Seed Production Areas Research Articles

Australian native seed sector characteristics and perceptions indicate low capacity for upscaled ecological restoration: insights from the Australian Native Seed Report

The Australian Native Seed Sector survey was conducted in 2016–2017 under the auspices of the Australian Network for Plant Conservation. Respondents self‐selected into a seed supply (Seed Collector, Seed Production Area Grower) or seed demand (Seed Purchaser, Other User) group category. Issue statements facing the sector with respect to limiting opportunities for ecological restoration were presented to survey respondents who ranked them in order of importance. Findings revealed that the order of statement importance varied depending on the primary role (Group) of the respondent in the sector. When combined across groups, the issues of most importance were: future seed demand will be difficult to meet from wild harvest; the seed market is unwilling to pay for the true cost of seed collection/seed production; there is a lack of available seed from a broad range of species; and demand for seed is inconsistent and/or unpredictable. The survey also revealed that the native seed sector is underpinned by a remarkably small and underresourced workforce, composed primarily of sole or small operators, which presents a clear concern to all users of native seed, not only in terms of current capacity for ecological restoration, but also to meet any large and rapid increases in future demand.

Natural establishment of Pinus spp. around seed production areas and orchards

This study aims at verifying the establishing potential of the main species of the Pinus genus planted in Brazil and broaden the knowledge on the conditions that facilitate the invasion. The density of spontaneous establishment of plants neighboring pine stands planted with 35 populations of Pinus spp. (P. caribaea (var. bahamensis and var. caribaea), P. elliottii, P. kesiya, P. merkussi, P. oocarpa, P. patula, P. pseudstrobus, P. strobus, P. taeda, and P. tecunomanii) was evaluated in three locations in the state of São Paulo. The vegetation covers neighboring the pine stands were evaluated regarding native vegetation occupation, open area, and eucalypts plantation. The spontaneous establishment of plants census was conducted up to 100 m away from the pine stand edges; samples were collected over an area divided into four 25 m-wide transects. In each transect, the spontaneous establishment were quantified and classified into three size classes: seedlings (≤0.3 m), saplings (≥0.3 m ≤ 1.0 m), and trees (>1.0 m). The results indicate that Pinus elliottii is the species with the greatest invasion potential in the studied areas. Areas without established vegetation favored regeneration, indicating the effect of the environment on regeneration occurrence. The number of spontaneous regeneration increased near the seed source but decreased significantly between 50 and 100 m away, despite the directional effect of the prevailing winds and the long-distance dispersal capacity of the genus.

Seed production areas are crucial to conservation outcomes: benefits and risks of an emerging restoration tool

Seed production areas (SPAs) are critical infrastructure for ecological restoration, particularly in fragmented landscapes where wildland seed crops are unavailable or wildland harvest is unsustainable. SPAs are useful for a wide range of species that are amenable to cultivation. Despite increasing research on SPAs, their value for biodiversity conservation has yet to be comprehensively described. Here, we highlight the key benefits of SPAs to biodiversity conservation. First, SPAs allow restoration to be conducted on a much greater scale than could be accomplished with wildland-harvested seed, thus protecting key biodiversity assets from harvest pressures. Second, the native seed production industry adds to the base of stakeholders who are invested in restoring and enhancing biodiversity. Third, SPAs provide novel opportunities for research and public exposure to native biodiversity. We also describe how cultivation can alter plant fitness compared to wildland plants, which acts as a multiplier to their conservation implications. SPAs could lead to two interrelated negative consequences that generate risks for taxonomic and genetic diversity at multiple scales: (1) SPAs can cause and multiply negative genetic legacies as a result of cultivation practices, and (2) SPA progenies can numerically and genetically dominate wildland plant populations. Nevertheless, SPA cultivation offers an opportunity to genetically diversify SPA-derived populations for success in restoration and enlarge the pool of species available for restoration, thus mitigating or solving some of these risks. Targeted government policies toward SPAs, additional research, and sound SPA management are necessary to minimize genetic risks and taxonomic redundancy, and also to maximize the conservation benefits of SPAs.

Factors Associated with the Technical Efficiency of Maize Seed Production in the Mid-Hills of Nepal: Empirical Analysis

Maize is the second most important staple crop in Nepal. Its demand is rapidly increasing due to a growth in the poultry sector. The national maize yield is low, leading to insufficient domestic production and thereby increasing imports. Maize seed is considered as one of the crucial inputs in achieving the targeted yield growth, but usually is in short supply during the cropping season. Farmers are involved in maize seed production, which eases its supply. Thus, understanding the efficiency of maize seed production will have a direct impact on the efficiency of the country’s maize production. This paper aimed to assess the technical efficiency (TE) of maize seed production and the major factors affecting TE. Semistructured questionnaire survey was administered in June 2016 to 182 maize seed farmers selected randomly from a total of 260 maize seed growers in Palpa District, a leading maize seed producing district in the mid-hills of Nepal. TE is estimated based on the stochastic frontier production model, and the factors affecting TE are assessed using the Tobit model. TE ranged from 0.25 to 0.92 with an average of 0.71. This revealed the scope of increasing TE by 29%. TE in the study area is largely affected by the age and schooling year of household heads. Similarly, the experience of maize seed production, livestock holding, the share of maize seed area, seed source, and access to extension services affect TE. Hence, a focus on motivating experienced educated maize seed growers to expand the maize seed production area supplemented by a better seed source and extension services would contribute to improving TE.

Special feature: An overview of the ANPC audit of seed production areas in NSW report

Special feature: An overview of the ANPC audit of seed production areas in NSW report

Managing Genetic Diversity and Representation in Banksia marginata (Proteaceae) Seed Production Areas Used for Conservation and Restoration

Landscape degradation is a major threat to global biodiversity that is being further exacerbated by climate change. Halting or reversing biodiversity decline using seed-based restoration requires tons of seed, most of which is sourced from wild populations. However, in regions where restoration is most urgent, wild seed sources are often fragmented, declining and producing seed with low genetic diversity. Seed production areas (SPAs) can help to reduce the burden of collecting native seed from remnant vegetation, improve genetic diversity in managed seed crops and contribute to species conservation. Banksia marginata (Proteaceae) is a key restoration species in south-eastern Australia but is highly fragmented and declining across much of its range. We evaluated genetic diversity, population genetic structure and relatedness in two B. marginata SPAs and the wild populations from which the SPA germplasm was sourced. We found high levels of relatedness within most remnants and that the population genetic structure was best described by three groups of trees. We suggest that SPAs are likely to be important to meet future native seed demand but that best practice protocols are required to assist land managers design and manage these resources including genetic analyses to guide the selection of germplasm.

Effect of nitrogen levels and Mepiquat chloride on plant height of Bt cotton (Gossypium hirsutum L.)

The field experiment was conducted at National Seed Production area of CCS Haryana Agricultural University, Hisar, during kharif 2018. The experiment comprised of three levels of nitrogen (100%, 125% and 150% RDN) and three spray of mepiquat chloride (control, single spray at 60 DAS and two sprays at 60 and 75 DAS) was conducted in factorial randomized complete block design with three replication. Results reveal that plant height was statistically higher with 150% RDN, while with mepiquat chloride spray it was significantly higher in control. Highest plant height recorded at harvest with 150% RDN (154.78, 154.58 and 144.09 cm) followed by 125% and 100% RDN respectively. However application of mepiquat chloride reduces the plant height. Double spray of mepiquat chloride @ 20g a.i. per ha at 60 and 75 DAS significantly reduced plant height (114.66, 210.89 and 128.4 cm) compare to control, while it at par with single spray at 60 DAS respectively. The present study highlighted the practical importance of the different nitrogen levels and mepiquat chloride spray on plant height of Bt cotton.

Population survey of Milicia excelsa, Pouteria adolfi-fridercii, Antiaris toxicaria and Prunus africana in south and south-western Ethiopia: implications for domesticating and establishing Seed Production Areas

The population dynamics and genetic qualities of stem height and dbh of the populations of Milicia excelsa, Pouteria adolfi-fridercii, Antiaris toxicaria and Prunus africana were assessed and studied in 14 forest ecosystems in south and south-western Ethiopia. A systematic random quadrat sampling technique was employed to identify potential habitat area for selected timber species in south and south-western Ethiopia. So, a total of 10 parallel transect lines were set out across each forest habitat. Milicia excelsa was assessed in four forest ecosystems; Bebeka -Duduka natural forest (45 tree stem ha-1) and Yayu coffee mixed forest (40 tree stem ha-1) appeared to have relatively denser population of M. excelsa compared to the other pilot forests. Similarly, statistically larger stem height (m) is observed in Bebeka-Duduka natural forest (x̅=29.5, SD=4.2) and larger dbh size (cm) in Bebeka 1 coffee mixed forest (x̅=48.5, SD=25.2) at p<0.05. Hence, Bebeka-Duduka natural forest and Bebeka 1 coffee mixed forests are identified for in-situ SPA establishment project of the target species. Pouteria adolfi-fridercii was assessed in eight forest ecosystems; Masha-Gora shewi forest appeared to have dense population of P. adolfi-fridercii (150 tree stem ha-1) followed by Bebeka-Kebereta (80 tree stem ha-1) as compared to the remaining pilot forests. However, statistically larger stem height (m) is scored in Bebeka 2 natural forest (x̅=30.6, SD=2.98) and Bebeka-kebereta forest (x̅=30.0, SD=4.4) and larger dbh size (cm) in Bebeka 2 natural forest (x̅=96.5, SD=19.9) at p<0.05. So, Bebeka 2 natural forest and Bebeka-kebereta forest are identified for SPA establishment project of the target species. Antiaris toxicaria was assessed in two forest ecosystems where both forest habitats appeared to have the same density of Antiaris toxicaria in hectare. Moreover, analyses of mean stem height (cm) of Bebeka 1 forest (x̅=21.4, SD=5.2) and Bebeka-kebereta forest (x̅=22.4, SD=2.7), and mean dbh size (cm) of Bebeka 1 forest (x̅=48, SD=16.4) and Bebeka-kebereta forest (x̅=48, SD=8.2) appeared to have not significantly different at p<0.05. Prunus africana was assessed in five forest ecosystems; Masha-Gora shewi forest appeared to have dense population of Prunus africana (150 tree stem ha-1) followed by Kaho-shemeta forest (130 tree stem ha-1) as compared to the remaining pilot forests. However, statistically larger stem height (m) is scored in Kaho-shemeta natural forest (x̅=31, SD=7.6) and larger dbh (cm) in Masha-Gora shewi forest (x̅=64.7, SD=28.2) at p<0.05. As the result, Kaho-shemeta natural forest and Bonga-Teja-adela forest are identified for establishment of seed production area of the target species in-situ. Hence, while implementing the project of domestication and seed production area establishment in south and south-western Ethiopia, in-situ and ex-situ areas must be selected and delineated in accordance with this preliminary information of the population dynamics and genetic qualities of stem height and diameter at breast height. The survey data generated in this study would bridge the research gap in relation to the population status of the target tree species in the designated area.

An Economic Analysis of Paddy Seed Production in Mau District of Eastern Uttar Pradesh

Paddy is an important cereal crop of the country and Uttar Pradesh, which is second largest producer of paddy in the country with 11.99 per cent share. The current study was conducted on primary data collected from 50 farmers from Mau district of Uttar Pradesh during the agricultural year 2017-18. The fixed and variable cost ratio in paddy seed production was 20:80. Human labour was the major cost component (42.21 per cent of total cost) followed by manures and fertilizers (11.85 per cent), bullock & machine labour (11.80 per cent), plant protection chemicals (4.53 per cent), irrigation (3.18 per cent) and seed (1.99 per cent). Total cost incurred in seed production of paddy was Rs. 51882 per hectare, while the net and gross returns were Rs. 28506 and Rs. 80388 per hectare respectively with the BC ratio 1.55. Total cost pertinent to paddy certified seed production was 11.36 per cent higher than grain production. The gross return was 18.92 per cent higher in seed production (Rs. 80388/ha) than grain production (Rs. 67600/ha). Net return from seed production of paddy was 35.66 per cent (Rs. 28506/ha) higher than grain production (Rs. 21012/ha). According to cost C2, cost of production of paddy grain and seed calculated to Rs. 1096 and Rs. 1231 per quintal. The return to the farmers on cost C2 was 45.07 and 55.0 per cent above cost of production for paddy grain and seed respectively. Similarly, cost of production according to cost A2 & FL (Family Labour) of paddy grain and seed calculated to Rs. 863 and Rs. 996 per quintal. The return to the farmers on cost A2 & FL was 84.24 and 91.57 per cent above cost of production for paddy grain and seed respectively. Production of paddy seed showed higher profitability to the farmers with encouraging net returns, which implies that the quality seed production area could be increased for higher income generation.

Comparing the early growth performance of plantation–grown Eucalyptus hybrid and Eucalyptus pellita, South Johore, Peninsular Malaysia

Eucalyptus spp. is an important species in the worldwide quality tropical hardwood sector, which has also gained significance in Sabah and Sarawak, Malaysia since the first large plantations established in 2008s. In October 2018, the trial planting of Eucalyptus hybrid (E. grandis x E. urophylla) and Eucalyptus pellita F. Muell was conducted in Hulu Sedili Forest Plantations, Kota Tinggi, Johore a tropical site with year–round high rainfall and humidity. The E. hybrid were formerly raised using tissue culture technique in the laboratory, Forest Research Institute Malaysia (FRIM) using the plantlets introduced from Tawau, Sabah. While the E. pellita seedlings were conventionally raised from seeds obtained from Seed Production Areas in Sabah Softwood Bhd, Tawau. After 18 months, it was clear that diameter, height growth and periodic increments of E. hybrid out performed E. pellita in the humid tropical environment. The average diameter at breast height, total height, periodic annual diameter and height increments of E. hybrid were significantly different in comparison with E. pellita. The initial vegetative measurement revealed the growth performance of Eucalyptus hybrid with respect with achieved diameter at breast height and total height was higher as compared with Eucalyptus pellita with good survival rate of greater than 90 percent.

Selection of adaptive teak provenance in Gunungkidul

The teak planting program for rehabilitation and research, as well as for social forestry purposes, requires a constant supply of planting materials with good phenotype and genetic qualities. Most of teak seeds in Indonesia are collected from seed production areas, and even from unidentified stands when the improved stands are unavailable. Vegetative material production from hedge orchards has also been used in a lesser number due to the more complex production techniques and the more expensive cost. Therefore, it is a need to look for any other alternatives for teak planting material supplies. The success of Wanagama on rehabilitation of critical land area suggested an idea to increase the value of Wanagama plantations as a seed source. A 31 years old provenance trial plantation PPGM-T73-88 consists of 21 provenances, located in Compartment 17 Wanagama, made in 5 blocks, 4 tree plots, and 4 m x 4 m spacing, was selected to be an alternative seed source. This study was aimed to evaluate the possibility of the plantation to be a seed source, by selecting the adaptive provenances based on survival rate, height, and diameter. This study concluded that Malabar and Central Province provenances have the highest survival rate. Kouai and Deling provenances are the highest rank of height and diameter characteristics. Respectively, the heights of both provenances are 14.58 m and 13.86 m; the diameters are 31.95 cm and 34.73 cm. Key words: teak, provenance trial, seed source, Wanagama

Результати 20-річних випробувань кандидатів у сорти-популяції синтетичні сосни звичайної в умовах ДП «Зміївське ЛГ» на Харківщині

Висвітлено результати дослідження сортовипробних культур сосни звичайної в ДП «Зміївське ЛГ» Харківської області, де представлено потомства дев’яти клонових насінних плантацій та однієї постійної лісонасінної ділянки – кандидати у сорти-популяції синтетичні та їхні регіональні контрольні варіанти (Харківська, Київська, Рівненська й Волинська області). Оцінено ростові (висота, діаметр), якісні (прямизна стовбура) показники та стан насіннєвих потомств у 5- та 20-річному віці. Відзначено добру збережуваність потомств у сортовипробних культурах (46,7 %). Кращими за результатами комплексного балового оцінювання потомств у 5-річному віці визнано кандидати у сорти-популяції з Харківщини 'Прихилки-2' та 'Географічний', у 20-річному віці – 'Географічний'. Потомства з Харківської та Київської областей за сумою отриманих балів не поступаються місцевому контролю, а деякі випереджають його; до групи з гіршими за контроль результатами віднесено потомства з Волинської та Рівненської областей.

Prevalence of Acidovorax citrulli in Commercial Cucurbit Seedlots During 2010-2018 in China.

Acidovorax citrulli is the causal agent of bacterial fruit blotch (BFB), a serious threat to cucurbit fruit and seed production worldwide. In recent years, the BFB has spread to many areas of China, mainly via the inadvertent distribution of contaminated commercial seeds. To assess the prevalence of seedborne A. citrulli in commercial watermelon and other cucurbitaceous seedlots in China, a 9-year survey was conducted between 2010 and 2018. A total of 4,839 seedlots of watermelon and other cucurbitaceous species were collected from 13 major seed production areas of China and tested by a semiselective media-based colony PCR technique for A. citrulli. Overall, A. citrulli was detected in 18.00% (871/4,839) of all cucurbitaceous seedlots. The bacterium was detected in 21.59% (38/176), 19.19% (33/172), 23.44% (214/913), 40.76% (247/606), 13.28% (85/640), 15.40% (95/617), 13.25% (73/551), 8.03% (48/598), and 6.71% (38/566) of all commercial seedlots tested from the 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, and 2018 growing seasons, respectively. Additionally, the prevalence of A. citrulli in cucurbit seedlots was determined for different seed production areas. The prevalence of A. citrulli in cucurbitaceous seedlots produced in Xinjiang, Gansu, Ningxia, Inner Mongolia, and 9 other provinces was 18.76% (582/3103), 26.34% (103/391), 21.47% (82/382), 11.11% (14/126), and 10.75% (90/837), respectively. This is the first survey for A. citrulli in commercial cucurbit seeds in China, and the relatively high prevalence suggests that commercial seeds represent a substantial source of primary inoculum that can threaten cucurbit seed and fruit production in China.

Pengaruh Pemangkasan Cabang dan Mikoriza terhadap Produksi dan Mutu Benih Mentimun (Cucumis Sativus L.)

The Effect of Branch Pruning and Mycorrhiza on Production and Seed Quality of Cucumis sativus L. The purpose of this study was to obtain the best branch pruning, with or without mycorrhiza application, in order to increase the production and quality of cucumber seeds. Pruning the branch at the beginning of cucumber growth is expected to delay fruit formation and support good vegetative growth. This research was carried out in the PT. Primasid Andalan Utama seed production area in Kalibeji Village, Tuntang District, Semarang Regency, Seed Technology Laboratory and Plant Physiology Laboratory, Faculty of Agriculture and Business, Satya Wacana Christian University. This study was conducted by the split-plot randomized complete block design with 2 factors. The main plot consists of 2 levels, namely control/without mycorrhiza (M0) and mycorrhiza application (M1). Pruning the branches as the subplots consist of 4 levels, were pruning to the second, third, fourth and fifth branches of the cucumber plant (P1, P2, P3 and P4). DMRT was used to differentiate the significance of the treatment. The results showed that mycorrhiza application increased the percentage of root infections. The pruning to the fifth branch (P4) is the best; in control without mycorrhiza (M0P4) increased for the number of fruits, the seed weight per plant, and the germination simultaneously; whereas in mycorrhiza application (M1P4) increased the number of fruits and the seed weight per plant. It is also observed that the pruning to the second branch (P1) increased the weight of 1000 grains, the speed of germination and the simultaneous of germination; both with and without mycorrhiza application.

Socio-economic Dynamics of Farmers and Economics of Certified Seed Production of Paddy in Karimnagar District, Telangana

Paddy plays a vital role in the national food security and principal food crop cultivated throughout the Telangana state providing food for its population, fodder to the cattle and employment to the rural masses. The present study was based on primary data in Karimnagar district of Telangana during the agricultural year 2014-15. Analysis of data shows that majority of seed farmers belongs to small category (1-2 ha) followed by semi-medium (2-4 ha) and marginal (< 1 ha) category. The overall average land holding size of paddy seed farmers was 2.04 ha followed by grain farmers (1.27 ha) and district average (1.03 ha). Study area was dominated by paddy, cotton and maize with a cropping intensity of 159. Net irrigated area of paddy grain producer, certified seed producer and district average was 71.00, 90.60 and 73.95% respectively. Non-availability of labour was the most important constraints hindering adoption of paddy seed production technology. The seed production area is dominated by variety BPT- 5204 which covers 31.57% area under paddy seed production. Current study illustrates a ratio of 32:68 towards fixed and variable costs in paddy certified seed production with a total cost of Rs. 57315 per hectare and the gross and net returns were Rs. 83150 and Rs. 25835 per hectare respectively. The total cost of cultivation in paddy seed production was around 13.63% higher than grain production while, gross return was about 28.42% higher in seed production. Consequently, net return from seed production of paddy was 80.56% higher than grain production. Hence, production of certified seed has resulted in a win-win situation for the farmers with higher yield and increased returns. Higher yield and profitability associated with certified seed production can be effectively popularized among farmers, results in increased certified seed production. Farmers can be promoted in this endeavour by providing required quantity of foundation seed along with technical guidance.

Influence of alfalfa seed belts on yield component and seed yield in mainland China - A review

Alfalfa is widely cultivated, and the seed yield differs in different regions due to the climate environment and so on in China. In order to obtain higher yield, alfalfa seed production must choose the most suitable area. Therefore, according to the geographical and climatic conditions, the alfalfa seed production area can be divided into four belts: Hexi Corridor belt, Hetao Plainbelt, the northern slope of the Tianshan Mountains belt and the Hotanbelt in mainland China. Under different cultivation measures, the seed yield of four alfalfa seed production zones, varied in the range of 360-1833 kg/hm2, 234.96-1560.1kg/hm2, 179.10-1197.33 kg/hm2, 225-300 kg/hm2, respectively. These different cultivation measures can provide theoretical guidance for alfalfa seed production in different production zones.

Pollen limitation and seed set associated with year-to-year variation in flowering of Gmelina arborea in a natural tropical forest

The year-to-year variations in flowering, pollen and fruit production in ten Gmelina arborea individuals in a natural forest were observed over a period of five years, 2009−2013, and pollinator visits were observed closely over two years, 2011 and 2012. A pollen supplementation experiment was also undertaken in two years (2011 and 2012) of contrasting flowering levels. Considerable year-to-year variations were observed in flower, pollen and fruit production. The observed variation represented a normal sequence of good-year and poor-year cycling which is most parsimoniously attributed to resource allocation. The average level of pollen production per individual tree in good flowering years oscillated between 6.6 and 9.62 × 108, which in the poor flowering years was between 1.92 and 3.07 × 108. The magnitude of pollen limitation across years was highly significant (p < 0.0001). Fruit set through supplemental pollination was 73% and 96% greater than that of the open-pollinated branches in the year 2011 and 2012, respectively. Pollen limitation, irrespective of the arrival of outcross pollen, can reduce annual seed set in predominantly bee-pollinated trees. However, various other factors may cause flower abortion in addition to pollen limitation. The results of this study would be very valuable to the seed orchard managers and the silviculturists to manage the seed production areas (SPAs) of G. arborea. The study ultimately recommends supplemental pollination in seed orchards of G. arborea for better genetic gain and good seed yield.

Impact of fertility variation on genetic diversity and phenotypic traits in second generation seed production areas and clonal seed orchards of Eucalyptus camaldulensis

Abstract Fertility and gene diversity were estimated in three second generation (F 2 ) seed stands (SPA 1-3) and two clone trials (CSO 1&amp;2) of Eucalyptus camaldulensis to assess the impact on seed crop. F 2 seedlots were evaluated in comparison to native provenances, ten commercial clones and interspecific hybrids at diverse sites. SPA 1&amp;2 were genetic gain trials of five first generation (F 1 ) orchard seedlots, SPA 3 a plantation of one F 1 orchard seedlot, and CSOs were clone trials of 21 commercial clones established at two contrasting sites. Fertility variation, as indicated by sibling coefficient, was high (Ψ, 9-14) in the SPAs as only about 26 % trees were fertile compared to 81 % trees in CSOs. Effective population size was higher in SPA 1 and 2 (N s , 95 and 74, respectively) than SPA 3 (N s = 39). Fertility was highly skewed in CSO 2 resulting in low effective population size (N s = 2) compared to CSO 1 (N s = 11). Constant seed collection enabled 3-fold increase in relative population size and 22 % higher predicted gene diversity in CSO 2. Genetic diversity (H e ) estimated using SSR markers was higher in SPA 1&amp;2 and native provenances (NAT), compared to SPA 3 and CSO 1, whereas CSO 2 and clones had lower values. There was a high positive correlation between estimated H e and predicted gene diversity values of SPAs and CSOs. H e was positively correlated to mean field survival and negatively correlated to kraft pulp yield (KPY), evaluated at three years in progeny trials across three locations. Number of alleles per locus was higher in SPAs and native provenances compared to CSOs and clones. Discriminant principal component analysis clustered CSO, NAT and SPA seedlots in different groups while commercial E. camaldulensis clones clustered close to NAT. Multilocus outcrossing rate was generally high (t m , 91-100 %), though selfing was observed in two families of SPA 3 and CSO 2. Selected interspecific hybrid families of commercial E. camaldulensis clones (with E. urophylla and E. pellita) evaluated at two of the sites had higher H e and KPY than clones at three years.

Constraints encountered by nursery operators in establishing agroforestry tree nurseries in Burundi

A nursery operator survey was conducted to identify major constraints encountered by nursery operators for tree nursery establishment in Burundi. The survey covered two main contrasting agro-ecological zones of the country in Muruta commune and Bugesera region in Bugabira and Busoni communes. It was found that most planting materials used by nursery operators were collected from sources of unknown genetic quality. It was also noted that few tree species were raised in nurseries of Muruta and Bugesera areas. The growing medium used in individual and group nurseries was of low quality. The lack of capital and nursery material inputs was another impediment to small-scale nursery sustainability. Most nursery operators lacked sufficient technical knowledge on nursery establishment techniques and had limited skills on vegetative propagation techniques. The low involvement of non-governmental organizations and government agencies impedes the sustainability of nursery operations in the two areas of study. Finally, the low demand and price for tree seedlings do not motivate nursery operators to produce seedlings for income generation. The government intervention may develop a well-structured nursery management system to support sustainable production of high-quality seedlings. It is then necessary to organize trainings of nursery operators on source and collection techniques of germplasm or planting material. The establishment of seed orchards and seed production areas of a large number of tree species is also of great importance. The support of nursery operators in financial and material inputs may promote tree species diversity and increase seedling production. The link of tree operators to good market may improve the sustainability of tree nursery operations.

Spatial variability in soybean seeds quality and in chemical attributes of the soil of a production field in the Brazilian Cerrado

Abstract: The objective of this study was to evaluate the spatial variability in soybean seeds quality and in soil chemical attributes of a production field. Data were collected at 138 georeferenced points of a soybean production property located in Santo Antônio de Leverger - MT. Soil related variables, such as phosphorus, potassium, calcium, magnesium, and organic matter (OM) contents, pH, cation exchange capacity (CEC) and base saturation (V%) were evaluated. On the other hand, yield, one thousand seed mass, size, germination, emergence in seedbed, electrical conductivity, accelerated aging and tetrazolium reaction were evaluated as seed variables. The data were submitted to descriptive and geostatistical analysis, and the fit semivariogram parameters were used to elaborate spatial distribution maps of the analyzed variables. After the analysis, it was possible to conclude that there was spatial variability in the evaluated attributes for both seeds and soil related variables, indicating that the soybean seed production area can be divided into management zones, which allows the definition of areas to be harvested or discarded within a field of seed production.