Mating System and Pollen Contamination in a Pinus brutia Seed Orchard

Mating system parameters and pollen contamination were estimated in an 11-year-old Pinus brutia Ten. clonal seed orchard, located in Antalya, Turkey, with the aid of isozymes. Isozyme analysis was performed on both maternal (megagametophyte) and embryo tissues of seeds collected from the seed orchard and the surrounding natural stand. Fourteen loci encoding nine enzyme systems were assayed. Based on a multilocus estimator, the proportion of viable seeds originating from outcrossing (tˆ_m) in the seed orchard was found to be 0.947; the remainder (0.053) was due to selfing. We estimated that 85.7% of the orchard seed resulted from pollen contamination by trees in surrounding stands. This may be related to the young age and subsequent low pollen production of the orchard. Only 9% [i.e., 1.0−0.857 (contamination)−0.053 (selfing) = 0.090] of the orchard offspring was due to cross-pollination among clones within the orchard. Due to the high level of pollen contamination, it is estimated that genetic gain in this seed crop is less than 57% of that expected if all offspring resulted from random mating among orchard clones (i.e., no contamination).     

Genetic variation in <Emphasis Type="Italic">Pinus taeda</Emphasis> wood properties predicted using non-destructive techniques

• Background   

Tree breeders have been reluctant to include wood traits in tree improvement programs owing to logistic difficulties and the cost associated with the assessing the traits.     

Rice straw biochar amended soil improves wheat productivity and accumulated phosphorus in grain

Abstract

Biochar is a pyrolyzed biomass produced under limited oxygen or oxygen absent conditions. Few investigations have been conducted to determine the combined effect of biochar with chemical fertilizer on growth, yield and nutrient distribution pattern in root, shoot and grain in wheat as well as changes in soil physiochemical properties. This research was designed to study the combined effect of chemical fertilizer and rice straw-derived biochar on soil physio-chemical properties, growth, yield and nutrient distribution pattern within wheat plant tissue and grain. Results showed that rice straw biochar caused a significant decrease in soil pH and increase in soil organic matter as well as nutrients like total nitrogen (TN), potassium (K), magnesium (Mg) and boron (B) due to incubation. Result also showed that root biomass and straw did not differ between Bangladesh Agricultural Research Council (BARC) and ½ BARC?+?rice straw biochar treatment. Similarly, thousand grain weight and grain yield did not differ between the same treatments. The phosphorus concentration in wheat grain was highest in ½ BARC?+?rice straw biochar as compared to other treatments. The use of rice straw biochar in addition to the chemical fertilizers in wheat production systems is an economically feasible and practical nutrient management practice. Our findings urged that reduction of chemical fertilizer application is possible with supplementation of rice straw biochar.     

Bio‐economic efficiency of creep supplementation of forage legumes or concentrate in pasture‐based lamb production system

A 2‐year study in the Central Anatolian Region of Turkey compared the performance of pasture‐fed suckling lambs and their dams, set‐stocked on grass‐legume pastures supplemented either with forage legumes or concentrate through a creep grazing/feeding system in a randomized block design. The treatments included continuous pasture grazing + creep grazing alfalfa; continuous pasture grazing + creep grazing birdsfoot trefoil; continuous pasture grazing + creep feeding concentrate (170 g kg^?1 CP; 11.3 ME MJ kg^?1 DM); and continuous grazing without creep feeding (control). In both years, creep feeding/grazing commenced in early June following a 42‐day pasture grazing period (period 1) and continued until mid‐summer for two separate periods of 21 days each (periods 2 and 3). Creep‐supplemented lambs grew faster (p < .001) than those that grazed pasture alone, with no significant difference across all creep supplementation treatments. Across the years, the lambs grew at 223 and 161 g per head day^?1 for creep‐supplemented and control groups respectively. None of the lamb feeding strategies affected the ewe liveweight gains (p > .05). Results from a bio‐economic optimization model, however, showed that supplementing the pasture with birdsfoot trefoil and alfalfa in periods 2 and 3, respectively, maximized economic returns with an extra profit of US$88.83 per lamb above those that grazed the pasture alone.     

Best timing for glyphosate treatments and possible combinations with pre and post-emergence weed control practices in no-till maize

Use of reduced and no-tillage systems has increased in recent years due to concerns for ecological and economic sustainability of agricultural production. Effective weed control is a serious concern in reduced tillage production. This study was conducted to investigate weed control practices in reduced and no-till maize production. The most effective timing of glyphosate application, either before or after sowing, was investigated in combination with pre-emergence application of acetochlor (840 g a.i/L), post-emergence application of foramsulfuron (22.5 g a.i/L), and two hoeing treatments. The treatments were maintained on the same plots during 2011 and 2012 to evaluate the cumulative effects of the treatments. Main plot treatments consisted of four timings of glyphosate application: 20 or 10 days before sowing, day of sowing, 5 days after sowing, and an untreated control. Sub-plot treatments were: pre- plus post-emergence herbicides, pre-emergence herbicide plus rotary hoeing, post-emergence herbicide plus rotary hoeing, and post-emergence herbicide plus two hoeing treatments (rotary and lister hoe). In the main plots, the lowest weed biomass was produced in glyphosate treatments at sowing and 5 days after sowing; the highest biomass was produced in control plots and in the plots with glyphosate treatments 20 days before sowing. In the sub-plots, the greatest weed biomass was produced in plots with two hoeing treatments (rotary and lister hoe). Glyphosate treatments at sowing and post-emergence herbicide treatment combinations produced the best weed control. Economic analysis revealed that pre-sowing, non-selective herbicide treatments provided a slight increase in net profit. Mechanical hoeing decreased net income due to increased production costs. The highest income was obtained from the pre-emergence plus post-emergence herbicide treatment combinations with no glyphosate.     

Control of the pink bollworm <Emphasis Type="Italic">Pectinophora gossypiella</Emphasis> by the mating disruption technique on cotton in a semi-arid region of Turkey

This study evaluated the effectiveness of mating disruption pheromones for the pink bollworm (PBW) Pectinophora gossypiella (Saund.) (Lep.: Gelechiidae) and determined the damage levels of cotton plants in Turkey in 2007 and 2008. Adult populations were monitored by pheromone traps, with 250 pieces ha⁻¹ of PBW rope dispensers used for each treated field of approximately 12 ha. Calculations were based on comparing cotton yield in the control field with that in treated fields. The PB-Rope L dispensers significantly decreased both number of males in the pheromone traps and cotton boll damage. Results showed that PB-Rope L dispenser application during the square period of cotton plants effectively reduced damage. Cotton yield of treated fields was increased compared with control fields by 20.28% and 10.28% in 2007 and 2008, respectively. Infestation ratios were determined by comparing cotton bolls collected from treated fields with bolls from control fields; the results were 25% and 15% for control fields and 16% and 4% for treated fields in 2007 and 2008, respectively. Larval densities in the control fields were higher than those in the treated fields in both years. Results showed that the PB-Rope L dispensers released pheromone satisfactorily to disrupt pest mating.     

Instability of ovine babesiosis in an endemic area in Turkey

This study was designed to determine the endemic status of Babesia ovis in sheep in Turkey. A total of 2000 sheep, from different age groups (i.e. 0-3, 4-6, 6-9, 10-12, and >12 months), were selected randomly from 132 sheep flocks. The presence of specific antibodies against B. ovis was diagnosed by indirect fluorescent antibody test (IFAT). A total of 843 (42.15%) serum samples were determined to be positive. The seropositivity rates in the age groups stated above were 31.90, 31.64, 47.69, 40.22, and 52.99%, respectively. The endemic status of the disease was determined by calculating the inoculation rate (h) of each group. The h value for each group was determined to be lower than 0.005, which revealed that the endemic status of B. ovis was instable. This report may indicate the necessity of vaccination.     

Prediction of wood density breeding values of Pinus taeda elite parents from unbalanced data: A method for adjustment of site and age effects using common checklots

? Wood density of elite parents of loblolly pine (Pinus taeda L.) was investigated in 6 to 18 year-old progeny trials. The sampling was carried out separately in seven testing regions in the southeastern US. A checklot was the only connection between elite parents planted at different trials in a testing region.

? We used a data normalization method suggested for unbalanced designs in cDNA microarray experiments to remove confounding site and age effects using the checklot as a reference sample. Wood density breeding values of parents were predicted by fitting a linear mixed model to the normalized data.

? Using the reference samples to remove site and age effects appears to be an effective method for analysis of unbalanced progeny tests data. In general, wood density (kg/m³) decreased from coastal to inland plantings and from the southern to the northern planting. Considerable genetic variation for wood density was detected among these fast-growing elite parents in six of seven testing regions, with half-sib family mean heritabilities ranging from 0.71 to 0.97 within a testing region. With the exception of two regions, checklots were stable across trials in a region, based on regressing the checklot means on trial means.