios with ≥90% resistant rice significantly increased the pest suppression efficiency, with the lowest occurrences of the non-target pests Sesamia inferens, Chilo suppressalis and Cnaphalocrocis medinalis for S100 and S10R90 seed mixture ratios. Furthermore, there were no significant differences in the 1000-grain dry weight and grain yield between R100 and other treatments with ≥80% resistant seeds in the mixture (S20R80, S10R90 and S05R95). S10R90 produced a good yield and provided the most effective control of both target and non-target pests, with the potential to significantly reduce the application of chemical pesticides for integrated pest management in paddy fields. It is further presumed that the strategy of seed mixture with resistant and susceptible rice would be advantageous for rice yield stability. © 2018 Society of Chemical Industry.

Bioprospecting microbes for single-cell oil production from starchy wastes

ABSTRACTProduction of lipid from oleaginous yeast using starch as a carbon source is not a common practice; therefore, the purpose of this investigation was to explore the capability of starch assimilating microbes to produce oil, which was determined in terms of biomass weight, productivity, and lipid yield. Saccharomyces pastorianus, Rhodotorula mucilaginosa, Rhodotorula glutinis, and fungal isolate Ganoderma wiiroense were screened for the key parameters. The optimization was also performed by one-factor-at-a-time approach. Considering the specific yield of lipid and cell dry weight yield, R. glutinis and R. mucilaginosa showed superiority over other strains. G. wiiroense, a new isolate, would also be a promising strain for starch waste utilization in terms of extracellular and intracellular specific yield of lipids. Extracellular specific yield of lipid was highest in R. glutinis culture (0.025 g g−1 of biomass) followed by R. mucilaginosa (0.022 g g−1 of biomass) and G. wiiroense (0.020 g g−1 of biomass). Intracellular lipid was again highest in R. glutinis (0.048 g g−1 of biomass). The most prominent fatty acid methyl esters among the lipid as detected by GC-MS were saturated lipids mainly octadecanoic acid, tetradecanoate, and hexadecanoate. Extracellular lipid produced on starch substrate waste would be a cost-effective alternative for energy-intensive extraction process in biodiesel industry.

SILICON FERTILIZATION AND SEED MICROBIOLIZATION ON DISEASE SEVERITY AND AGRONOMIC PERFORMANCE OF UPLAND RICE

ABSTRACT Rice is one of the world’s most consumed cereals, however, its production is affected by fungal diseases. Thus, the objective of this work was to evaluate the severity of diseases and grain yield potential of upland rice with silicon fertilization combined with seed microbiolization with Bacillus methylotrophicus isolates. Two experiments were conducted, one in Igarapé do Meio, Maranhão (MA), Brazil, with rice seeds of the variety Palha-Murcha and one in São Bento MA with rice seeds of the variety BRS-Primavera. A randomized block experimental design in a split-plot arrangement with five replications were used in both experiments, with agro-silicon rates (0.0, 1.0, 2.0, 4.0 and 6.0 Mg ha-1) in the plots and microbiolized and non-microbiolized rice seeds with B. Methylotrophicus at concentration of 108 CFU ml-1 in the subplots. The seedling emergence, grain yield, number of panicles, plant height, plant dry weight and severity of brown leafspot, leaf scald and grain spot were evaluated. Soil fertilization with agro-silicon affected positively the plant height of the variety Palha-Murcha and the number of panicles, plant dry weight and grain yield of the variety BRS-Primavera, and negatively the germination of the variety BRS-Primavera. Leaf scald severity in the variety BRS-Primavera reduced with microbiolized seeds with B. methylotropicus. Microbiolization with B. methylotropicus had no effect on severity of brown leafspot and grain spot in the varieties evaluated.

Plant species-specificity and effects of bioinoculants and fertilization on plant performance for nickel phytomining

To investigate the effects of fertilization and bacterial inoculation on the growth, health and Ni phytoextraction capacity of three Ni-hyperaccumulators, Odontarrhena bracteata, O. inflata and O. serpyllifolia. Plants were grown for three months in serpentine soil fertilized with inorganic NPK or amended with cow manure and inoculated with five rhizobacterial strains (previously isolated from O. serpyllifolia). Shoot and root dry weight (DW) yields, Ni accumulation and removal, nutritive status and stress indicators were determined. Plants grown in manure-amended soil showed significantly higher DW yields, improved nutritive status and higher total Ni phytoextracted. Some bacterial inoculants enhanced Ni removal due to the stimulation in growth and/or increase in shoot Ni concentration but this depended on the plant species, soil type and inoculant. Pseudoarthrobacter oxydans strain SBA82 enhanced shoot DW yield of all three Odontarrhena spp. in at least one soil type. Paenarthrobacter sp. strain LA44 and Stenotrophomonas sp. strain MA98 promoted growth of O. serpyllifolia and O. bracteata. Inoculated plants showing growth promotion presented lower activities of antioxidative enzymes, and concentrations of malondialdehyde (MDA) and H2O2, indicating a protective effect of these inoculants on the plants. Rhizobacterial inoculants applied in combination with manure can improve plant growth and health, and Ni phytoextraction, in some hyperaccumulating Odontarrhena spp.

Interaction of biological nitrogen fixation with sowing nitrogen fertilization on common bean in the two seasons of cultivation in Brazil

ABSTRACTSowing nitrogen (N) fertilization can limit biological nitrogen fixation (BNF) reducing common bean yield. The aim of this study was to evaluate the effect of sowing N fertilization plus inoculation on the growth and yield of plants in the two seasons of cultivation in Brazil. In the dry season, N fertilization and inoculation promoted a greater shoot dry weight and higher pod number and yield than only inoculated. In contrast, in the rainy season, this treatment promoted no increase in shoot dry weight and yield compared with the inoculated alone. The number of nodules was greater for the inoculated alone treatment, but nodule weight was not affected by N fertilization in either season. Therefore, sowing N fertilization and inoculation can be an agronomic practice to achieve a higher common bean yield in the dry season, while in the rainy season, the inoculation without N fertilization can support a high yield at a lower cost.

The Impact of Organic Biofertilizer Application in Dairy Cattle Manure on the Chemical Properties of the Soil and the Growth and Nutritional Status of Urochroa Grass

ABSTRACTThe management of nitrogen (N) fertilization in pasture has great importance for yield and maintenance of Brazilian livestock. The objective of this study was to evaluate soil chemical attributes, shoot dry weight yield (SDWY) and roots dry weight yield (RDWY), nutritional status and nutritive value of Mulato II Urochloa grass that received organic biofertilizer rates as N source. The treatments were arranged in completely randomized blocks, were fertilized with six organic biofertilizer rates (0, 25, 50, 100, 200, and 400 m3 ha−1) and five replicates during four harvest cycles. There was a quadratic response in the accumulated SDWY for up to a rate of 400 m3 ha−1 and RDWY with 330 m3 ha−1 of organic biofertilizer. The organic biofertilizer influenced the soil chemical attributes and foliar nutrient concentration. However, only the crude protein content presented a quadratic response, and neutral detergent fiber and acid detergent fiber levels were not affected by the influence of organic biofertilizer applied to the soil.

Pengaruh Takaran dan Frekuensi Aplikasi PGPR terhadap Pertumbuhan dan Hasil Tanaman Selada (Lactuca sativa L.).

Penelitian ini bertujuan untuk mengetahui dan membuktikan pengaruh takaran dan frekuensi aplikasi PGPR terhadap pertumbuhan dan hasil tanaman selada dan juga mengetahui takaran dan frekuensi aplikasi PGPR yang tepat untuk mendapatkan pertumbuhan dan hasil tanaman selada yang terbaik. Rancangan yang digunakan adalah rancangan acak kelompok (RAK) faktorial dengan tiga kali ulangan. Faktor pertama adalah takaran PGPR yang terdiri dari tiga aras yakni 25 g, 50 g dan, 75 g. Faktor yang kedua adalah frekuensi aplikasi yang terdiri dari tiga aras yakni tanpa penyiraman (kontrol), satu kali penyiraman dan, dua kali penyiraman. Hasil penelitian menunjukkan interaksi antara takaran dan frekuensi aplikasi PGPR terjadi pada semua parameter pertumbuhan dan hasil selada yakni tinggi tanaman, jumlah daun, luas daun, berat trubus baik segar maupun kering, berat akar baik segar maupun kering, berat tanaman baik segar maupun kering, berat tanaman per petak baik segar maupun kering dan indeks panen. Aplikasi PGPR sebanyak dua kali dengan takaran 25 g memberikan pertumbuhan dan hasil tanaman selada yang terbaik. ©2018 dipublikasikan oleh Savana Cendana.

Impacts of Irrigation with Reclaimed Wastewater on Forages Production, Nutrients, and Heavy Metals Content

In order to investigate the effect of reclaimed wastewater (RWW) on soil chemical properties and heavy metal uptake of selected forages, an experiment was carried out at Dhaid Research Station, UAE during three growing seasons (2014-2016). Alfalfa, Rhodes and Buffel grass were irrigated by RWW and grown in a randomized complete block design with four replications. Composite soil samples were collected from the experimental site before starting the study and every six months from planting date to test the macro and heavy elements concentration in soil and forages tissues. Chemical analysis for soil, crops and wastewater were analyzed. RWW irrigation has significantly increased the soil salinity (1 to 8 dSm-1) in 2014 but soon these values were declined in 2015 and 2016 growing seasons due to the enhanced irrigation water quality and the use of good water management.Results revealed that UAE (Sharjah) domestic RWW is suitable to be reused for irrigate forages as its quality match international standards for RWW irrigation except its Na and Cl content. The results of the plants tissues analysis during 2014 season indicated a rise in the nutrients concentration, particularly nitrogen, potash, iron and boron, compared with the critical limits. While, the results have also shown a significant increase of zinc (Zn) and copper (Cu), especially in Buffel grass and Alfalfa tissues during the third season (2016) which exceeded the critical limits.The highest mean yearly dry weight yield during the study period were recorded for Buffel grass (50.5 ton ha-1) followed by Rhodes (44.5 ton ha-1) and Alfalfa (11.1 ton ha-1). It can be concluded that regular monitoring of recycled wastewater, soil and appropriate management are needed to mitigate the negative impacts of sodium and salts accumulations.

An Attempt to Mitigation of Irrigation Water Deficit Stress in Pea (Pisum sativum, L) Plants by Phosphorus Fertilizer

This investigation was carried in order to elucidate the response of pea (cv. Master pea) to various levels of Phosphorus fertilizer, i.e 45, 60, 75 and 90 kg as P2O5 /fed. under three levels of irrigation water deficit (100% of common irrigation as control, moderate stress 75 % of common irrigation and severe stress 50 % of the common irrigation). Therefore, two field experiments were conducted in the Experimental Station, Faculty of Agriculture, Mansoura University during 2015 and 2016 in winter seasons. The results indicated that vegetative growth characters (plant height, plant fresh weight, branches number, leaves fresh weight, leaves number and leaves area) per plant, leaves chemical composition (N, P, K and chlorophyll pigments), pods yield and its quality (pods weight per plant, pods number per plant, seeds fresh weight per plant, 100 seeds fresh weight, seeds dry weight yield and pods yield per fed., Vit. C and TSS) and plant water relations (leaf relative water content and leaf membrane stability index) were decreased by increasing of irrigation water deficit. On the contrast, leaves and seeds dry matter % were increased by increasing of irrigation water deficit. On the other hand, water use efficiency is not affected with irrigation water deficit. With respect to the effect of phosphorus fertilizer rates, the data show that, the mentioned attributes were increased up to 60 kg as P2O5 /fed then declined at and 75 kg as P2O5 /fed. On the other hand, 45 kg as P2O5 /fed gave the lowest values for most effective mentioned parameters. As for the interaction between irrigation water deficit and Phosphorus fertilizer rates showed that common irrigation and 60 kg as P2O5 /fed combination recorded the maximum values for more effective mentioned characters. In addition, results showed that common irrigation or moderate stress treatments with Phosphorus fertilizer rates had insignificant differences for most effective previous parameters.

Sweet potato response to biochar application on sub-optimal dry land

This trial was aimed to evaluate the performance of sweet potato cultivars on biochar application. The treatments were carried out using a Split-plot Design with three replications. The cultivars were placed on main plots and biochar doses were on sub-plots. The thirteen cultivars consisted of seven varieties and six accessions from Tribhuwana Tunggadewi University and Brawijaya University collections. The applied biochar doses were B 0 (0 t/ha) and B 1 (5 t/ha). The experimental unit measuring of 5 m x 0.6 m consisted of single row and planted with a spacing of 25 cm in row or 20 cuttings/row. The storage root weight, % dry matter, storage root dry weight, dry weight of biomass, harvest index and yield estimation were determined. The results showed that the sweet potato cultivars gave a significant response to the biochar application on fresh storage root weight, storage root dry weight, biomass dry weight, harvest index and storage root yields, but no interaction between cultivars and biochar doses. Storage root yield ranged from 8 to 21 t/ha without biochar and from 10 to 23 t/ha with 5 t biochar /ha, except for Beta 1 and Boko. The use of 5 t biochar /ha increased storage root yields that ranged from 8 to 45%.

Rooting Pattern and Anatomical Alteration in Roots of Sugarcane Genotypes under Waterlogged Conditions

Twenty three sugarcane genotypes consisting six commercial varieties (CoLk 94184, BO91, CoS 767, CoJ 64, CoS 97264, UP 9530) and 17 germplasm lines (CoLk 12204, CoLk 12202, CoLk 12206, CoLk 07201, CoLk 04238, LG 06605, LG 04439, LG 05350, LG 05020, LG 03040, A-46-11, B-44-12, A-27-12, D-12-9, D-6-13, S 5085/11, S 5087/11) were assessed for rooting pattern and root anatomy under waterlogged condition. Results indicated in general reduce shoot dry mass in all the genotypes. Except in CoLk94184, CoLk 12204, CoLk 12206, LG06605, LG04439, D-6-13 and S 5085/11, rest of the genotypes showed decreased shoot dry mass. However, root dry mass was observed relatively higher under waterlogged condition. Aerial rooting pattern varied among genotypes as some of the genotypes showed aerial roots up to the 12th nodes. Genotypes, namely CoLK 94184, UP 9530, CoS 97264, LG 04439, LG 05020, D-6-13, S5985/11 and S 5087/11 genotypes showed dense aerial root growth. Anatomical studies indicated cortical cell distortion and loss of uniformity in endodermis and pericycle due to waterlogging. The size of metaxylem vessel of roots declined when compared with control roots, however, number of metaxylem vessels increased in shoot roots. Correlation analysis indicated positive association of root dry mass (R2=0.655) and number of metaxylem vessel (R2=0.392) with stalk dry weight (yield contributing attribute) under waterlogging condition. Based on root attributes, seven genotypes, namely UP 9530, CoS 97264, LG 04439, LG 05020, D-6-13, S5085/11 and S 5087/11 were defined as tolerant lines exhibiting better tolerance to waterlogging.

Foliar application of molybdenum enhanced quality and yield of crispleaf lettuce (Lactuca sativa L., cv. Grand Rapids)

La aplicación foliar de molibdeno (Mo) puede mejorar la adquisición de nitrógeno (N) por las plantas y aumentar el rendimiento y la calidad de las hortalizas. Se realizó un estudio para investigar el efecto de la pulverización Mo foliar sobre la nutrición N y el rendimiento de la lechuga crespa (Lactuca sativa L., cv Grand Rapids) cultivada en el período de primavera-verano. El experimento se llevó a cabo en Ourinhos, São Paulo, Brasil, desde octubre de 2013 a enero de 2014. Los tratamientos consistieron en cinco ratas de Mo [0 (control), 25, 50, 75 y 100 g ha-1 de Mo] divididas en dos aerosoles foliares, a los 14 y 21 días después de la siembra. La aplicación foliar de las tasas de Mo redujo la concentración de nitrato (NO3-) y aumentó las concentraciones de amonio (NH4 +), N total y Mo en las hojas de lechuga. Estos datos indican que la aplicación foliar de Mo mejoró la asimilación de N de las plantas de lechuga, lo que resultó en una menor acumulación de NO3- en las hojas y, por lo tanto, mejoró la calidad de la hortaliza. El número de hojas por planta no se vio afectado por la aplicación foliar de Mo. Los 55 a 62 g ha-1 de la aplicación de Mo dieron como resultado un aumento del peso fresco de las hojas (33%), el peso seco (28%) y el rendimiento comercial (34%) de la lechuga crespa, respectivamente. Los resultados sugieren que la deficiencia de Mo puede comprometer el metabolismo del N de las plantas y dar como resultado un menor rendimiento comercial de la lechuga crespa.