Cocksfoot (Dactylis glomerata L.) seed production : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University

Seed yield reduction due to variation in genotype, management, and incidence of diseases is common and well documented in grass seed crops. Two New Zealand cultivars (Grasslands Wana, Grasslands Kara) and two Japanese (Akimidori Makibamidori) cocksfoot cultivars from a three year old stand (sown in September 1991) at Grassland Aorangi Research Farm in the Manawatu were evaluated for their seed yielding capacity. In addition these cultivars were evaluated to determine the effectiveness of bactericide (Streptomycin), nematicide (Vydate/Oxamyl) or a combinations of bactericide and nematicide to determine their effect on seed yield with traditional Fungicide (Folicur) application being used as a control. The unit plot size was 1.2 X 3.0 m2, with each plot containing 4 rows. randomized block design with two factors (cultivar and pesticide) was utilized with 4 replications. In each cultivar pesticide were sprayed in four replicates from each block. The New Zealand cultivar Wana outyielded the other three cultivar and produced about 23%, 32%, and 70% higher pure seed/unit area than that cvs Kara, Makibamidori and Akimidori respectively. The ability of cv Wana to outyield other cultivar was largely due to its ability to produce a greater numbers of fertile tillers and higher number of florets/head. Seed yields in the New Zealand cultivar Kara and the Japanese cultivar Makibamidori were similar but significantly higher than cv Akimidori. The significantly higher seed yield of cv Kara was due largely to its significantly higher seed weight than the other cultivars. Similarly the higher seed yield in cv Makibamidori compared to Akimidori was mainly due to higher seed weight. The lower pure seed yield in cv Akimidori was apparently due to lack of proper photoperiodic effect or cold temperature during anthesis and its earlier seed developing resulted in more empty florets than the New Zealand cultivar and cv Makibamidori. Fertile tiller numbers spikelets/ head and florets/ head were significantly higher in cv Wana compared to the other 3 cultivars. However, the TSW was low. The TSW was highest in cv Kara. Highest recovery of pure seed was obtained from cv Wana in screen and blown fraction. Highest pure seed was obtained from cv Makibamidori in clean seed fractions. Foliar disease intensity in all the four cultivars was found to be similar at all 3 stages of plant growth although disease levels were generally low. Percentage purity in clean seed as well as in different cleaning fractions varied depending on cultivar but cv Akimidori was always ranked lowest. Seed germination percentage in single and in multiple florets was higher in cv Akimidori compared to the other 3 cultivars. Different cultivars reacted differently to the application of pesticide. Cultivar Wana produced the highest yield 103 g pure seed/m2 in the Fungicide (Folicur) treatment compared to 55, 38 and 22 g/m2 in cv. Kara, Makibamidori and Akimidori respectively. However all cultivars produced lower yields following the application of Streptomycin. Seed yield in cv Akimidori was not affected by any pesticide application. The lower yield in Streptomycin treatments was mainly due its phytotoxic effect on leaf tissue. Seed yield in Fungicide, Vydate and in V+S treated plots was similar but significantly better than in Streptomycin treated plots. Fertile tiller numbers were also similar in these treatments but spikelet and total floret numbers were higher in the V+S treatment than in the Fungicide treatment. TSW and florets/ spikelets was not affected by pesticide application. The recovery of pure seed was always lowest in the Streptomycin treatment in all fractions of machine cleaning of seed but was higher in V+S than Fungicide treatment, particularly in the machine clean fraction. However, the recovery of pure seed from the screen fraction did not vary significantly. Over all the foliar disease severity was low in Fungicide and V+S treatment and highest in Vydate treatment at maturity but no difference during vegetative growth or at peak flowering. The percent purity varied only in the air screen fraction but was high in the Vydate treatment. Seed germination was high in all pesticide treatments and being above 90% in term of single florets and 85% in multiple florets with minor improvement in V+S treatment both in single and multiple florets and in Fungicide treatment with multiple florets only. The second trial involved only one cultivar (cv Tekapo) and involved 4 plots from each block with 3 different types of fungicide Alto (cyproconazole), Bavistin (carbendazim), and Bravo (chlorothalonil) applied from flower initiation to harvest maturity at intervals of 14 to 21 day. No effect of fungicide occurred in seed yield or in yield components. Disease severity varied significantly only at harvest maturity and was lowest in Alto treated plots (2.75) compared to the control (4.25). However, no difference occurred in assessment at the vegetative stages or at peak flowering. No significant effect of fungicide was observed in terms of seed cleaning. The percentage purity was found higher in Alto and Bravo treated plots. Germination results were well above accepted levels (90%) in all fungicide treatments with Bavistin treatments being particularly useful

On the Control of the Invasive Banana Bunchy Top Disease in Africa: Lessons from a Conciliate Interaction

Controlling an invasive species, in Agriculture, is a context variable activity, borrowing the technical advances of numerous sciences, including the insect sciences. The Banana bunchy top disease (BBTD), caused by the bunchy top virus (BBTV), is spread between regions through planting infected suckers and locally by the banana aphid feeding off infected plants. It is present in 16 countries in Sub Saharan Africa; and causes accelerating production losses and reduced access to clean seed. Although yield decline is more rapid in some cultivars, none is resistant. Our work towards recovery of banana production in nine BBTD-affected sites in eight countries; thus includes a cross talk between different natural sciences, social sciences and policy studies, relying on existing knowledge and technologies: reliable clean seed supply system and tactics to reduce re-infection pressure, vector entomology, virus detection, epidemiology, imaging and mapping. We developed a non-intrusive DNA extraction methods and used it to amplify the mtCOI gene to differentiate the two species of banana aphids, Pentalonia nigronervosa and P. caladii while preserving voucher specimens for morphological studies. ELISA, key diagnostic approach should be supplemented by early symptom recognition. We also studied cropping systems and banana diversity as potential options and indicators of long term BBTD control, as varieties showed different attractiveness to the vector and human preferences. Seed systems studies revealed that clean seed systems (like other control approaches) need to incorporate diversity, vector, human behaviour and policy. BBTD is a spreading invasive disease, a potential model in regional invasive species management. What then is our role as Insect Scientists working in this region in limiting of the spread of BBTD? How can we foster an interplay between entomology, ecology, other natural scientists, social sciences and regulatory services and the private sector to prevent its spread to the banana growing areas in Africa. (Résumé d'auteur

Farmer seed enterprises: a sustainable approach to seed delivery?

A major reason for the low adoption of modern varieties of seed among small-scale farmers in developing countries is the inability of formal, centralized seed production systems to meet their complex and diverse seed requirements. Drawing on experiences in Uganda with the common bean, the paper proposes seed production by farmer seed enterprises (FSEs) as a strategy for meeting dual objectives: to sustainably distribute and promote modern crop varieties and to establish a regular source of “clean” seed of either local or modern varieties. It reports on lessons learned from the Ugandan experience and offers a conceptual framework and guidelines for establishing economically and institutionally sustainable FSEs. While FSEs offer a potentially sustainable solution to the problem of seed supply, the challenge of implementing and scaling up this approach in eastern and southern Africa remains formidable. Collaborative linkages need to be fostered between farmers, researchers, agro-enterprise specialists, NGOs, and the formal seed industry. Seed policy reforms need to be implemented and more client-oriented research systems must be institutionalized

Proper seed storage (Liveseed Practice abstract)

What causes seed ageing? Seed ageing is caused by oxidation of the cell membranes, mitochondria, DNA, RNA and proteins in the seeds. This oxidation is stimulated by four factors: seed moisture level, temperature, oxygen and time. The main factors stimulating this ageing are moisture and oxygen. How to reduce ageing Keep sealed commercial seed packages closed until use, to avoid moisture uptake from the air. Never store an open package in a cold place like a refrigerator, were the humidity is high and the seeds will absorb moisture. If not all seeds are used, store the remainder in a dry environment. For this we developed an easy system with a ‘seed drying and storage box’ (Fig 2). The principle is an airtight transparent box. In the box is a bag with silica gel and a relative humidity (RH) meter. The optimal RH is between 20 and 40%. Home produced seeds can also be dried in the box. If the RH surpasses the 40%, the silica gel needs to be regenerated in an oven at 100 °C. The dried silica gel can be cooled down in a closed clean jam jar or alike. It is possible to store the airtight box with seeds in a cooler place, to reduce ageing further. For larger amount of seeds the box could be replaced by a large vacuum bag, as available for storage of clothes

Varieties of field vegetables and potatoes for organic production and marketing OF0304

The objectives of the work were to investigate the suitability of selected varieties of vegetables and potatoes for organic production using organic or untreated seed on certified organic sites. Organic growing of vegetables and potatoes imposes restrictions on the treatments which growers can apply to crops to maximise yield and maintain quality. Hence choice of variety is more critical in organic situations than for conventional crops where problems can be solved at a later date by application of pesticides or fertilisers. Varieties are needed that can respond to the sometimes sub optimum conditions that are imposed by the restrictions of organic systems and identification of these are not always evident from trials under conventional conditions. In addition, variety choice may be restricted for organic growers as they are required to use organically produced seed of a variety where it is available. Derogation allows the use of untreated conventional seed where suitable varieties are not available organically. This project tested: available organic seed as much of it has not been evaluated in any UK trials untreated seed of varieties in production for organic seed attempted to identify varieties of conventional seed that would be useful in organic systems so that organic seed can be produced. In this 3 year period trials were carried out on leeks, cabbage, celery, broccoli, lettuce, cauliflowers, carrots and potatoes. Varieties were assessed for yield, quality, pest and disease resistance and shelf life and storage where appropriate. Seed health was also checked to ascertain levels of seed borne disease. Results from these trials; Leeks Leeks were reasonably easy to grow organically. In our trials the main problems were weed control and leek rust infection although there is also the risk of thrip and White Tip infection. In some of the trials there was also an obvious nutrient shortage. A wide range of varieties is available differing in maturity, shank length disease resistance and winter-hardiness. In general the requirements of organic leek growers closely match those of conventional growers. Very few hybrids are available as organic seed. Cabbage 2001 to 2003 trials included a wide range of types. As for other brassica crops aphid infestation and speed of development were the most important factors in discriminating between varieties. In general smooth varieties were less affected than blistered varieties, early maturing varieties less affected than lates and red varieties less than green or white types. Celery Organic celery needs to be grown on water retaining soils and given adequate irrigation. just like the ICM crop. The biggest problem for the crop is Septoria, which can devastate plants very quickly. Starting with clean seed is essential but air-borne infection can come in from infected crops or debris. Giving plants better airflow from wider spacings or bed systems seems to delay infection. Slugs can also cause problems and data on both these problems was recorded and included in the published results. Broccoli Growing organic broccoli trials presented similar pest problems to other brassica crops in that cabbage root fly has to be avoided at establishment and aphid and caterpillar attacks later on. Fleece was used on all early trials but in later years it was not used to allow for easier weed control. Broccoli was fairly competitive with weeds and some recent trials were only hand weeded once. Fertility seems to be a problem and we did not achieve heavy crown weights. Lettuce A wide range of types of lettuce are important for organic growers and this series of trials included butterhead, crisphead, Batavian, Cos, Little Gem and leaf types. Vigour, flavour, disease, pest and tipburn resistance are all important characters for a successful organic variety. Fortunately there are more genetic pest and disease differences available in lettuce than for most other vegetable crops. In addition a large number of varieties are available as organic seed. Cauliflower Three maturity periods were sampled i.e. summer, late autumn and Spring Heading. Aphid and caterpillar damage were major problems and there was some evidence of varietal differences in susceptibility. When conventional trials with similar varieties were grown from the same planting dates the organic varieties were slower to mature. This may have been because nitrogen was more limited. Very few varieties of cauliflower are offered as organic seed and growers would struggle to find a good continuity program. Carrots The 2001 to 2003 trials concentrated on main crop varieties. A successful organic carrot variety needs most of the following: good early vigour to emerge quickly and compete with weeds, rapid bulking to compensate if late sowing is used to ovoid first generation carrot fly, large top for weed suppression and any pest or disease resistance available. Several mainly hybrid varieties performed very well in these trials. Potatoes Good seed quality is a fundamental in the production of a quality crop. Chitted seed will encourage rapid emergence and aid in better weed control and earlier bulking leading to bolder tuber samples. Variety selection should be made for rapid establishment, good ground cover, early bulking yield potential and a good resistance to pests and diseases, especially late blight. Sharpo Axona and Sharpo Mira had outstanding blight resistance. Shelf Life Shelf life depended on the health of produce tested. If healthy clean material was tested results were similar to those of conventional vegetables. If there was disease or pest damage at the beginning of a shelf life test then produce tended to deteriorate more quickly. Seed Health Seed borne disease levels were checked by the OSTS. In general brassicas were reasonably clean but some carrot and celery seed lots had high levels of Alternaria or Septoria infection. All trials were reported as NIAB One year results and also made available on the COSI web site: www.COSI.org In addition, data for over 400 varieties was summarised and published in the NIAB Organic Vegetable Handbook

Multi-cultural visualization : how functional programming can enrich visualization (and vice versa)

The past two decades have seen visualization flourish as a research field in its own right, with advances on the computational challenges of faster algorithms, new techniques for datasets too large for in-core processing, and advances in understanding the perceptual and cognitive processes recruited by visualization systems, and through this, how to improve the representation of data. However, progress within visualization has sometimes proceeded in parallel with that in other branches of computer science, and there is a danger that when novel solutions ossify into `accepted practice' the field can easily overlook significant advances elsewhere in the community. In this paper we describe recent advances in the design and implementation of pure functional programming languages that, significantly, contain important insights into questions raised by the recent NIH/NSF report on Visualization Challenges. We argue and demonstrate that modern functional languages combine high-level mathematically-based specifications of visualization techniques, concise implementation of algorithms through fine-grained composition, support for writing correct programs through strong type checking, and a different kind of modularity inherent in the abstractive power of these languages. And to cap it off, we have initial evidence that in some cases functional implementations are faster than their imperative counterparts

Improving Methane Production During the Anaerobic Digestion of Waste Activated Sludge: Cao-ultrasonic Pretreatment and Using Different Seed Sludges

AbstractThree individual seed sludges, which domesticated by filter paper (SS1), food waste (SS2) and grease (SS3), respectively, were used for enhancing the methane production of waste activated sludge (WAS). Also CaO-ultrasonic pretreatment was performed on WAS to evaluate the effectiveness on improving efficient anaerobic digestion (AD). The results showed that WAS being acidated for 24h after CaO-ultrasonic pretreatment was an effective method for increasing initial methane production rate. The daily concentration of volatile fatty acids (VFAs) during the AD course showed that the propionic was easier to be reduced after adding seed sludge. The optimum seed sludge for improving methane production and biodegradability of WAS was SS3, which led to an increase in the methane production of 68.92% and VS reduction of 69.20% higher than the control. This pretreatment combined with adding optimum seed sludge can greatly improve clean energy generation from WAS