Research Article
GENOTYPIC DIFFERENCES IN CARDINAL TEMPERATURES FOR IN VITRO POLLEN GERMINATION AND POLLEN TUBE GROWTH OF COCONUT HYBRIDS
- C. S. RANASINGHE, M. D. P. KUMARATHUNGE, K. G. S. KIRIWANDENIYA
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- Published online by Cambridge University Press:
- 25 July 2017, pp. 731-743
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Successful fruit set in coconut depends on several reproductive processes including pollen germination and pollen tube growth. High temperature (˃33 °C) during flowering reduces fruit set in coconut. Therefore, identification and development of coconut varieties or hybrids with high reproductive heat tolerance will benefit the coconut industry in view of the climate changes. This experiment was conducted to quantify the response of pollen germination and pollen tube growth of seven coconut hybrids to increasing temperature from 16 to 38 °C. A Principal Component Analysis (PCA) was carried out to classify coconut hybrids on the basis of their temperature tolerances to pollen germination. Pollen germination and pollen tube length of the hybrids ranged from 56 to 78% and 242 to 772 µm, respectively. A modified bilinear model best described the response to temperature of pollen germination and pollen tube length. Cardinal temperatures (Tmin, Topt and Tmax) of pollen germination and pollen tube length varied among the seven hybrids. PCA identified Tmax for pollen germination and Topt for pollen tube length as the most important parameters in describing varietal tolerance to high temperature. PCA also identified SLGD × Sri Lanka Tall and Sri Lanka Brown Dwarf × Sri Lanka Tall as the most tolerant hybrids to high temperature stress and Sri Lanka Tall × Sri Lanka Tall and Sri Lanka Green Dwarf × San Ramon as less tolerant ones based on cardinal temperatures for pollen germination and pollen tube length. Tmax for pollen germination of the most tolerant and less tolerant hybrids were 41.9 and 39.5 °C, respectively. Topt for pollen tube length in the most tolerant and less tolerant hybrids were 29.5 and 26.0 °C, respectively.
OPTIMIZED TIMING OF USING CANOPY TEMPERATURE TO SELECT HIGH-YIELDING CULTIVARS OF WINTER WHEAT UNDER DIFFERENT WATER REGIMES
- XIAOYU ZHANG, XIYING ZHANG, SUYING CHEN, HONGYONG SUN, LIWEI SHAO, XIUWEI LIU
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- Published online by Cambridge University Press:
- 04 April 2016, pp. 257-272
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Selecting high-yielding cultivars under drought is an important practice to improve crop production. Canopy temperature (T) shows a relative reliable association with grain yield. In this study, we compared the suitability of canopy T and other agronomic as well as physiological traits associated with grain yield under different water regimes. Field experiments over two seasons (2011–2012 and 2012–2013) were carried out under three water regimes, represented about 64, 76 and 89% of potential evapotranspiration, with 16 local winter wheat (Triticum aestivum L.) cultivars in each season. Results showed that cultivars with higher yield usually performed consistently lower canopy T under three water regimes, while the relationships of grain yield with other agronomic or physiological traits were more influenced by soil moisture. In addition, the relationship between canopy T and grain yield varied with different growth stages: From the time of heading to early grain filling stages, a more significant negative linear relationship (p < 0.001) existed under the three irrigation levels.
CAN GOOD AGRICULTURAL PRACTICES SUSTAIN OIL PALM YIELDS FOR BIOENERGY PRODUCTION IN NORTHEAST THAILAND?
- SIRILUK SOMNUEK, MAJA SLINGERLAND
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- Published online by Cambridge University Press:
- 18 October 2017, pp. 915-930
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The government of Thailand aims for sustainability of palm oil production in the Northeast for bioenergy and farmers’ income. This study investigated whether producers in Northeast Thailand managed their oil palm according to good agricultural practices (GAP) and if not, what effects this has on yield. A survey was conducted amongst 108 randomly selected farmers. For 25 selected plots, management and yields were monitored twice a month for two full years. Compliance to GAP was high for weeding, harvesting, pruning and pest and disease control but not for irrigation (40%) and fertiliser application (20–40%). GAP adoption scores per households positively correlated with income from other crops, tree age and degree of training. We showed that rainfall was insufficient for good oil palm growth between October and April. In the monitored group, use of irrigation and amounts of N, P, K and Mg applied were strongly correlated. The yield was significantly greater with irrigation and fertiliser, reaching similar levels as in the South of Thailand (up to 25–30 Mg Fresh Fruit Bunches: FFB ha−1), but did not differ with soil texture. This allows us to conclude that better application of GAP, especially including a combination of irrigation and fertilisers overcame the unsuitable soil and rainfall conditions in the Northeast of Thailand. However, the costs of fertilisers compared to the price of FFB affected the profitability of FFB production, which may affect farmers’ motivation to apply GAP, especially on unsuitable soils. When the government aims for sustainable palm oil production in the Northeast it needs to invest in frequent technical support, irrigation infrastructure and affordable fertilisers. Otherwise, farmers may not apply GAP because of low returns on investments and yields will remain very modest.
Review
CHALLENGES AND PROSPECTS OF WHEAT PRODUCTION IN BHUTAN: A REVIEW
- SANGAY TSHEWANG, ROBERT F. PARK, BHAGIRATH S. CHAUHAN, ARUN K. JOSHI
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- 11 April 2017, pp. 428-442
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Bhutan is a small country in the Himalayan mountains where subsistence agriculture is practiced due to small land holdings and undulating mountainous terrains. Due to diverse altitudinal and agro-ecological environments, many food crops are cultivated. Wheat is currently a secondary cereal, grown over an area of 1,964 ha with a total production of 3,465 Mg. While there are enormous opportunities to increase wheat production in Bhutan, it is challenged by numerous biotic and socio-economic factors such as labour shortage and low economic return. Among the biotic constraints, stripe rust and leaf rust are the most important diseases. Stem rust has not yet been reported. Poor crop nutrition, both through low soil fertility and inadequate external supply, also results in low productivity. In addition, better remunerative crops and affordable-imported products discourage wheat production. However, the availability and accessibility to higher yielding disease-resistant varieties, fertilization (both organic and inorganic), appropriate seed rate, optimum planting time, mechanization, rotation with legumes and expansion of wheat area are some measures that will play a crucial role in managing sustainable wheat production in Bhutan. In this paper, we provide a brief overview of the current scenario of wheat production, discuss the constraints and provide strategic guidance to improve wheat production in Bhutan.
Research Article
RELATIVE PERFORMANCE OF BORON, SULPHUR AND ZINC COATINGS ONTO PRILLED UREA FOR INCREASING PRODUCTIVITY AND NITROGEN USE EFFICIENCY IN MAIZE
- VIJAY POONIYA, YASHBIR SINGH SHIVAY, MADAN PAL, RADHIKA BANSAL
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- 23 June 2017, pp. 577-591
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Deficiencies of micro (Zn, B) and secondary (S) nutrients are well-documented in soil as well as in cereal crops, leading to decreased crop yields and low nutritional quality of food. We evaluated the effects of coated urea on maize yield, N and Zn uptake, and input cost relationships. Field experiments were conducted on maize to test boron-coated (BCU), sulphur-coated (SCU) and zinc-coated urea (ZnCU) during 2013 and 2014. On the basis of 2 years’ average data, the highest grain yield was achieved with 0.5% BCU, 5% SCU and 2.5% ZnCU as zinc sulphate hepta hydrate. These treatments increased yields by 5.4, 12.8 and 9.9% over prilled urea (PU), respectively. Application of 0.5% BCU (supplying 1.4 kg B ha−1), 5% SCU (supplying 14.1 kg S ha−1) and 2.5% ZnCU (supplying 7.05 kg Zn ha−1) registered the highest N concentrations and uptake in grain and stover. Total N uptake (grain + stover) was increased by 7.6, 16.7 and 17.1% with BCU, SCU and ZnCU treatments over PU. As compared to PU, Zn concentration in maize grain was significantly higher and total Zn uptake (grain + stover) increased by 32.4% with 2.5% ZnCU. Coated urea materials also enhanced the partial factor productivity (PFPN), agronomic efficiency (AEN), recovery efficiency (REN) and harvest index (HIN) over those of PU. From the economic viewpoint this study suggests that coating of urea with 0.3% boron, 5% sulphur or 2% zinc gives maximum net returns and benefit-cost ratio. Our data indicate that coating of B, Zn and S onto urea increases maize yield, profitability and nitrogen use efficiency in the western Indo-Gangetic plains of India.
MANGANESE NUTRITION IMPROVES THE PRODUCTIVITY AND GRAIN BIOFORTIFICATION OF BREAD WHEAT IN ALKALINE CALCAREOUS SOIL
- AMAN ULLAH, MUHAMMAD FAROOQ, ABDUL REHMAN, MUHAMMAD SHAKEEL ARSHAD, HIRA SHOUKAT, ASIF NADEEM, AHMAD NAWAZ, ABDUL WAKEEL, FAISAL NADEEM
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- 20 July 2017, pp. 744-754
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Manganese (Mn) is one important microelement for plants and the human beings. This study was conducted to evaluate the potential of Mn nutrition in improving the productivity and grain biofortification of wheat. For optimization of Mn seed treatments, seeds were primed with 0.1 and 0.01 M Mn solution, or were coated with 250 and 500 mg Mn kg−1 seed. The optimized treatments were used in the second experiment replicated over time and space. In the first experiment conducted at Faisalabad during 2012–2013, maximum grain yield was recorded with Mn seed priming (0.1 M Mn solution), while maximum grain Mn concentration was recorded with foliar application of 0.75 M Mn solution and seed coating with 250 mg Mn kg−1 seed. In the second experiment, conducted at Faisalabad and Sheikhupura during 2013–2014, and at Faisalabad during 2014–2015, maximum grain yield and grain Mn concentration were recorded from seed priming with 0.1 M Mn solution. Regardless of method, Mn application improved the productivity and grain biofortification of wheat. Overall order of improvement in grain yield was seed priming (3.87 Mg ha−1) > foliar application (3.74 Mg ha−1) > seed coating (3.57 Mg ha−1). Regarding grain Mn concentration, the best treatment was seed priming (41.40 µg g−1) followed by seed coating (39.87 µg g−1) and foliar application (36.94 µg g−1). Maximum net returns and benefit-cost ratio were obtained with Mn seed priming, while maximum marginal rate of return was obtained with Mn seed coating. In conclusion, Mn application through seed treatments was cost effective for improving the productivity and grain biofortification of bread wheat in alkaline calcareous soil.
ACCESS TO IMPROVED HYBRID SEEDS IN GHANA: IMPLICATIONS FOR ESTABLISHMENT AND REHABILITATION OF COCOA FARMS
- RICHARD ASARE, VICTOR AFARI-SEFA, SANDER MUILERMAN
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- Published online by Cambridge University Press:
- 23 March 2016, pp. 273-285
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Poor access to improved seeds in West and Central Africa has compromised crop yields and productivity as most farmers source the bulk of their seeds from informal channels. The use of farmer produced seeds has mostly resulted in high seedling mortality thereby presenting challenges to cocoa rehabilitation programmes across the sub region. With the aid of a mobile data collection system (MDCS), the first of its kind to enhance accuracy of survey results in an improved seed supply system through brokerage and linkages among diverse actors, this study assesses Ghanaian farmers’ access to improved hybrid cocoa seeds and provides evidence on the socio-cultural factors that affect field performance of such planting materials. Results show that farmers value a seed brokerage system (SBS), which is facilitated through group bulk purchase, timely acquisition and delivery of seeds. The study also revealed that farm size, land use type and gender have significant effect on survival rate of transplanted hybrid cocoa seedlings over two dry seasons. Regardless of the rehabilitation process, mean survival rate was high (79%) although an 11% (p < 0.000) difference occurred between gender with men recording a higher rate. The majority of farmers prefer cultivating cocoa on forest and fallow lands, implying continues degradation of forest areas. There is therefore an urgent need for a change of mind set, to advocate for land recycling to spare forest areas to thrive.
EFFECTS OF PLANT DENSITY ON THE PERFORMANCE OF COWPEA IN NIGERIAN SAVANNAS
- ALPHA Y. KAMARA, ABDULLAHI I. TOFA, STEPHEN KYEI-BOAHEN, REUBEN SOLOMON, HAKEEM A. AJEIGBE, NKEKI KAMAI
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- Published online by Cambridge University Press:
- 21 October 2016, pp. 120-132
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Grain yields of cowpea [Vigna unguiculata (L.) Walp.] in the Nigerian savannas are low even with the cultivation of improved varieties. The recommended spacing for cowpea is 75 × 20 cm with two seeds planted per stand. This corresponds to plant population of 133333 plants ha−1, which may not be sufficient for optimal cowpea yield. Field experiments were conducted to determine plant density effects on cowpea performance in the Northern Guinea and the Sudan savannas of Nigeria and also to determine if genotypes varied in their response to plant density. Four cowpea varieties with contrasting maturity duration were planted in single, double and triple rows on ridges spaced 75 cm apart to achieve corresponding densities of 133333, 266666 and 400000 plants ha−1, respectively. Plant densities of 266666 and 400000 plants ha−1 gave higher crop performance in terms of light interception, biomass production, yield and yield components for all cowpea varieties. Yield increases were related largely to increased pod and seed production but the effect of seed size on yield was relatively minor. Our results provide evidence that the current density of 133333 plants ha−1 used by farmers is not optimum for cowpea production. Smallholder farmers can increase cowpea grain and fodder yields if they use a density of 266666 plants ha−1 in cowpea cultivation. Further yield increases when cowpea is planted at 400000 plants ha−1 may not be sufficient to offset the cost of seed.
EVALUATION OF CASSAVA VARIETIES FOR WEED TOLERANCE ABILITY
- IRIÉ R. DJE BI, KOUADIO I. KOUASSI, KOUAMÉ K. KOFFI, KOUAKOU L. KOUAKOU, JEAN-PIERRE BAUDOIN, BI IRIÉ A. ZORO
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- Published online by Cambridge University Press:
- 24 April 2017, pp. 443-451
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Many types of weeds occur in cassava fields causing enormous yield losses due to competition for nutrients, light and space. The purpose of this study was to evaluate the growth and yield of four traditional varieties of cassava (Bonoua Blanc, Tambou, Yassé and Six mois) produced in Côte d'Ivoire and select the highest tolerant variety to weed competition. Six treatments were induced by varying the period in which cassava varieties were grown with weeds. Varieties and exposure time to competition with weeds significantly affected the productivity of cassava. The number of leaves per plant (NLP), the number of tuberous roots per plant (NTRP) and the weight of tuberous roots per plant (WTRP) declined with increasing duration of weed presence. After an initial period of weeding, the first four months of grassing proved critical for the four varieties. Despite the presence of weeds, Bonoua Blanc has higher growth and yield than Tambou, Yasse and Six mois. This suggests that Bonoua Blanc was more tolerant to weed competition than the others from planting to harvest, being a suitable variety in intercropping systems.
STRUCTURE ANALYSIS AND BIOMASS MODELS FOR PLUM TREE (PRUNUS DOMESTICA L.) IN ECUADOR
- B. VELÁZQUEZ-MARTÍ, C. CAZCO-LOGROÑO
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- 25 January 2017, pp. 133-141
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The development of dendrometric methodologies could allow accurate estimation of variables associated with the crown, such as primary production (fruit and timber) and tree vigor. The aim of this work was to develop a suitable method to estimate woody biomass in plum trees (Prunus domestica L.) in Imbabura, Ecuador by using an adapted dendrometry. Form factors and regression models were defined for branch volume calculation. From this, the distribution of woody biomass in the crown tree was characterized in every stratum. Occupation Factor and regression models were obtained in order to calculate the biomass in the crown tree, which can be used to estimate the CO2 captured in its structure during its development. Regression models for calculation of whole volume of the tree and pruned biomass were directly obtained from crown diameter and crown height with Rajustated2 of 0.74 and 0.81. The average moisture content of green material was 51%, and the average density of dry material was 0.66 ± 0.07 g cm−3. Proximate analysis of plum wood showed at 79.8 ± 9.2% volatiles and 2.1 ± 0.3% ash. Elemental analysis of the wood pointed to 46.5 ± 1.2% C, 6.1 ± 0.5% H, 46.3 ± 1.2% O, 0.6 ± 0.3% N, 0.06 ± 0.02% S and 0.02 ± 0.01% Cl. Cl, S and N contents are lower than the limits established by the standard EN 14691-part 4. With 46% of C, considering the relation 3.67 (44/12) between CO2 and C content, the CO2 sequestrated in the materials is 1.11 Mg m−3 wood material. Such method represents a tool to manage orchard resources and for assessing other parameters, such as raw materials for cultivation, fruit production, CO2 sink and waste materials (residual wood) used for energy or industry.
CHANGES IN TILLERING DYNAMICS OF INTERCROPPED BLACK OAT AND ANNUAL RYEGRASS ENSURE A STABLE SWARD
- PAULO GONÇALVES DUCHINI, GABRIELA CRISTINA GUZATTI, HENRIQUE MENDONÇA NUNES RIBEIRO-FILHO, ANDRÉ FISCHER SBRISSIA
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- Published online by Cambridge University Press:
- 18 October 2017, pp. 931-942
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Mixing species with different tillering peaks may enhance pasture stability, but intercropping may also alter the plants’ tillering patterns. This study aimed to evaluate tillering dynamics in black oat (Avena strigosa Schreb.) and annual ryegrass (Lolium multiflorum Lam.) pastures grown as monocultures or intercropped. Three following treatments are established: black oat and annual ryegrass pastures grown as monocultures and an intercrop composed of these two species. Tillering dynamics were measured for black oat and annual ryegrass populations separately. When intercropped, tiller birth rates of black oat decreased (20.0 vs. 28.9 tillers 100 tillers−1) and those of annual ryegrass increased (30.5 vs. 14.3 tillers 100 tillers−1), compared to their monocultures. Tiller death rates for annual ryegrass did not differ between monoculture and intercropping (23.9 tillers 100 tillers−1), but black oat presented higher mortality in monocultures (48.8 vs. 36.4 tillers 100 tillers−1). The black oat monoculture had the lowest population stability index (0.80), whereas annual ryegrass in monoculture and intercropped pastures exhibited greater values (on average, 0.92). Our results indicated that black oat and annual ryegrass present distinct tillering dynamics whether grown as monoculture or intercropped, and suggest that intercropping species with elevated death rates (black oat) with later species (annual ryegrass) could be an important tool for maintaining pasture stability throughout the growing season.
MECHANISED MINIMUM SOIL DISTURBANCE ESTABLISHMENT AND YIELD OF DIVERSE CROPS IN PADDY FIELDS USING A TWO-WHEEL TRACTOR-MOUNTED PLANTER SUITABLE FOR SMALLHOLDER CROPPING
- R. W. BELL, M. E. HAQUE, C. JOHANSEN, W. VANCE, M. E. KABIR, M. A. MUSA, M. N. N. MIA, M. G. NEOGI, M. A. ISLAM
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- Published online by Cambridge University Press:
- 31 July 2017, pp. 755-773
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Shortages of hired labour are leading to greater interest in mechanisation for crop establishment in smallholder agriculture. Due to small field sizes, mechanised planters mounted on four-wheel tractors are not a suitable technology. The Versatile Multi-crop Planter (VMP) was developed for zero tillage (ZT), strip planting (SP) or single pass shallow tillage (SPST) on flat land and for forming and planting on tops of beds, each in a single pass operation, when mounted on a two-wheel tractor (2WT). The aim of the present study was to evaluate the field performance of the VMP in comparison to conventional broadcast seeding and full rotary tillage (2 to 4 passes; called CT) for establishing chickpea (Cicer arietinum L.), jute (Corchorus olitorius L.), lentil (Lens culinaris Medikus), maize (Zea mays L.), mung bean (Vigna radiata L. R. Wilczek), rice (Oryza sativa L.) and wheat (Triticum aestivum L.) in 15 locations of Bangladesh. Plant populations emerging from all single pass operations viz. SP, ZT, and bed planting (BP) were generally satisfactory and in 12 out of 15 experiments plant populations after SP were similar to or greater than after CT. In addition, SP gave comparable or greater plant populations than SPST and BP planting methods. Overall, the SP planting achieved comparable yields and lower costs of establishment than CT. We conclude that effective and reliable planters are now available for sowing a range of crop species on small fields with minimum soil disturbance. This opens up realistic options for the development of mechanised conservation agriculture suited to small field sizes.
PERFORMANCE AND SURVIVAL OF PERENNIAL RICE DERIVATIVES (ORYZA SATIVA L./ORYZA LONGISTAMINATA) IN LAO PDR
- BENJAMIN K. SAMSON, SINGTTY VORADETH, SHILAI ZHANG, DAYUN TAO, SISAVANH XAYAVONG, THIRAVONG KHAMMONE, KHAMSOUK DOUANGBOUPHA, VORACHITH SIHATHEP, PHENG SENGXUA, VIENGSAVANH PHIMPHACHANHVONGSOD, BOUNTHONG BOUAHOM, TAMARA JACKSON, DOME HARNPICHITVITAYA, FENGYI HU, LEN J. WADE
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- Published online by Cambridge University Press:
- 07 June 2017, pp. 592-603
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Genotype by environment (G x E) interactions for grain yield were investigated in 13 perennial rice (Oryza sativa L./Oryza longistaminata) derivatives over three sites and 2 years in Lao PDR. Genotype accounted for 29.0% of the total sum of squares, with environment and the G x E interaction responsible for 60.2 and 10.8%, respectively. Cluster analysis identified three environment and six genotype groups, which accounted for 49.7, 98.0 and 42.8% of the E, G and G x E sums of squares, respectively. Principal component axes 1, 2 and 3 accounted for 54.0, 30.6 and 11.7% of the G x E sum of squares, respectively, with PCA1 indicating yield potential, PCA2 timing of cessation of rainfall in the 2011 wet season, and PCA3 environmental stresses affecting regrowth in the 2012 wet season. Genotype groups differed in adaptation to these contrasting conditions. G6 (Line 213, 240 and RD23) was widely adapted to all environments, with G5 (Line 248) being especially adapted to the 2012 environments. G3 and G4 were neutral, though G3 (Line 53) showed some preference for the Na Pok environments. G1 and G2 were poorly adapted everywhere, with the tall and late G1 (Line 11) being especially poor at Na Pok 2011 in a dry finish. While yields were lower in 2012, all derivatives survived the dry season with access to life-saving irrigation. This is promising, as the annual rice RD23 was unable to ratoon under these conditions, and had to be re-sown. Importantly, Line 213, 240 and 248 yielded comparably to RD23 from regrowth in 2012. Development of perennial rice should target rainfed and especially upland environments.
LOW-INPUT PINEAPPLE CROPS WITH HIGH QUALITY FRUIT: PROMISING IMPACTS OF LOCALLY INTEGRATED AND ORGANIC FERTILISATION COMPARED TO CHEMICAL FERTILISERS
- MARIE DARNAUDERY, PATRICK FOURNIER, MATHIEU LÉCHAUDEL
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- 20 April 2016, pp. 286-302
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Fruit and vegetable farming generally involves high levels of chemical inputs despite the fact that consumers are increasingly concerned about the sanitary and organoleptic aspects of fruit quality. Pineapple is largely subject to these issues since it is dominated by conventional monocropping with high levels of agrochemical inputs due to nitrogen (N) and potassium (K) fertilisation, weed management, crop protection and flowering induction. However, low-input pineapple cropping systems are both rare and little documented. Our study aimed at replacing all or part of the chemical fertilisers used with local organic fertilisers. It was conducted on the cultivar ‘Queen Victoria’, without pesticides or herbicides, in Reunion Island. We compared the impacts of three fertilisation treatments on pineapple growth and yield, fruit quality traits, symptoms of two major fungal diseases in fruit and production costs and labour times: (i) conventional: NPK fertiliser at recommended doses (265.5 kg ha−1 N–10.53 kg ha−1 P–445.71 kg ha−1 K); (ii) integrated: Mucuna pruriens green manure (240.03 kg ha−1 N, 18.62 kg ha−1 P, 136.11 kg ha−1 K) incorporated into the soil and a half-dose of NPK fertiliser and (iii) organic: M. pruriens green manure incorporated into the soil and foliar applications of sugarcane vinasse from a local distillery, rich in K (14.44 g L−1). Our results showed that NPK fertilisation could be replaced by organic fertilisers as well as by integrated fertilisation. ‘D’-leaf analysis showed that vinasse supplies a largely sufficient K level for growing pineapples. With organic fertilisation, pineapple growth was slower, 199 days after planting vs. 149 days for integrated or conventional fertilisations, and fruit yield was lower, 47.25 t ha−1 vs. 52.51 and 61.24 t ha−1, probably because M. pruriens green manure provided an early increase in soil mineral N, whereas N requirements are much higher four months after planting. However, the fruit weight (709.94 ± 123.53 g) was still within the size range required for the export market (600–900 g). Interestingly, organic fertilisation significantly reduced Leathery Pocket disease and produced the best quality fruit with the highest total soluble solids contents (TSS) and the lowest titratable acidity (TTA). Fruit quality was also significantly improved with integrated fertilisation, with fruit weight similar to that of conventional fertilisation. To conclude, these findings have implications for the sustainability of pineapple production and could lead to low-input innovative cropping systems that reduce production costs and develop local organic inputs.
USING A SOCIO-PSYCHOLOGICAL MODEL TO IDENTIFY AND UNDERSTAND FACTORS INFLUENCING THE USE AND ADOPTION OF A SUCCESSFUL INNOVATION BY SMALL-SCALE DAIRY FARMERS OF CENTRAL MEXICO
- CARLOS GALDINO MARTÍNEZ-GARCÍA, CARLOS MANUEL ARRIAGA-JORDÁN, PETER DORWARD, TAHIR REHMAN, ADOLFO ARMANDO RAYAS-AMOR
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- 08 November 2016, pp. 142-159
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This paper seeks to make an exploratory investigation regarding farmers who have been using an innovation for a relatively long period (established users), compared to farmers who have only recently started (recent users). Therefore, the aims of this research were to identify (i) the extent to which intentions, attitudes and social pressure are similar or different between these two groups and (ii) whether comparison of the groups can improve academic understanding and provide insights into what is influencing the uptake of innovations. The study was conducted with 80 farmers who are already engaged with the use of improved grassland. In order to develop an understanding of the differences in drivers of the adoption of new technology, the sample was divided into established users and recent users of the innovation. To identify differences between groups regarding farmer and farm characteristics, 11 quantitative variables were analysed through a dependent t-test. The theory of reasoned action (TRA) was used as a theoretical framework and the Spearman rank-order correlation was used in data analyses. To identify differences in farmers’ perceptions of the components of the TRA, we used the Mann–Whitney U test. The results showed that established users had stronger intention to use improved grassland in the next 12 months, which would be attributed to activity based on milk production as a main source of family income. Advantages of improved grassland included lower animal feeding expenses; increases in quantity, quality and availability of fodder production and increases in milk production. We concluded that established and recent users’ intention to use improved grassland over the 12 months was influenced in different ways. Established users’ intention to adopt was strongly influenced by normative beliefs, i.e. social pressure from salient referents, where the father, uncle and veterinarian played the most important role, whereas recent users’ intention was mainly influenced by behavioural beliefs (positive and negative beliefs regarding the innovation) and the variables that describe the farm characteristics, i.e. the advantages and disadvantages that farmers perceive of the use of improved grassland on their farms, which were also considered as drivers of adoption.
NEMATODE MANAGEMENT IN RAIN-FED SMALLHOLDER MAIZE PRODUCTION SYSTEMS UNDER CONSERVATION AGRICULTURE IN ZIMBABWE
- SANDRA M. MADAMOMBE, ISAIAH NYAGUMBO, BRIGHTON M. MVUMI, PHILLIP NYAMUGAFATA, MENAS WUTA, CLEOPAS C. CHINHEYA
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- Published online by Cambridge University Press:
- 25 April 2017, pp. 452-466
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Nematode infestation in Sub-Saharan Africa's (SSA) cropping systems, worsened by poor crop rotations, is a major factor contributing to limited utilisation of applied nutrients and water, leading to low maize (Zea mays L.) yields particularly on sandy soils. The effects of nematode infestation on maize productivity were evaluated under conservation agriculture (CA) on granitic sandy soils in sub-humid smallholder farms of Goromonzi district of Zimbabwe. Four treatments were tested for three seasons on six smallholder farmers’ fields in a randomised complete block design, each farm being a replicate: fenamiphos 40EC (a commercial synthetic nematicide), lime + fenamiphos 40EC, lime and an untreated control. Results of the study showed that independent application of fenamiphos 40EC and lime significantly reduced plant parasitic nematode infestations in maize roots by more than 10 times those present in the untreated plots while maize yield also increased significantly. Yield increase from fenamiphos and lime applications amounted to 53 and 42% respectively, compared to the untreated controls. Maize yield was negatively correlated with density of Pratylenchus spp. nematodes. Nematode management strategies involving fenamiphos 40EC or lime could significantly reduce maize yield losses in maize-based smallholder farming systems of SSA under CA. It was more economical to use fenamiphos than lime to control nematodes.
RELIABILITY OF NDVI DERIVED BY HIGH RESOLUTION SATELLITE AND UAV COMPARED TO IN-FIELD METHODS FOR THE EVALUATION OF EARLY CROP N STATUS AND GRAIN YIELD IN WHEAT
- PAOLO BENINCASA, SARA ANTOGNELLI, LUCA BRUNETTI, CARLO ALBERTO FABBRI, ANTONIO NATALE, VELIA SARTORETTI, GIANLUCA MODEO, MARCELLO GUIDUCCI, FRANCESCO TEI, MARCO VIZZARI
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- Published online by Cambridge University Press:
- 06 June 2017, pp. 604-622
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This study was aimed at comparing in-field parameters and remote sensing NDVI (normalized difference vegetation index) by both satellite (SAT) and unmanned aerial vehicle (UAV) for the assessment of early nitrogen (N) status and prediction of yield in winter wheat (Triticum aestivum L.). Six increasing N rates, i.e., 0, 40, 80, 120, 160, 200 kg N ha−1 were applied, half at tillering and half at shooting. Thus, when the crop N status was monitored between the two N applications, consecutive N treatments differentiated from each other by just 20 kg N ha−1. The following in-field and remote sensed parameters were compared as indicators of crop vegetative and N status: plant N% (w:w) concentration; crop N uptake (Nupt); ratio between transmitted and incident photosynthetically active radiation (PARt/PARi); leaf SPAD values, an indirect index for chlorophyll content; SAT and UAV derived NDVI. As reliable indicators of wheat N availability, in-field parameters were ranked as follows: PARt/PARi ≅ Nupt > SPAD ≅ N%. The PARt/PARi, Nupt and SPAD resulted quite strongly correlated to each other. At all crop stages, the NDVI was strongly correlated with PARt/PARi and Nupt. It is of relevance that NDVI correlated quite strongly to in-field parameters and grain yield at shooting, i.e., before the second N application, when the N rate can still be adjusted. The SAT and UAV NDVIs were strongly correlated to each other, which means they can be used alternatively depending on the context.
PHYTOSOCIOLOGICAL CHARACTERIZATION OF WEEDS AS A FUNCTION OF RESIDUAL HERBICIDES APPLIED TO RICE GROWN UNDER SPRINKLER IRRIGATION
- G. CONCENÇO, A. ANDRES, G. M. TELÓ, M. B. MARTINS, I. S. MOISINHO
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- Published online by Cambridge University Press:
- 27 February 2017, pp. 303-314
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We aimed to characterize the weed community in sprinkler irrigated rice, previously applied with residual herbicides for two years, as well as to infer about sustainability of the management applied to the fields based on an ecological approach. The experiment was conducted during the cropping seasons 2013/14 and 2014/15, under sprinkler irrigation. Rice was planted in the second-half of October, using the cultivar PUITA INTA CL. Herbicides were applied in pre- and post-emergence (sequential application) of crop and weeds. Ryegrass (Lolium multiflorum) was planted in winter. In May 2015, soil samples were collected for the soil seed bank study. Phytosociological characterization of weeds emerged from the seed bank was conducted from May 2015 to January 2016, until soil seed bank depletion. Echinochloa crusgalli, Fimbristyllis sp., Cyperus esculentus and Killinga brevifolia were the weeds to which most concern should be directed when growing rice under sprinkler irrigation in lowland areas of Southern Brazil. Their competition strategies are based on density. Herbicides used should be efficient in controlling at least these four weed species. A selecting action of herbicides on weed species was botanically characterized, as the weed species reported after two cropping seasons depended on the herbicide treatment applied.
ASSESSING A DEMONSTRATION FARM APPROACH FOR TECHNOLOGICAL INNOVATIONS IN PASTORAL LIVESTOCK PRODUCTION SYSTEMS OF NORTHERN PATAGONIA: PARTICIPANTS’ PERCEPTIONS OF STAKEHOLDER ROLES AND INNOVATIONS
- MARKUS FRANK, MARCOS H. EASDALE, BRIGITTE KAUFMANN
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- Published online by Cambridge University Press:
- 02 November 2017, pp. 774-793
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Using a qualitative case study design, a demonstration farm approach implemented in northern Patagonia, Argentina, was assessed to examine differences in perceptions between participating stakeholder groups regarding their roles and how these affect the collaboration process. Moreover, differences in stakeholder perceptions regarding positive impacts and constraints of the implemented innovation (supplemental feeding of small ruminants) were assessed, as one exemplary innovation to improve low-external-input pastoral livestock systems. Three cases of demonstration farm projects were selected and a total of 31 semi-structured and narrative interviews were carried out with participating livestock keepers, extension workers and scientists. Together with information gained by employing visual tools and participant observation, data was analysed using qualitative content analysis. Results reveal that major decisions regarding the collaboration process were taken by scientists in advance, hence, livestock keepers' participation was used to meet predetermined objectives, which is characteristic to the concept of functional participation. While scientists seemed to transfer the control principles of on-station research to the on-farm situation, extension workers recognised the need for replacing teaching by the aim of creating learning opportunities. Here, incongruences in role understanding indicate an overall lack of joint role definition and the need of balancing power differences. Livestock keepers' perceptions of the supplemental feeding strategy highlight substantial management constraints for implementation, which were not recognised by scientists and extension workers, nor were they captured by the monitoring system implemented. We recommend furnishing the demonstration farm approach with principles, methods and tools of collaborative learning, to create a change in actors' understanding of roles and to induce a shift towards increased transdisciplinarity.
GENOTYPE BY ENVIRONMENT INTERACTION AND GRAIN YIELD STABILITY OF ETHIOPIAN WHITE LUPIN (LUPINUS ALBUS L.) LANDRACES
- MULUGETA ATNAF, DAGNE WEGARY, KIFLE DAGNE, KASSAHUN TESFAYE
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- Published online by Cambridge University Press:
- 02 November 2017, pp. 943-956
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Genotype by environment interaction is a common phenomenon in crop production and remains an important issue in genotype evaluation and recommendation. However, no detailed multi-environment evaluation of Ethiopian white lupin has been undertaken so far. Thus, this study was undertaken with the objectives to evaluate the performance and stability of white lupin landraces in six locations; and characterize white lupin growing environments in Ethiopia. Twelve white lupin landrace collections of Ethiopia were evaluated across six different locations in Ethiopia during the 2014/15 main growing season using a randomized complete block design with four replications. The genotype main effect plus genotype by environment interaction (GGE) biplots analysis was used to visualize the patterns of the interaction components. The results depicted that the tested landraces had differential performances across locations implying the presence of crossover interaction. The first two principal components (PC1 = 41.6% and PC2 = 21.8%) of the GGE explained 63.4% of the GGE sum of squares. All test locations were found to be representative with different degrees of reliability whereby Finote Selam and Dibate were found to be most representative. In addition, all test locations, except Mandura and Injibara, had generally similar and good discriminating power. Finote Selam and Dibate were found to be the most representative and discriminating environments and are characterized as most desirable test locations for white lupin improvement in northwestern Ethiopia. G2 was found to be the highest yielding and most stable landrace across the test environments, and hence identified as most desirable genotype recommended for production.