Foraging behavior and ruminal fermentation of dairy cows grazing ryegrass pasture alone or with white clover

The objective of this work was to evaluate the influence of pasture composition and regrowth age on the relationship between feeding behavior and ruminal fermentation in dairy cows grazing perennial ryegrass with or without white clover. The experiment was carried out in a 2x2 factorial arrangement, with two sward types and two ages of regrowth. Swards of perennial ryegrass sown alone (PRG) and of perennial ryegrass mixed with white clover (GC) were evaluated. Twelve late-lactation Holstein cows, fistulated at the rumen, were distributed in a 4x4 latin square experimental design with four 12-day periods. Daily distribution of grazing was similar in the PRG and the GC swards, but the concentration of rumen volatile fatty acids (VFA) was higher and the proportion of propionate was lower on mixed swards during the day. Daily distribution of grazing was similar in pastures of different ages. However, in the oldest swards, rumen fluid pH increased and VFA concentration decreased after evening milking. Time spent grazing does not influence ruminal fermentation, which depends on the changes that occur as different sward layers are grazed.

Maintenance requirement and deposition efficiency of lysine in pigs

The objective of this work was to determine the maintenance requirement and the deposition efficiency of lysine in growing pigs. It was used the incomplete changeover experimental design, with replicates over time. Twelve castrated pigs with average body weight (BW) of 52±2 kg were kept in metabolism crates with a controlled temperature of 22ºC. The diets were formulated to supply 30, 50, 60, and 70% of the expected requirements of standardized lysine, and provided at 2.6 times the energy requirements for maintenance. The trial lasted 24 days and was divided into two periods of 12 days: seven days for animal adaptation to the diet and five days for sample collection. The increasing content of lysine in the diet did not affect dry matter intake of the pigs. The amount of nitrogen excreted was 47% of the nitrogen intake, of which 35% was excreted through feces and 65% through urine. The estimated endogenous losses of lysine were 36.4 mg kg-1 BW0.75. The maintenance requirement of lysine for pigs weighing around 50 kg is 40.4 mg kg-1 BW0.75, and the deposition efficiency of lysine is 90%.

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.

Defoliation of strawberry mother plants for the production of runner tips

The objective of this work was to determine the sink-source relationships and their effects on the number and growth of runner tips of 'Camino Real' strawberry stock plants. Three types of sources were evaluated: one defoliation at 96 days after planting (DAP), two defoliations at 50 and 96 DAP, and mother plants without defoliation. Four types of sink were accessed: runner tips collected weekly and monthly, four stolons with rooted runner tips in pots, and four freely-grown stolons. A completely randomized experimental design was used in a split-plot arrangement, with four replicates. The source types were placed in the plots, and sink types in the subplots. The number of runner tips, the crown diameter, and the dry matter mass were determined. Number and growth of tips were higher on plants without defoliation, and decreased 44.7% on twice-defoliated mother plants. The two-defoliation management did not reduce runner tip dry matter mass only on plants with rooted stolons, which produced runner tips 50% heavier. Defoliation of mother plants bearing rooting stolons can be used to reduce their growth, without reducing the emission and growth of runner tips.

Field data and prediction models of pesticide spray drift on coffee crop

The objective of this work was to generate drift curves from pesticide applications on coffee plants and to compare them with two European drift-prediction models. The used methodology is based on the ISO 22866 standard. The experimental design was a randomized complete block with ten replicates in a 2x20 split-plot arrangement. The evaluated factors were: two types of nozzles (hollow cone with and without air induction) and 20 parallel distances to the crop line outside of the target area, spaced at 2.5 m. Blotting papers were used as a target and placed in each of the evaluated distances. The spray solution was composed of water+rhodamine B fluorescent tracer at a concentration of 100 mg L-1, for detection by fluorimetry. A spray volume of 400 L ha-1 was applied using a hydropneumatic sprayer. The air-induction nozzle reduces the drift up to 20 m from the treated area. The application with the hollow cone nozzle results in 6.68% maximum drift in the nearest collector of the treated area. The German and Dutch models overestimate the drift at distances closest to the crop, although the Dutch model more closely approximates the drift curves generated by both spray nozzles.

Common snook fed in alternate and continuous regimens with diet supplemented with Bacillus subtilis probiotic

The objective of this work was to evaluate the addition of Bacillus subtilis probiotic to the feed of common snook (Centropomus undecimalis) fingerlings, in alternate and continuous regimens. Six hundred and sixty fish, with average length of 5.90±0.88 cm and weight of 1.92±0.28 g, were stocked in 12 cages of 1.0 m3, with 55 fish each. The experimental design was completely randomized, with three treatments and four replicates. The treatments consisted of diet with the addition of probiotic, provided in alternate regimen for 7 days and in continuous regimen; besides a control without probiotic in the feed. Zootechnical performance, body composition, immune response, and blood parameters were evaluated. No significant differences were observed in zootechnical performance indexes and in body composition of fish treated with probiotic, when compared to the control. Fish from the alternate regimen showed an increment in respiratory burst and a lower total erythrocyte count than fish from the continuous regimen and the control. Fish from the continuous regimen did not differ from those of the control. The addition of Bacillus subtilis does not increase growth rates of common snook fingerlings; however, it has an immunostimulant action when supplied in alternate regimen.

Pineapple yield and fruit quality effected by NPK fertilization in a tropical soil

There is a lack of information about fertilization of pineapple grown in the State of São Paulo, Brazil. So a field experiment with pineapple 'Smooth Cayenne' was carried out to study the effects of NPK rates on yield and fruit quality. The trial was located on an Alfisol in the central part of the State of São Paulo (Agudos county). The experimental design was an incomplete NPK factorial, with 32 treatments set up in two blocks. The P was applied only at planting, at the rates of 0; 80; 160 and 320 kg/ha of P2 0(5), as superphosphate. The N and K2O rates were 0; 175; 350, and 700 kg/ha, applied as urea and potassium chloride, respectively, divided in four applications during the growth period. Response functions were adjusted to yield or to fruit characteristics in order to estimate the nutrient rates required to reach maximum values. The results showed quadratic effects of N and K on yield and a maximum of 72 t/ha of fresh fruit was attained with rates of 498 and 394 kg/ha, respectively of N and K2O. In order to reach the maximum fruit size, and to improve the percentage of first class fruit (mass greater than 2.6 kg), were necessary rates of N and K respectively 11 and 43 % higher than those for maximum yield. No effect of P rates was observed on pineapple plant growth, despite the low availability of this nutrient in the soil. The effect of N rates was negative on total soluble solids and total acidity while the opposite occurred with K, which increased also the content of vitamin C. High yield and fruit size were closely related to N and K concentrations in the leaves.

Zn and K influence in fruit sizes of Valencia orange

In orange commercial farms, Zn deficiencies symptoms and small fruits were observed in Corrientes, Argentine. During four years (1995 to 1998), Valencia orange (Citrus sinensis Osb.) on Rough lemon (C. jambhiri Lush.) rootstock, implanted in 1974 in sandy soil, where six treatments were tested. Treatments varied from 1 to 3 Kg KCl.tree-1.year-1 (applied in April and December) with and without Zineb 80, 0,35%. year-1, 20 L. tree-1 (13,3 g Zn.tree-1 applied in December). The experimental design was a randomized complete block with four replications, with a single tree and borders in the experimental plot. Foliar sample were taken every year in Autumn and Summer, foliar concentrations of Zn and K were determined by atomic spectrum absorption. Harvested fruits were classified into small, medium and big. Analysis of Variance, Tukey test and Pearson correlations between production and foliar concentrations were performed. Higher fertilization levels of K with Zn increased medium and big fruits production (Kg and percentage). Foliar concentrations of K and Zn were positively correlated with big and medium fruit production and negatively correlated with small one. Chemical names used: Ethilenbis-ditiocarbamate of Zn (Zineb).

Metabolic responses of guava trees irrigated withdifferent N and K levels in São Francisco Valley

The guava (Psidium guajava L.) cv. Paluma has been cultivated in São Francisco Valley, Northeastern of Brazil, for in natura consumption and processing purposes. In spite of its importance, there are few scientific knowledge regarding guava physiology, nutrition, irrigation and fertigation. The objective of this work was to evaluate the effect of weather conditions and different concentrations of N and K applied by fertigation in foliar contents of reducing sugars, total soluble sugars, starch, sucrose, amino acids, and proteins. The field experiment was carried out at Bebedouro Experimental Field and the biochemical evaluations at the Laboratory of Seed and Plant Physiology, both located at Embrapa Semi-Árido, Petrolina-PE. The doses of 200 g N and 100 g K2O; 400 g N and 200 g K2O; 600 g N and 300 g K2O; and 800 g N and 400 g K2O per plant were applied in an experiment field. The experimental design was totally randomized blocks, with four treatments and five blocks. The weather conditions influenced the plant photosynthesis, which affects the plants metabolism. Guava presented specific responses to N and K fertigation for each parameter evaluated. The weather conditions during the evaluation period influenced guava responses to N and K fertigation.

Evaluation of substrates on the emergence of "araticum-de-terra-fria" (Annona emarginata (Schltdl.) H. Rainer) Seedlings

Choosing a substrate is the determinant factor for the seedling producer; thus, the aim of this study was to evaluate the effect of different types of substrates on the emergence of "araticum-de-terra-fria" (Annona emarginata (Schltdl.) H. Rainer) seedlings. The experiment was carried out in a greenhouse and the experimental design was in randomized blocks, with three treatments and five replicates of 72 seeds per plot. The treatments consisted of the following substrates: coconut fiber, vermiculite and Plantmax® Citrus. The number of emerged seedlings was weekly counted for 105 days. Data regarding seedling height were obtained, and the emergence velocity index and mean time, besides total emergence percentage and that over time were calculated. Results from total mean emergence percentage, seedling height, emergence velocity index (EVI), and mean emergence time (MET) were subjected to analysis of variance and means were compared by the Tukey's test at 5% significance. The curves concerning the emergence percentage over time were fit by the logistic growth equation for each treatment and the means of each parameter (A, B, C) were compared by the Duncan's test at 5% significance. The substrates vermiculite led to the highest values of emergence percentage differing from the PlantMax® Citrus, but not of the coconut fiber, however the vermiculite promoted seedling height in a shorter time; therefore, this substrate is recommended for the initial development of "araticum-de-terra-fria" (Annona emarginata (Schltdl.) H. Rainer) seedlings.

Fruit size and quality of pineapples cv. Vitória in response to micronutrient doses and way of application and to soil covers

The objective of this study was to evaluate the effects of foundation and leaf fertilization with micronutrients on fruit size and quality of pineapple cv. Vitória under the environmental conditions of the Baixo Acaraú irrigated perimeter in Northern Ceará State, Brazil, under two covers (bagana and black plastic) of the sandy soil of low fertility. The experimental design was a randomized split blocks one with four levels of soil dressing and four levels of foliar fertilization, with five replications. Micronutrient soil dressing was studied as FTE-12 at doses of 0, 60, 120 and 180 kg ha-1. The four levels of foliar fertilization were: LF0 (without fertilizer), LF 1 (15 leaf fertilization, using the amount of 1158.75 g Fe ha-1, 844.65 g Mn ha-1, 391.5 g ha-1 Zn, 322.65 g ha-1 Cu and 216 g ha-1 B), LF2 (15 leaf fertilization, using twice the quantities of level LF1) and LF3 (15 leaf fertilization, using three times the amount of level LF1). At 13 months after planting the micropropagated plantlets was carried out the floral induction treatment and five months later the fruit harvest determining the following variables: fruit weight and median diameter, soluble solids content (SS) and titratable acidity (TA). Both fruit weight and diameter increased with increasing doses of micronutrients applied to the soil and to the leaves, of plants grown both on bagana soil cover and plastic mulch. On the other hand fruit pulp quality was little affected by the treatments studied. There were a small increase of SS contents for plants grown on bagana soil cover and a small decrease of titratable acidity for those grown on plastic mulch, in both cases just in response to micronutrient foliar application.

Peaches tree genetic divergence for brown rot reaction

It was evaluated the genetic divergence in peach genotypes for brown rot reaction. It was evaluated 26 and 29 peach genotypes in the 2009/2010 and 2010/2011 production cycle, respectively. The experiment was carried out at the Laboratório de Fitossanidade, da UTFPR - Campus Dois Vizinhos. The experimental design was entirely randomized, considering each peach genotype a treatment, and it was use three replication of nine fruits. The treatment control use three replication of three peach. The fruit epidermis were inoculated individually with 0.15 mL of M. fructicola conidial suspension (1.0 x 10(5) spores mL-1). In the control treatment was sprayed with 0.15 mL of distilled water. The fruits were examined 72 and 120 hours after inoculation, and the incidence and severity disease were evaluated. These results allowed realized study for genetic divergence, used as dissimilarity measure the Generalized Mahalanobis distance. Cluster analysis using Tocher´s optimization method and distances in the plan were applied. There was smallest genetic divergence among peach trees evaluated for brown rot, what can difficult to obtain resistance in the genotypes.

Leaf nutritional levels in peach and nectarine grown in subtropical climate

The study evaluated the leaf nutritional levels of peach and nectarine trees under subtropical climate in order to improve the fertilization practices. The experiment was carried out in São Paulo state University, Botucatu, São Paulo State, Brazil. The experimental design consisted of subdivided plots, in which plots corresponded to cultivars and subplots to the leaf sample periods. The evaluated peach cultivars were: Marli, Turmalina, Precocinho, Jubileu, Cascata 968, Cascata 848, CP 951C, CP 9553CYN, and Tropic Beauty, and that of nectarine was 'Sun Blaze'. The sample periods were: after harvest, plants in vegetative period; dormancy; beginning of flowering and fruiting (standard sample). Results indicated significant variations in the levels of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn for the sampling period and in N, Ca, Mg, S, B, Fe and Mn levels for the cultivars.

Lipid peroxidation and seed emergency in progenies of the yellow passion fruit plant

The objective was to evaluate the percentage of emergency plantlets and lipid peroxidation in seeds of 29 half-sib progenies of yellow passion fruit (Passiflora edulis Sims.) after 24 months under storage. The experimental design was completely randomized, with four replications of 50 seeds each, from which the treatments were the progenies (1-29). The evaluation of the percent plantlet emergency was accomplished at 14 and 28 days after sowing. The lipid peroxidation of the seeds was expressed as malondialdehyde (MDA) content that was determined by the TBARS method. Approximately 21% of those half-sib progenies maintained the viability of their seeds for twenty-four months under storage. The results point out a remarkable genetic variability for vigor and emergency of the yellow passion fruit plantlets, with occurrence of individuals with high and other ones with low capacity to maintaining the physiologic quality of their seeds after storage.

Growth, production and quality of pineapple in response to herbicide use

In pineapple fields, weed competition is exacerbated by the fact that the crop is small and has a very slow vegetative development. The objective of this study was to determine the effects of herbicides on growth, yield and quality of pineapple, cultivar 'Pérola'. The experimental design was in randomized blocks with four treatments and four replications. Treatments consisted of weeding by hoe and the herbicides diuron; fluazifop-p-butyl and atrazine + S-metolachlor applied in post-emergence. The characteristics evaluated monthly during the vegetative stage were stem diameter, D-leaf length, number of leaves, number of emitted leaves and percentage of natural floral induction. In the reproductive phase, evaluations were made of average fruit weight (g) with and without crown, fruits length and diameter, number of slip, slip-sucker and sucker type seedlings, determination of soluble solids and pH in the pulp. There was no effect of herbicide treatment on the vegetative growth characteristics. Stem diameter increased until 330 days after planting, showing a decrease after this period. The D-leaf grew over time in all treatments, although phytotoxicity symptoms were observed after the first application of herbicides. The traits evaluated on the reproductive phase showed no significant differences in response to treatments. Therefore, the use of diuron fluazifop-p-butyl and atrazine + S-metolachlor did not affect growth, yield and fruit quality of pineapple, cultivar 'Pérola'.