Grain legumes are represented by around 13,000 species spread around the world (Aykroyd and Doughty, 1982). The Fabacaea family is the most represented (around 10,000 species) and exploited by humans
(Rasool et al., 2019). From a food point of view, food legumes are used mainly for their protein-rich seeds (broad ‘faba’ beans, field peas, beans, lentils and chickpeas), (Graham and Vance, 2003). Grain legumes have been cultivated for a long time in the world, they occupy an important place in the human diet for many developing countries
(Rasool et al., 2019). These rich in proteins allow to a certain extent to correct the deficiencies in animal proteins of a population whose food is exclusively based on cereals
(Rasool et al., 2019). According to Obaton (1980), one hectare of pulses produces 1 ton of protein, ten times more than the production of a meat farm on the same surface.
At present, in the world, grain legumes occupy more than 104 Million Hectares, with total production more than 169MT (Fig 1), (FAO, 2020). This production was distributed as: 4.9 MT of Faba bean; 3.4 MT of Peas; 17MT of Chickpeas; 6.3 MT of Lentil; and 5.5 MT of Bean (FAO, 2020). The yield varies according to the kind of grain legume and phenological criteria like number of seeds per pod, seed size and weight (Fig 2), (FAO, 2020). In contrast, in Algeria faba beans is the first class concerning the harvest areas and annual production, with yield 13.5 Quintals/Ha (Fig 2 and 3), (FAO, 2020).
In Algeria, the cultivation of food legumes has a national interest because it must meet protein needs, reduce imports and limit our economic independence from abroad (Boudjenouia and Fleury, 2002). Despite the cultivation of several food legumes in our country, their current situation is not encouraging (Toulaiti, 1988). Indeed, the cultivation of food legumes occupies an important place in the diet, but it is far from having a place equivalent to that of cereals and legumes crops in the production system (Kebede, 2020). Problems related to the installation of the legume culture (date and dose of sowing), phytosanitary protection (pests, diseases and weeds), losses during the harvest and the unavailability of adapted varieties, are the causes main reasons for low yields (Maatougui, 2002).
The purpose of this review is therefore to present the constraints of growing food legumes in Algeria, with a proposal for a model to cure or limit these constraints in order to achieve sufficient production for our population and reduce imports.
Situation of grain legumes cultivation in Algeria
Cultural aspects and importance
In Algeria, food legumes (pulses) have been part of the agricultural landscape for millennia. These crops are used in rotation with cereals because they enrich the soil with nitrogen
(Rasool et al., 2019). Legumes are also cultivated, because they are an important protein source capable of replacing animal proteins that are difficult to access for a large section of the population
(Jukanti et al., 2017). They are as calorific and rich in carbohydrates as wheat
(Jukanti et al., 2017). Their total area over the last decade 2009-2018 has been around 1.31 million hectares, production does not exceed 14.79 MT per year (Fig 3) and the yield does not reach 23.00 Q/Ha on average was good where compared with world yield average (23.8Q/Ha), (Fig 2),(FAO, 2020). The most cultivated species are in order of importance, faba bean, peas, chickpeas, beans and lentils (Table 1),
(Seetharamu et al., 2020). The marginal production very remarkable for the cultivation of beans and lentils (Fig 3).
Major constraints of grain legumes cultivation
The stagnation in the production of food legumes has often been explained by the low yields due to the climatic conditions most often unfavorable for this type of crop, the insufficient and poorly distributed rains compared to the needs of the vegetative cycle of the leguminous plant (Maatougui, 2002). In a semi-arid and arid climate, the most appropriate technique is that of seeking to wedge the cycle of the plant to that of the rains (Winter sowing) and carrying out cultivation operations which mobilize water in the soil (Deep plowing) or which limit water losses (Weeds) (Boudjenouia and Fleury, 2002). Despite the fact that cultivated food legumes have been benefited from some development programs (ITGC, 1987), national production of food legumes has not experienced the expected improvement, in terms of both area and seed production. On the contrary, all species, particularly the lentil, experienced a decline. The reasons for this situation are biotic, technical and agronomic, but also socio-economic (ITGC, 1999).
Technical and agronomical constraints
We can explain this kind of constraints by these points:
- Low productivity of the plant material used.
- Regression of areas.
- Lack of certified seeds.
- Traditional management of cultures.
- Inadequate weed control.
- Lack of mechanization.
- Existing research assets poorly transferred.
Major grain legumes diseases
The major diseases can causes a damages to grain legumes in Algeria are mainly: Anthracnose (
Colletotrichum lindemethianum), Ascochyta blights (
Ascochyta sp.), Fusarium wilt (
Fusarium oxysporum), Powdery mildew (
Erysiphe polygoni), Downy Mildew (
Peronospora viciae), Rust (
Uromyces viciae-fabae) and gray mould or Chocolate spot (
Botrytis cinerea, B. fabae) and some viral plant diseases
(Gautam et al., 2013; Boumaaza et al., 2018; Kumar et al., 2019; Benzohra et al., 2020), (Table 1).
Social and economical constraints
There is a lot of social and economic factors can limit the grain legumes production in Algeria:
- Low profit margin (low productivity and heavy load).
- Difficulties in financing.
- Cultures considered family (self-consumption).
- Competition of imported products often of better quality and well packaged.
- Low capacity processing industry (canned peas and beans) or absent (broad beans, chickpeas and beans).
- Low promotion during marketing (packaging and presentation of poor quality products).
Intgrated Disease Management
Agronomical techniques
Look for varieties better suited to less intensive cropping systems with less irrigation needs, because the majority of our climate is semi-arid or arid and the type of cultivars are spring protein varieties (peas, beans, chickpeas, lentils), many situations require the use of irrigation to secure yields. For this purpose, it is preferable in Algeria to cultivate the varieties of winter type, because they consume only 300 mm of water per year and there will be no coincidence with the period of drought (Munier-Jolain and Carrouée, 2003). With the exception of the arid zones where the water deficit is very remarkable and precocious and can be spread out in all the season of production what requires to introduce by an irrigation of 50 to 80 mm at least at the end of spring is enough between flowering and the start of seed filling
(Duc et al., 2011).
Biocontrol
The use of pesticides must be reduced in the program of IDM (Integrated Disease Management), for combating the diseases, with other methods of cultural control (rotations, types of cultivars, sowing dates,
etc.),
(Arasu et al., 2016). The biocontrol based on using of antagonistic fungi (
Trichoderma harzianum, T. viride ) and bacteria (
Bacillus subtilus, Pseudomonas spp.) against fungal diseases (Table 2). And also genetics method can be used (creation and selection of varieties), (Graham and Vance, 2000).
Although the genetic approach described above is important, other innovative research is currently being developed. Thus, with regard more specifically to peas, the fight against ascochyta blight is mainly based on fungicide treatments applied systematically: at least three applications are made on peas and winter chickpeas
(Duc et al., 2011). New directions in environmental protection lead to an attempt to cut the number of fungicide applications in half. Research aimed at reducing the number of chemical applications, through better management of the architecture of the pea cover, has been developed for several years. The characteristics of the plant and the plant cover (resistance levels and architecture) are indeed major determinants of the epidemic development of aerial diseases and therefore of their control in integrated phytoprotection strategies (Le
May et al., 2005). The architectural characteristics of plants and cutlery are linked, on the one hand, to the varietal type and its physiological and phenotypic characteristics and on the other, to the methods of cultivation. If we take the example of the
Mycosphaerella pinodes-Pea pathosystem, the density of stems, the height of the stem, the number of nodes and the distribution of leaf area according to the stages contribute to the establishment of a particular architecture which influences the microclimate within the plant cover (variation in temperature and duration of wetness) and therefore, the development, but also the spread of the disease (Le
May et al., 2009a, b;
Tivoli et al., 2006). The simplification of rotations and varieties and the intensive use of fungicides have reduced survival and diversity in different microbial organisms, animals, plants associated with the cultivated plot. However, in rotations or crops in combinations, winter or spring protein crops can potentially serve as habitat or nutritional reserve for different associated organisms and we can hypothesize that the development of these crops especially in integrated or organic farming conduits can lead to a greater diversity of soil microflora and microfauna, preserve auxiliary insects and pollinators and contribute to the diversity of cultivated plant and weed species in large crops
(Duc et al., 2011).
Resistant cultivars
Host resistance is the most acceptable component in virus control for environment protection and also by farmers
(Pande et al., 2009).
The information that will be collected and analyzed relates to the main socio-economic and technical constraints of farmers of this type of crop, it allows to:
• Identify the constraints and solutions at the level of the different socio-economic categories of farmers in all communities.
• Develop more effective extension methods and farmer field school programs.
• Identify the needs of other more in-depth studies.
• Identify and prioritize research problems, emphasizing the research program required by the request.
Since the 1980s, studies have been developed on the resistance of grain legumes to diseases: research of sources of resistance, development of screening tests for resistance, studies of the mechanisms and genetics of resistance (Moussart and Tivoli, 2005;
Duc et al., 2011). These studies made it possible to highlight sources of resistance and to develop methods for assessing varietal behaviour for grain legume/ascochyta blight pathosystem
(Onfroy et al., 2007; Wicker et al., 2001a, b), faba beans/Botrytis and ascochyta blight pathosystems
(Tivoli et al., 1986, 1987, 1988, 2006;
Maurin et al., 1993; Kharrat et al., 2006). In addition, the French institute INRA research program in France has made it possible to define
Medicago truncatula as a model species for a molecular analysis of resistance to diseases of grain legumes
(Moussart et al., 2007). The results of this research are passed on to grain legume breeders.
Therefore, the development of pulses is a necessity that must focus on the following objectives: organize the sector “profession-development-research), organize the environment (market-price), put in place the necessary incentives” FNR ( national research fund) - development of food legumes and allow the emergence of local development projects, particularly in areas where these crops are popular, as in the case of northwest Algeria (Ain-Temouchent, Tlemcen, Mascara and Sidi-Bel-Abbes) (Labdi, 1995). It’s necessary to take all measuring to increase the productivity and harvested areas, as well as developing the grain legumes production sector, must be strategic objectives to pursue.
