Бобовият компонент на горски садинови ливади в условията на „детелинова година“

A Petridish and hydroponic culture experiments were conducted at Crop Physiology Laboratory, Department of Crop Botany and Agriculture Chemistry Laboratory, Bangladesh Agricultural University, Mymensingh during the period from August to October 2011 to investigate the effect of aluminium on morphological characters and growth of wheat seedlings. The experiment comprised of two levels of aluminium concentrations viz., 0 μM (control) and 100 μM and five varieties viz; Kanchan, Shatabdi, Sourav, Bijoy (BARI-23) and Sufi (BARI-22). The experiment was laid out in two factors completely randomized design with three replications. Applications of 100 μM aluminium had a profound influence on hypocotyls and epicotyls length, germination percentages, and rootshoot length, fresh and dry mass production in wheat. Results indicated that germination percentage, hypocotyls and epicotyls length, root and shoot length, leaf length, leaf sheath length, plant height, fresh and dry mass plant were greater in control than aluminium stress conditions. It revealed that wheat seedlings are susceptible to aluminium stress. However, among the varieties, the reduction of dry mass under aluminium stress was minimum in Shatabdi followed by Kanchan showed that Shatabdi was more tolerant to aluminium stress than the other varieties namely Sourav, Bijoy (BARI-23) and Sufi (BARI-22). Sufi and Sourav were more susceptible to aluminium stress.
 SAARC J. Agri., 17(1): 65-76 (2019)

The objective of this study was to evaluate the effect of nitrogen doses on the agronomic characteristics of Convert grass in the fourth year after establishment. The experiment was carried out in the experimental area of ​​the University of the State of Mato Grosso, in Tangará da Serra – Mato Grosso, Brazil. The experimental design was in randomized blocks, with six treatments (0, 100, 200, 300, 400 and 500 kg ha-1 of nitrogen) and four replications. The characteristics evaluated were production of green and dry mass per hectare, percentage of dry mass, number of leaves per tiller, dry mass per tiller, production of leaves, stalks, senescent material, weeds, plant height and leaf:stem ratio. Nitrogen doses positively influenced the characteristics of plant height, dry mass per tiller, number of leaves per tiller, production of green mass and dry mass, dry mass of leaves and stems of Convert grass in the fourth year of production. However, there was no effect of nitrogen fertilization on the percentage of dry mass, leaf: stem ratio, dry mass of senescent material and weeds. The best productivity results in Convert grass are obtained at the dose of 500 kg ha-1 of nitrogen.

O Norte de Minas Gerais cultiva basicamente bananeira 'Prata-Anã', cultivar especialmente exigente em zinco. A possibilidade de fornecimento de Zn, sem que esse entre em contato com o solo, é importante para a região, uma vez que vários fatores levam à baixa disponibilidade do elemento fornecido via solo, como: elevado teor de matéria orgânica na camada superficial (resultante de resíduos culturais); manutenção de elevado pH do solo - acima de 6,00 - como estratégia contrária à proliferação do agente causal do mal- do-panamá; adubações frequentes com potássio e magnésio, que além de basificar o meio, diminuem a participação do Zn no equilíbrio cátion-ânion do solo, dificultando a absorção deste micronutriente pela planta. Para determinar a distribuição de biomassa e minerais na bananeira Prata-Anã, cultivada sob irrigação no norte de Minas Gerais, quando o zinco é fornecido via broto desbastado, foi conduzido um experimento no Perímetro Irrigado de Jaíba. As plantas foram adubadas com 0,00; 1,66 e 3,33 g.família-1 de Zn (0; 25 e 50 g.família-1.ano-1 de sulfato de Zn), via muda desbastada. Um mês após as adubações de outubro de 2007 e junho de 2008, avaliaram-se a produção de massa fresca (MF) e massa seca (MS), os teores e conteúdos de minerais em todos os órgãos de uma ''família'' de bananeira composta por planta-mãe com cacho + planta-filha alta + planta-neta. As doses de Zn não influíram na produção de MF e MS das plantas na primeira avaliação, enquanto na segunda avaliação observou-se efeito positivo do tratamento apenas para MF acumulada nas folhas inferiores, nas porções do terço médio e inferior do pseudocaule, e no rizoma da planta-mãe. Tanto o teor quanto o acúmulo de nutrientes nas plantas-mãe apresentaram a seguinte ordem decrescente: K > N > Ca > Mg > P > S > Fe > Zn > B > Cu. Os teores de Zn foram afetados pela dose desse micronutriente na maioria das situações estudadas. O Zn fornecido via broto desbastado ascendeu na planta-mãe, e daí se redistribuiu na ''família'' da bananeira.

Alternative metrics exist for representing variation in plant body size, but the vast majority of previous research for herbaceous plants has focused on dry mass. Dry mass provides a reasonably accurate and easily measured estimate for comparing relative capacity to convert solar energy into stored carbon. However, from a “plant's eye view”, its experience of its local biotic environment of immediate neighbors (especially when crowded) may be more accurately represented by measures of “space occupancy” (S–O) recorded in situ—rather than dry mass measured after storage in a drying oven. This study investigated relationships between dry mass and alternative metrics of S–O body size for resident plants sampled from natural populations of herbaceous species found in Eastern Ontario. Plant height, maximum lateral canopy extent, and estimated canopy area and volume were recorded in situ (in the field)—and both fresh and dry mass were recorded in the laboratory—for 138 species ranging widely in body size and for 20 plants ranging widely in body size within each of 10 focal species. Dry mass and fresh mass were highly correlated (r 2 > .95) and isometric, suggesting that for some studies, between‐species (or between‐plant) variation in water content may be unimportant and fresh mass can therefore substitute for dry mass. However, several relationships between dry mass and other S–O body size metrics showed allometry—that is, plants with smaller S–O body size had disproportionately less dry mass. In other words, they have higher “body mass density” (BMD) — more dry mass per unit S–O body size. These results have practical importance for experimental design and methodology as well as implications for the interpretation of “reproductive economy”—the capacity to produce offspring at small body sizes—because fecundity and dry mass (produced in the same growing season) typically have a positive, isometric relationship. Accordingly, the allometry between dry mass and S–O body size reported here suggests that plants with smaller S–O body size—because of higher BMD—may produce fewer offspring, but less than proportionately so; in other words, they may produce more offspring per unit of body size space occupancy.

“Diminishing returns” in leaf economics occurs when increases in lamina mass (M), which can either be represented by lamina dry mass (DM) or fresh mass (FM), fail to produce proportional increases in leaf surface area (A), such that the scaling exponent (α) for the M vs. A scaling relationship exceeds unity (i.e., α > 1.0). Prior studies have shown that FM vs. A is better than DM vs A in assessing diminishing returns in evergreen species. However, the superiority of FM vs. A over DM vs. A has been less well examined for deciduous species. Here, we applied reduced major axis protocols to test whether FM vs. A is better than DM vs. A to describe the M vs. A scaling relationship, using a total of 4271 leaves from ten deciduous and two evergreen tree species in the Fagaceae and Ulmaceae for comparison. The significance of the difference between the scaling exponents of FM vs. A and DM vs. A was tested using the bootstrap percentile method. Further, we tested the non-linearity of the FM (DM) vs. A data on a log-log scale using ordinary least squares. We found that (i) the majority of scaling exponents of FM vs. A and DM vs. A were >1 thereby confirming diminishing returns for all 12 species, (ii) FM vs. A was more robust than DM vs. A to identify the M vs. A scaling relationship, (iii) the non-linearity of the allometric model was significant for both DM vs. A and FM vs. A., and (iv) the evergreen species of Fagaceae had significantly higher DM and FM per unit area than other deciduous species. In summary, FM vs. A is a more reliable measure than DM vs. A when dealing with diminishing returns, and deciduous species tend to invest less biomass in unit leaf light harvesting area than evergreen species.

Dry mass production, leaf characteristics and diurnal photosynthesis of two N. tabacum L. genotypes selected for survival at low CO2 and the parent Wisconsin-38 (control plants) were measured on water-stressed and well-watered plants in the field. Differences in photosynthesis per unit leaf area were small and not significant between genotypes, but different patterns of photosynthesis were observed in stressed and non-stressed plants, with water stress reducing total net carbon fixation by 45% in all genotypes. More dry mass was produced by the selected genotypes than by Wisconsin-38 under irrigation. Production was smaller and the same for all three genotypes when stressed. The increased dry mass of the selected genotypes was related to greater total leaf area per plant which was accompanied by more cells per unit leaf area but smaller cell volume than in the control plants. The decrease in dry mass production under water stress was related to a decrease in total leaf area per plant and a decrease in cell number per unit leaf area; however, cell volume increased.

Elephant grass has high biomass production potential and can benefit from biological nitrogen fixation (BNF) as its main external nitrogen source. This study evaluated the effect of BNF on biomass productivity and total nitrogen accumulation in different elephant grass genotypes. This experiment was conducted in a 120 m2 concrete tank filled with soil labeled with 15N to estimate the contribution of BNF. The experimental design was randomized blocks with four replications, and the evaluation was over three years of cultivation, with semiannual cuts. The productivity of fresh and dry mass of the shoot, Nitrogen (N) accumulation, and the contribution of BNF by the 15N natural abundance technique were evaluated. The annual average of BNF was 38%. There was a statistical difference between the treatments, with the genotype P13G13 presenting fresh and dry mass productivity 50% higher than P6G4. The annual average of fresh mass, dry matter, total N, and N derived from BNF in the genotypes was approximately 70, 30, 100 Mg ha−1, and 35 kg ha−1, respectively. The results obtained by the P13G13 genotype allow us to recommend its use for biomass production aimed at bioenergy, favoring sustainability, reducing greenhouse gas emissions, and dependence on synthetic nitrogen fertilizers.

The experiment was carried out under sub-tropical condition (24°75´ N latitude and 90°50´ E longitude) to investigate the growth, dry mass production and its partitioning into plant parts of three lentil varieties viz. BINA masur1, BINA masur2 and BINA masur3. The leaf area and total dry mass plant−1 were superior in BINA masur3 over its growth period followed by BINA masur2 with same statistical rank. In contrast, BINA masur1 performed inferiority in leaf area and total dry mass plant−1. Dry mass partitioning into seed (HI) was significantly greater in BINA masur2 and BINA masur3 with being the highest in BINA masur2 but total economic yield and its related traits were greater in BINA masur3 than in BINA masur2. Results indicated that percent contribution of dry mass partitioning into different plant parts had no significant influence on seed yield but leaf and stem dry mass production had influence on seed yield in lentil. BINA masur3 produced the highest in leaf and stem dry mass and also showed the highest seed yield followed by BINA masur2. In contrast, BINA masur1 showed the lowest seed yield for contributed lower leaf dry mass.

Productivity and nutritional quality of Tobiata grass as a function of NPK fertilization. The present study had as objective to study five N rates (0, 50, 100, 150 and 200 kg ha -1 ), two P2O5 rates (96 and 30 kg ha -1 ) as superphosphate triple, and two doses of K2O (170 and 143 kg ha -1 ) as potassium chloride, in the forage Panicum maximum cv. Tobiata, with irrigation. The experiment was conducted using a randomized blocks design with four replicates. In the implantation of the experiment, P and K were applied based on theoretical doses required to reach values of 40 mg dm -3 of P and K 5% of CTC. After three cuts, dry mass produced by the forage was estimated in order to obtain the values of the nutrients exported by the plant. Only after this procedure did the application of the doses of N take place. The production of dry mass - DM, crude protein - CP, neutral-detergent fiber - NDF, and acid-detergent fiber - ADF, were influenced by cuts; increasing N fertilization increased the production of DM, CP and decreased ADF and NDF, providing better forage quality. The fertilization with phosphorus and potassium can be done based on DM production or P and K content in soil.

Plant growth promoting bacteria (PGPB) are an alternative to increase the productivity of several crops, including lettuce. Several reports are found in the literature with the use of plant growth-promoting bacteria in lettuce cultivation, but most seek increments during the production of seedlings. Aiming to provide increments in the cultivation of lettuce in the field and to generate subsidies to technicians and producers, the present work aimed to study the influence of the application of commercial products based on Azospirillum brasilense, Bacillus subtilis + B. megaterium and Pseudomonas fluorescens, on agronomic characteristics and quality of crisp lettuce. The experiment was implemented in two locations, in a randomized block design, in a 4 x 3 factorial scheme, with four replications. The first factor refers to the application of different PGPB: control, without inoculation; inoculations with A. brasilense; B. subtilis + B. megaterium and P. fluorescens. The second factor was composed of three times of application of PGPB, the first being on the day of seedling transplantation (DAT), the second at 15 STR and the third on the day of seedling transplantation + 15 DAT. At 15 DAT, the relative chlorophyll content, plant height, head diameter, number of leaves per plant, leaf area, leaf dry mass, stem dry mass, root dry mass, total dry mass, root volume were evaluated. and root length. At harvest, the same variables analyzed at 15 DAT + leaf fresh mass, stem fresh mass, head fresh mass, root fresh mass, total fresh mass and leaf contents of nitrogen, phosphorus and potassium were analyzed. The inoculated plant growth-promoting bacteria did not promote a significant increase in the development of the lettuce cultivar Vera when compared to the control (without PGPB application).

Objetivou-se, neste trabalho, avaliar o crescimento aéreo e radicular de cultivares e híbridos de milheto em solo submetido a quatro níveis de compactação do solo. Foram utilizados sete híbridos de milheto - Pennisetum glaucum L. (40425, 40853, 41312, 51499, 60018, 60019 e ADR7010) e as variedades ADR300 e ADR500; aos 30 dias após o plantio determinaram-se as massas da matéria seca da parte aérea e das raízes, a densidade do comprimento radicular e o diâmetro médio radicular. Na densidade de 1,74 Mg m-3 as cultivares e híbridos de milheto apresentaram uma redução elevada da massa verde da parte aérea, massa seca da parte aérea, altura de plantas e área foliar. Os híbridos 40853 e 60019 apresentaram comportamento inferior aos demais híbridos e cultivares na produção de matéria verde e seca da parte aérea e altura de plantas na densidade de 1,65 Mg m-3. As cultivares ADR500 e ADR300 e os híbridos 40425 e 51499 se destacaram na produção de massa verde e seca e altura de plantas na densidade de 1,65 kg m-3. A maior densidade de comprimento radicular média entre as cultivares de milheto foi verificada na densidade do solo de 1,46 Mg m-3. A cultura do milheto demonstrou potencial como planta descompactadora do solo.

Thirteen of the new synthetized 2-R substituted benzothiazole derivatives have been tested for plant growth regulatory (PGR) activity. The effect on growth elongation was studied on wheat coleoptile segments Triticum aestivum L. cv. Blava, and on the hypocotyl and roots in cucumber Cucumis sativum L. cv. Evita. The formation and number of adventitious roots and the length of hypocotyl in Vigna radiata (L.) Wilczek and, the effect on the length of stem, fresh and dry mass in buckwheat Fagopyrum esculentum Moench. cv. Pyra were evaluated. Cytokinin activity was determined on segments of barley leaves Hordeum vulgare L. cv. Jubilant on the basis of senescence inhibition and chlorophyll content. The benzothiazole derivatives were tested in the range of 10<sup>–3</sup>–10<sup>–7</sup>M concentrations, and PGR activity was compared with indole-3-acetic acid, indole-3-butyric acid and 6-furfurylaminopurine. All tested derivatives showed different auxine-like effects on elongation growth of plants and the stimulative effects were found to depend on applicable concentrations. At higher concentration rates, derivatives acted as growth retardants and inhibited the length of cucumber hypocotyl and roots. The derivatives increased the formation of adventitious roots of mung bean hypocotyl cuttings, as well as stem elongation and production of fresh and dry mass of buckwheat. Cytokinin activity was confirmed in one derivate only with a significant effect on the inhibition of leaf senescence and higher chlorophyll content. The tested benzothiazole derivatives may be characterized as biologically active substances with dominant auxine-like growth promoting activity

Chitinolytic activity and dry mass production were determined in culture filtrates from 17 Metarhizium anisopliae strains grown in liquid medium containing chitin as the only carbon source. The objectives were to estimate parameters such as genetic variance among strains, heritability and expected gain from selection, as well as correlations between tested traits. Wide genotypic variability was observed among strains in chitinolytic activity, permitting the exploitation of this property in selection. The high heritability suggests that progress can be made through phenotypic selection. The genotypic correlation coefficient between dry mass production and chitinolytic activity detected in the filtrates was negative (<img src="http:/img/fbpe/gmb/v21n2/pg171-1.jpg" alt="wpe1.jpg (777 bytes)" align="absmiddle">= - 0.588). One of the isolates was also investigated for variation in the two traits as a function of culture growth time. The results showed an increase in enzyme activity up to the 8th (and last) day of the experiment and a decrease in dry mass from the 4th day on.

Knowledge regarding the interactive effects of elevated [CO2], warming and drought on dry mass production, allocation and water use efficiency (WUE) of tree seedlings is limited, particularly in trees exhibiting different stomatal regulation strategies. Seedlings of Callitris rhomboidea (relatively anisohydric) and Pinus radiata (relatively isohydric) were grown in two [CO2] (Ca (400 μmol mol−1) and Ce (640 μmol mol−1)) and two temperature (Ta (ambient) and Te (ambient + 4 °C)) treatments in a sun-lit glasshouse under well-watered conditions prior to imposition of the drought. Ce increased mass production in C. rhomboidea (but not in P. radiata), while drought limited mass production in both species. Mass production was greatest in the combination of Ce, Te and well-watered conditions. Pinus radiata allocated relatively more dry mass into roots and had higher plant WUE than C. rhomboidea. Noticeably, mass allocation patterns in C. rhomboidea varied as a function of the treatments, but those of P. radiata were constant. Ce enhanced leaf WUE of both species, but to a greater degree under drought stress than well-watered conditions. Moderate drought stress increased both leaf and plant WUE compared to well-watered conditions. C. rhomboidea exhibited plasticity to variable climate conditions through morphological adjustments, while P. radiata exhibited a highly conservative strategy. Collectively, these findings indicate that the two species have different strategies in resource acquisition and utilisation under changing environmental conditions. Future studies on tree response to climate change need to fully consider the integration of species traits, including stomatal behaviour and hydraulic strategies.

With the objective of evaluating the effect of different ionic concentrations of the nutrient solution on growth of summer squash cultivated in raw rice husk substrate with leaching recirculation, two experiments were conducted in two crop-seasons: spring-summer of 2005 and summer-autumn of 2006, in Pelotas, RS. Four ionic concentrations of the nutrient solution (based on electrical conductivity - EC) were studied: 1.3; 1.7; 2.1 and 4.2 dS m-1. Crop growth was determinated by accumulated dry mass production and partitioning among the different above-ground plant organs (leafs, stem and fruits) at the end of the crop-seasons. Fruit yield was also evaluated. The obtained results indicate that ionic concentrations equal or lower than 1.7 dS m-1 were limiting for proper growth and yield of the crop. The effect of high ionic concentration of the nutrient solution (above 2.1 dS m-1) on dry mass production and partitioning varied according to the crop-season. The lower solar radiation availability of the summer-autumn crop season minimized the effects of the different concentrations of nutrient solution on dry mass production and partitioning to the fruits, as well as on the yield. The fruits comprised from 28 to 52% of the total above-ground dry mass production. Fruits represented the largest sink of assimilates of the plant only at 2.1 dS m-1 ionic concentration of the nutrient solution and in crescent solar radiation availability condition (spring-summer). According the mathematics models, the electrical conductivity that maximizes dry mass production and yield is approximately 3.0 dS m-1 for both crop-seasons.