Popping expansion and yield responses of popcorn cultivars under different row spacings and plant populations

The objective of this work was to evaluate the agronomic traits and the popping expansion index of three Brazilian popcorn cultivars under different row spacings and plant populations. The trials were performed during two crop seasons, under field conditions. The experimental design used was a randomized complete block, in a split-split plot, with 27 treatments and four replicates. Treatments were represented in a triple factorial arrangement: three row spacings (0.40, 0.60, and 0.80 m), three plant populations (40,000, 60,000, and 80,000 plants per hectare), and three popcorn cultivars (IAC-TC 01, IAC 12, and Zelia). The increase in plant population causes a reduction in the number of grains per ear, lower prolificacy, and grain weight loss. Cultivar grain yield is affected by row spacing and popcorn plant population. Cultivar IAC 12 shows highest grain yield under row spacings of 0.40 and 0.60 m and plant population between 60,000 and 80,000 plants per hectare. The popping expansion index is not affected by row spacing or plant population.

Quantitative descriptors and their direct and indirect effects on corn yield

The objective of this study was to evaluate the direct and indirect effects of ten quantitative descriptors of agronomic importance in productivity of 25 maize hybrids and their respective influences of heritability. The experiment in randomized blocks with four replications, was conducted in 2010/2011 crop in a soil under humid subtropical climate. The quantitative descriptors were: ear length, ear diameter, cob diameter, number of rows of grains, stem diameter, plant height, ear height, weight of 100 grains, grain weight per ear and number of grains per ear. The grain weight per ear and ear length showed high correlation with grain yield, and the descriptors with the highest potential for selecting superior genotypes and showing high heritability.

Leaf gas exchange and yield of three upland rice cultivars

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Lima beans production and economic revenue as function of organic and mineral fertilization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Organic and inorganic sources of zinc, copper and selenium in diets for dairy cows: intake, blood metabolic profile, milk yield and composition

The present study was carried out with the objective of evaluating the effects of feeding dairy cows with organic or inorganic sources of zinc (Zn), copper (Cu) and selenium (Se) on blood concentrations of these minerals, blood metabolic profiles, nutrient intake and milk yield and composition. Nineteen Holstein cows were selected and randomly assigned to two groups for receiving organic (n = 9) or inorganic (n = 10) sources of Zn, Cu and Se from 60 days before the expected date of calving to 80 days of lactation. Samples of feed, orts and milk were collected for analysis. Body condition score (BCS) was determined and blood samples were collected for analysis of Zn, Cu and Se concentrations, as well as for metabolic profile. Supplying organic or inorganic sources of Zn, Cu, and Se did not affect dry matter and nutrient intake, blood metabolic profile, milk yield and composition, plasma concentration of these minerals, and BCS or change the BCS in cows from 60 days before the expected date of calving to 80 days of lactation. An effect of time was observed on all feed intake variables, plasma concentrations of Zn and Se, milk yield, milk protein content, BCS and change in BCS.

Soil resistance to penetration and least limiting water range for soybean yield in a haplustox from Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic parameters for test-day yield of milk, fat and protein in buffaloes estimated by random regression models

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitrogen and silicon fertilization of upland rice

O silício não é considerado um elemento essencial para o crescimento e desenvolvimento das plantas, entretanto, sua absorção traz inúmeros benefícios, principalmente ao arroz, como aumento da espessura da parede celular, conferindo resistência mecânica a penetração de fungos, melhora o ângulo de abertura das folhas tornando-as mais eretas, diminuindo o auto-sombreamento e aumentando a resistência ao acamamento, especialmente sob altas doses de nitrogênio. O presente trabalho teve por objetivo avaliar os efeitos da adubação nitrogenada e silicatada nos componentes vegetativos, nos componentes da produção, na altura da planta e na produtividade da cultivar de arroz IAC 202. O experimento foi constituído da combinação de três doses de nitrogênio (5, 75 e 150 mg de N kg-1 de solo) aplicado na forma de uréia e quatro doses de silício (0, 200, 400 e 600 mg de SiO2 kg-1 de solo), aplicado na forma de silicato de cálcio. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 3 ´ 4 (N = 5). A adubação nitrogenada aumentou o número de colmos e panículas por metro quadrado e o número total de espiguetas, refletindo na produtividade de grãos. O perfilhamento excessivo causado pela adubação nitrogenada inadequada causou redução na porcentagem de colmos férteis, na fertilidade das espiguetas e da massa de grãos. A adubação silicatada reduziu o número de espiguetas chochas por panícula e aumentou a massa de grãos sem, contudo, refletir na produtividade de grãos.

Phosphorus and potassium balance in soil under crop rotation and fertilization

The use of crop rotation and manure application can provide sustainability for an agricultural production system by improving soil quality and increasing nutrient use efficiency. This study aimed to evaluate the effect of mineral, organic and mineral+organic fertilization on grain yield and on soil phosphorus and potassium balance, in two crop systems under no-till, with and without rotation of cover crops. The experiment was carried out from 2006 to 2008 on a clayey Rhodic Hapludox in Marechal Candido Rondon, Parana State, Brazil. The cropping sequence in the rotation system involving cover crops was black oat + hairy vetch + forage turnip/corn/pigeon pea/wheat/mucuna + brachiaria + sunn hemp, and in the succession system was wheat/corn/wheat/soybean. Organic and mineral+organic fertilizations consisted of the application of solely manure and manure combined with mineral fertilizer, respectively. Soil P and K balances were calculated after the second year of the experiment, up to a depth of 0.40 m. First year corn yields were higher in the crop succession system accompanied by mineral fertilization. In the second year, wheat and soybean yield did not vary between crop systems and nutrient sources, demonstrating the residual effect of crop rotation and manure use. Crop rotation with cover crops resulted in an increase in soil K levels by promoting the recycling of this nutrient in the soil. In both crop systems, the application of mineral and organic fertilizers - either in isolation or in combination - resulted in a negative soil P and K balance in the short term. This represents a threat to the sustainability of the agricultural production system in the long term, due to the depletion of soil nutrient reserves.

Response of irrigated wheat cultivars to different nitrogen rates and sources

Altas produtividades de trigo requerem um bom manejo da adubação nitrogenada. O objetivo deste trabalho foi avaliar os efeitos de diferentes doses de nitrogênio na semeadura usando o Entec (fonte de N com inibidor de nitrificação), ou em cobertura, utilizando a ureia, em quatro cultivares de trigo. O experimento foi desenvolvido em área experimental pertencente à Faculdade de Engenharia de Ilha Solteira - UNESP, em um Latossolo Vermelho distrófico epieutrófico álico textura argilosa, o qual foi nativamente ocupado por vegetação de Cerrado. O delineamento estatístico foi o de blocos ao acaso, com quatro doses de N (0, 60, 120 e 180 kg ha-1) na semeadura, usando o Entec, ou em cobertura aos 40 dias (início do alongamento), empregando a ureia e os cultivares E 21, E 22, E 42 e IAC 370, em quatro repetições. Os cultivares de trigo mais produtivos foram o E 21 e o E 42. O cultivar E 22 apresentou maior altura de plantas e altas notas de acamamento, com consequente menor produtividade de grãos. Não houve diferença significativa entre o Entec (aplicado na semeadura) e a ureia (aplicada em cobertura) para produtividade de grãos e para nenhuma das outras avaliações, porém a ureia proporcionou maior teor de N foliar, e o Entec, maior número de espiguetas não desenvolvidas. O incremento das doses de N influenciou negativamente a massa hectolítrica, alterando assim a qualidade dos grãos de trigo. O N aumentou a produtividade de grãos de trigo até a dose de 82 kg ha-1 de N, usando Entec aplicado na semeadura ou ureia aplicada em cobertura.

Application times, sources and doses of nitrogen on wheat cultivars under no till in the Cerrado region

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Soil management and nitrogen fertilization for sprinkler-irrigated upland rice cultivars

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitrogen fertilization and soil management of winter common bean crop

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Feedlot performance, feed efficiency and carcass traits in Nellore cattle selected for postweaning weight

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of prebiotics and probiotics of bacterial and yeast origin for free-range broiler chickens

This study aimed to evaluate the effects of probiotics and prebiotics of bacterial and yeast origin on the performance, development of the digestive system, carcass yield and meat quality of free-range broiler chickens. Five hundred and sixty male chicks of the strain ISA S757-N were reared from one to 84 days old. The birds were distributed in four treatments according to a completely randomized block design: T1 = Control, T2 = Probiotics and Prebiotics of bacterial origin, T3 = Probiotics and prebiotics of yeast origin, T4 = Probiotics and prebiotics of bacterial origin + probiotics and prebiotics of yeast origin. There were four repetitions with 35 birds per repetition, and the birds had access to a pasture area after 35 days of age. Characteristics evaluated were performance, development of the digestive system, carcass and parts yield, abdominal fat, breast meat physical measurements (length, width and height) and meat quality parameters (pH from breast and leg meat, cooking loss and shearing force from breast meat). Lower mortality (p<0.05) and higher weight gain from 64 to 77 and 64 to 84 days of age were seen in birds supplemented with probiotics and prebiotics of bacterial origin compared to the non-supplemented birds (control). There were significant differences (p<0.05) among treatments for carcass yield. Birds supplemented with both probiotics and prebiotics of microbial and yeast origin (T4) showed higher carcass yield than control birds. Supplementation with probiotics and prebiotics of bacterial origin (T2) or the supplementation of these together with those of yeast origin (T4) reduced mortality and increased the carcass yield in free-range broiler chickens.