Numerous scientific researches confirm the fact that mycorrhiza is a highly useful symbiosis between roots and fungi. Due to differences in morphology, it is divided into ectomycorrhiza and endomycorrhiza. Endomycorrhiza forms mycellium inside the root tissue and ectomycorrhiza out of the tissue. Such root and fungi association have a large number of positive effects, which are best reflected in poor soils and stress conditions. As the orchards are often planted on poor soils, mycorrhiza may also be necessary for sustainable agriculture. In poor soils it affects the absorption of mineral substances, and most phosphorus. It also contributes to improve water absorption in soils with low content of available water. These two most important effects are a consequence of significantly greater root system biomass but also the ability of fungi to penetrate the hyphae into the smaller soil capillaries in which the root can't penetrate. These two effects indirectly results in better tolerance of plants to stress agroecological conditions such as low and high temperatures, salinity, soil pH and air pollution. The important role od mycorrhiza is to prevent the uptake od heavy metals, which is very important in conventional production. It also affects the prevention of the soil pathogenes. It can be assumed that mycorrhiza can be the key in sustainable agriculture production. It is financially achievable, it reduces the use of expensive mineral fertilizers and pesticides, and provides the plants with favorable balance of nutrients and water, which can be of crucial importance to vines. Thesis performed at: Faculty of Agriculture in Osijek Mentor: Prof.dr.sc. Suzana Kristek

Sveučilište josipa jurja strossmayera u osijeku poljoprivredni fakultet u osijeku

The continuous growing of rice has led to a deterioration in soil quality, resulting in a serious threat to agricultural sustainability in the high rainfall zone of south Gujarat, India. Therefore, crop diversification with a wider choice in the production of crop varieties is being promoted to restore the soil quality. A field experiment was conducted in Navsari, India during 2003–2007 on a Vertisol to evaluate the productivity, sustainability, resource-use efficiency and economics of 10 rice-based cropping systems. The results showed that system productivity for rice–fenugreek (Trigonella foenum-graecum)–okra (Abelmoschus esculentus) was highest (25.73 t ha−1), followed by rice–onion (Allium cepa)–cowpea (Vigna sinensis L.) (24.15 t ha−1); and the lowest system productivity was observed with the rice–wheat (Triticum aestivum)–fallow system (7.85 t ha−1). The sustainable yield index (0.97), production efficiency (102.94 kg ha−1 day−1) and field water use efficiency (15.98 kg ha−1 mm−1) were maximum with ...

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Diversification of rice (Oryza sativa L.)-based cropping systems for higher productivity, resource-use efficiency and economic returns in south Gujarat, India

Allelopathy can be employed effectively for weed management in different ways; one such aspect may be its utilization for reducing the use of synthetic herbicides. Considering its importance as a natural weed control approach, a study comprising two doses of sorgaab (Sorghum bicolor L. water extract) 12 and 15 L ha -1 combined with lower doses i.e. ½ and 1/3 rd (1075, 717 g a.i. ha -1 ) of synthetic herbicide (S. metolachlor) as pre-emergence spray against purple nutsedge was undertaken in cotton (Gossypium hirsutum L.) under irrigated conditions in central Punjab, Pakistan. Label dose of S. metolachlor (2.15 kg a.i. ha -1 ) and untreated treatment were maintained as control. The results of two years field trials revealed that 62-92% purple nutsedge control was achieved from sorgaab application in combination with reduced doses of herbicide. Similarly purple nutsedge dry weight was reduced by 75-88% than untreated control indicating that sorgaab with lower S. metolachlor doses was quite effective in suppressing purple nutsedge.

Purple nutsedge (cyperus rotundus l.) management in cotton with combined application of sorgaab and s-metolachlor

Allelopathy is an ecological phenomenon that involves the production and release of biomolecules from different crops, cultivated plants, and bacteria or fungi into the soil rhizosphere and impacts other organisms in the vicinity. Sorghum possesses vital allelopathic characteristics due to which it produces and releases different biomolecules from its root hairs, stems, and grains. Several studies have reported that sorghum acts as an allelopathic crop, decreasing the growth and eco-physiological attributes of surrounding plants and weeds growing simultaneously or subsequently in the field. Sorghum allelopathy has been exploited in the context of green manure, crop rotations, cover crops, and intercropping or mulching, whereas plant aqueous extracts or powder might be an alternate method of weed control. A diverse group of allelochemicals, including benzoic acid, p-hydroxybenzoic acid, vanillic acid, ferulic acid, chlorogenic acid, m-coumaric acid, p-coumaric acid, gallic acid, caffeic acid, p-hydroxibenzaldehyde, dhurrin, sorgoleone, m-hydroxybenzoic acid and protocatechuic acid, have been isolated and identified from different plant tissues of sorghum and root exudates. These allelochemicals, especially sorgoleone, have been investigated in terms of their mode(s) of action, specific activity and selectivity, release in the rhizosphere and uptake and translocation in sensitive species. The present review describes the importance of sorghum allelopathy as an ecological tool in managing weeds, highlighting the most recent advances in the allelochemicals present in sorghum, their modes of action, and their fate in the ecosystem. Further research should focus on the evaluation and selection of sorghum cultivars with high allelopathic potential, so that sorghum allelopathy can be better utilized for weed control and yield enhancement.

Unraveling Sorghum Allelopathy in Agriculture: Concepts and Implications.

This paper presents the results of the research on allelopathic effect of cold aqueous extracts from root systems of Johnson grass (Sorghum halepense (L.) Pers.) on the seed germination and the initial development of soybean (Glycine max (L.)), pea (Pisum sativum (L.)) and vetch (Vicia sativa (L.)) under laboratory conditions. It was established that the inhibitory effect of aqueous root extracts on the seed germination of soybean, peas and vetch varied between 28.8 and 86.3%. Furthermore, the inhibitory effect of aqueous root extracts of Johnson grass varied between 17.1 and 86.1% on the development of the initial germ and between 8.3% and 97.9% on the accumulation of fresh biomass in the initial germ of soybean, peas and vetch. The values of LC50(P=0.05) were established to vary between 46.40 and 98.28 g l-1 dry biomass from root systems of Johnson grass and can be arranged in the following order: soybean → peas → vetch.

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Allelopathic effect of aqueous extract from root systems of Johnson grass on seed germination and initial development of soybean, pea and vetch

Sorghum allelopathy has recently been recognized as an effective, economical and environmentally safe natural weed control technology for wheat crop. Allelopathic potential of sorghum has successfully been manipulated for reducting dry weight of important weeds as, Bathu, Dumbi Sittiy, Jangli Javi, Jangli Pallak, Hazardani, Billibooti, and Jangli Halooon by 20-24%, and increasing wheat yield by 10-20%. Inclusion of Sorghum in Cotton-Wheat rotation also helps in reducing deela and Lehli population to a considerable extent.

Z.A. Cheema

Papers

Sorghum allelopathy a new weed control technology for enhancing wheat productivity