Maximum Total Dry Matter Research Articles

Evaluation of forage qualities of sorghum (Sorghum bicolor L.) under varying jeevamrit formulations and their spraying interval

An experiment was conducted at ICAR-Central Institute for Research on Goats, Makhdoom to generate precise information about different jeevamrit formulation and their spraying interval on forage quality of fodder sorghum during summer season of 2022. The treatments consisted of three jeevamrit formulations viz. jeevamrit-1 (5 kg cow dung + 2.5 litre cow urine), jeevamrit-2 (10 kg cow dung + 5 litre cow urine) and jeevamrit-3 (15 kg cow dung + 7.5 litre cow urine); and three spraying intervals viz. spraying at every one week’s interval, spraying at every two week’s interval and spraying at every three week’s interval. The experiment was laid out in factorial randomized block design with three replications. The results showed that among the different jeevamrit formulations, jeevamrit-3and among the different spraying intervals, spraying at every one week’s interval recorded maximum total dry matter yield, crude protein, ether extract, TDN content, dry matter intake, relative feed quality, net energy for lactation, nitrogen, phosphorus and potassium content in forage sorghum. However, among the different jeevamrit formulations, jeevamrit-2 and jeevamrit-3; and among the different spraying intervals, spraying of jeevamirt at every one week and every two week’s interval recorded at par values of all the nutritive parameters in fodder sorghum.

Evaluation of forage qualities of sorghum (Sorghum bicolor L.) under varying jeevamrit formulations and their spraying interval

An experiment was conducted at ICAR-Central Institute for Research on Goats, Makhdoom to generate precise information about different jeevamrit formulation and their spraying interval on forage quality of fodder sorghum during summer season of 2022. The treatments consisted of three jeevamrit formulations viz. jeevamrit-1 (5 kg cow dung + 2.5 litre cow urine), jeevamrit-2 (10 kg cow dung + 5 litre cow urine) and jeevamrit-3 (15 kg cow dung + 7.5 litre cow urine); and three spraying intervals viz. spraying at every one week’s interval, spraying at every two week’s interval and spraying at every three week’s interval. The experiment was laid out in factorial randomized block design with three replications. The results showed that among the different jeevamrit formulations, jeevamrit-3and among the different spraying intervals, spraying at every one week’s interval recorded maximum total dry matter yield, crude protein, ether extract, TDN content, dry matter intake, relative feed quality, net energy for lactation, nitrogen, phosphorus and potassium content in forage sorghum. However, among the different jeevamrit formulations, jeevamrit-2 and jeevamrit-3; and among the different spraying intervals, spraying of jeevamirt at every one week and every two week’s interval recorded at par values of all the nutritive parameters in fodder sorghum.

Growth and yield performance of sunflower (Helianthus annuus L.) as influenced by cow dung and NPK fertilizers

A field experiment was conducted at the research farm of Charfasson Govt. College, Bhola, Bangladesh in rabi season in 2015-2016 to evaluate the effect of cow dung and chemical fertilizers on growth and yield of sunflower cv. BARI-2 (Keroni-2). Highest plant height (208.4 cm), leaf area (410.5 cm2) and leaf area index (12.75) were recorded in T16 (7.5 ton CD ha-1 +N120P90K150kg ha-1). Highest dry matter yield viz. stem (60.67g plant-1) found in treatment T16 (7.5 ton CD ha- 1+N120 P90K150kg ha-1). Maximum dry weight of leaf (25.33g plant-1) and dry weight of root (12.83g plant-1) were found in treatment T15 (7.5 ton CD ha-1 +N80P60K100kg ha-1). Highest dry weight of seed (64.7 g plant-1) and dry wt. of 100 seed (9.8 g) were found in treatment T15 (7.5 ton CD ha-1 +N80P60K100kg ha-1) but the highest number of seed (735.7plant-1) and florescence diameter (52.67 cm) were observed in treatment T13 (5 ton CD ha-1 +N120P90K150kg ha-1). Maximum total dry matter yield per plant was 92.01 g and per hectare was 5.75 ton in T16 (7.5 ton CD ha-1+N120P90K150kg ha-1). Results revealed that the combined application of cow dung and NPK fertilizers produced better growth and yield of sunflower in field condition at the coastal belt of Bangladesh. Dhaka Univ. J. Biol. Sci. 32(1): 83-90, 2023 (January)

Evaluation of forage berseem (Trifolium alexandrinum L.) for yield and nutritive qualities under varying seed rates and phosphorus fertilization

A field experiment was conducted at agriculture farm, ICAR-Central Institute for Research on Goats, Makhdoom, Mathura (Uttar Pradesh) during the rabi season of 2020–21 to study the effect of different seed rates and levels of phosphorus fertilizer on dry matter yield and nutritive value in berseem. The treatments consisted of three seed rates viz. 20 kg ha−1, 25 kg ha−1 and 30 kg ha−1 and five levels of phosphorus viz. 40 kg P2O5 ha−1, 60 kg P2O5 ha−1, 80 kg P2O5 ha−1, 100 kg P2O5 ha−1 and 120 kg P2O5 ha−1. The experiment was laid out in factorial randomized block design with three replications. The result showed that maximum total dry matter yield (8.65 t ha−1); crude protein yield (1501.2 kg ha−1) and ether extract yield (317.7 kg ha−1) was recorded with the seed rate of 30 kg ha−1 which was at par with the seed rate of 25 kg ha−1. However, proximate chemical constitute and other quality parameters viz. TDN content, dry matter intake, digestible dry matter, relative feed value and quality; and net energy for lactation did not influenced significantly due to different seed rates. Further it was revealed that application of 120 kg P2O5 ha−1 recorded highest value of crude protein (19.20, 18.15, 17.12 and 17.05%), TDN content (62.46, 61.62, 60.49 and 59.66%), dry matter intake (2.71, 2.68, 2.51 and 2.49%), relative feed quality (137.46, 134.16, 123.80 and 120.90%) and net energy for lactation (1.51, 1.49, 1.47 and 1.45 Mcal kg1) in I, II, III and IV cut, respectively. However, application of 100 and 120 kg P2O5 ha−1 recorded at par value of all these quality parameters.

Slow-release nitrogen fertilizers enhance growth, yield, NUE in wheat crop and reduce nitrogen losses under an arid environment

Higher demands of food led to higher nitrogen application to promote cropping intensification and produce more which may have negative effects on the environment and lead to pollution. While sustainable wheat production is under threat due to low soil fertility and organic matter due to nutrient degradation at high temperatures in the region. The current research explores the effects of different types of coated urea fertilizers and their rates on wheat crop under arid climatic conditions of Pakistan. Enhancing nitrogen use efficiency by using eco-friendly coated urea products could benefit growers and reduce environmental negative effects. A trial treatment included N rates (130, 117, 104, and 94 kg ha-1) and coated urea sources (neem coated, sulfur coated, bioactive sulfur coated) applied with equal quantity following split application method at sowing, 20 and 60 days after sowing (DAS). The research was arranged in a split-plot design with randomized complete block design had three replicates. Data revealed that bioactive sulfur coated urea with the application of 130 kg N ha-1 increased chlorophyll contents 55.0 (unit value), net leaf photosynthetic rate (12.51 μmol CO2 m-2 s-1), and leaf area index (5.67) significantly. Furthermore, research elucidates that bioactive sulfur urea with the same N increased partial factor productivity (43.85 Kg grain Kg-1 N supplied), nitrogen harvest index (NHI) 64.70%, and partial nutrient balance (1.41 Kg grain N content Kg-1 N supplied). The neem-coated and sulfur-coated fertilizers also showed better results than monotypic urea. The wheat growth and phenology significantly improved by using coated fertilizers. The crop reached maturity earlier with the application of bioactive sulfur-coated urea than others. Maximum total dry matter 14402 (kg ha-1) recorded with 130 kg N ha-1application. Higher 1000-grain weight (33.66 g), more number of grains per spike (53.67), grain yield (4457 kg ha-1), and harvest index (34.29%) were obtained with optimum N application 130 kg ha-1 (recommended). There is a significant correlation observed for growth, yield, and physiological parameters with N in the soil while nitrogen-related indices are also positively correlated. The major problem of groundwater contamination with nitrate leaching is also reduced by using coated fertilizers. Minimum nitrate concentration (7.37 and 8.77 kg ha-1) was observed with the application of bioactive sulfur-coated and sulfur-coated urea with lower N (94 kg ha-1), respectively. The bioactive sulfur-coated urea with the application of 130 kg N ha-1 showed maximum phosphorus 5.45 mg kg-1 and potassium 100.67 mg kg-1 in the soil. Maximum nitrogen uptake (88.20 kg ha-1) is showed by bioactive sulfur coated urea with 130 kg N ha-1 application. The total available NPK concentrations in soil showed a significant correlation with physiological attributes; grain yield; harvest index; and nitrogen use efficiency components, i.e., partial factor productivity, partial nutrient balance, and nitrogen harvest index. This research reveals that coating urea with secondary nutrients, neem oil, and microbes are highly effective techniques for enhancing fertilizer use efficiency and wheat production in calcareous soils and reduced N losses under arid environments.

Effects of chemical mutagens on the physio-chemical traits of Tomato (Lycopersicon esculentum)

A field experiment was conducted at the Horticultural Research station, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha during Rabi 2017 and 2018 seasons. Five hundred seeds of variety Utkal Kumari (BT 10) were taken and subjected to single and combined mutagenic treatment as per the specification. The experiment was laid down in Randomised Block Design (RBD) with three replications. Leaf area (dm2/plant), total dry matter and chlorophyll content were measured at 30, 60 and 75 days after transplanting(DAT). NAR (Net assimilation rate) and CGR (Crop growth rate) were also calculated at 30-40 DAT and 50-60 DAT. All the treatments showed increase in yield over control and buffer except in treatment Sodium Azide (SA) 0.06% which indicated that the mutagens had positive effect on the plant for increasing yield. The increase in yield depends on leaf area or photosynthesizing tissues, total respiring tissues or total biomass, photosynthetic efficiency as reflected by chlorophyll content, Net assimilation rate (NAR) and crop growth rate (CGR). Ethyl methane sulphate (EMS) at 0.6% concentration had shown maximum increase in yield which was attributed to maximum leaf area (55.19 dm2/plant), maximum total dry matter (19.44g/plant) and maximum crop growth rate (0.347g.m−2.day−1). The chlorophyll content and NAR (Net assimilation rate) were also significantly high for this treatment.

Influence of integrated nutrient management on growth and yield of Safed Musli (Chlorophytum borivilianum Sant. and Fernand.)

An experiment on “Influence of integrated nutrient management (INM) on growth and yield of safed musli” was carried out at KRC college of Horticulture, Arabhavi, Gokak, Karnataka during 2018-19 as a part of Ph.D programme. The result revealed that plant supplied with humic acid recorded maximum plant height (29.99 cm) which was on par with the panchagavya (29.76 cm). Significantly maximum total dry matter production of 1.66 g plant-1 and maximum fresh root yield was observed in (0.70 kg plot-1 and 33.42 q ha-1, respectively) observed in panchagavya drenched plants. Among inorganic and organic application, 100 per cent RD NPK 50:40:40 kg ha-1 recorded significantly maximum plant height (31.53 cm), maximum number of leaves (17.48 plant-1), total dry matter production (2.18 g plant-1) and significantly highest fresh root yield per plot and per hectare (0.74 kg plot-1 and 36.26 q ha-1, respectively). Among interaction effect, panchagavya (3%) + 100 per cent RD NPK 50:40:40 kg ha-1 recorded maximum plant height (33.10 cm), total dry matter production (2.30 g plant-1) and significantly highest fresh root yield per plot and per hectare (0.81kg and 38.34q, respectively).

English

Garlic (Allium sativum L.) is an important vegetable crop in Ethiopia. The yield of the crop is often constrained by low and unbalanced nutrient supply in the soil. This study was undertaken to assess effect of vermicompost (VC) on growth, quality and economic return of garlic variety Chelenko I during 2016 main rainy season in Haramaya University main campus, Ethiopia. The treatment consisted of four levels of vermicompost (0, 2.5, 5 and 7.5 tons ha-1) laid out in a randomized complete block design in three replication. Data were collected and analyzed on days to emergency, plant growth, quality, and economic return of garlic. Results revealed early emergency (8.07 days) with application of 7.5 tons ha-1 of vermicompost while late emergency (10.13 days) was at nil application of vermicompost. Significant (P<0.05) maximum leaf area (37.05 cm2), leaf area index (1.36) and biomass (61.54 g) were recorded with application of 7.5 tons ha-1. Besides to this, maximum total dry matter (32.71%) and total soluble solid (12.72 Brix°) were also recorded at the rate of 7.5 tons ha-1. Due to application of 7.5 tons ha-1 fertilizer, the economic analysis showed the highest net benefit cost of 431,188 ETB ha-1 and marginal rate of return (168.87%) with incurred highest total variable cost of 79,350 ETB ha-1. Thus, it can be reasonably generalized that on short time basis, the application of high amounts of VC fertilizers can result in higher economic return than the low dose of VC fertilizer. Therefore, it can be concluded that, the maximum growth and quality and economic return of garlic was obtained with application of 7.5 tons of VC ha-1 fertilizer as it gave the highest net benefit cost. However, since the experiment was done only once and at one location, similar experiments should be carried out using additional higher rates of VC fertilizer over several seasons and locations to make a conclusive recommendation. Key words: Chelenko I, economic return, marginal rate return, net benefit, total soluble solids.

Evaluating the Intercropping of Millet with Cowpea for Forage Yield and Quality

A field study was scheduled to estimate the impact of intercropping of pearl millet with cowpea on forage yield and quality at Agronomy Research Farm, University of Agriculture, Faisalabad. It was done in kharif season 2016. Randomized complete block design was used to conduct this experiment. It has three replications. The size of net plot is 3.6 m × 6 m. It comprised of five treatments (T1 = one row of millet alternating with one row of cowpea (1M:1C), T2 = two rows of millet alternating with one row of cowpea (2M:1C), T3 = one row of millet alternating with two rows of cowpea (1M:2C), T4 = sole millet, T5 = sole cowpea). We found that intercropping significantly effected the yield and quality of forage. Intercropping system had significant effects on nutritive value of forage crop. Within various treatments of intercropping, it is evident that treatment T2 (two rows of millet alternating with one row of cowpea) gives maximum total dry matter yield (9.68 t ha-1). It was then tracked by treatment T1 (one row of millet alternating with one row of cowpea) and treatment T3 (one row of millet alternating with two rows of cowpea) producing dry matter yield (9.07 t ha-1 and 8.33 t ha-1, respectively). Based on high grain and suitable environmental condition, intercrop productivity compared to sole crop could be selected for improving the productivity of millet/cowpea mixture in the Punjab.

English

The growth and senescence of Urochloa brizantha cv. Marandu were analyzed under the Brazilian Cerrado conditions. The seeds were sowed in November at the beginning of the rainy season. Samples of tillers were collected. The culms, inflorescences, along with green and dead leaves were removed to obtain leaf area and dry matter measurements. The maximum leaf area index (LAI = 5.80 m2 m-2) was achieved at 97 days after emergence (DAE), the maximum above ground total dry matter (TDM = 22.8 Mg ha-1) at 151 days, and the maximum crop growth rate (CGR = 0.260 Mg ha-1) at 70 days. Leaf senescence began at 55 DAE, with less than 0.001 Mg ha-1 of dead leaves dry matter (DLDM), and reached 1.753 Mg ha-1 at 151 DAE. Between 117 and 151 DAE, in the final cycle of the plants, there was lodging of the canopy by wind. This lodging had favored the sprouting of new tillers and a sudden increase in net assimilation rate (NAR). The LAI values did not show such expressive increase during the same period, suggesting that NAR may contribute to crop growth more than LAI due to increased light penetration after the occurrence of the lodging. In this paper an equation that estimates the net photosynthetic rate from the net assimilatory rate was presented. Key words: Leaf area, dry matter, growth rate, net assimilation rate, pasture grass

Effect of nitrogen and phosphorus on growth and seed yield of French bean

Field experiments were conducted during rabi (winter) seasons of 2010-11 and 2011-12 at the Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur to study the effects of nitrogen and phosphorus on growth, dry matter production and yield of French bean. A randomized complete block design was followed with 10 combinations of N (0,50, 100, 150 and 200) and P (0,22, 33, 44 and 55) kg ha-1 along with a blanket dose of control. All the treatments showed the maximum leaf area index (LAI) at 65 days after sowing (DAS). All the treatments showed the maximum total dry matter production, crop growth rate and net assimilation rate at harvest and at 55-65 DAS, respectively in both the years. LAI, dry matter production, CGR, NAR and seed yield significantly increased with the increase in nitrogen and phosphorus level upto 150 kg N and 44 P kg ha-1 , respectively. Similar trend was followed in maximum number of pods (9.45) and seed yield (1563.33 kg ha-1). The treatment comprises with 150 kg N and 44 P Kg ha-1 gave the highest seed yield which was 51.40 and 54.30 % higher than control plots.Bangladesh J. Agril. Res. 41(4): 759-772, December 2016

Growth and development of sourgrass based on days or thermal units

This work was carried out with the objective of evaluating growth and development of sourgrass (Digitaris insularis) based on days or thermal units (growing degree days - GDD). Two independent trials were developed aiming to quantify the species' phenological development and total dry matter accumulation in increasing or decreasing photoperiod conditions. Plants were grown in 4 L plastic pots, filled with commercial substrate, adequately fertilized. In each trial, nine growth evaluations were carried out, with three replicates. Phenological development of sourgrass was correctly fit to time scale in days or GDD, through linear equation of first degree. Sourgrass has slow initial growth, followed by exponential dry matter accumulation, in increasing photoperiod condition. Maximum total dry matter was 75 and 6 g per plant for increasing and decreasing photoperiod conditions, respectively. Thus, phenological development of sourgrass may be predicted by mathematical models based on days or GDD; however, it should be noted that other environmental variables interfere on the species' growth (mass accumulation), especially photoperiod.

Yield and Quality of Irrigated Bermudagrass as a Function of Nitrogen Rate

Bermudagrass [Cynodon dactylon (L.) Pers.] is a perennial grass capable of producing a large amount of forage for either hay or grazing. Information on harvest frequency and rate of N for bermudagrass production is scarce for southwest Kansas. The objectives of this research were to determine economically and environmentally justified N rates for bermudagrass grown under supplemental irrigation (161–222 mm yr−1) and to determine annual harvest frequency. A field study was conducted from 2004 to 2007 near Rolla, KS, with five N rate treatments (0, 168, 336, 672, and 1344 kg N ha−1). On five harvest dates per year, biomass yield, feed quality, soil nutrient content, and soil pH were measured. Biomass yield was relatively high in the second, third, and fourth harvest dates out of five harvest dates within a year. In each of these five harvest dates, biomass yield increased with increasing N rates from 0 to 672 kg N ha−1. A quadratic curve explained 80% of the variation for the relationship between total annual biomass yield of bermudagrass and N rate. The maximum average total annual dry matter production of about 18.5 Mg ha−1 was possible with 900 kg N ha−1. The economic N rate that confers profit, however, varied from about 120 to 600 kg ha−1 depended on value of bermudagrass forage and variable cost of production. An increase in N rate from 0 to 672 kg N ha−1 also increased protein content and biomass feed quality without adversely affecting soil quality.

Dry matter accumulation and nutritive value of winter forage crops sown in Canterbury on different dates

Supplementary forage crops are used in New Zealand to overcome feed shortages during winter and early spring. The objective of this study was to maximize annual dry matter (DM) yield by optimizing sowing and harvest dates. Forage crop options include faba bean, oats and Italian ryegrass. These were sown on five dates in the autumn and winter of 2008 and on three sowing dates in the autumn of 2009. The maximum total DM ranged from 4420 to 26,310 kg ha−1 across all species and sowing dates for both seasons. Oats yielded the highest maximum total DM in both years. The quality analysis showed oats sown in early March and harvested at the end of August attained herbage metabolisable energy (ME) of 11.5 MJ kg−1 DM and high total ME per ha which was suitable for the lactation of dairy cows. Thus, oats was the beneficial alternative forage crop for farmers to choose. Faba bean had lowest maximum total DM yield compared with oats and Italian ryegrass in the first season; however, faba bean had higher maximum total DM compared with Italian ryegrass but lower than oats and faba bean-oat intercrop in the second season. Faba bean sown from early March to mid-April and harvested at the end of November attained a herbage nitrogen (N) content of more than 2.4% and had the highest total N uptake per ha compared with oats and Italian ryegrass at 2.4% of herbage N.

Crescimento e nutrição de clone de eucalipto em resposta à aplicação de concentrações de c-ácido húmico

Os efeitos das substâncias húmicas nas propriedades dos solos são conhecidos, porém poucos são os estudos que avaliam os efeitos desses materiais nas plantas; assim, dependendo da concentração e da natureza química das moléculas húmicas aplicadas, pode haver maior expansão radicular, incremento na absorção de nutrientes e maior crescimento das culturas. Com o objetivo de avaliar os efeitos de concentrações de C-ácido húmico na nutrição e no crescimento de mudas de eucalipto, foi realizado um experimento em solução nutritiva, em casa de vegetação. Os tratamentos constituíram-se de duas fontes de ácidos húmicos (material húmico - MH e ácido húmico p.a. - AH p.a.), sendo cada fonte adicionada na solução nutritiva nas seguintes concentrações de C-ácido húmico: 0, 10, 30 e 150 mg L-1. Outros tratamentos foram também testados, utilizando-se a fonte AH p.a. nas concentrações de 0, 10, 30 e 150 mg L-1 C-ácido húmico, acrescidas de 21 mg L-1 de ácido cítrico e 9 mg L-1 de ácido oxálico. Foram analisados a condutividade eletrolítica na solução nutritiva, diâmetro do caule e altura das plantas, matéria seca de caule, de folhas, da parte aérea, da raiz e total, relação matéria seca de raiz:parte aérea, acúmulo de nutrientes no caule e nas folhas. A altura e o diâmetro de caule diminuíram linearmente com a aplicação de concentrações de C-ácido húmico da fonte AH p.a. A utilização do MH, em baixas concentrações de C-ácido húmico (0,07-4,3 mg L-1), propiciou a máxima produção de matéria seca de raiz, caule, folha e total. O maior acúmulo de alguns nutrientes (principalmente N, P e B) resultou, em alguns tratamentos, em reduzidos incrementos (2,4 a 9,3 %) nas produções de matéria seca de raiz, folha, caule e total; assim, não é aconselhável, em solução nutritiva, a aplicação das fontes de ácidos húmicos utilizadas neste estudo para o cultivo de mudas de eucalipto.

Potassium Substitution by Sodium in Root Medium Influencing Growth Behavior and Potassium Efficiency in Cotton Genotypes

ABSTRACT Potassium (K) deficiency affects cotton (Gossypium hirsutum L.) growth. Sodium (Na) can substitute K for some non-specific functions in plants. Four cotton genotypes were evaluated for their growth rates and K use efficiency grown at various K:Na. The cotton genotypes and treatments had significant (p < 0.01) effect on biomass production, growth rate related parameters, K use efficiency, and K: Na ratio. Maximum total dry matter (2.57 g plant-1) was accumulated by ‘NIBGE-2’ and minimum (1.91 g plant−1) was by ‘FH-1000’. Maximum K:Na ratio in shoot was obtained by ‘MNH-786’ and minimum was by ‘NIBGE-2’when 1/3rd K was replaced with Na. Genotypes and various treatments significantly (p < 0.05) influenced specific utilization rate (SUR) and K transport rate (KTR). There was a significant relationship (R2 = 0.84, n = 60) between shoot dry matter and K: Na ratio in shoot. Overall, the growth was better when K and Na were added in ratio of 3:1.

Evaluation of growth performance and dry matter partitioning of four processing potato (Solanum tuberosum) cultivars

Climate, cultivar, and crop management determine the growth and dry matter (DM) production of a potato (Solanum tuberosum) crop. Drought and high temperature affect leaf area development and its persistence, and these in turn limit the photosynthetic activity of the crop and finally DM production and allocation. The objective of this experiment was to evaluate four potato cultivars for growth performance and DM partitioning to the sink by efficient use of the microclimate of the specific growing location. Four potato cultivars, namely ‘Frodo’, ‘Pentland Dell’, ‘Darius’, and ‘Shepody’, were used in the experiment. Four different harvests were undertaken during the growing season to determine DM partitioning to various parts of the plant. The results revealed that during the first harvest the percentage of leaf DM and tuber DM did not differ significantly among cultivars. The total DM accumulation for ‘Shepody’ was found to be significantly higher during the first harvest. During the second harvest, however, ‘Shepody’ and ‘Frodo’ had significantly lower DM partitioned to leaf and stem respectively, but ‘Shepody’ still had maximum total DM accumulation. Again, during the third harvest, ‘Shepody’ maintained its highest total DM accumulation and had the highest DM translocation towards tuber and the least towards leaf. ‘Shepody’ is an early maturing cultivar, and the high tuber DM during this harvest did not necessarily indicate a high final yield. This is substantiated by the final tuber harvest, where ‘Frodo’ produced a significantly higher fresh tuber yield and ‘Shepody’ yielded the least. Average leaf area index followed the same trend as the total DM accumulation, where ‘Shepody’ had significantly the highest and ‘Darius’ remained the lowest. From this, it can be concluded that ‘Frodo’ appeared to be the highest yielder, followed by ‘Pentland Dell’.

PASTAGEM DE AZEVÉM ASSOCIADA COM LEGUMINOSAS DE INVERNO SOB DIFERENTES NÍVEIS DE OFERTA DE FORRAGEM, NA REGIÃO SUL DO PARANÁ

Uma pastagem de azevém (Lolium multiflorum Lam.) associada com leguminosas de inverno: trevo vermelho (Trifolium pratense L.), trevo branco (Trifolium repens L.) e cornichão (Lotus corniculatus L.), submetida a quatro ofertas de forragem (OF), 4; 8; 12 e 16 kg de massa seca (MS) por 100 kg-1 de peso vivo (PV), foi avaliada num delineamento em blocos ao acaso, com duas repetições, no período de julho a novembro de 1995, no Centro de Estações Experimentais do Setor de Ciências Agrárias – UFPR - Canguiri, em Pinhais-PR, com o objetivo de avaliar quatro níveis de oferta de forragem sobre a produção de pastagem de azevém associada a três leguminosas de inverno. O método de pastejo foi o contínuo com lotação variável, utilizando-se a técnica “put-andtake”. Observou-se que a imposição de diferente OF condicionou diferentes quantidades de resíduo por unidade de área. Com o aumento na OF, aumentou gradativamente a MS residual ha-1. Maiores produções de MS ocorreram nas OF intermediárias. Na faixa de 14% do PV, associada ao resíduo médio de 3564 kg de MS ha-1, ocorreu à máxima produção total de MS, bem como, diminuindo a oferta de forragem aumentava a taxa de desaparecimento de MS.

Exigência a boro em cultivares de soja

O conhecimento quanto à exigência a boro de genótipos da soja pode ser relevante para: recomendações de corretivos e fertilizantes, recomendação de cultivares e programas de melhoramento. O objetivo deste trabalho foi estudar a resposta de cultivares de soja à adição de doses de boro em solução nutritiva. O experimento foi realizado em casa de vegetação do Instituto Agronômico de Campinas - IAC, Campinas (SP). Foram estudados quatro cultivares de soja (IAC-1, IAC-8, IAC-15 e IAC-17) e cinco doses de boro (0,0; 0,05; 0,20; 0,80 e 2,00 mg L-1 de B), utilizando-se delineamento em blocos ao acaso, em esquema fatorial com cinco repetições. As plantas foram avaliadas quanto aos sintomas de deficiência à toxidez, produção de matéria seca, altura das plantas, teores críticos de B nas folhas, B absorvido pela planta e teores de P, K, Ca e Mg. As plantas foram colhidas no início do florescimento para determinação da massa da matéria seca e teores de nutrientes. Os teores limites de B nas folhas para a deficiência variaram de 25 a 30 mg kg-1, mostrando diferenças entre os cultivares nesta susceptibilidade. O sintoma inicial de toxidez foi observado a partir da dose de 0,8 mg L-1 de B na solução, cujo teor correspondente nas folhas foi de 83 mg kg-1 de B (média dos cultivares), enquanto o acúmulo máximo de matéria seca total ocorreu para concentrações na solução estimadas entre 0,1 e 0,2 mg L-1. A severidade dos sintomas visuais variou entre cultivares dentro do mesmo tratamento, indicando diferentes tolerâncias ao excesso do nutriente. Assim, quanto aos sintomas de deficiência e de toxidez, o cv. IAC-1 foi o mais susceptível à deficiência e à toxidez de B, e o cv. IAC-17 foi, aparentemente, o mais tolerante ao excesso de B. Os cvs. IAC-8 e o IAC-15 acumularam as maiores quantidades de B, mesmo nos tratamentos com baixa concentração de B na solução. Os teores de P, K, Ca e Mg nas folhas não variaram significativamente entre os tratamentos que receberam boro (0,05 a 2,0 mg L-1), com exceção das plantas com deficiência severa.

Response of Quercus petraea seedlings to nitrogen fertilization

In view of increasing concern about long-term effects of N deposition on forest ecosystem, decline of oak stands in many central European countries, and poor documentation of nutrient budgets of oak stands, a pot experiment was performed on N-fertilized oak seedlings (Quercus petraea Liebl.) to study impact on biomass, morphology and nutrition. Seedlings were treated at equivalent N amounts with ammonium sulfate, calcium nitrate, a mineral multi-nutrient fertilizer (N, P, K, Mg) and a slow release organic fertilizer (N, P, K, Mg, Ca) and grown in an acidic soil low in nutrients and a calcareous soil with high nutrient supply. All N-fertilization types increased biomass production, number of leaves and leaf area; however, total mass produced per leaf mass declined. Multi-nutrient fertilized oak seedlings were able to maintain the highest leaf area by means of lowest amounts of fine roots. Each N addition increased N foliar contents. Nitrogen-induced growth caused dilution effects indicated by suboptimal N levels of both foliage and fine roots. Nitrogen fine-root contents were a better indicator of N inputs than foliar contents. All fertilization types increased N storage of the plants. In the acidic soil, the highest N storage per seedling (multi-nutrient fertilizer) was coupled with the highest total biomass production, while the organic fertilizer treatment, which induced maximum total dry matter gain on the calcareous soil, represented the lowest N storage of all N treatments. Differences of N partitioning (leaves, shoot, coarse roots, fine roots) were small. Plant uptake of added N was estimated up to 61%. N/P ratios of all treated seedlings exceeded the harmonious range and it is concluded that further N input will cause severe N-induced nutritional imbalance for base cations on substrates with low nutrient supply as well. In general, effects of N additions to the oak seedlings were more pronounced on the substrate with lower nutrient supply.