Yield, yield components and plant architecture in the F3 generation of common bean (Phaseolus vulgaris L.) derived from a cross between the determinate cultivar ‘Prelude’ and an indeterminate landrace

Growth trials were conducted outdoors in the UK to determine the yield, yield components and plant architectural differences between determinate and indeterminate Phaseolus vulgaris bean plants. F3 lines derived from crosses between ‘Prelude’, a determinate cultivar and ‘V8’, an indeterminate landrace, were grown together with the parents and ‘Carioca’, an indeterminate landrace from Brazil. Data were recorded on flowering date, number of nodes on main stem at flowering, plant height at maturity, number of pods/plant, number of seeds/pod, number of seeds/plant, 100-seed weight, seed mass/plant, percentages of diseased and healthy seeds/plant. Determinate F3 lines had significantly lower (P < 0.05) seed mass/plant, fewer pods/plant, fewer seeds/pod, fewer seeds/plant, lower harvest index, shorter stems, earlier date of flowering, fewer nodes at flowering and fewer healthy seeds/plant than indeterminate F3 lines. However, determinate genotypes had significantly larger (P < 0.05) pods to accommodate their larger seeds compared with indeterminate lines. A similar situation was found when the yield and yield components of ‘V8’, ‘Prelude’ and ‘Carioca’ were evaluated; the highest seed mass/plant was given by ‘V8’ and the lowest by ‘Prelude’. Furthermore, some indeterminate genotypes with Type IV growth habit yielded significantly higher (P < 0.05) than the high-yielding parent, ‘V8’, indicating a positive influence on seed yield by crossing different genotypes.     

Irrigation rate and plant density effects on yield and water use efficiency of drip-irrigated corn

The efficient use of water by modern irrigation systems is becoming increasingly important in arid and semi-arid regions with limited water resources. This study was conducted for 2 years (2005 and 2006) to establish optimal irrigation rates and plant population densities for corn (Zea mays L.) in sandy soils using drip irrigation system. The study aimed at achieving high yield and efficient irrigation water use (IWUE) simultaneously. A field experiment was conducted using a randomized complete block split plot design with three drip irrigation rates (I₁: 1.00, I₂: 0.80, and I₃: 0.60 of the estimated evapotranspiration), and three plant population densities (D₁: 48,000, D₂: 71,000 and D₃: 95,000 plants ha⁻¹) as the main plot and split plot, respectively. Irrigation water applied at I₁, I₂ and I₃ were 5955, 4762 and 3572 m³ ha⁻¹, respectively. A 3-day irrigation interval and three-way cross 310 hybrid corn were used. Results indicated that corn yield, yield components, and IWUE increased with increasing irrigation rates and decreasing plant population densities. Significant interaction effects between irrigation rate and plant population density were detected in both seasons for yield, selected yield components, and IWUE. The highest grain yield, yield components, and IWUE were found for I₁D₁, I₁D₂, or I₂D_1, while the lowest were found for I₃D₂ or I₃D₃. Thus, a high irrigation rate with low or medium plant population densities or a medium irrigation rate with a low plant population density are recommended for drip-irrigated corn in sandy soil. Crop production functions with respect to irrigation rates, determined for grain yield and different yield components, enable the results from this study to be extrapolated to similar agro-climatic conditions.     

Interactive effects of biochar and micronutrients on faba bean growth,symbiotic performance,and soil properties

Leguminous crops are significantly involved in the global symbiotic biological N₂ Fixation (BNF), an eco‐friendly process in the agriculture system. Biochar is considered as a vital amendment in improving growth and quality of crops and soils. Few investigations have been conducted to determine the combination effect of biochar with microelements on growth of legumes and soil properties. This study was designed to study the effect of soybean straw‐derived biochar (SSDB) with or without microelements on soil microbial and chemical properties, growth, yield, and seed chemical composition of faba bean (Vicia faba L.). Results revealed that dehydrogenase (DHA) and phosphatase (P‐ase) activities were markedly improved with the increase of SSDB rates under addition of microelements and their highest values were recorded after 90 d. Significant increases were noticed in nodulation activities, nodulation numbers (30.1–72.8), concentrations of N (1.62–1.93%), P (0.15–0.21%), and K (0.53–0.67%), and seed chemical constituents due to the addition of SSDB in the presence of microelements. Moreover, the combination of biochar with microelements caused significant changes in microbial counts. Overall, this investigation shows the potential and role of SSDB in enhancing the growth quality of faba bean seeds as well as an improvement of soil characteristics.     

Effect of Two Nitrogen Forms on the Growth and Iron Nutrition of Pea Cultivated in Presence of Bicarbonate

ABSTRACT

Two cultivars of pea: ‘PS210713’ (‘PS’), sensitive to iron deficiency, and ‘Marveille de Kelvedon’ (‘MK’), tolerant, were cultivated in controlled climatic conditions during one month, on a nutrient solution containing either nitrate (NO₃ ^?, 4 mM) or ammonium (NH₄ ⁺, 4 mM) and in the presence of bicarbonate (10 mM). The effects of these nitrogen forms on the growth and the mineral nutrition, and especially iron nutrition are analyzed.

The reduction of growth by bicarbonate was approximately 30% in case of NO₃ ^? nutrition in the two cultivars, whereas in ammoniacal treatment the reduction is only 6% and 18% respectively in ‘PS’ and ‘MK’ cultivars.

In presence of bicarbonate, the plant growth is not stimulated by NO₃ ^?relatively to its growth on ammoniacal medium, as often noticed when plants are cultivated on medium without bicarbonate: In presence of this compound, the biomass production of plant pea, was not influenced by the nitrogen forms. The nitric source led to a ferric chlorosis in the sensitive cultivar plants whereas any chlorosis was noted when ammoniacal source was applied. On the other hand, nitric nitrogen form decreased the nitrogen feeding of plants and increased the potassium one, while the effect of the ammoniacal nitrogen form on these nutrients was quite the inverse. In addition, the later increased the allocation of iron towards shoots. Besides, with this nitrogen source there was not accumulation of nitrate in the plant tissues. In nitric feeding case, the nitrate is mainly accumulated in the roots of the two cultivars. It is noticeable that the sensitive cultivar (‘PS’) accumulates three times more nitrate than the tolerant one (‘MK’).

On the level of the whole plant, the iron and phosphorus nutrition seems unaltered by the nitrogen form.     

Towards sustainable farming systems: Effectiveness and deficiency of the French procedure of sustainable agriculture

There is a widespread consensus about the importance of sustainable agriculture. In France, the Farming Orientation Law of July 1999 has set down a precise procedure for the implementation of sustainable agriculture: the contrat territorial d’exploitation – or territorial farm contract (TFC). This paper aims to analyse the TFC effectiveness. An analysis has been made of the TFCs signed in the Midi-Pyrenees Region in south-western France, using statistical analysis and qualitative surveys of a sample of farms. The results show that the most valuable effects have been mainly economic. Effects regarding social and environmental aspects were very limited. But from the point of view of an integrated approach, indirect effects of TFCs can be observed on social and environmental aspects. These results are explained, on the one hand, by farmers’ motivations guided by economic objectives, and on the other hand, by the dominance of professional farming organisations in the implementation of TFC’s procedure. Given these results, two ways of improving the elaboration procedure for TFCs are proposed. Firstly, technical improvements can be made to the diagnostic assessment of farms, and to the choice of actions addressed by the contract. Secondly, organisational improvements can be applied to TFCs elaboration and implementation process, in order to adopt a participatory approach which would involve all rural stakeholders.     

Performance assessment of small irrigation schemes along the Mauritanian banks of the Senegal River

Irrigation plays a fundamental role in world food provision but, to date, it has performed below expectations in Sub-Saharan Africa. The present study assesses and diagnoses the performance of 22 small and medium size community-managed irrigation schemes, mainly devoted to rice production, in different locations along the Mauritanian banks of the Lower Senegal River. The evaluations followed the Rapid Appraisal Process in which semi-structured interviews were held with representatives of the Cooperatives’ Boards in charge of each scheme to obtain information about the organisation of the cooperative, land tenure, irrigation system and organization, cropping pattern and soils. Additionally, for each irrigation scheme, the water-delivery service was characterized by making qualitative and comparative observations during field inspections; the pumping station's performance was diagnosed by a local specialist; the discharge at the head of the system was measured; daily irrigation time was recorded; and crop yields were determined by plot sampling. Then a set of performance indicators was computed. Water delivery capacity referred to irrigated areas was insufficient in a third of the schemes, and this insufficiency was exacerbated by poor maintenance. Irrigation intensity in habilitated areas was rather low being less than 0.66 in 50% of the schemes. The average productivity of land, irrigation water, and fuel (3.38 t ha⁻¹, 0.30 kg m⁻³ and 2.37 kg kWh⁻¹, respectively) were well below potential.     

Effects of water infiltration and storage in cultivated soil on surface irrigation

Surface irrigation analysis and design require the knowledge of the variation of the cumulative infiltration water Z (L) (per unit area) into the soil as a function of the infiltration time t (T). The purpose of this study is to evaluate water infiltration and storage under surface irrigation in an alluvial clay soil cultivated with grape yield, and to determine if partially wetted furrow irrigation has more efficient water storage and infiltration than traditional border irrigation. The two irrigation components considered were wet (WT) and dry (DT) treatments, at which water applied when available soil water reached 65% and 50%, and the traditional border irrigation control. Empirical power form equations were obtained for measured advance and recession times along the furrow length during the irrigation stages of advance, storage, depletion and recession. The infiltration (cumulative depth, Z and rate, I) was functioned to opportunity time (t_o) in minute for WT and DT treatments as: Z_WT = 0.528 t_o^0.6, Z_DT = 1.2 t_o^0.501, I_WT = 19 t_o^−0.4, and I_DT = 36 t_o^−0.498. The irrigation efficiency and soil water distribution have been evaluated using linear distribution and relative schedule depth. Coefficient of variation (CV) was 5.2 and 9.5% for WT and DT under furrow irrigation system comparing with 7.8% in border, respectively. Water was deeply percolated as 11.88 and 19.2% for wet and dry furrow treatments, respectively, compared with 12.8% for control, with no deficit in the irrigated area. Partially wetted furrow irrigation had greater water-efficiency and grape yield than both dry furrow and traditional border irrigations, where application efficiency achieved as 88.1% for wet furrow irrigation that achieved high grape fruit yield (30.71 Mg/ha) and water use efficiency 11.9 kg/m³.     

Bacteria wilt of Casuarina equisetifolia in India

Pseudomonas solanacearum (Smith) was consistently isolated from the wilted plants of Casuarina equisetifolia. The isolate gave positive reaction to oxidase, catalase and gas production from nitrate and negative reaction for arginine dihydrolase and acid was produced from various carbohydrates. Wilt produced on tomato, egg plant and capsicum indicated that the pathogen belongs to Race I and Biovar III of P. solanacearum which is a new record from India.     

Agroforestry Impacts on Soil Fertility in the Rima'a Valley,Yemen

Yemen is one of the world's least developed countries and experiences problems of scarcity of natural agricultural resources as well as soil erosion and degradation. Agroforestry systems (AFS) are being promoted as a more appropriate land use system than monocropping systems (MCS) worldwide. Unfortunately, long-term studies on agroforestry and other land use systems (LUS) do not exist in Yemen. Agroforestry in the Rima'a region has started to deteriorate and many farmers turned to (MCS). This study was conducted in the Rima'a Valley, near Alsharq town, Dhamar, Yemen. The study evaluates the soil nutrients, organic matter (OM), and other soil properties such as pH, bulk density, and porosity under AFS and compares it with soil under MCS. Standard procedures for soil sampling and analyzing were used to collect and analyze 36 composite samples from Site 1 and 36 composite samples from Site 2 from six cropping systems (treatments). The results showed that there were significant variations in relation to LUS. Agroforestry practices—mixed trees with coffee (S1), and Cordia africana L. with coffee (S2) have higher nitrogen concentration (0.17–0.26%) as compared to the Ziziphus spina-christi L. with maize (S3) and the monocropping maize (S5), (<0.16% in both Sites 1 and 2). Similar results were seen on the effect of the different LUS on the soil P, K, and OM contents at the two sites (p < .01). While soil N, P, and soil K were higher under agroforestry systems S1, and S2 in both sites, it was the lowest in S5 in both sites. It can be concluded that agroforestry has more favorable effects on soil fertility and other soil properties. The government should establish programs and campaigns to disseminate AFS technology and promote the importance of agroforestry in soil conservation.